V'#uv TREASURY DEPARTMENT UNITED STATES COAST GUARD A PRACTICAL METHOD FOR DETERMINING OCEAN CURRENTS BY EDWARD H. SMITH Lieut. Commander, U. S. Coast Guard, (Coast Guard Bulletin, No. 14) r MA'^iNE \ LASORATOaV L 1 B R A R Y WOODS HOLE, W. H. 0. fyAss. WASHINGTON GOVERNMENT PRINTING OFFICE 1926 I f / . vv TABLE OF CONTENTS Vanf Foreword v The origin of currents 1 Static consideration of a water mass 2 Three general static conditions 3 Dynamic consideration of a water mass 4 Three variables in the sea 6 Gravity 7 Pressure 9 Application of dynamic units 12 Depth at which greatest obliquity of isobaric surfaces occur 13 Specific volume 14 Given temperature and salinity — a graphic method to find density 16 Tables for converting densities into specific volumes in situ 18 Distribution of mass 19 Effect of earth rotation on ocean currents 20 Resolution of forces in gradient currents 23 The practical methods and form of computations generally followed in dynamic physical oceanography 24 Determination of dynamic depth, stations 205 and 206 28 Velocity of a current — how determined 31 Direction of flow 35 General suggestions for a program of hydrographical survey 36 Description of a dynamic topographical chart (current map) 37 Friction 41 Effect of bottom configuration on currents 43 Tides _ _ 44 Variations in atmospheric pressure 45 Winds _ 46 (in) FOREWORD The following paper has been compiled from a series of lecture notes made by the writer when he took an advanced course on ocean- ography under Prof. Bjorn Helland-Hansen, Geo-Physical Institute, Bergen, Norway. Writers of textbooks on oceanographj", fail from time to time, due to the rapid growth of this science, to keep pace in print with the newest methods in practice. The need for the appearance of the present treatise is emphasized when it is realized that a complete exposition of the methods elucidated herein has never before, to the WTiter's knowledge, been collected in a single publica- tion, and the particular hydrographical information, prior to this, has been unavailable short of personal instruction in Europe. Although the illustrations to be found tliroughout the paper are in most cases examples taken from observations of the International Ice Patrol off Newfoundland, and although the bulletin is intended especially to assist the prosecution of Ice Patrol service, the application of the text is, nevertheless, quite broad in its scope. It is therefore recom- mended to the attention of all students interested in the subject of physical oceanography. The foundation upon wiiich this paper rests was first laid down by Prof. V. Bjerknes, (see "Dynamic Meteorology and Hydrography,'' Carnegie Institution publications, Wasliingtpn, 1910-11). In the lines of history which record attempts to apply mathematics to the natural sciences tliis treatise by Bjerknes stands out as one of the most successful and progressive. A perusal of the book can not fail to impress one with the infinite care and exactitude with which the theories have been presented and the exposition developed. It is a model of scientific treatment, but he who is searching for a practical method directly applicable to a hydrographical problem is bound to note the absence of just this sort of pertinent information. Since the time when Bjerknes' theories became recognized by scien- tists there have been a few oceanographers, especially Helland-Hansen, Nansen, Ekman, and Sandstrom, who have done much to give the for- mulae of motion a practical application to the sea. As a result of such development we are now supplied with a scientific method whereby if the temperature and salinity of the ocean are given from several known depths and stations the direction and velocity of the currents even in the deep water off soundings can be computed and mapped. In this connection it may be of interest to know that the currents calculated from the observational data collected in 1922 off the Grand Banks have been found to agree very closeh^ with the drifts of the icebergs of that same year and region. (V) VI This paper endeavors to encompass in a general way the foregoing subject with its various aspects. The contents deal with the fol- lowing : The causes of currents ; static consideration of a water mass ; dynamics and Bjerknes' theory; and a practical method for mapping currents. Other related subjects discussed are friction; effect of bottom configuration; tides; variations in atmospheric pressures; and the winds. The writer has tried to present a rather technical scientific subject in such a manner that it may easily be understood by the ordinary student. Always there has been the hope that the methods elucidated herein would serve some practical economic service. I wish to recognize with appreciation the advice and suggestions made with regard to this paper by the curator of the Museum of Comparative Zoology, Harvard University, and the hydrographic engineer, United States Hydrographic Office. The foreword is not complete unless this place is reserved to express a sincere appreciation and acknowledgment of the untiring, generous assistance and instruction given me in this work by the director of the Geo-Physical Institute, Bergen, Norway. He has in many in- stances placed even his personal notes at my disposal, and in a hun- dred other ways has shown an unselfish spirit of cooperation and friendship. As I leave Norway I bid him a fond farewell. E. H. S. August 13, 1925. A PRACTICAL METHOD FOR DETERMINING OCEAN CURRENTS Edward H. Smith THE ORIGIN OF CURRENTS In order to make a systematic exposition of the circulation taking place in the oceans with especial regard to the origin of currents, we have found it convenient to divide the forces into two general classes: (1) Internal and (2) external. (1) Internal forces appear in an ocean mass whenever any change takes place in the physical character of the water itself; that is, if either the temperature or the salinity varies in the sea then the dynamic equilibrium is upset and a tendency to readjust must follow. The internal system of forces in an ocean are disturbed whenever that mass radiates or absorbs heat; evaporates from the surface; receives additions of fresh water; or suffers internal physical trans- formation as a result of its turbulent activity. Radiation is simply a gain or loss of heat by the ocean, which tends to vary the temperature of the surface layers. Evaporation tends to vary the salinity of the surface. The ocean receives fresh water from rain, snow, or melting ice. When an ocean mixes internally it alters its physical character within the region of mixing. (2) Forces classified as external and provocative of currents are winds, tides, and variations in atmospheric pressure. The winds we shall divide into two groups, determined primarily by their extent and duration : (a) Those winds which by a tangential pressure on the surface of the sea frictionally propagate a pure wind current only; and (b) those winds which by virtue of friction drive water particles against boundary surfaces in the sea and give rise to gradient currents. Winds classified as (b) are by far the most important of the external forces assisting to maintain the more or less prevailing system of circulation in the oceans. There are, however, two other forces which are classified as second- ary, but only in so far as they tend to deform the components estab- lished by (1) and (2). They are, nevertheless, of the utmost im- portance in the consideration of currents, namely, (a) the quasi force due to terrestial rotation which acts simultaneously as soon as a movement as described in paragraph (1) or (2) begins; and (6), fric- (1) tion, that due primarily to land and bottom configuration as it tends to guide and shape the direction as well as to effect the velocity of ocean currents. Friction also is an important factor, arising whenever water particles of dissimilar motions interact among one another. A well-known example of this process is contained in the waters of a mixing zone which lies adjacently inshore of the Gulf Stream and stretches along the American continental slope. It is difficult, even in such a well-known current as the Gulf Stream, to state which class of forces, internal or external, is the fundamental cause of movement, yet the subsequent forces tending toward alterations of the movements spring from two influences — friction and rotation of the earth. A discussion of some of the fore- going features will assist to a clearer understanding of the entire subject. STATIC CONSIDERATION OF A WATER MASS Let us imagine that we can pass a plane vertically downwards through the ocean and can regard a cross section of the water in profile, with a view to studying its static condition, or distribution of mass. If now the water particles could be colored with reference to their relative weights, we would find the lightest water in the surface layers, and the heaviest particles on the bottom. The two fundamental essentials usually determined and which lead to hydrostatic examination are tem- perature and salinity; once they are found the specific gravity (density) follows as a dependent from convenient hydrographical tables. It is often desirable to speak in terms of specific volume, it being the volume of a body per unit mass, or the reciprocal of the density. If ^ == den- sity, and 1; = specific volume, then v = -j' As an example of the con- tractions which are customarily adopted by practical hydrographers, we may have given, cZ= 1.02711; this is written, for the sake of brevity, 27.11. The corresponding value of v in this case is 0.97361, and this is often shortened to a numeral of only three digits, viz, 361. The greater the specific volume at any point the lighter the water is there. If now we return to our vertical section in the sea and connect all points wherein the water particles have the same specific volume for differences of every 10 units of the latter, we obtain a number of lines called isosteres running throughout the profile. An isoster is a line all points along which represent like values of specific volume; an isosteric surface merely increases the consideration to the two dimen- sions of an area. An isosteric surface may be visualized as spread out beneath the surface of the sea— an undulating floor whose depth can be determined with the same reality as the more tangible floor of the ocean is sounded out by the hydrographer. THREE GENERAL STATIC CONDITIONS There are three general static conditions revealed by vertical sec- tions of the ocean arranged in accordance with a grouping of rela- tive positions of the isosteric surfaces, and with reference strictly to the vertical. (1) The water may be found to have the same density throughout its column when compression is disregarded — i. e., homogeneous as to temperature and salinity. The specific volume in such cases, due to pressure, will necessarily decrease downward, thus it follows that the isosteric surfaces will be arranged solely in dependence with pressure. Such conditions may prevail at the end of winter when vertical convection has attained a maximum in- fluence, or in the cases of strong winds which mix the surface layers, sometimes to a considerable depth. Such a water mass is homo- thermal and homohaline, and thus presents a consequent neutral Fig. 1. — A type of stratified water mass found over the Grand Banks south of Newfoundland. The boundary of discontinuity between the two distinct layers is shown by the closely spaced parallel lines equilibrium verticallj". (2) When one homogeneous mass of water lies over another, then the water is in layers and is said to be stratified; it will be found that there are few isosteric surfaces in each layer compared \vith the number between two adjacent layers. An ex- ample of stratification often occurs in the column lying over the Grand Banks, when a cover of heavy water from the slopes is spread over the bottom; above this, and extending to the surface, is a layer of lighter, coastal water, maintained more or less homogeneous by the turbulent effect of the winds. (3) But the most common dis- tribution in the sea is where the density increases proportionally and more or less regularly with the depth. The water in such cases is characterized by numerous isosteric surfaces lying in greater abundance at those levels where transitions of density occur; and this condition is termed stable. A direct measure of the stability of any water column is to be found in the number of isosteric surfaces in excess of that contained in homogeneous water per unit increase 71321— 26t 2 in depth. The sea above the abyssal water, furthermore (with the exception of comparatively restricted places, such as a turbulent mixing zone during a gale), is in a condition pronouncedly stable. Winter cooling of the surface layers, it is true, sets up temporary, vertical, convectional currents, but this condition is short lived when we consider the entire year's span. DYNAMIC CONSIDERATION OF A WATER MASS In support of what has just been remarked, we might continue by regarding a vertical section of a stable water mass devoid of circulation. We will find the densest water rests on the bottom of the basin; the lightest water on the surface; and the isosteric surfaces will be exactly horizontal. If now a water particle from a bottom layer be shifted to the surface it will begin to sink to the isosteric sheet from which it was removed. A surface particle, just as truly, if submerged to the bottom will tend to rise and return to its former level. But if a sample be taken from one position to another posi- tion, all within the same layer, then there is no force giving rise to its return. It is obvious from this that water particles resist any tendency toward removal from their own particular isosteric sheet, but may move freely within such, if friction does not hinder the motion. Every motion may be regarded simply as a displacement of masses, therefore a study of various types of distribution of mass in the sea is bound to reveal a vast deal regarding the currents, and in this respect the extreme importance of isosteric bounds governing the movements of the water particles can not be over emphasized. It will be seen, therefore, in the light of further remarks that once we have determined the general contour of the isosteric surfaces we have gained an insight, not only of the direction in which the water is moving, but also a measure of its relative rate of flow. The well- known principle of Archimedes is of great assistance in clarifying the components of the forces due to varying densities. Let us again regard in profile a vertical section of any body of sea water wherein a distribution of density prevails from which dynamic variations may easily follow. Such a case may arise, as we have pointed out, as an effect of either one of two classes of forces. (See internal and external forces, page 1.) For example, imagine that the ocean has absorbed and mixed heat unevenly during the summer, causing the water to become lighter in a zone over a shallow coastal shelf than the water farther offshore; or perhaps an abnormal per- centage of onshore winds have amassed a quantity of light water from the surface layers against a coast. Here, then, class (1) or class (2) forces have produced similar results which can best be ex- amined by recourse to a vertical section normal to the coastal trend. In Figure 2 the oblique lines are isosteres which have been formed by the intersection of the vertical plane of the section with the isosteric siufaces running through the water mass. The space between any two isosteric surfaces is called an isosteric sheet. The uppermost isosteric sheet on the left-hand side of Figure 2, in wedge- shaped form, bounds the body of lightest water that has accumu- lated against the coast. Now the water in the deepest portion of this isosteric sheet ''A" is specifically lighter than the water at the same level in any of the other isosteric sheets, so according to the Archi- median principle this portion of sheet "A" will tend to be driven bodily upwards. The water in the highest portion of sheet ''B" is specifically heavier than the water at the same level of the inshore sheet, and thus it will be dragged downwards. It is plain to see that Fig. 2. — A vertical profile of a water mass showing a distribution of light and heavy water and dynamic tendencies which would prevail in such a state there are forces tending to turn all the isosteric sheets into a hori- zontal position, and the greater the obliquity of the isosteric surfaces the greater the forces tending toward the leveling process. The water particles themselves, however, as a result of these stresses, will be forced from the thicker portion of the isosteric sheet to the thinner portion of it, the particles tending to keep, for reasons as pointed out in a previous paragraph, wholly within their own re- spective layer. When the sheets have attained a mean uniform thick- ness, then the isosteric surfaces have resumed the horizontal, dynamic equilibrium is established and circulation ceases. The causes provoking currents were divided, it will be recalled, as being due to two classes of forces — viz, internal and external. The distinction between the two rests mainly on the manner in which energy is transmitted to the sea. This conception should be clearly understood. (1) Internal class of forces refers to those agencies, the effects from which appear forthwith to alter the internal character of the water mass itself. This results in varying the distribution of density. An example has been given when, by the absorption of heat, the water becomes lighter over a coastal shelf in summer. (2) External class of forces can not possibly produce the slightest physical change in the character of the water particles themselves (when the turbulent effect of the wind is disregarded), but either they directly drive the water particles in a current or they deform a water mass that is qualified by boundary conditions. The latter type, similar to (1), tends to vary the distribution of density in the sea; an example has been given in the case of an onshore wind piling up the lighter surface water against a coast. Thus we may sum up the distinction between the two classified origins of currents — viz, class (1) forces tend to alter the physical character of the sea water while class (2) forces tend either (a) to move the water particles in a current or (b) to deform eventually a given water mass. THREE VARIABLES IN THE SEA It is best to begin by treating the distribution of density in the light of mechanics and physics. We may regard each type as being a field of strain inherent to the mass itself, an effect of stresses, the fields of which in the sea can be treated when expressed in terms of three variables classified as follows: (1) Gravity, (2) pressure, (3) specific volume. Let us examine each one of the tlu-ee variables separately and their combinations as they lead to dynamic measiure- ment of currents. First, however, it will be helpful to review some of the fundamen- tals elementary to a physical science. The three fundamentals in physics are mass, length, and time, represented by the letters M, L, and T, respectively, and m these terms we may express any form of physical phenomena belonging to the sea. If a length, which is the most tangible of the three, be squared, the result is an area; if cubed, a volume. Z = length, L^^^rea, Z,^ = volume. If we consider any mass with respect to unit volume we then are determining density, or q = Y3^ ML~^. But inversely, if we contemplate a volume with respect to unit mass, the result is termed specific volume, or v = -jy=DM-\ If we divide a length by a time then it gives rise to a consideration of motion called velocity, or c = yp=LT~^; con- tinuing to divide a velocity by a time (rate of rate of motion) is called c L acceleration or a = yp= -Fp2 = L T~^. A force is that agent which gives motion to a mass. It is expressed in a measurement which considers the mass relative to its rate of change of motion — ^i. e., acceleration. K=Ma; but substitutmg a = LT-\ we get 1= MLT-\ If M is unity then we see that the force is equal to the acceleration. The force per unit mass is called the accelerating force. The most com- mon natural force is that of gravity, and is expressed, of course, like other forces, in relation to a mass — e. g., Tc^ M g — where g is the rate of change of motion (acceleration) ot a falling body. Work is con- sideration of a force and length; w = lc L, but substituting for h its value ML T-^, we get ic = ML- T-~. Work may also be spoken of in other fonns as energy or potential — ^viz, the ability to do work. There is another force which enters h3"drodynamics — namely, pres- sure— and it is defined as a force with respect to an area, or p = Y^= ML-^T~^. The pressure at any depth in the sea is equal to the weight of a column of water of unit depth h with respect to unit area, or p = qgh. But substituting q= ML"^, g = LT~-, and h — L,we get p= ML-' T-\ The distribution in space of the value of the variables in the sea — viz., gravity, pressure, and specific volume — may be represented by a series of equiscalar surfaces. Those of gravity are known as equi- potential surfaces; those of pressure are called isobaric surfaces; and those of specific volume, isosteric surfaces. The space between two successive equiscalar surfaces is called an equiscalar sheet. If we construct the equiscalar surfaces for unit differences in numerical value of the quantities in question, then we obtain unit scalar sheets. For example, the differences between equiscalar surfaces of poten- tial corresponds to equiscalar units of work. GRAVITY Let us contemplate this force apart and alone with respect espe- cially to the envelope of water which surrounds the earth. We may imagine that all the equipotential surfaces throughout an ocean's mass are level, then the surface of such a sea must also be exactly level, and a line to the center of the earth, with an attractive force to that point, called gravity, will plumb exactly perpendicular. Every- where in such a sea gravity will exert a pull at right angles to the equiscalar surfaces, and the sea surface itself will be an example of a level equipotential plane. Such a motionless state is represented by Figure 3, {a), page 8. For the purposes of measuring and coordinating the accelerating force exerted by gravity in the hydrosphere, we shall endeavor to construct a series of concentric equipotential spheroid surfaces, each one separated by equipotential unit sheets. The thick- ness of such sheets wnll vary with the latitude, and in our particular subject (the sea) with the depth. The fundamental basis for fixing the relative position of equipotential surfaces in the sea, rests, of course, upon the presence of an attractive force which exists between the earth and the water masses on it. 8 A free-falling body, regardless of time or its velocity of descent, will be continuously accelerated at the constant rate of about 10 meters per second. For the purpose of measuring forces in the sea we wish to construct a series of coordinate equipotential surfaces, not merely a linear distance apart, but separated by a difference equal to 1 unit of work. Since gravity accelerates a free falling mass about 10 meters, it performs a unit amount of work, not in 10 meters, or even 1 meter, but in one-tenth of a meter, and this unit is recog- nized as the unit distance fixing equipotential gravity surfaces, always measured along the plumb. A unit of work, therefore, is definitely fixed and unalterable, it being, in the meter-ton-second system of imits, the amount of work equivalent to raising 1 ton vertically -> or about one-tenth of a meter. The unit work-length — viz, one-tenth of a meter (decimeter) — has been called by V. Bjerknes, who first used it, the dynamic decimeter; the other multiples being named dynamic meter, dynamic centi- meter, etc. It is obvious that this new measure has all the equiv- alents of linear measure but is restricted in its use solely to the vertical. The dynamic depth of any point is not the common linear distance of this point below the surface of the sea, but it is a direct statement regarding the amount of potential or work inherent to that point relative to the sea surface. r y REST. MOTION Co^) W Fig. 3.— The two states of "rest" and "motion" considered with regard to the position of the sea surface, (a), "rest," all equiscalar surfaces, including the sea surface are level, and the entire force of gravity is directed as a component perpendicularly downward; (6), "motion," the equiscalar siu-faces, including the sea surface, are tilted, which gives rise in such surfaces to a component of the force of gravity and causes a movement of the water particles We have considered a motionless sea, and its equipotential surface. Suppose, on the other hand, we regard a sea surface not level; let us say, raised near the coast by a wind pressing the water masses up the inclined, continental slope. Now the sea surface being no longer level is, by definition, no longer of equal value potentially, and grav- ity exerts a component in the plane of the sea. Here we have the birth of a current. The size of the component force is directly pro- portional to the obliquity of the surface, the two conditions, "rest" and ''motion," being graphically illustrated in Figure 3. 9 If D in Figure 3 (6) is the distance in dynamic decimeters between two points in the sea, and h is the unit vertical distance in common meters, then D=g h, where g is the acceleration of gravity. In (&), if we know the difference in dynamic depth units (the number of dynamic decimeters) between any two points, A and B in the sea, this number will be the same as the gravity potential released by a unit water mass flowing from A to B. Expressed geometrically we have from the figure, two points A and B between two level surfaces M and N, the two latter of which are h decimeters apart. The angle between line L and the planes M and N is called a w = L sin a ^ = h g = D. where D = difference between M and N in dynamic decimeters, and a is so small in all cases that sin a may be put equal to a. Let us, before passing on to a discussion of pressure, glance at the more exact values of acceleration due to gravity at various points on the earth, and also determine the corresponding values of potential expressed in dynamic measure. The attractive force of the earth, g, increases both with the latitude and with the depth in the sea, therefore the distances between equipotential unit surfaces — i. e., the dynamic decimeters — will be longer at the equator and near the surface of the sea, where g is comparatively small, than at the pole and near the bottom where g is comparatively large. In the meter-ton-second system of units a free falling body will accelerate approximately 9.8 meters in one second, therefore the dynamic deci- meter, or unit of gravity potential, will be equal numerically to the reciprocal of this value, or 1.02 common decimeters. Stated inversely one common decimeter equals 0.98 dynamic decimeters. Simply multiplying units by 10 give results in terms of ordinary meters and dynamic meters, both of which are of a magnitude most convenient for practical investigations in hydrodynamics. PRESSURE Pressure is defined as a force, the intensity of which msij be repre- sented at any depth by the weight of a column of water of unit area extended vertically upwards to the surface. The force of pressure, though present at every point in the ocean, does not actually manifest itself as an active agent until we extend our consideration to two points and the difference of pressure arising. This statement, of course, holds true more or less for all forces, but it seems worth re- marking here, as sea pressure, to most people, is an effect difficult to comprehend; yet a difference in pressure, such as exists when a hollow sphere is submerged in the sea, immediately becomes tangible. Let us take, for example, the motionless ocean in wliich we con- structed a system of equipotential surfaces 1 dynamic decimeter 10 apart (about one-tenth of a meter) and calculate tlie pressure per unit area on such a plane at a depth of about 1 decimeter. The pres- sure of the atmosphere being subject to comparatively slight and compensating variations can be totally disregarded throughout hydrodynamic works. (See p. 45.) We have given by definition values of pressure = weight per unit area = area, height, density, acceleration of gravity, area Since the area values cancel, we have pressure = 7t g q. But it has been determined that g 7i = D, where D equals 1 dynamic decimeter. Substituting : p=q D Now it remains to find a suitable system of units of pressure based upon the value equal to a water column 1 dynamic decimeter high and possessing a mean density q. The most conmion example of natural pressure with which we are familiar is that of the atmosphere. It has been a practice, long established, to balance the perpendicular column of the atmospheric envelope against an equal cross-sectional area of mercury. Tliis is a well-known experiment of any physics laboratory in which mercury has come to be adopted because of its great density; other liquids being forced to too great a height by the balance. We employ exactly the same equation, of course, as evolved in the case of a motionless ocean; in fact, we might imagine finding the pressure at various depths in the sea, theoretically, by means of a balanced column of mercury. It has been found that at 0° C. and 45° latitude at sea level, the normal height to which mercury is forced by the ever pressing air envelope, is 0.76 meters, sometimes termed an ''atmosphere." Since the acceleration of gravity at 45° latitude is known, viz, 9.8 meters, and the density of mercury at 0° C. is 13.59, let us calculate the pressure p in meter-ton-second units — i. e., the system upon which previous dynamic figures have been based. Substituting in p = qgh,we have p = 13.59 X 9.8 X 0.76 = 101.218. V. Bjerknes has used this quantity of 101.218 as a guide in deciding upon the value ascribable to p. He has selected as a unit suitable for hydrodynamic computations, the nearest integral number of 10 to 101.218, viz, 100, and has called this a bar. A bar is approxi- mately the pressure exerted by a column of water 10 meters in height; therefore the pressure of 1 meter of water is very nearly equal to the 11 pressure of 1 decibar. We should note the coincidence that 1 meter below the surface the gravity potential is very nearly 1 dynamic meter less, and the pressure 1 decibar more. p^q D .... in terms of decibar units (a) D=v p . . . . in terms of dynamic meter units (b) In order to show the close coincidence existing between dynamic units and pressure units of this system for increasing depth, we may regard the various values for the three arguments, viz, common meters, dynamic meters, and decibars, as they exist in a sea of 0° C. temperature, and 35 per mille salinity. Decibars .. Meters Dynamic meters... 100 99 200 198 300 1 400 298 397 500 496 600 595 700 693 800 792 900 891 1,000 990 1, 200 1, 400 1, 187 1, 385 1,600 1,582 1,800 1,779 97 194 292 389 486 583 680 777 874 970 1,164 1,357 1,551 1,744 2,000 1,975 1,936 It will be seen from the foregoing that under conditions as specified there is a dift"erence of about 1 per cent between a depth expressed in pressure decibars and that expressed in common meters. This difference becomes even smaller under natural conditions prevailing on the earth, and thus being so insignificant, when contemplating the horizontal extension of ordinary sea areas, permits us, with the same number, to express a depth either in common meters or in decibars. The difference between dynamic meters and common meters averages about 2 per cent, and between dynamic meters and decibars about 3 per cent, and these are of a magnitude that can not be disregarded. ^ The two foregoing equations (a) and (b), in the case of equili- brium, expresses as simply as possible the relation existing between gravity potential, pressure, and specific volume. Thus it follows that we may by (a) find the pressure in decibars at a given dynamic depth, or by (b) the dynamic depth of a certain given pressure. We have already described the equipotential gravity surfaces and the potential sheets \vith a thickness of 1 d3aiamic meter. Now the surfaces of equal pressure are given, called isobaric surfaces, which are separated by isobaric sheets 1 decibar thick. It is seldom that we have under natural conditions a motionless water mass, and so then it will usually be found that isobaric and level surfaces intersect. In other words, an isobaric surface contains varying potentials of gravity, and a level surface, in like manner, contains many baric variations. The intersections of these two surfaces may be considered as lines of the one inscribed on the plane of the other, accordingly as we employ equation (a) or (b) . If the lines of inter- section are considered inscribed on the level surfaces, they are isobars, and the chart is similar to the ordinary meteorological charts 71321— 26t 3 12 which show the distribution of pressure. But if we employ equa- tion (b) we must represent the result as dynamic isobaths inscribed on an isobaric surface and drawTi — e. g., for unit differences of 5 dynamic millimeters. Such a method of representation corresponds to that of a common topographical chart, but the contour lines on a dynamic chart instead of showing ordinary, linear heights, show levels of equal potential. A dynamic topographical chart of a certain isobaric surface is the most approved method employed in modern dynamic oceanography to map ocean currents. APPLICATION OF DYNAMIC UNITS The number of unit equipotential sheets found in an isobaric sheet between two different station verticals represents a certain amount of potential energy existing between the two verticals. Fig. 4. — A vertical section tlirough a sea basin and including the two stations A and B, with the respective points C and D separated by the distance L. C and D are at a depth of p decibars below the surface Figure 4 shotvs a section through a sea basin which includes two stations, A and B. The horizontal lines represent the intersections with some equipotential surfaces, and the oblique lines the inter- sections with sonie isobaric surfaces. The dynamic distance from the sea surface to the isobaric surface of p decibars is d^. at station A, and db at station B. According to equation (b) we have: <^b = Pb ^b But Pa = Pb and therefore da. — db = p{Va, — Vb) . . . . in terms of dynamic meters (c) (^a — dh represents the difference of potential energy, due to gravity, between the points D and C in Figure 4. This energy may be con- verted into work, da,~d\) = Tc L, where Jc is a force and L is the distance between the two points. Hence the force per unit mass due to gravity may be expressed 7. ^ ^a -db_p{Vai- Vb) 13 DEPTH AT WHICH GREATEST OBLIQUITY OF ISOBARIC SURFACES OCCUR It is important to distinguish where the greatest obhquity of the isobaric surfaces prevail in an ocean mass. D3'namic measurements and pressures have been considered as being laid off from the surface of the sea downwards on the assumption that the sea surface is always level — an equipotential surface. This premise demands considerable revision, as we shall see, in the light of the following facts : As a result of compiled oceanographic observations, it is well known to-day that the greatest variations in temperature and salinity of the water take place in the upper levels of the sea. In the North Atlantic, for example, below depths of 3,000 meters there is little variation, as we proceed from place to place, in the temperature or the salinity. Now, if we regard two stations with widel}^ differing specific volumes, we shall generally find that their difference decreases more or less rapidly with an increase in depth, and gradually approaches a constant or zero. Where the water is light we shall observe a relatively low pressure in decibars at a certain dynamic depth, or conversely at a given observed pressure in decibars, the dynamic depth will be least where the water is heaviest. In view of this natural state of the ocean, if the sea surface be level, then the obliquity of the isobaric surfaces must increase downwards and the maximum of forces and currents would be relegated to the greater depths, a condition which we know is contrary to fact. It follows alternatively that at an appreciable depth below the surface there will generally be a sheet where motion most nearly approaches zero and where isobaric, isosteric, and equipotential surfaces are parallel. It follows, further- more, that above such a motionless plane, the water, over any given horizontal extent, lies at the greatest height (the surface of the sea highest) at that place where the water is the lightest — i. e., the specific volume the greatest. We should endeavor to select from a group of observations indi- cative of a surveyed area an isobaric surface which in itself has the most nearly equal dynamic depths, thereby sounding out a level or motionless plane and which as stated before generally will be found to lie at a relatively great depth beneath the sin*f ace of the sea. When employed as a " bench mark " this surface provides a means of measur- ing the currents which usually are present in the upper levels. The velocities are determined by a comparison of any two dynamic heights measured upwards from the level, isobaric plane to the surface of the sea. Figure 5, page 14, shows in exaggerated form the obliquity of the sea surface, and also the other isobaric surfaces of observation as they lay May 5-7, 1922, south of the Grand Banks, between stations 206 and 201. The state of relative obliquity is based upon the assumption that the maximum depth of observation, the 750 declbar 14 surface, was a level plane. Other observations in this locality indicate that the 750 isobaric plane, however, is not always level, but a motionless state probably lies at some greater depth. The depth of 750 decibars, nevertheless, approaches most nearly to the level where absence of motion may prevail of any depth of which the International Ice Patrol records ; therefore, it has been employed in this paper as an illustration of the most accurate base upon which to calculate surface currents in the vicinity of the Grand Banks. 7SO x)-e>.^f«-<£'(/-« 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 24 2344 2353 2363 2372 2387* 2391 2401 2410 2420 2430 25 2439 2449 2458 2468 2477 2487 2496 2506 2515 2525 26 2534 2.'i44 2553 2563 2572 2582 2591 2601 2610 2620 27 2629 2638 2648 2657 2667 2676 2686 2695 2705 2714 28 2724 2733 2743 2752 2762 2771 2780 2790 2800 2809 fK 19 Table IV - - + - D Sd -2° -1" 1° 20 3° 4° 5° 6" 7° 8° 9° 10° 11° 12° 13° 14° 16° 16° 17° 18° 0 0 0 0 0 0 10 5 0 15 7 _0 20 9 0 25 11 _0 30 14 -2 35 16 19 21 0 _o 0 _o _0 1 40 ~T 45 ~T 1 50 23 1 0 ~ ~ 1 55 25 0 1 1 1 60 27 0 1 1 1 1 65 29 _0 1 1 1 1 1 2 70 31 0 1 1 1 1 1 2 2 2 75 34 ^ 1 1 1 1 2 2 2 2 2 2 80 36 1 1 1 1 2 2 2 2 2 2 2 85 38 1 1 1 1 2 2 2 2 2 2 2 3 90 40 1 1 1 2 2 2 2 2 2 3 3 3 100 45 56 68 90 1 0 1 0 0 -f T 1 1 1 2 1 1 2 2 2 2 3 2 2 2 3 2 2 3 4 2 2 3 4 2 2 3 4 2 2 3 5 2 3 3 5 2 3 4 5 3 3 4 5 3 3 4 6 3 3 4 6 3 4 5 6 3 4 5 6 125 32 33 341 36 150 z\ 1} 0 0 0 200 0 250 112 1 2 3 3 4 4 5 5 6 6 6 7 7 7 8 8 — 1 — 1 0 0 300 135 2 1 2 2 3 4 4 5 5 6 7 7 8 8 8 9 9 9 9 — 1 — 1 0 0 350 157 2 1 2 2 3 4 5 5 6 7 8 8 9 9 10 10 11 11 11 — 1 — 1 0 0 400 180 2 1 2 3 4 5 6 6 7 8 9 9 10 11 11 12 12 13 13 -2 — 1 — 1 +1 450 202 2 1 3 3 4 5 6 7 8 9 10 10 11 12 13 13 -2 — 1 1 +1 500 225 3 1 3 4 5 6 7 8 9 10 11 12 13 14 14 15 -2 -2 +1 600 269 3 2 2 3 5 6 7 8 10 11 12 13 14 15 15 16 17 -3 -2 — 1 +1 700 313 4 2 2 4 5 7 S 10 11 13 14 15 16 17 18 19 20 -3 _2 — 1 + 1 750 336 4 2 2 4 5 7 9 10 12 13 15 16 17 18 19 20 21 -3 -2 — 1 +1 800 358 4 2 2 4 6 8 10 11 13 14 16 17 18 19 20 21 23 -4 -2 — 1 +1 900 402 5 2 2 5 7 9 11 13 14 16 18 19 20 22 23 24 26 -4 -3 — 1 +1 1,000 446 6 3 3 5 7 10 12 14 16 18 20 21 22 23 25 27 29 -5 -3 — 1 +1 1,100 491 6 3 3 6 8 11 13 16 17 19 21 23 24 25 27 29 31 -5 -3 — 1 +1 1,200 533 7 3 3 6 9 12 14 17 19 21 23 25 26 28 30 32 34 -5 -4 -2 +2 1,400 620 8 4 4 7 10 13 16 19 22 25 27 29 31 33 35 37 40 -6 -4 -2 +2 1,600 706 9 4 4 8 12 15 19 22 25 28 31 33 35 37 39 42 45 -7 -5 -2 +2 1,800 791 10 5 5 9 13 17 21 24 28 31 34 37 -8 -5 -3 +3 2,000 876 11 5 5 10 14 19 23 27 31 34 38 41 -9 -6 -3 +3 DISTRIBUTION OF MASS Information as to the distribution of mass in a free-moving media, such as in an ocean, furnishes a direct insight of the dynamic condi- tions there. Representation of mass distribution is clearly shown by isosteric lines, which in profile form, after all corrections have been made, including that of compressibility, is called a dynamic section. An example of such is to be seen in Figure 12, page 30, which has been constructed from a group of stations taken by the International Ice Patrol, 1922, and extended in a line across two cur- rents in the ice regions south of Newfoundland. The importance of the position of isosteric surfaces as an indicator of the motions taking place in a water mass, was pointed out in a pre- vious paragraph. Enlargement of this exposition can be continued hereby regarding such a vertical section where a system of isobaric and isosteric surfaces, by intersection with the vertical plane, divide the latter into a set of parallelograms. If we extend the vision to three dimensions, then the parallelograms take form as a set of tubes. 71321— 26t i 20 Since they lie between adjacent isobaric surfaces their continuation must cease only by turning on themselves or by meeting the sides of the basin. V. Bjerknes has given the name "solenoid" to an isobaric-isosteric tube. It is convenient to select as a unit tube one included by isosteric surfaces constructed for intervals of 10~^ of specific volume, and isobaric surfaces constructed for intervals of one centibar. Bjerknes has also called attention to the significance of solenoids by stating that the measure of the intensity of forces in a given vertical sectional area is in direct proportion to the number of solenoids running through it. This number depends upon the degree of stability and inclination; the greater the stability and the inclination, the greater the number of solenoids per unit cross- sectional area. EFFECT OF EARTH ROTATION ON OCEAN CURRENTS Dynamic tendencies of water particles have been discussed purely as indicated by mass distribution; now the behavior of such phenom- ena are traced in the form of actual motion on, and as qualified by, the veering surface of a rotating sphere. In order to understand the effect of earth rotation on currents, we might begin by studying very closely the absolute movement of a fixed body at the pole of a rotating sphere and another similar body on the equator. It will soon be perceived that the former enjoys a pure centric movement while the latter has a pure transla- tory motion, and any intervening point partakes a centric-transla- tory path. Bodies at rest relatively to the globe, as also the surface of the earth itself, are, strictly speaking, under a phase of centric and translatory motion, the relation between the two depending upon the geographical latitude. This phenomenon is very difficult to comprehend, since all of our senses are trained to accept the earth and resting bodies as a stationary base, and these remarks in so short a space, can hope to touch generalities only. Those who are interested in a detailed exposition of the subject are referred to Krummel (cf., Handbuch der Ozeanographie, vol. 2). Also Humph- reys (cf., " Physics of the Air." 1920). As long as all bodies remained in fixed relations, a state of "rest" may be said to prevail, by virtue of the fact that no variations from the relative positions exist. But distinction immediately arises whenever any free motion whatsoever, relatively to the earth, is introduced. At any other point on the earth's surface than along the equator, due to the element of centricity previously described, divergence takes place between the straight path of a particle due solely to inertia, and the movement of other particles held fast to the surface of the earth and carried around with it as it rotates. This fact was proven years ago when the straight line of motion possessed by Focault's pendulum swinging to and fro soon revealed 21 that the surface of the earth was veering to the left in the Northern Hemisphere. It is more natm-al to regard the inverse perspective — that is, the earth and resting bodies as stationary — then the paths of inertia are apparently being continuously deflected to the right. Earth rotation exerts no effect on a water mass free from circulation relatively to the earth, but on the other hand no true conception of free-moving currents can be had unless this great influence is con- sidered. In this connection it should be realized, from the foregoing remarks on motion on a rotating sphere, that currents can not be traced solely to a provocative force at their source, but they are only to be observed as a resultant of a force, the effect of which is constantly being deformed by the earth ''sliding" beneath it. If a water particle moves solely due to inertia, without being acted upon by any force, it will follow a course ''cum sole" (clockwise with the sun). As the latitude increases the tendency which drives a water particle to the right of its course becomes more and more intensified, and the faster it moves, the greater becomes the quasi force tending to deflect it. In order to study this quasi force in detail, it is convenient, similar to the procedure employed in the investigation of varying mass and pressure (see fig. 4, p. 12) to regard the circulation of the curve in a plane between any two verticals. We may take, for example, stations A and B (fig. 6, p. 22), with their verticals AC and BD forming the plane ABD C. The development of an equation for expressing the rota- tion effect demands too great a digression into mathematics and is not warranted here, but it has been evolved by V. Bjerknes as equal to ds where co represents the angular velocity of the earth, viz, 0.0000729; and is the projection of the closed curve of the circulation, as illus- ds trated here by the rectangle ABDC, on the equatorial plane; and -,: represents the rate of change of the projection on the plane of the equator. In Figure 6, page 22, if the curve of circulation ABDC, which is being investigated, is projcted upon the equatorial plane, it is evident that a change of the proportional area is eft'ected only by components normal to the plane and not by those tangential to it. Also the vertical movements can be considered negligible, since they are in- significant as compared with horizontal magnitudes. Helland- Hansen and Sandstrom have, by this means, found the value for Bjerknes' equation in terms of the projection on the plane of the sea surface ds da . dt = dJ'''''^ 22 where a is the projection on the sea surface, and 0 is the geographical latitude. Substituting this new value for -tt we have 2co -t7 sm ^ (d) da hut^=A'B'D"C' = {co-Ci),L where Co = velocity per second in a given horizontal plane. Ci = velocity per second in another horizontal plane. L = distance between stations. Substituting in (d) for the new value -tt we have 2a) sin (t> (Co — c^Z, (e) STA^XIOM ^ Fig. 6.— Lines AA' and BB' represent the velocity of the surface current, or co, per unit T; CC and DD' indicate the velocity of the current at a greater depth, or ci. The difference in the velocity of the two movements is equal to D" B', or co— ci. The movement is assumed to be normal to the vertical plane ABDC, which is passed through the two stations A and B. Area C" D" B' A', indicated by the symbol . Thus by (e) we are furnished with an expression for the effect of terrestial rotation in terms of the latitude; the distance between stations; and the difference in velocity of the current between any two levels. It is easy to see that if we are able to find some point along the verticals where zero velocity prevails, then we have a means of expressing the real velocity. It is customary to extend the investi- gations to depths where it is believed motionless water lies, and then Ci = 0, and Co is the true velocity on the surface. (See p. 13 regarding the obliquity of isobaric surfaces.) ^-B 23 RESOLUTION OF FORCES IN GRADIENT CURRENTS It has been pointed out in the previous section that the effect of rota- tion tended to deflect currents to the right in the Northern Hemisphere. This quasi force can be represented by a vector of a certain magnitude which lies 90° to the right of the current. If we let the line AB, Figure 1, represent a more or less steady current of sufficient size to give the water particles a translatory path, then the effect of terrestial rotation may be shown by the line AC, Figure 7. Since the rotation effect is always present, as represented by the line AC, it follows that the only condition under which a current can flow, stream, and be pre- served, is fulfilled by a force or system of forces (when friction is dis- regarded) which acts equal and opposite to AC, and is represented in Figure 7 as the line AE. AE illustrates the force characterized as due to varying mass and pressure, and is measured by the equated values of the three variables — >'■ gravity, 'pressure, and specific vol- ume. It is, moreover, the impel- ling force of such gradient currents (i. e., currents resulting from an obliquity of equiscalar surfaces) ; and it should be remarked here q that this driving force is to be no. 7— a diagrammatic front view showing the sought not back along the current's ^^^.tW^ positions of the major elements belong. . ,., , ing to a steady gradient current. AB represents course to a riVer-llke source, but the path of flow of the water particles; AE, the it alwaVS lies on the right hand position of the forces due to Archimedean tend- ... ^ . encies which impel the current; and AC the po- Stretchmg along the entire extent sltlon of the quaslforce of earth rotation in a of flow. The Gulf Stream, for ex- P^^^e ^° to t^e right (in the northern hemi- . sphere) of the direction of the current ample, as it lollows a general path around the periphery of the North Atlantic basin, is energized along the shores of Europe (a fact which is just as vital for its propagation) as well as receiving propulsion in the Caribbean. Where the velocity is relatively great, there the dynamic gradient is correspondingly steep, and without such energy distributed around Atlantic slopes, the Gulf Stream would directly disintegrate. If we divide gradient currents into the forces which combine to give flow to the water particles we have (1) dynamic inequalities due to vary- ing densities, and (2) the effect of earth rotation, each one of which acts in a plane perpendicular to the path of the moving water parti- cles. Since (1) and 2) lie in the same plane, and inasmuch as the acceleration of the closed curve ABDC (see fig. 6, p. 22) (represented by the line AC, fig. 7) has been determined, let us now regard the rectangle ABDC with respect to acceleration tending in the opposite direction. (Sho^vn as line AE, fig. 7.) 24 It will be recalled that the force of varying mass and pressure tending to produce acceleration by equation (b) is equal to and the accelerating force in a closed curve ABDC between stations A and B, in the plane formed by the verticals AC and BD, is equal to d^-db = p (Va-Vb). Since AC equals AE, (fig. 7, p. 23), we may substitute (e) and obtain the following: da — db = p {Va — V],) =2 CO sin 4> (co — Ci)L (f) Thus finally we are furnished with an expression which includes the forces due to the distribution of mass and pressure tending to accele- rate a current moving on a rotating earth, and moreover, it is formed of terms which readily lend themselves to the requirements of practical oceanography. THE PRACTICAL METHODS AND FORM OF COMPUTATIONS GEN- ERALLY FOLLOWED IN DYNAMIC PHYSICAL OCEANOGRAPHY We may now continue by describing the manner in which the un- known terms of (f) are determined by observational data secm-ed from a closed curve ABDC in a plane formed by verticals AC and BD, between stations A and B. First we shall regard the forces tending to /\ (Station ZOS). M ETER& or DE:CIBAR.&. g, (pTAmoH Zos). _V--- -Vs--\-P. -y,---\-^^- v,-^Ps- o- - 50 - 1^5 fa — 250. .A50 -ISO ^o- ^, -__V.,... — V3— --Vo-- D - M,— Fig. 8.— Two verticals A and B at stations 206 and 205, respectively, and with the observed values of V and p at depths expressed in decibars or meters as follows: 0, 50, 125, 250, 450, and 750 accelerate the particles as a result of varying degrees of stability in the water columns of any given area. The abstract exposition, further- more, has been supplemented by a practical example wherein stations A and B are replaced by stations 206 and 205, respectively. (See com- putations, p. 28.) These stations were taken by the International Ice Patrol in 1922, the sectional line forming approximately a right angle with the northern edge of the Gulf Stream south of the Grand Banks. 25 It is assumed that the specific volumes in situ have been calculated from the tables, as based upon the temperature and salinity records from the observed depths, viz, 0, 50, 125, 250, 450, and 750 meters. The values of p are, for all practical purposes, equal to the depth in meters — that is, at a depth of 750 meters the pressure is 750 decibars (see p. 11). In order to compute as accurately as possible the value of D (the dynamic depth) for the vertical AC, it is necessary to consider the change at frequent depths which occurs in the value of v (the specific volume) . In order to comprehend the method of mathe- matical computation customarily followed, e. g., p. 28, it will be help- ful to regard Figure 9. dp M N so <^, / 15 A. y ^i iZ5 di / 1 1 "4 ZOO . / 600 is _P-.L.. 1 ! 1 ■ C ) ^5 M^ XVo Fig. 9.— a graphic means of illustrating the mathematical integration customarily employed in computing the dynamic depth to a given observed pressure beneath the sea surface The area MNPO (assumed equal numerically to Da) is formed part- ly by the ciu've NP, which represents varying values of v, and the side MO, which indicates the scale of pressure. The value of Da, therefore, represented by the area MNPO is equal in value to the sum of aU the smaller areas ^ S "3 § n '& m C3 ■^ O 'o J2 a s ^ 'O Si LI o § « a o 0 10 vT) 0 ^ ^ ^ L -^3^ 0 O „ © e © o ^ o o o o m A-^^ .•*^»' Z o c- t t I ' I Q O O O O <9 Q O g * _o ~ 2^ OS (S O 2 c 'i : o .o o i "^ *^ S 5 2' " ft I 2 ft E •« 'i ^ 03 J2 ■? ^ d a S O £: ■^ ^ .2 O -< trated in Figure 10, page 26, will intersect the solenoidal tubes form- ing a number of parallelograms, each one of which indicates the presence of 400 solenoids. The distribution of forces tending to produce acceleration in such a verticalsectionmay be further emphasized by erasing all tlie isobaric- isosteric lines after the location of the centers of the parallelograms have been marked out. This method of illustration is shown in Figure 11. 28 Where the isosteres lie deepest and the inclmation is greatest, there is indicated at that place a tendency to push the water upwards with a maximum strength, and where the isosteres lie highest, there the force is at a maximum tending to drive the water downwards. But whatever the position of the isosteres may be, it is well to bear in mind that when the section lies at right angles to the direction of the current, there is no actual movement of the water particles within the vertical plane whatsoever. The value of the solenoids lies in the fact that they express the presence of a force or forces tending to cause circulation around the rectangle. The Ferrelian force (effect of earth rotation) precludes actual movements restricted solely parallel to the current path AB, Figure 7, page 23, as previously described. DETERMINATION OF DYNAMIC DEPTH, STATIONS 205 AND 206 We may continue to treat the Ice Patrol records of stations 201 to 206 dynamically, by computing the values of specific volume from the given station data and correcting the same to specific volume in situ ; then, by means of the equation on page 25, determine the dynamic depth of the successive isobaric surfaces of observation. In order simply to illustrate the methods customarily employed, we have selected two stations only, stations 205 and 206 located on the northern edge of the Gulf Stream south of Newfoundland. Similar procedure and similar results follow, of course, in like manner from other given station data. dp Meter depth dt Table III Table IV I Mean I 2l 21m-5p 22 (E- EOlOii V105 (V- Vi)10« STATION 205 50 75 125 200 300 0 50 125 250 450 750 5.7 33.93) 26.77 12.0 35.3l! 26.85 10. 1 35. 161 27. 07 6.7 35.00; 27.48 5.4 35.04 27 4.6 35.01! 27.75 2607 2615 2635 2674 2694 2700 0 22 53 109 197 327 2607 2637 2688 2783 2891 3027 2622. 5 2662. 5 2735. 5 2837. 0 2959. 0 1311251 199687 341938' 567400 887700! 131125 330812 0 48. 68875 121.69188 672750 243.27250 1240150 437. 59850! 2127850 728. 72150 0 . 06225! . 14676 . 25251 . 36501 . 50201 . 97393 . 97363 . 97312 . 97217 .97119 .96973 129' 121 104 65 47 44 STATION 206 50 75 125 200 300 0 50 125 250 450 750 18.1 18.0 16.3 12.9 9.2 6.6 36.21 36.33 36.11 35.56 35.12 34.95 26.18 26.31 26.55 26.86 27.20 27.46 2551 2564 2587 2616 2648 2672 0 22 50 106 193 323 2551 2586|' 3637| 2722i 2841 1 2995: 2568.51 128425 --;5oi5; 2611.51 195862 ^;°*a^ 2679. 5\ 334937 iitioA 2781.5! 556500 ^'^^■'"^ 2918.0, 875400i i\ 1215724 0 0 . 97449 48. 71750 .09100 .97414 121. 75713 . 21201 . 97363 243. 40776 . 38777 . 97278 437. 84276 . 60927 . 97159 729. 08476 . 86527 . 97005 185 172 155 126 97 76 Col. 1 C0I.2; C0I.3 I C0I.4 C0I.5 Col .6 Col.7! C0I.8 C0I.9 Col.lO Col. 11 Col. 12 Col. 13 Col. 14 Col. 15 The abbreviations appearing at the top of the columns in the pre- ceding compilation of computations are explained as follows : Column 1 (dp) represents the difference of pressure in decibars of successive observed depths, which for all practical purposes is equal to the differences in depths of observation in meters. Column 2 contains the depths at which observations were made. 29 Column 3 (t) contains the observed temperatures. Column 4 (s) contains the determined salinity. Column 5 (dt) contains the density as found directly from the tem- perature and the salinity. (Contraction adopted, see p. 2.) Column 6 (Table III) is a form of inversion table combined with other corrections (seep. 18). Column 7 (Table IV) contains the combined corrections with due regard to signs for the three factors, pressure with depth, with tem- perature, and with salinity (see p. 19). Column 8, contains the values of (1 — v) 10 ^ where v represents the specific volumes in situ. Column 9, contains the mean values between the successive depths of observation as they appear in column 8. Column 10, contains the product of the values as contained in col- umn 9 and the difference of pressure in decibars as shown by column 1 . Column 1 1 (Sa) contains the results obtained by adding progres- sively the successive ciphers as contained in column 10. Values from columns 6 to 11, inclusive, are negative throughout. Column 12 (E) contains the calculation of the dynamic depths of the observed isobaric surfaces. Found by combining values in col- umn 2 with those in column 11. Column 13 (E — Ei) 10^ contains the anomaly of the dynamic depth of observation — i. e., it represents the difference in dynamic depth between the isobaric surface actually observed and the position of the same isobaric surface in a sea of 0.0° C. and 35 per mille salinity. Column 14 (V) 10^ contains the specific volume in situ, or one minus the value as contained in column 8 multiplied by 10^. Column 15 (V — Vi) 10'^ contains the anomaly of specific volume in situ, or, in other words, the difference in specific volume in situ as found from that at a similar depth in a sea of zero degrees Centrigrade and 35 per mille salinity. The values for the dynamic depth (Di) and the specific volume in situ, (Vi) , as found in an ocean of zero degrees Centigrade and 35 per mille salinity, are given in the following table, Table V. The selected depths recorded therein are the same as those previously carried in Table IV. Table V* El = dynamic depth in sea 0° C, 35 per mille. Vi = specific volume in sea 0° C, 35 per mille. Deci- bars El Vi Deci- bars El v, Deci- bars E, Vi Deci- bars El Vi 0 0 . 97264 50 48. 62650 . 97242 125 121.54512 . 97208 700 679. 74949 . 96951 0 4. 86315 . 97262 55 53. 48854 . 97240 150 145. 84574 . 97197 750 728.21949 . 96929 10 9. 72620 . 97260 60 58. 35045 . 97237 200 194. 43849 . 97174 800 776. 67849 .96907 15 14. 58914 . 97257 65 63. 21225 . 97235 250 243. 01999 .97152 900 873. 56349 . 96863 20 19. 45195 . 97255 70 68. 07395 . 97233 300 291. 59024 . 97129 1000 970. 40449 . 9681* 25 24. 31465 . 97253 75 72. 93554 . 97231 350 340. 14924 .97107 1200 1163.95549 . 96732 30 29. 17725 . 97251 80 77. 79700 . 97228 400 388. 69699 . 97084 1400 1357. 33249 . 96645 35 34. 03974 . 97249 85 82. 65835 . 97266 450 437. 23349 . 97062 1600 1550.53649 . 96559 40 38. 90210 . 97246 90 87. 51960 . 97224 500 485. 75899 . 97040 1800 1743, 56849 . 9C473 45 43. 76435 . 97244 100 97. 24175 . 97219 600 582.77649 . 96995 2000 1936.42949 . 96388 * Tlie values shown are based upon those contained in Table 8H, Bjerknes' " Dynamic Meteorology and Hydrography," Carnegie Inst. Pub., 1910. 30 The isosteric lines, Figure 10, page 26, represent in vertical section, the distribution of the specific volume in situ (v). But except in regions where rapid currents prevail, the lines of equal specific volume vary little, especially in the greater depths, from either the lines of equal pressure or the lines of equal depth. This is due to the fact that the effect of the increasing pressures with the depth more than 0 o 0 0 0 0 ^ vD N o offset the variations in the specific volume due purely to temperature or salinity variations. In order to secure a more striking graphic representation of the distribution of specific volume in situ, it is customary to draw the isosteres in accordance with the values of V — Vi (see computations, column 15, p. 28). Although these ciphers are of a smaller numerical value than the actual specific volumes, yet they provide a greater contrast than the latter, and a section thus I 31 drawn is the type most commonly employed for purposes of illustra- tion. A dynamic section, Figure 12, formed by stations 201 to 206, International Ice Patrol, 1922, is shown on page 30. VELOCITY— HOW DETERMINED We may now return to a consideration of e,quation (f ) , page 24 , in order to find the velocity of the current between stations 206 and 205, by substituting at the same time for dg, and d\y the values as found at the six levels of observation of the two foregoing stations. Since the velocity is the term desired, equation (f), page 24, may be written in the following form: (^a-4)10- ^° ^' 2cosm0„,XlO^ ^^> where 105 = 14.58 sin0 0 1 2 3 4 = 6 7 8 1 9 0 0.00 00.26 00.51 00.76 01.02 01.27 01.52 01.78 02.03 02.28 10 02.53 02.78 03.03 03.28 03.53 03.77 04.02 04.26 04.51 04.75 1 20 04.99 05.23 05.46 05.70 05.93 06.16 06.39 06.62 06.85 07. 07 30 07.29 07.51 07.73 07.94 08.15 08.36 08.57 08.78 08.98 09.18 I 40 09.37 09.57 09.76 09.95 10.12 10.31 10.49 10.67 10.81 11.01 50 11.17 11.33 11.49 11.65 11.80 11.95 12.09 12.23 12.37 12.50 60 12.63 12.75 12.87 12.99 13.11 13.22 13.32 13.42 13.52 13.61 1 70 13.70 13.79 13.87 13.95 14.02 14.09 14.15 14.21 14.26 14.31 1 80 14.35 14.40 14.44 14.47 14.50 14.53 14.55 14.56 14.57 14. 58 j Since the value of i, the distance between stations, is expressed in kilometers, a conversion table of nautical miles to kilometers is included herewith : 33 Table VII Kilometers Nautical miles . 0 1 2 3 4 0 6 / 8 9 0 0.0 1.9 3.7 5.6 7.4 9.3 11.1 13.0 14.8 16.7 10 18.5 20.4 22.2 24.1 25.9 27.8 29.6 31.5 33.3 35.2 20 37.0 38.9 40.7 42.6 44.4 46.3 48.2 50.0 51.9 53.7 30 55.6 57.4 59.3 61.1 63.0 64.8 66.7 68.5 70.4 72.2 40 74.1 75.9 77.8 79.6 81.5 83.3 85.2 87.0 88.9 90.7 50 92.6 94.0 96.3 98.2 100.0 101.9 103.7 105.6 107.4 109.3 60 111.1 113.0 114.8 116.7 118. 5 120.4 122.2 124.1 125.9 127.8 70 129.6 131.5 133.3 135.1 137.1 138.9 140.8 142.6 144.5 146.3 80 148.2 150.0 151.9 153.7 155.6 157.4 159.3 161.1 163.0 164.8 90 166.7 168.5 170.4 172.2 174.1 175.9 177.8 179.6 181.5 183.3 100 185.2 187.1 188.9 190.8 192.6 194.5 196.3 198.2 200.0 201.8 The velocity values as they are usually finally shown, represented by Co, page 31, are the differences between the movement on the surface and that at a level where it is believed motionless water lies. But it is important to bear in mind that as a result of dynamic computations, the values of velocities are expressed .in terms normal to the VERTICAL SECTION which may include any two stations. Another step is necessary if it is desired to obtain the value of the real velocity. Let us as- sume that the direction of flow but not the rate is known. In Figure 14 suppose the direction of the current is represented by the parallel lines AM and BMi, between the two stations A and B. Fur- thermore, let it be given that the velocity normal to the section has been computed by means of equation (g) , page '4 1 , and that it is given on the figure as the line K. We now wish to determine the true velocity, V, which lies in a cUrection parallel to the lines AM and BMi, and which forms the angle a with the computed velocity. The value of K Fig. 14.— Lines AM and BMi indicate the known direction of the circulation. K repre- sents the computed velocity normal to the sec- tional line AB. To find: The true velocity (V) of the current V, it is easy to see from the figure, is equal to cos a The same results may be obtained graphically by laying off the angle a and dropping a perpendicular from the end point of the known side K upon the unknown side V, and then measuring the length of the latter in units the same as K. ->-B 34 In Figure 15, AB represents the path of the current; AE, the result- ant of the real physical forces; and AC, the quasi force due to earth rotation, acting with the same magnitude but in the opposite direc- tion. The two vectors AE and AC lie in one and the same plane, EAC, which is perpendicular to the course of the current. The fields of forces may be investigated by regarding them graphically in either a vertical view, called a dynamic section (see fig. 12, p. 30) or in a horizontal view called a dynamic topographical chart (see fig. 19, p. 39). Both vertical and horizontal projections, it will be found, assist to reveal particular knowledge regarding the types of forces in- volved. It will lead also to a clearer understanding of the rel- FiG. 15.— ResolutiotLof the two principal forces in . . . r .\, jt j a gradient current AB; AE, the forces due to atlVC pOSltlOU Ot the torCCS, and, Archimedean tendencies; AC, the Ferrelian morCOVCr, tO the COUrSC of the force J ■!• • c current, it we now review some oi the fundamental notions pertaining to such representations of forces. The well-known method of regarding a force as represented by equi- scalar surfaces and unit scalar sheets is especially applicable here. The potential value of an irregularly formed equiscalar surface, obviously, can be traced by its intersections with a series of unit parallel horizontal planes. The rate of variation of contours (inter- sections) measured along a normal vector called the gradient is a direct expression of the acceleration of the scalar force. In Figure 16- M O E ; 1, A^ ''^« R ^ Cl' \ / N P C Fig. 16. — A diagram offerees similar to that shown in Fig. 15, but with the addition of dynamic isobaths MN, OP, etc., which show the position of such contours (when friction is disregarded) relative to the actual movement of the water particles the vector AE representing the acceleration due to primary forces in the sea provoking currents may be regarded as a gradient force due to the variations in level. These variations are in horizontal projection shown by a series of horizontal lines (dynamic isobaths) MN, "OP, etc., all perpendicular to line AE, and inscribed on the scalar field of the force. But MN, OP, etc., are also parallel to the line AB, the stream line of the current. Lines MN, OP, etc., then, correspond to the 35 d3niamic contours of a given isobaric surface as illustrated by the dynamic topographical chart described on page 37 (see fig. 19). Therefore it follows that the dynamic isobaths recorded on such charts possess a tremendous significance in as much as they delineate the courses of the water particles over any given area that has been investigated. Not only may the paths of the currents be traced on such charts, but the degree of compactness of the djmamic isobaths along the gradient at right angles to the current, is a measure of the relative velocity of the current. The closer together the contours lie in any given latitude indicates the more rapidly the current is flowing at that time and place. DIRECTION OF FLOW The direction toward wliich the water moves is, of course, requisite information which may be obtained best perhaps by reference to a vertical section — i. e., the d3niamic section. If a plane be passed 20fc> 2o5 205 20X AROHIMEDEAtM " RERRELIAN :ndemoy en deisjcv Fig. 17.— Showing the two types of distribution of specific volume in vertical section and the resultant tendency toward flow of the water in consequence vertically downward through the plane of the forces AC and AE (fig. 16 p. 34) and a distribution of specific volume be secured, a dynamic section similar to Figure 12, page 30, will result. Consideration of the closed curve formed by the two verticals at stations 206 and 205 will reveal the fact that the water being lighter to a greater depth at 206 than at 205 tends to be forced upward at 206 and dowTiward at 205. But when the current is constant there is no actual movement of the water particles in these planes, as the real forces are exactly counter- balanced by the Ferrelian force (effect of earth rotation), the latter of which acts in a direction opposite to the tendency of the Archi- medean forces. The real movement of the water particles, as repre- sented by the foregoing figure, takes the form of a current which flows at right angles to the plane of the dynamic section. In such a distribution of forces as shown by Figure 17 the current would run in a direction through the paper, either toward or away from the 36 eye of the reader. Provided that the water is moving faster in the surface layers than in the depths, the rule follows: Look in the DIRECTION TOWARD WHICH THE CURRENT IS RUNNING, IN THE NORTH- ERN Hemisphere, and the lightest water will always lie on THE RIGHT HAND. The Vertical differences of velocity may be calcu- lated from equation (f), see page 24, which is affected fundamentally by the values of temperature, salinity, and depth, at any two verticals in a plane and which it is important to note lies at right angles across the path of flow. GENERAL SUGGESTIONS FOR A PROGRAM OF HYDROGRAPHICAL SURVEY Ocean currents, it has been pointed out, may be determined by a distribution of temperature and salinity in a plane, the position of which is perpendicular to the flow of the water. Conversely, if no forces are found as represented by the position of the isosteres and isobars in vertical section, then there is no current at right angles to the plane of the section. It is easy to see, on the other hand, that a section parallel with the course of a current contains no informa- tion whatsoever regarding its movement. Hydrographical survey of extensive ocean surfaces involves in any event a large program of time and expense, and the task grows to considerable magnitude, especially when the work devolves upon the efforts of one vessel. An ideal program, of course, includes a maximum number of oceano- graphic stations distributed netlike over the area to be investigated, and wherein the promulgation of the work most nearly approaches a simultaneousness of observation. Unfortunately, the ideal survey rarely occurs, and it is usual that resort is made to lines of stations along a vessel's track. Under such conditions it is apparent that before commencing the observational work the particular area should be studied carefully with respect to all previous, available knowledge of a hydrographical nature, remembering that the lines of stations in a program of dynamic investigation should run in such a manner that the sections secured approach most nearly to right angles across known or suspected currents. As an example let us take the region around the tail of the Grand Banks where there are two main move- ments. (1) The Labrador Current is the inshore set, which flows southward along the east side of the Grand Banks and to a variable distance around the "Tail." (2) Offshore in the Atlantic basin the easterly moving masses of the Gulf Stream, guided by the trend of the bottom configuration, progress in a generally opposite direction to the cold water inshore. A program of dynamic investigation in this region should be based upon a series of lines of stations rimning offshore in a direction normal to the Grand Banks' slopes as shown by Figure 18. Stations should be taken as close together (and repeated as often) as practicable in order that the influence belonging to tem- 37 porary boundary waves and vortex movements be disassociated from a representative picture of prevailing conditions, (cf . Helland-Hansen and Nansen, "The Norwegian Sea," Bergen, 1909.) To such an end the dynamic features of modern physical oceanography are best carried out by several craft cooperating in one systematic program of investigation, which may or may not extend over great expanses of the ocean. Here is an important requirement which would appear to demand certain revisions in the program of expeditions, which in the past have usually been performed by one vessel sailing under a more or less roving commission. These modern methods in dynamic se 54- 44 4Z Aa -*8 4fe •tSo -^ r .^ «e> SG SA- £2 •So 4.8, •44 42 -sje -44- ^ Fig. 18. — A series of station lines radiating from the Grand Banks is an example of the correct methods to employ in order to obtain the best collection of material leading to an investigation of the currents in this region oceanography, particularly the graphic repi-esentation as embodied in the dynamic topographical chart, provide, furthermore, an easy and efficient means of mapping currents over extensive ocean surfaces — advantages which are bound to guarantee a great employment for this science in future hydrographical surveys. DESCRIPTION OF A DYNAMIC TOPOGRAPHICAL CHART (CURRENT MAP) We now come to the description of a dynamic topographical chart, a subject which has been reserved until the close of the various methods of illustration, because, from its practical importance, it merits especial emphasis. The basis for the construction of such a projection depends fundamentally on the dynamic computations 38 previously discussed on'page 28. It possesses great practical advan- tages in that it presents two pertinent, desirable pieces of information, viz, (1) the direction of movement, and (2) the relative rate of flow of the current, over any given area. Let us suppose that the tem- perature and salinity data, surface to 750 decibars, have been collected from a sufficient number of stations in the region south of the Grand Banks. This, as a matter of fact, corresponds to an actual oceano- graphical investigation carried out by the International Ice Patrol in these waters during the spring of 1922. Dynamic treatment of these data leads through the accepted methods of calculation as shown on page 28. Column 12 on that page contains the dynamic depths of the successive surfaces of observation, and also the material for the construction of a dynamic topographical chart, of which Figure 19, page 39, is an example. An isobaric surface, the dynamic topography of which is the sub- ject of interest, may be visualized as spread out beneath the surface of the sea, an undulating floor, the depth of which we plumb with the same reality as the more tangible floor of the ocean is sounded out by the hydrographer. As a first step toward the mapping of currents, let us investigate any one of the standard isobaric planes of observa- tion adopted by the International Ice Patrol, viz, 50, 125, 250, 450, and 750 decibars, by plotting its dynamic soundings on a map at those positions in latitude and longitude where the respective stations have been located. This procedure, it is plainly seen, is identical to that in which depths to the bottom are fixed on any ordinary navigational chart. If, as a next step, equipotential (level) planes are passed at frequent heights through the selected isobaric surface which is under investigation, a number of lines of intersection are formed, which for convenience may be called dynamic isobaths. If now we recall the fact that when the accelerating force of friction is disregarded the movement of water particles on an isobaric surface tends along such a surface, as well as along the same equipotential surface (see p. 34, fig. 16), it is not difficult to appreciate the significance of dynamic isobaths. The small sketch in the lower left-hand corner of Figure 19, page 39, shows a series of dynamic isobaths and the direction of the two forces which are always present wherever there prevails trans- latory movements of water particles in a steady current. Friction, for all practical purposes, may be disregarded, (See p. 43). (1) AE illustrates the resultant of the forces which impel and maintain gradi- ent flow; (2) AC represents the Ferrehan force acting in a plane 90*^ to the right of the current; and (3) AB is the path of the actual estab- lished movement following along the dynamic isobaths. When these latter are recorded on an ordinary geographical map, as a series of dynamic contours, it permits the reader, at a glance, to picture the course followed by a water particle throughout the region which is under survey. Figure 19 is shown as an example of a dynamic 39 40 It is interesting to observe that the easterly position of cyclone track B on Figure 6, was due without much doubt to the presence of the aforementioned anticyclone. Weather bulletins were received May 5, 6, and 7, containing information that a depression was form- ing in the region of Bermuda, but due to the lack of ship reports it was impossible to ascertain definitely the movement of the center. During the night of May 8 our barometer began to fall., which from past experience indicated the approach of a storm within a radius of about 500 miles. The next morning upon constructing the weather map the center was revealed near Port aux Basque; it probably had followed a northerly path from Bermuda as indicated on Figure 6. During the next few days the weather maps indicated a tendency of \ x:^ ^x/S^Y J^Ti /X i ■""■""^-■ -^ "^"^^^y^^^^ ^K'' ^ / / / i ^ ^'^//y^ '"-^./ ^ i > ; / 1 la CYCLONE TRACKS MAV- I92e / r'*— w \ 1 Fig. 6.— May cyclone tracks the pressure to remain relatively low to the westward, depression centers being recorded from Nantuc)vet to Sydney. On May 11 a deep center appeared near Sydney and moved in a path across the Gulf of St. Lawrence and out to sea. The effects of this distribu- tion set up an indraft of southeasterly winds consisting of warm moisture-laden air pulled across the ice regions from out in the Atlantic. This condition incidently produced the longest period of fog which we experienced for the season. The two weeks from the 13 th to the 27th marked a change in the previously noted tendency of the cyclones to travel consistently along northeasterly tracks Where prior to this period individual centers moved rapidly across the country we now saw several small vortices (families) following meandering paths as if they were the 41 prey to several factors no one of which exerted outstanding control. For example, on May 13 a slight shallow depression moved from Illinois eastward to the Potomac and the next day spread into a spacious depression with two centers. One traveled eastward while the other remained stationary until two days later it coalesced with a third depression which had been drifting slowly eastward from the Great Lakes. Contemporary with this modification in the weather we noticed that the wind velocities in general had gradually become less than they had been earlier in the season. CYCLONE. TRACKe JUNE -I52e> Fig. 7. — June cyclone tracks May 25 to 30 an anticyclone of vast proportions expanded from the region of central Canada and spread over the entire eastern half of the United States and extended out to include the ice regions. It finally divided into two centers and soon afterward disintegrated completely. It is interesting to examine the flatness of the baro- graph curve and the presence of clear weather, both of which are recorded on Figure 3, page 35. JUNE The most important lesson contained in the cyclone tracks for June (fig. 7) is obtained by comparing the position of the average with the position of the average for the months of March and April. It is clearly indicated that a migration to the northward of the mean cyclone track took place in the course of two months. It is estimated as approximately 150 miles. The explanation for track C, Figure 7, 42 Gulf Stream, and is well illustrated by the velocity diagram (fig. 13, p. 32). In "B," Figure 20, the velocity of ''a" being greater than adjacent particles, or adjacent sheets above and below, is thereby retarded and friction acts to hinder the translatory progress of particle ''a." In '' C," the velocity of particle "a" is less than either of its immediate neighbors, above or below, and friction therefore Fig. 20. — Three general types of current velocity diagrams tends to accelerate the velocity of ''a." If the water particles in a current be retarded by a constant accelerating force of friction throughout the depth, then the velocity diagram will assume the form of a parabola. Cases as shown in '^B" and " C" (fig. 20) may also be illustrated by components and force diagrams in horizontal projection as foUows: The dotted lines in Figure 21 represent the direction of flow of the current, and the solid lines are equipotential lines inscribed on the scalar field of the force tending to produce a movement in the sea. Fig. 21. — The two types of force diagrams belonging to gradient currents when friction is included either as (1) a retarding or as (2) an accelerating force The gradient AE being perpendicular, of course, represents the force due to variations in gravity potential. AC is the force due to terres- tial rotation lying 90° to the right of the direction of the current. By vector analysis we may find the force AF due to friction, where in "A" it retards the current AB, and in ''B" it accelerates the same. If all but one of the parallel lines of flow and aU but one of the parallel 43 equipotential projections be removed, the angle between these two may be more easily seen and designated as a, in the figure. It follows that: AF=AC tana = ^cosin (111) FOREWORD The London Convention of 1914, the recommendation of which paved the way for the United States to undertake the direct oper- ation of a patrol of the ice regions of the North Atlantic, also went on record in favor of a scientific program and the publication annu- ally of a report of the patrol work. In accordance with the latter feature a bulletin has been pubUshed after the expiration of each one of the patrols since 1913.^ The bulletin herewith follows the customary arrangement of the subject matter of those appearing in former years. First comes the general program and statement of policies which have in the past 13 years become pretty well estab- lished. Then follows a narrative of the events which occurred during a total of the seven cruises that made up the patrol for 1926. A brief account is given of the radio operations for the season, a subject which obviously is a vital one when estimating the patrol's efficiency. The oceanographic work this season was featured by the application of new and progressive methods ^ to map the currents in the so-called critical area around the Tail of the Grand Banks. 6 1 Copies are obtainable free of charge from Commandant, U. S. Coast Guard, Washington, D. C. ' Smith, Edward H.: "A Practical Method for Determining Ocean Currents." U. S. Treas. Dept. Bull. No. 1-1. (V) THE INTERNATIONAL ICE PATROL 1926 The International Ice Patrol for the season of 1926 was carried on by the United States Coast Guard cutters Tampa and Modoc; the former was in command of Commander H. G. Fisher, and the latter was in command of Commander H. H. Wolf. The Coast Guard cutter Mojave was designated as the stand-by vessel. Lieut. Com- mander Edward H. Smith, was detailed to assist and advise the commanding officers while on patrol. As in former years the object of the patrol was to locate by scout- ing, and radio information, the icebergs and ice fields nearest to and menacing the North Atlantic lane routes. In doing this it was necessary to determine the southerly, easterly, and westerly limits of the ice and to keep in touch with it as it moved southward. Radio broadcasts were sent out twice daily giving the whereabouts of this ice and particularly that which was in the immediate vicinity of the North Atlantic lane routes. In order that an intelligent service of the highest degree be rendered to shipping, an oceanographic program was laid down the results of which, it was hoped, would furnish the vessel on patrol with a practical up-to-date current map of the critical, infested ice area under surveillance. The oceano- graphic work being supportative and secondary in importance was so arranged that it would not hamper the patrol in its primary duty of ice scouting. A scientific program from which conclusions of practical value may be drawn is an established policy of the ice patrol. The work carried out in 1926 progressed along two general lines: (a) Sonic depth recorder experimentation. The ice patrol was equipped with one sonic depth recorder in 1925 in order that experi- mental tests be carried out which might lead to the design of a prac- tical device for determining the proximity of bergs not visible because of fog, snow, or darkness. It was found impossible to continue with this phase of the sonic work in 1926, but about 450 hydro- graphical soundings were taken in order that an accurate and au- thenic map of the ice regions around the Grand Banks may ulti- mately result. (See pp. 49 to 52.) (6) Oceanographic work: If the patrol had knowledge of the drift tracks which bergs would follow after arrival at the Tail of the Grand (1) Banks, more valuable information could be furnished approaching vessels, especially during the protracted periods when fog enshrouds the cold-water regions. Since nearly all the bergs at this gateway to the Atlantic are controlled by a relatively deep-seated circulation, a current map of the critical area where the Labrador current and the Gulf Stream meet, is an indicator of the courses menacing bergs will follow. A practical means of determining oceanic circulation in critical areas was instituted for the first time with the season of 1926. (See pp. 108 to 117.) The methods of this work ^ are set forth in a pamphlet recently published by the Coast Guard. After the ice was located the patrol began transmitting fom- daily radio broadcasts, giving ice information for the benefit of ship- ping, each broadcast being repeated once with an interval of two minutes between the messages. The times at which these broad- casts were sent and also the wave lengths used are given below : Greenwich civil time Time sev- enty-fifth meridian Wave length Frequency 0000 1900 0600 0700 1800 Meters 1,713 706 1,713 706 Kilocycles 175 HOC 425 1200 175 2300 425 In addition to this service ice information was given to any ship that made inquiry and in cases where vessels were standing danger- ously close to ice, the patrol sent them a special message. The ice patrol in transmitting routine dispatches to Washington operated under the following schedule which had been arranged before the ships sailed from port. After getting the "XA" set in working order a slightly modified schedule superseded the one here. (See p. 16.) Green- wich civil time Time, seventy- fifth meridian 1300 1700 1800 0100 0300 0330 0400 0800 1200 1300 2000 2200 2230 2300 Ice patrol transmits Weather Bureau report to Bar Harbor on 175 kilocycles (1,713 meters), using the "no answer" method. Washington transmits "no answer" method acknowledgement for 0800 schedule on 113 kUocycles (2,650 meters). Ice patrol receipts by "no answer" method to Bar Harbor receipt for Washington's 1200 schedule. Use 175 kilocycles (1,713 meters). Ice patrol transmits "no answer" method to Bar Harbor on 175 kilocycles (1,713 meters), dispatch for Weather Bureau and Hydrographic Office. Washington transmits "no answer" method acknowledgement for 2200 schedule on 113 kilocycles (2,650 meters). Washington transmits "no answer" method, a weather forecast for the ice patrol, 113 kilocycles (2,650 meters) . Ice patrol receipts by "no answer" method to Bar Harbor for Washington's 2230 and 2300 schedules. 1 Smith, Edward H.: No. 14. 'A Practical Method of Determining Ocean Currents." U. S. Treas. Dept. Bull. A more detailed account of the radio activities for the season of 1926 are contained in the section devoted to radio communications, page 14. A full and detailed description of the behavior of icebergs in the currents in 1926, together with illustrated sketches is contained on pages 53 to 77. The principal features of the ice patrol season of 1926 have been taken from the detailed reports covering the seven cruises that were made, and this narration forms the first section of this bulletin. The detailed discussion of the weather, ice observation, results of sonic sounding work, and the oceanography have been grouped together in sections that follow consecutively throughout the bulletin. 3203&— 27 2 CRUISE REPORTS THE FIRST CRUISE, "TAMPA," MARCH 25 JO APRIL 11, 1926 In accordance with headquarters telegram the Tampa sailed from Boston at 11.55 on the morning of March 25, 1926, and stood out to sea setting a course from the harbor entrance for the Tail of the Grand Banks. Thus was inaugurated the season of 1926. On the second day out we received the first steamer's report of icebergs which re- ferred to a group of seven located on the eastern part of the Grand Bank between latitudes 45° and 43° 30'. This same information was contained in the radio broadcast from Arlington and so it was thought to be the real reason for dispatching the first of the patrol ships to the ice regions. Sunday, which was our fourth day out, found us about 200 miles west of the Tail of the Grand Banks and there we stopped for an hour to take the first oceanographic station of the year (No. 554), and especially to give new members of the Tampa's crew an opportunity during good weather and daylight, to see the manner in which the station work is performed. In the afternoon dispatches were ad- dressed to the wireless officer, Halifax, Nova Scotia, officer in charge compass station, Cape Race; commercial radio station, Cape Race; and the French radio station at St. Pierre, informing them all that the ice patrol ship had now arrived in the ice regions and the same service as rendered to shipping in previous years would be carried out. Early in the morning of March 29 we arrived at the position of oceanographic station No. 555, located about 75 miles off shore of the southwestern edge of the Grand Banks. It was blowing with gale force at the time and in order that an up-and-down cast be secured the vessel was maneuvered head to the wind and sea with sufficient headway only to prevent her from "falling off." A careful and quick management of the helm under such conditions is neces- sary, but the maneuver was easily affected and the sounding work carried out with excellent results. When the third station, this same day, however, was to be taken just south of the Grand Banks, it was found that the oceanographic electric winch was burned out. More careful investigation proved the trouble to be so serious that the oceanographic program for the remainder of the cruise would have to be abandoned. Added to this information came the news that (4) the motor starter of the sonic depth finder had broken. New parts for both these defective ones were the subject of dispatches sent to Washington that night. An eventful day was March 31 when at 1.55 p. m. we received an SOS flashed from the steamer Laleham, without lifeboats and foun- dering in latitude 39° 06', longitude 56° 42'. We immediatel}^ headed toward the spot and increased speed but other ships (including the Mauratania) much nearer responded to the call. At 9 a. m. the steam- ship Shirvan reported having completed the rescue of the crew, so we headed back toward the Tail of the Bank. On account of the SOS call no evening ice broadcast was sent, this being the first time in the history of the ice patrol that such a situation has arisen. Easter Sunday dawned bright and clear, decidedly the best day experienced so far on the cruise. We started early in the morning searching northward along the eastern side of the Banks, 10 miles seaward of the 100-fathom contour, in a zone which has come to be recognized as the heart of the cold current which bears the freight of ice southward. And so it proved this day, for at 2.45 o'clock in the afternoon- the patrol sighted the first ice of the season in the form of broken Arctic fields. The position of this southern tongue waS recorded as latitude 43° 59', longitude 48° 55'. The next morning we ran up to the edge of the ice and from sights found that it had drifted southward during the night at the rate of 1 knot per hour. We steamed about 30 miles northward inshore of the ice skirting its Avestern limits, and returned before nightfall to a position southward of the southern edge. This ice had a \ev\ short survival for on the 8th we searched this same area and nothing of it could be seen. The first and only bergs sighted on the first cruise were raised by the masthead lookout about 2 p. m. on April 9. There were three small bergs in latitude 44° 10', longitude 47° 51', which were drifting northeastward at the rate of 0.7 knots per hour. The fact that this ice of small size was floating in water with a temperature of 51° F. (the northern edge of the Gulf Stream), coupled with the report that the Modoc was standing eastward to relieve, caused us to head west- ward this same night and the following day. The Tampa was relieved of the patrol duty the morning of April 11 just to the westward of the Tail. During the cruise we received eight reports of ice from passing vessels; furnished ice information to four ships and received a total of 617 reports of sea-water temper- atures. THE SECOND CRUISE, "MODOC," APRIL 11 TO 25, 1926 After relieving the Tampa the Modoc was anchored temporarily in on the Grand Bank, but the wind began to freshen on April 12 and before daylight it was found more comfortable to get under way and head into a moderate westerly gale. The day was spent in this manner with sufficient steerageway only to hold the ship's head up to wind and sea. Due to the fact that we were on the shallowest part of the Bank, the waves were very short and "cobbly, " and one sea larger than the others caught our starboard bow just at the right moment, breaking on board and washing a deck box aft beyond the galley. It also bent over and fractured a stanchion which held the forward part of a small canvass awning spread between the cabin and rail. Under such w^eather conditions as prevailed this day any plans for carrying on a program of ice scouting were forced to be postponed. April 13 provided better weather and so a start was made to search part of the icy current. At 3 o'clock in the afternoon we reached a position for heading northward along the eastern edge of the Bank, and we paused long enough to hold memorial services for the Titanic dead. This ceremony has now become a more or less established custom of the ice patrol vessel each year, and as usual a message was broadcasted to passing ships requesting, them to observe a respectful silence from 0700 to 0715 Greenwich civil time, while the actual rites were being paid on the Modoc. Earh^ this morning the steamer Alaunia informed us that she was stuck fast in an ice field which was located to the south and west of the entrance to the Gulf of St. Lawrence (Cabot Strait). Later this same day this ship discovered a lead and freed herself in open water. Every- thing was all right with the Alaunia when on April 14 she sent the patrol a radio that she had left behind the last of the St. Lawrence fields and was then proceeding eastward past Cape Race. The Modoc made an excursion to the eastward of the Grand Banks on the 14th to the 17th in search of three small bergs reported by a passing vessel. The cruise was a fruitless one as the ice was not located. A great deal of fuel was expended in returning to the westward because of bucking the strong westerly gales and mountain- ous seas. We finally reached the east edge of the Bank on the 19th instant where the ship remained anchored for the next four days. The weather made a change for the better on the 22d which was in agreement with the atmospheric pressure distribution as outlined on the meteorological map. This plainl}'- indicated that the pressure gradients were quite small and the progressive movements of the centers of low pressure were relatively slow. All of this pointed toward the advent of summer time conditions and marked a great change from the weather that had prevailed since the inauguration of the patrol. Many reports were received this day from ships on track E bound for St. Lawrence ports. As they crossed from the deep water of the Atlantic on to the continental shelf they sighted considerable ice, all of which has been listed in detail in "Table of ice and of other obstructions, " pages 21 to 30. The Modoc had an opportunity on the 23d instant to search northward along the eastern edge of the Bank for menacing ice. We proceeded northward as far as the forty-fifth parallel but found nothing. We could do nothing more in this line because of foggy conditions, so on April 24 the ship was headed westward in order to meet the relief. The Tampa was met about 4 in the afternoon of the 25th. During this cruise the Modoc received a total of 53 reports of ice sighted by passing vessels, furnished information to 16 ships, and received a total of 950 reports of sea water temperatures. THE THIRD CRUISE, "TAMPA," APRIL 25 TO MAY 10, 1926 After effecting the relief and assummg the duties of patrol ship the Tampa was kept off on a course for the first one of several ocean- ographic stations arranged in positions around the Bank in accord- ance with a previously arranged program. In view of the fact that no ice was south of the fortj^-fifth parallel and also that there had been considerable postponement in the oceanographic work, the patjrc^ decided the work better be commenced while opportunity existed. Bergs, moreover, were to be expected soon invading the waters around the Tail and it was desirous that the patrol vessel have on board a current map of this critical area. The next nine days were mostly devoted to collecting data of temperature and salinity from several depths at stations scattered netlike around the Grand Banks. During this period the work was delayed by the presence of a fog and near the latter part of the inves- tigation a strong westerly gale was encoimtered. Wliile heading the gale on the 2d of May a report was received from the steamship Rousillon regarding the position of an iceberg on the east side of the Bank in latitude 44° 10'. This was without doubt one of a group of five bergs that had previously been reported by Cape Race track steamers but it was the southernmost berg so far for 1926 and in that respect was a poiat of interest for the patrol. A fog prevented us searching for this berg and so we waited until conditions became clearer. During this period the oceanographer with the data collected calculated the direction and rate of flow of the water in the regions surveyed and a map of the currents was drawn and posted for the information of those in charge of the patrol work. This is the first time in any expedition that the results have been immediately determined on board ship for practical employ- ment. \lsij 7 the Tampa was near the fishing fleet and one vessel was spoken and another was boarded. Sea stores were traded for fresh fish and we anchored for the night in on the Bank. The oceanog- 8 rapher gave a 15-minute talk this same evening on the history of the ice patrol and general behavior of Arctic ice south of Newfound- land. Nothing could be done during the day of the 8th on account of fog but the 9th it cleared, the very same day that the patrol ships were meeting on the southwest side of the Bank. Two reports were received from steamers on the east of the slope which had sighted bergs and which plainly indicated that the ice was beginning to drift southward around the Tail. The Tampa during the third cruise for the season covered about 1,255 miles, and took 24 oceanographical stations. There were 54 ice reports received and 9 ships were given special ice information. A total of 835 surface temperature reports were contributed by passing vessels. We requested that 22 steam- ships give receipted acknowledgment for the ice broadcast because their courses were laid near the ice danger zone. THE FOURTH CRUISE, "MODOC," MAY 10 TO 25, 1926 The Modoc met the Tampa the morning of May 19, 120 miles west of the Tail, where the oceanographic party was received on board and the relief effected. As soon as the boat was hoisted the Modoc was headed eastward with plans to search the region around the Tail the next day. Unfortunately a dense fog shut in before the close of the day which necessarily suspended all searching work. Foggy conditions continued for the next two days but about 5 o'clock the afternoon of the 12th the wind shifted to the westward during a rain squall and the blanket of fog was swept away. We were not slow to take advantage of such ideal conditions and for the next 36 hours conducted a search which led as far north as the 43° 30' parallel. There were four bergs found in the searched area, the south- ernmost one on the forty-third parallel in the heart of the Labrador current drifting south-southwest at the rate of 0.8 knots per hour. The scouting work on the 14th instant revealed more ice than the patrol had found heretofore this year. There were a total of 21 bergs found south of latitude 44° 15' which was fartherest north for the trip. This ice was strung out along the eastern edge of the Bank and in positions which indicated that the bergs were tending to set on shore and strand. Many of the bergs had growlers near them and it was observed, moreover, that there were no extraordinary large bergs sighted. The rate of drift was estimated at 1.1 knot- per hour. Fog shut in again on the 15th and lasted with occasional brief "light ups" until May 20. During this time the Modoc steamoi over an area lying off the southwest slope and around the Tail where a total of 12 stations of salinity and temperature were occupied A current map was constructed upon the basis of these data and the bergs which had been lost in the fog were thought to have drifted either up on the southwest slope of the Bank or to the northeast in the counterset. In any event the current map showed that there was very little likelihood to suppose that the ice had been transported southward in the fog toward the steamship lanes. Late in the afternoon of the 20th the steamer Tiger sighted 20 bergs off the Tail about 30 miles and so during the night we shaped a course so as to be in an advantageous position to commence search- ing at daylight on the 21st. During the next two or three days the patrol searched this entire area and plotted the positions of a total of 20 bergs and three growlers. As this discussion with sketches is taken up on page 65, it will not be entered upon here. On the 23d it was observed that the bergs farthest offshore to the southeast were slowly being turned in the current and were beginning a counter drift to the northeast. Later in the morning the Modoc laid a course to the southward and westward because no chances wished to be taken on bergs drifting unawares in that dangerous direction. While we were steaming in this quarter a fog bank rolled in completely enveloping the ice infested waters. The approach of the Tampa returning for a new tour of duty was announced by radio the night of the 23d and so we headed over to the westward, meeting at a rendezvous about 100 miles west of the Tail. The Modoc received 67 reports of ice sighted by passing vessels, furnished ice information to 10 ships, requested acknowl- edgment from 22 vessels for the regular ice broadcast, and received 775 surface temperature reports during the cruise thus terminated. THE FIFTH CRUISE, "TAMPA," MAY 25 TO JUNE 10, 1926 After relieving the Modoc the Tampa stood eastward toward the group of bergs last seen by the Modoc on the 23d instant but fog shut in the morning of the 26th causing us to drift until the arrival of clear weather again. Sometime during the morning we received a radio from the steamer Clearpool reporting a berg and growler in latitude 41° 49', longitude 50° 12'. We immediately requested the master of the Clearpool to verify his position and indicate how recently he had obtained astronomical sights, because this position was con- sidered surprisingly far south for any berg to drift so quickly. The reply stated that the previous position was in error and gave the latitude as 42° 24'. The Tampa got under wa}^ and had not pro- ceeded very far when a growler was sighted close aboard in the fog. This we thought might be the same growler that the Clearpool had seen earlier in the day, so taking it as a point of departure we headed eastward about 10 miles where a berg was found. When the fog cleared later on we beheld five bergs in sight to the eastward, and so we steamed over to the largest one. This group of bergs was 10 undoubtedly part of the same ice which the Modoc located to the northeastward on the last cruise. The fog cleared up for good on the morning of the 27th and gave us an opportunity not only to locate all the bergs in this region south of the Tail but also permitted of securing accurate sights. We had been without a definite fix of the ship 's position for nearly four days. Ten bergs were sighted during the day, five in the dead water di- rectly south of the Tail, latitude 42° 27'; two lay to the westward on about the same parallel but in longitude 51°; and three more bergs were observed grouped together at the farthest point south for the year, viz, latitude 42° 13' longitude 50° 29'. The distribution of this last lot was in agreement with the oceanic circulation as deter- mined May 18-20 by the Modoc. The bergs in longitude 51° 00' had drifted as far west as was possible on account of the counterset in that region, while the three southern ones had become caught in the inshore edge of the easterly flowing water and they were drifting east-southeastward at the rate of 0.5 of a knot per hour. On May 28 a message was received from the steamship Chicago reporting a berg in latitude 41° 51', longitude 48° 33'; this being the southernmost ice and only about 20 miles north of the west- bound steamer track, the Tampa was headed on an easterly course in order to get in touch with this ice as soon as possible. At daylight on the 29th we sighted the berg for which we were in search. It was not a very large berg, in fact it was medium to small and it showed signs of rapid disintegration. During the morning and afternoon demolition operations were carried on, making use of 6-pounder gun and 238-pound TNT mines. Considerable ice was shaken down but it is questionable whether the expenditure would be justifiable in continuing such a practice on a greater scale. That evening we spent close to the ice warning all approaching ships of its location. The next day our berg was only about half of its former size. The rapid disintegration was due without doubt to a heavy swell which continually washed the ice and broke off growlers one after another. The temperature of the water, 56°, of course also materially assisted to speed up the melting processes, and so May 31 witnessed the entire removal of this menace to navigation. This was the most rapid disintegration of which the patrol has record, to the best of our knowledge, and it is of interest because it was due in a great measure to the swell and sea which continually lashed and strained the berg. At 12.30 p. m. there was no longer any reason for remaining in the locality — latitude 40° 45', longitude 47° 38'— so we steamed ahead on course 310° toward the group of five bergs which we had left on the 28th instant. About 7 o'clock the morning of June 1 the steamer Stadsdijk reported seeing two bergs about 30 miles to the westward of where we were searching and this ice was believed to be the same that we 11 wished to sight. The course was accordingly changed for this new position and at the same time radiocompass bearings were taken of the Stadsdijlc. While we were maneuvering to get in touch with this ice a message was received from the steamship George Wash- ington that she had just passed a small berg about 35 miles to the eastward of where we were then and on the westbound steamer track. We immediately headed that way, made contact with the Washington at 11 o'clock, and picked up the berg just before sunset. The Tampa remained close to this berg during the next four days, as long as it continued to be a menace to navigation. During the night- time it was our practice upon the approach of steamers to throw^ the searchlight beam on the ice clearly marking its position. That this was appreciated is shown by the following message from the steam- ship Mauretania, which passed close to the Tampa one night. "We are passing south of you; can see berg in your searchlight beam. Thank you. Rostron." A dispatch on June 2 broadcasted from Arlington radio station stated that the trans- Atlantic track conference had decided to change from tracks B to tracks A immediately, the eastbound track being moved June 2 to 39° 30' latitude, and the westbound track being moved simultaneously to latitude 41°, with the complete shift of the westbound to latitude 40° 30' on the 9th instant. On June 4, wdth the melting of the aforementioned berg, the patrol vessel shifted its position 4 miles to the northward near a large berg which had been sighted the previous day. A survey was made of the exposed surface above water; a tower, the highest point on one end, measured 55 feet; the opposite end, 35 feet; and the length was 382 feet. It is worth mentioning here that the heights of bergs can be measured quite accurately by climbing the mast to a point where the line of sight of the observer passes tangent to the summit of the ice and through the horizon. A correction of 4 feet should be added to this as the correction for the dip of the horizon. Measured heights from the water line can be easily marked upon the mast in units of 5 feet, and it will seldom be found that heights of bergs will exceed the height of the crow's nest. While the Tampa was lying alongside of this ice on June 5 the steamer Leviathan passed close aboard about 9 o'clock in the morning. She thanked the patrol for its services and very complimentary added, "Your vigilance was an inspiring sight to everybody on board. Hartley." Captain Fisher replied, "Glad to be of service to the queen of the American merchant marine. Your passing ship was an inspiring and beautiful sight." The early jnorning hours of June 6 witnessed the complete melting of this ice. The last few days of the Tampa's cruise were spent patrolling along the southern boundary of the fog wall as it was impossible to carry on any ice scouting in the cold waters to the north w{iiPdt;";Th©-^ /C (S( [UJ L { ^ R #v R V J -., 12 Tampa received a total of 970 sea water temperatures from passing vessels; gave special ice information to 10 ships; and received a total of 159 reports of ice. There were 71 ships during the cruise from which we requested acknowledgment of receipt of the ice broadcast. THE SIXTH CRUISE, "MODOC," JUNE 10 TO 25, 1926 The 11th and 12th were foggy days but June 13 it cleared and the Modoc was headed westward in order to get into an advantageous position for searching for any ice south of the Tail of the Bank. Excellent visibility prevailed on the 14th and the Modoc for the second day of clear weather was cruised at forced draft over a large area where bergs were suspected. No ice was found, however, and this fact was interpreted as indicating a great dwindling in the num- ber of bergs from the high point earlier in the month. Not over three weeks previously in this same locality there were drifting more than 20 icebergs. A few reports continued to be received from steamers on the Cape Race tracks to the northward. The 15th of June the Modoc spent searching from a point 70 miles west of the Tail along the forty-third parallel to the eastward about 90 miles. No ice was sighted and excellent visibility prevailed the entire day except for a short time in the afternoon. When we attempted to search northward, however, along the eastern slope of the Bank a wall of fog was met. The water along the slope, with a temperature of 46°, was 4° or 5° cooler than any other part of the surrounding surface water. During the morning of the 16th we made another attempt to search northward along the east edge of the Bank but a heavy fog wall was soon entered which of course precluded all hopes of further ice search. The afternoon and evening were spent occupying a line of oceano- graphic stations extending south of the Tail, but this work had to be abandoned late at night due to a severe southerly storm and sea. The storm ended on the 17th as suddenly as it had begun so we were quick to take advantage of the clear visibility searching north- ward as far as latitude 44° 30' in the ic}^ current. No ice was found in the current and this was taken as a very hopeful sign that there would be very few bergs able to drift as far as the Tail during the rest of 1926. A small berg was reported well to the northwestward on the southwest part of Bank, however, but its position was not dangerous, and it was believed this ice was the same as that reported on the 13th instant to the patrol, then grounded on the Tail. We were able to continue the patrol's search on the 18th still farther to the northward, no bergs being found south of parallel 44° 45'. We anchored on the eastern side of the Bank on the 19th and 20th. The steamer United States sighted a small berg southeast of the Tail about 20 miles on the 19th but inasmuch as it was not 13 much larger than a growler in size and that it was floating in warm water, temperature 55°, it was not regarded as a potential menace. We searched this vicinity on the 22d, however, the first opportunity of clear weather but nothing was found so the Modoc was headed westward for a rendezvous with the relief ship. There were 144 reports of ice received from passing vessels; 3 steamers were furnished special ice information upon request; and a total of 1,002 reports of surface water temperatures were received. THE SEVENTH CRUISE, "TAMPA," JUNE 25 TO 30, 1926 After taking over the patrol work from the Modoc it was decided best to utilize the time compiling an ocean current map of the region around the Tail of the Bank, in order that a record might be made of the current conditions just before the patrol was discontinued. Sta- tions were occupied along lines normal to the trend of the slope and spaced at intervals of 50 to 75 miles. This work continued and the 26th found the Tampa running north- ward on a line just south of the Tail. The water temperature wall was found to lie in latitude 41° 55', longitude 50° 15', the thermometer dropping from 61° to 57° quite abruptly. The position of the temperature wall at this place refutes the belief that the position of the Atlantic water had been changed much from that found earlier in the season. Such an error of judgment is easily made because of the relatively high temperature of the surface water which is attained solely as an effect of the sun's heat with the approach of summer. The 27th, 28th, and 29th were spent on oceanographic survey and when the weather was clear advantage was taken to include a search for ice. Not a sign of bergs was found and so a recommendation was forwarded to headquarters that the patrol be discontinued at mid- night on June 30. A reply the next day directed the patrol to discon- tinue its activities at midnight June 30 and return to the United States. We headed westward on the last day of the month preparatory to returning to Boston. No ice had been reported or sighted by the patrol vessel south of the forty-fourth parallel since June 17 and this area had been repeatedly searched since that date. We were quite confident that no ice could possibly be in these waters. Bergs continued to be reported on the northern part of the Bank and near Cape Race as is usually the case at this time of the year. Messages were dispatched to the wireless officer, Halifax; the officer in charge radiocompass station, Cape Race; and the commercial wireless sta- tion. Cape Race, notifying them all of the discontinuation of the ice patrol and thanking them for cooperation during the 1926 season. During the cruise thus terminated the Tampa received 36 reports of ice, furnished special ice information upon request to 1 steamship, and received a total of 186 sea-water temperature reports. RADIO COMMUNICATIONS The vital importance of the radio to the plan of an ice patrol warning approaching ships of the dangers in their paths is quite obvious. It would be literally impossible to perform this humani- tarian service if it were not for Marconi's pioneer invention. Natu- rally the efficiency and value of the patrol, as it proportionately assists to increase the safety of life on the North Atlantic, is closely wrapped up in the entire subject of radio. Not only is it the ice which is actually found by the patrol that is reported to shipping, but also is included the ice from a much larger area than that which the patrol could possibly hope to cover. Such accomplishments can only be realized with the cooperative assistance received from passing ships which report to the patrol from positions scattered over the entire danger region. It can be seen that under such circumstances the patrol vessel assumes the role of a radio clearing house and thus becomes the disseminator of a digested report for the whole region. The story of the past season's work, as in former years, has been one of willing and efficient service on the part of the merchant vessels. We also want to add that the Canadian direction-finding stations and the Cape Race Commercial Radio Station have done everything possible to make the radio operations run smoothly and successfully. The summary of the work performed during the 1926 season will be found in the report of the ice patrol commander, page 17. A survey of the radio communications during 1926 particularly impresses us with a feature which excels previous years; and the part we have in mind refers to the great improvement regarding the ship to shore communication. The patrol, in its early years, depended upon forwarding its traffic to Washington via the nearest coastal station. Cape Race, Newfoundland, by means of an ordinary 2- kilowatt spark transmitter. There were, however, times during the first few weeks of the ice season, say until April 1, when direct communication was possible by this means, but for the major part of the season, it was necessary to transmit messages via Cape Race. Because of the expensive tariffs by this route it has long been the desire to establish official communication between the patrol and naval radio stations situated in the United States. When the then new ships Tampa and Modoc, in 1922, were assigned to patrol duty, more frequent communication with United States coastal stations was effected by means of arc sets with which these vessels were (14) 15 equipped. This service failed quite often, however, due to summer time static conditions and poor functioning of the sets. Such un- satisfactory conditions caused the officials in charge of the patrol Avork in 1925 to equip the ships with 2-kilowatt vacuum tube trans- mitters, especially designed and manufactured by the General Elec- tric Co. (See Ice Patrol Bull. No. 13, p. 51.) Communication by means of these sets with the naval coastal station at Bar Harbor, Me., was more reliable and satisfactory than at any time during patrol history. Summer time static conditions even then, quite frequently in June, necessitated an auxiliary service, communication being effected via the patrol ship off duty in Halifax. Realizing the natural difficulties which the patrol had met for several years with ship-to-shore traffic, a new type of set was installed just before the ships sailed in 1926. This set employs a short-wave, high-fre- quency transmitter, 35 or 70 meters, and it represents a new design which the United States Navy is manufacturing. In fact the work was rushed in order that the patrol might be equipped for 1926. During the first half of the season minor alterations were found necessary before the best performance was attained, but by the latter part of the patrol the sets were operating satisfactory. Direct communication with the high-frequency sets was maintained with few exceptions the entire patrol of 1926 with the Navy Ex- perimental Laboratory, Bellevue, Aid. The set is described as a Navy model "XA," 500-watt crystal control, with a frequency of 4,205 and 8,410 kilocycles, and was manufactured at the laboratory, Bellevue. The other radio equipment carried on board the ice patrol vessels was the same as that in use during the 1925 patrol. (See Ice Patrol Bull. No. 13, pp. 51-52.) Information regarding the weather was broadcasted every night and morning by means of the 2-kilowatt tube transmitter (C. G. model T-2). Also information of a general char- acter as to the behavior and distribution of ice and currents were "talked" quite informally this past year as the steamers approached the ice regions. The officers of these vessels were especially invited to come to the radio room and listen in and it was apparent that these phone talks were of considerable value. It is human to forget with the passage of time even the lessons learned through great tragedies, and the mariner is no exception to this rule. It is, we believe, part of the spirit of ice patrol, to educate by talks on the entire subject of this danger eVery spring. The patrol has trained experts and it is certain that their knowledge will be of interest and stimulate educational thought along similar lines with the navigator. The amount of ice patrol traffic handled by radio is always inter- esting and indicative of the amount of work performed by that means. There were approximately 5,488 reports received from pass- 16 ing steamers concerning their position, course, speed, and sea water temperature. A total of 470 official messages were transmitted to Washington, and 236 were received. It is estimated that a total of 252,299 words were handled during the season of 1926. (See p. 20.) There is appended herewith a schedule giving the times at which messages were sent and received by the patrol vessel. The schedule was not adopted until after several preliminary experiments and trials, so that the final draft as outlined here ought to furnish a very good schedule upon which to base radio operations for next year. (All times seventy-fifth meridian) 0600. Ice broadcast (spark) ; call on 600 meters then send on 706 meters twice with a two-minute interval. 0700. Ice broadcast (continuous wave) ; call on 600 meters then send twice on 1,713 meters with two-minute interval. 0800. Send weather report to Bar Harbor, Me., on 1,713 meters, using "no answer" method. 0915. Copy Cape Race weather broadcast. 1030. Copy Arlington weather broadcast. 1200. Copy time signals and ice patrol traffic from Arlington.- 1415. Copy weather broadcast from Cape Race. 1800. Ice broadcast (spark); call on 600 meters then send on 706 meters twice with two-minute interval. 1900. Ice broadcast (continuous wave); call on 600 meters then send on 1,713 meters with a two-minute interval. 1930. Clearallship to shore traffic with Navy Experimental Laboratory, Bellevue, Md., on 35 meters. 2000. Stand-by schedule with Bar Harbor, Me., on 1,713 meters only in case the 1,930 schedule fails. 2115. Copy Cape Race weather broadcast. 2200. Copy time signals and any ice patrol traffic from Arlington. 2230. Copy weather broadcast from Arlington. SUMMARY REPORT OF ICE PATROL COMMANDER Commander H. G. Fisher, Commander International Ice Patrol Ice patrol was inaugurated March 25, when the Tampa sailed from Boston for the Grand Banks. The Modoc departed from New York in sufficient time to relieve the Tampa on April 11, and thereafter these two ships took alternate 15-day tours of duty throughout the ice season. The patrol was discontinued at midnight June 30, having been on guard a total of 97 days. The ice patrol which is now 13 years of age, has during this period had opportunity to study its problems, and plan its general adminis- tration so that now many of the features of the work have become systematized, especially those events which have gradually grown to assume a more or less routine character. The work, as has often been remarked, possesses two main aspects — (a) the practical and (&) the theoretical. The first (a) embraces the primary function of locating by actual scouting and radio communication, the icebergs and field ice nearest to and menacing the North Atlantic lane routes, and the duty of placing that information at the disposal of all ap- proaching trans-Atlantic ships. The second (6) centers on carrying out an intelligent scientific program the results of which throw light of practical importance on the economic humanitarian service which the patrol endeavors to render to shipping. In speaking of the practical work it is customary to include in the summary report of each year a brief review of the distribution of ice in time and place, its drift, numbers of bergs, and a survey of the weather which has been experienced during the season. It ma}^ be quite confidently stated that less field ice drifted south of Newfound- land in 1926 than usual. In fact there were very few reports of field ice before the month of March with the flat ice attaining a maximum early in April, and with the last report dated May 11. Even at the date of its most southern extension, April 4 and 5, it did not reach as far as the Tail of the Bank, nor did it spread to any great extent over the Grand Banks south of Newfoundland as it often does. It held, however, more or less closely to the eastern and northern portions of the Grand Bank as usual. Ice conditions in the Gulf of St. Lawrence this year were very open, the patrol receiving a message from the Canadian ice patrol ship Mikula that the gulf and river were navigable to Quebec on April 18, or about one month earlier than usual. (17) l8 The first icebergs were reported south of Newfoundland in Feb- ruary; the number increased in March. No bergs drifted south of the Tail during April; few during the first half of May; but the latter half of that month saw the greatest number of bergs for the season. After June 6 no bergs of any size drifted south of the Bank. The total number of bergs drifting south of Newfoundland during 1926 was nearly normal but the seasonal distribution was not. (See p. 72.) Three bergs drifted much farther south than the others, crossing the westbound steamship lane route, known as track B. Due to the presence of this ice in such menacing positions the tracks were shifted to A, 60 miles farther south from June 5 to 30. As previously stated there were reports of only two bergs of any consequence in June around the Tail of theBank, one on the 12th and the otheron the 17th. The last two weeks of that month these waters were free of ice and under such conditions consequently it was considered safe to dis- continue the patrol on June 30. A considerable number of bergs, it should be added, were reported on the northern part of the Bank, from May on throughout the ice season. The patrol was treated to an unusually long rough spell of weather persisting to the latter part of April before the backbone of winter was finally broken. This agrees quite closely with the seasonal change to the westward over the United States when winter conditions prevailed unusually late into the spring of 1926. Winter atmospheric circula- tion of the ice regions dift'ers quite markedly from summer time condi- tions. The Grand Banks south of Newfoundland are located on the southern side of a cyclonic wind system caused by the normal winter distribution of atmospheric pressures. The barometric gradients are exceedingly steep, causing westerly gales to blow w^ith great and constant intensity for several days at a time, though they are often interrupted by low centers of marked disturbance, moving along a northeasterly track to die offshore in the Atlantic. It can be imagined that under such severe handicaps as prevailed this year, March 25 to AprU 22, little work of any value could be carried on. By the same token it is considered unwise in any year to inaugurate the patrol work so long as winter conditions persist. The scientific work carried on this season was under the super- vision of Lieutenant Commander Smith, who returned to the patrol after spending a year abroad on two of the most important natural problems which have for some time confronted us, viz (a) information regarding the probable drift of ice after arriving at the Tail of the Grand Banks, and (6) advance information about the annual amount of ice to be expected south of Newfoundland. The former subject is discussed under the section devoted to oceanography; the latter is taken up under the heading "Weather." 19 A notable advance in this year's work was the employment of dynamic methods to determine and map the currents around the Grand Banks. A special bulletin, No. 14, describing the work for use on ice patrol, has recently been published by the Coast Guard. The final answer as to the degree of success attending it depends on its practical employment on future ice patrols. It would be very wise and advisable if officers of the Coast Guard detailed to patrol duty were required to acquaint themselves with these methods in order that several may possess this knowledge instead of only one officer, as is now the case. The international ice patrol will give its most efficient and economic service to shipping only when useful scientific methods are employed to support the practical work. The patrol ships were equipped this year with practically the same outfits as they had on board in 1925, with the exception of new high- frequency radio sets, especially intended for use in communication with shore, and a second electric salinity set so that determinations might be made on board both ships instead of on one alone, as in previous seasons. The performance of the new radio sets for ship- to-shore communication, as stated in more detail under the section devoted to communications, page 14, well repaid the expense and effort expended in placing the apparatus on board. About 465 hydrographical soundings by means of the sonic appa- ratus were made during the season at various positions both in the shallow waters over the Grand Bank and offshore, particularly to the southward of the Bank in the deeper portions of the Atlantic Basin. These are described under the section devoted to sonic sounding, page 49. The value of carrying on this work on future patrols is emphasized, and in this connection it is believed that both ice patrol vessels ought to be equipped with sonic depth apparatus instead of one, as is now the case; steps also ought to be taken to have at all times at least one trained operator on board. About 450 steamships are known to have taken advantage of the services offered by the ice patrol in 1926. No doubt several other ships of which there is no mention also listened-in for the daily broad- casts. The following list is submitted in order that the reader may gain an idea of the service which is being given the ships of many nationalities. The masters of these vessels have been individually thanked, by letter, by the chairman of the interdepartmental board in charge of ice patrol. Belgian 8 British 171 Canadian 27 Chilean 1 Danish 8 Dutch 25 French 13 German 14 Greek 1 Italian 9 Japanese 1 Norwegian... 20 Argentian 1 Spanish 5 Swedish 11 United States 114 20 A summary of work performed, the dissemination of information, and other miscellaneous business handled by the Patrol for 1926 follows : Washington oflacial messages 470 Daily routine broadcasts 372 Special broadcasts (during fog) 42 Ice information to certain vessels, special 165 Special ice information requested 48 Position reports requested 1 Track information requested 4 Chronometer comparisons 1 Weather reports 102 Water temperature reports received 5,488 Ice reports received from: Steamships 414 Cape Race 172 Words handled by radio 252,299 Violation of steamship tracks reported 1 SOS not in jurisdiction of Patrol vessels 4 As in previous years, the cooperation received from passing ships was generous and indicative of a sincere appreciation of this service, which is being financially supported by international contribution. The commander of the ice patrol takes this opportunity to thank all those who assisted to make the past season's work successful. TABLE OF ICE AND OF OTHER OBSTRUCTIONS, 1926 No. Vessel reporting Position Nature of ice or obstruction Date Lati- tude, north Longi- tude, west Feb. 8 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Cape Race (station) 48 11 48 15 f 47 25 i to I 47 08 44 53 ! 49 13 ' Slush ice. 10 do 49 40 Field ice east of St. Johns. 10 do 49 50 to 51 05 59 52 -Occasional patches field ice. 10 do Field ice. 15 do. Bull Head to Canso. 100 miles NE. Cape Race. Along the coa.st Do. 16 do ... Do. 17 do. . Heavv ice field. 19 .....do f 44 46 i to 44 40 48 09 •{ to I 48 06 47 50 45 15 47 17 41 04 f 48 16 i to I 47 40 45 07 ♦o { 45 05 48 24 47 50 47 24 ( 47 54 \ to I 46 57 46 56 ( 45 00 \ to 1 45 30 f 45 40 < to 1 46 05 f 46 20 < to I 45 40 45 38 45 41 f 46 20 to I 45 40 45 10 45 15 45 16 45 17 45 09 44 55 44 50 44 35 44 22 44 18 45 17 45 30 45 15 48 10 48 20 f 43 47 \ to { 43 43 43 45 [ 48 45 \ to I 48 00 45 50 58 57 to 60 28 48 07 to 49 20 50 04 59 44 47 03 I Do. 20 do i Do. 20 do Slab ice and small bergs. 21 do Field ice. 21 do Several small beres. 22 do 37 40 Derelict schooner Cecil jr. Mar. 2 .....do 46 50 j) to >Small bergs and growlers. 2 do 47 50 J 57 13 to |>Fieldice. 6 .....do... 57 42 1) 46 22 Do. 15 do... 49 38 ; Field ice and occasional bergs. 16 do 50 57 Field ice. 18 .....do 47 58 !l to meavy field ice and small bergs. 48 45 il 47 49 I Field ice and growlers. 19 do 19 do 58 20 1 to [-Field ice. 19 do 57 40 1 47 00 1 to 1-Field ice and large growlers. 20 do 46 25 il 46 40 '1 to I^ Do. 48 30 J 46 23 Small bergs. 20 do 20 do.. 46 03 1 berg. 20 do 46 40 ] to '[-Field ice and growlers. 20 do 48 30 J 46 30 Large bergs. 20 do 46 45 Small berg. 20 do 47 29 Large berg. 20 do... 47 46 Do. 20 do 48 35 Do. 21 do 46 23 Growlers. 21 do 48 30 Numerous growlers; field ice. 22 do 57 20 Field ice. 22 do. 48 36 Field ice and growlers. 22 do 48 36 Small berg. 20 Hydrographic Office.. _ 46 30 4 large bergs. 20 do 48 10 3 bergs. 21 do 48 10 1 Large ice field. 23 Naturia 48 00 Large ice field: growlers. 23 Cape Race (station) 49 15 48 28 to Field ice. 23 do (■Field ice and growlers. 25 do 48 41 j) 48 07 ' Do. 25 do 49 20 J] to [Field ice. 48 00 1 4V 20 Do. 25 do (21) 22 Table of ice and of other obstructions, 1926 — Continued No. Vessel reporting Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction Mar. 26 46 47 48 49 50 51 52 52a 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 Cape Race (station). 0 1 42 51 47 00 44 20 ( 49 10 { to 1 47 31 47 33 46 40 40 32 39 05 44 42 45 11 47 47 47 20 f 46 15 I 45 00 42 43 43 59 43 33 42 23 ( 45 32 < to I 46 32 44 00 44 10 44 55 46 55 46 45 44 43 44 44 44 44 44 04 46 58 47 01 45 05 44 32 1 46 25 \ to 1 45 58 46 34 46 27 45 42 45 57 46 05 45 48 45 40 45 39 39 39 39 46 46 55 47 10 45 52 47 40 f 47 16 \ to I 47 14 46 46 45 53 47 00 47 40 58 04 48 00 49 10 49 23 to 46 34 46 23 47 24 47 36 56 37 57 15 45 00 52 05 52 09 47 35 to 48 50 55 40 48 55 49 12 49 12 48 20 to 47 36 48 10 47 54 46 52 47 25 48 00 60 32 60 26 59 10 56 47 46 30 45 16 46 34 45 16 47 00 to 47 45 47 54 47 47 48 15 47 45 47 22 47 42 45 25 45 28 55 26 57 45 45 45 51 00 47 57 46 15 47 10 to 47 20 45 39 45 12 48 00 46 21 Spar attached to wreckage. 27 .. .-do . . Large bergs. 27 do Large growlers. 27 Baltic [■Large ice field. 29 Noresfjord-- Field ice and growlers. 29 do . Large berg. 29 Dalvarian Derelict schooner Ma.x Horton on ?\ti . 31 Laleham _ Foundered steamer Laleham. Apr. 1 Cape Race Heavv ice field. 2 Helig Olav Ice berg. 2 Cape Race (station).. Ice field. 2 do Do. 3 London Exchange ■Field ice and growlers. 3 Cape Race (station) Spar attached to wreckage. 4 Ice patrol.. Field ice, southern extremity. 5 do Same as 59; drifting 190°, 1 knot. 5 do Same as 59; drifting 180°, 1 knot. 6 Tampa (steamer) vField ice and growlers. 8 Sulina 3 small bergs. 9 Ice patrol Same as 63; drifting 49°, 0.7 knot. 10 10 Carlsholm.. 1 iceberg. Field ice. 11 do.. Western side of ice field, same as 66. 12 Alaunia Field ice (St. Lawrence). 13 do Do. 13 Citv of Kimberly . Do. 14 Alaunia Do. 14 Cameronia Do. 14 do 4 bergs and growlers. 14 Bellflower 1 berg, 2 growlers. 16 London Mariner Small berg. 16 Transylvania [■Field ice and growlers. 16 Regina J 1 berg, 2 growlers. 16 do 1 berg. 16 Transylvania. 1 large berg. 16 do... 2 growlers. 16 do... 1 growler. 16 do Low lying ice field. 17 Bergensfjord 3 growlers. 17 do . . 1 growler. 17 Deck load of spars. 17 Cedarhurst-.. Sea covered with wreckage. 20 Idefjord 2 small bergs same as 73. 20 Terra Nova. Western edge field ice. 21 Athenia Large berg, same as 77. 21 Aurania 1 berg. 21 21 do... Montnairn 1 [■Field ice. Small berg, same as 73. 21 Ansonia Do. 21 Aurania . 1 berg. 22 Doric. Low Iving berg. 22 Station Belle Isle . . 84 bergs in sight; field ice. 22 Caronia 47 35 47 28 47 27 47 14 47 09 46 52 47 38 46 10 47 02 46 27 48 28 48 25 47 13 47 13 46 11 46 28 46 35 46 47 47 00 46 48 44 40 48 11 45 47 47 06 48 29 47 10 47 42 50 52 Small berg, same as 95. 22 do Small berg. 22 do.. Do. 22 do... Small berg and growlers. 22 do.- .. . 20 bergs in heavy pack ice. 22 do Field ice, same as 88. 22 Montrose ... 1 growler. 22 1 small berg. 23 Bothwell Large berg. 23 do.. Southern end field ice; seven bergs. 23 Twickenham Heavy field ice. 24 Cairntorr Do. 24 Field ice. 24 do Berg. 23 Table of ice and of other obstructions, 1926 — Continuetl Date Apr. 24 24 24 24 24 24 24 26 26 May No. Ill 112 113 114 115 116 117 118 119 121 122 123 124 125 126 127 128 129 130 133 134 135 136 1.37 138 139 140 141 142 143 144 145 147 148 149 150 151 152 153 154 155 156 157 158 159 161 162 163 Vessel reporting Geraldine Mary. Wirral Blackheath Arabic -...do Cairntorr. Maidenhead. Cairntorr .do. .do. do Unknown ship. do. do .do. do Minnedosa. do do Transylvania. Minnedosa Bawtry Montcalm do do Drottingholm. do Zealand-. do do do do Valemore. do Canadian Commander . Modig Frode.- Roussillon Suderoy Brandon.- Lord Downshire Montairn Athenic. Doric Thuban.. ^\ elshman Empress of France . Regina Winterswijk Athenia. Winterswijk. Ansonia do Procyon. Position Lati- Longi- tude, tude, north west o / o / 46 58 46 48 47 00 44 40 48 16 47 10 47 36 43 49 47 05 44 4] ( 48 25 46 30 \ to to I 47 49 46 40 46 11 48 48 46 45 47 30 ( 47 49 46 40 to to I 47 05 47 25 f 47 05 47 25 1 to to I 46 49 47 14 46 32 47 45 47 08 46 18 47 07 46 34 47 06 46 32 f 47 10 46 44 { to to I 45 56 47 35 45 57 47 37 47 10 46 03 47 12 46 19 47 03 46 30 44 48 48 41 f 45 48 47 00 ] to to 1 45 33 47 24 45 50 47 22 f 47 34 { to I 46 39 I 47 04 47 00 46 52 46 50 47 06 44 47 48 39 44 32 48 48 45 03 48 05 44 35 48 25 44 52 48 32 44 18 48 46 44 32 48 58 ( 45 29 47 45 ] to to I 45 29 48 02 45 29 48 21 45 28 48 03 f 48 33 45 35 to I 48 58 to 49 30 45 25 48 31 44 10 48 30 46 09 46 24 45 20 46 03 47 03 47 15 44 50 48 13 45 47 46 31 46 22 47 53 45 50 48 00 45 47 46 59 46 38 47 25 48 07 43 34 45 50 46 20 ( 45 51 48 50 to I 44 35 to 48 45 44 35 48 45 44 48 48 46 44 47 48 45 f 47 20 46 29 to to 1 47 23 47 30 Nature of ice or obstruction Field ice. 2 bergs. Scattered field ice. Small berg, same as 112. Do. rSlob ice. Large berg. Heavy field ice; numerous bergs. Open field ice; several bergs. ■Heavy field ice; many bergs. Western edge of field ice. Large berg, same as 101. Growlers, same as 101. Do. ■Heavy field ice; numerous bergs. Large berg. 5 growlers, same as 101. Berg, same as 122. Large ice field with many bergs, same as 101. Small berg and growlers. ■Patches of slob ice. Berg; patches field ice, same as 131. Patches of field ice. Berg, same as 101. 3 bergs, same as 101. Small berg and growler, same as 130. Large berg. Do. Do. Small berg, same as 136. Large berg, several growlers. Large berg, several growlers, same as 137. ^Southern end of ice field. Low lying ice berg. An ice field. ^Patches of field ice. Berg. Do. Field ice. Skirting southern end ice field. 2 bergs. 3 growlers. 1 berg. Field ice. Much field ice and small bergs. 2 growlers. Scattered field ice, same as 154. Western edge field ice. Laige growler. 3 bergs, several growlers. Field ice. 2 bergs, same as 160. Western ice. Many bergs and growlers. 24 Table of ice and of other obstructions, 1926 — Continued No. Vessel reporting Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction May 8 8 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 Ansonia 0 / 45 02 44 38 44 54 44 55 47 00 44 55 44 51 ( 45 07 { to I 45 00 45 45 45 47 44 27 44 21 46 40 45 31 46 12 44 15 45 58 45 37 44 15 45 38 45 03 45 38 45 38 44 08 44 00 45 44 45 30 43 01 46 34 46 38 46 21 46 24 46 39 46 18 f 47 50 ■ to 47 50 46 42 to I 46 34 39 32 45 35 46 00 to 46 00 47 17 43 21 43 21 46 05 45 50 46 12 46 05 45 59 45 59 46 06 46 18 46 06 46 01 45 32 43 30 43 24 43 05 43 10 43 23 46 30 46 47 46 32 45 46 46 53 40 38 44 00 to 43 35 43 50 to 44 15 49 18 48 51 48 46 48 38 47 25 46 00 46 51 47 51 to 48 36 49 51 49 49 46 31 46 44 56 10 49 49 48 40 48 30 48 28 48 00 48 56 49 00 49 09 49 20 49 37 49 05 49 12 47 29 48 19 49 33 48 34 48 41 48 52 48 58 49 00 49 07 48 20 to 47 30 46 55 to 47 06 50 47 50 26 50 02 to 49 00 47 00 49 13 49 02 49 50 49 50 49 24 49 22 49 16 49 20 49 23 49 44 49 31 49 40 49 46 49 10 48 50 49 15 49 26 49 29 47 50 47 40 48 18 49 31 48 15 54 10 49 10 to 49 19 49 22 to 49 15 Letitia 8 do Do. 8 do Do. 8 Montrose . Heavy ice field. 8 Ansonia 9 Letitia. Berg. 9 Tyrifjord >3 bergs, same as 166 to 168. 9 Minnedosa Small berg and growler. 9 do 10 Berk 2 bergs and ice field. 10 do Berg. 11 Sheafbrook Derelict bottom up. 12 Canada Small berg, same as 173. 12 Melita Large berg. 12 California _ Do. 12 Montroyal Berg. 12 Cairndhu 1 berg, 13 growlers. 12 California,. _.. Large growler. 12 Cairndhu Berg. 12 Lenfield Do. 12 Cairndhu - Do. 12 do 2 bergs. 12 Marbarn.. Large berg. 12 Alaunia Low-lying berg. 13 Metagama __ Large berg. 13 do_... 2 growlers. 13 Ice Patrol- Berg. 13 Cameronia Do. 13 do 2 growlers. 13 do_.._ _. Berg. 13 do.. _ Do. 13 do.. Do. 13 do _. Do. 13 Searstad... >Numerous bergs. 13 Marburn •Numerous bergs and growlers. 13 Delaware Spar attached to wreckage. 13 Metagama Berg. 13 Oxonion •Small bergs and growlers. 13 Ascania Berg. 13 Cornish City... Low-lving berg. 13 do Growlers. 13 Boswell Berg. 13 do Low-lying berg, same as 203. 13 Cameronia Berg, same as 207. 13 do Berg, duplicated. 13 do Berg. 13 do Berg, duplicated. 13 do Do. 13 do... Do. 13 do Do. 13 do. Do. 13 do 1 berg and growlers. 13 Mexico Berg. 13 do_ Do. 14 Ice patrol. ._ Low-lving berg, same as 205. 14 do.. Small berg. 14 do.... Low berg. 14 Megantic Berg. 14 do Do. 14 do Do. 14 Penland Growlers. 14 Berg. 14 Andersen... Spar attached to wreckage. 14 Ice patrol ■17 bergs along edge of Bank. 14 Jean D'Arc Ice field and several growlers. 25 Table of ice and of other obstructions, 1926 — Continued No. A'essel reporting Position Nature of ice or obstruction Date Lati- tude, north Longi- tude, west May 14 15 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 2.54 255 256 267 258 259 260 ,261 262 263 264 265 266 267 268 269 270 27 1 272 273 274 276 276 277 278 279 Brattingsborg 46 25 42 44 f 46 48 { to I 46 00 46 15 42 47 43 02 45 02 48 16 48 07 48 03 47 46 49 02 49 15 47 00 47 23 46 07 f 45 15 { to ( 45 10 45 16 47 14 47 16 47 05 47 00 46 63 46 19 47 48 47 45 48 22 f 43 04 \ to 1.43 02 43 03 42 59 42 58 46 06 46 09 46 14 46 36 1 44 00 { to I 44 00 42 43 42 45 42 54 42 30 47 34 47 33 47 48 46 29 46 26 46 17 46 22 46 17 46 27 46 23 46 11 46 27 47 32 48 45 48 46 49 33 49 24 49 23 49 22 49 25 49 16 48 45 49 08 48 30 48 25 48 18 47 00 49 59 46 36 to 49 50 48 00 49 50 49 52 50 00 49 40 46 66 50 08 50 40 49 30 48 64 45 40 47 14 49 44 49 42 to 48 56 49 54 46 35 46 37 46 45 47 11 47 20 48 57 48 09 48 26 46 16 49 20 to 49 20 49 41 49 53 50 02 48 45 48 56 48 25 47 40 49 02 to 48 26 50 10 50 08 50 09 50 10 49 15 49 32 48 13 46 22 46 45 46 60 46 50 47 35 48 22 48 26 48 51 60 13 49 56 48 56 47 67 45 05 45 05 45 26 45 25 43 35 45 36 48 47 47 47 47 55 48 08 48 14 Field ice and small bergs. Same as 229. >Bergs continuously and growlers. Numerous bergs, same as 233. Same as 232.| Same as 192, groundea berg on Tail. Several small bergs and growlers. 2 bergs. 1 berg. 2 bergs. 1 berg. 3 bergs. 2 bergs. Slot ice. 4 bergs. Several bergs, same as 101. [l2 bergs. 3 bergs, same as 247. Berg. Do. Large berg. Do. Berg. Large berg. 2 bergs, 1 growler. 2 large bergs. Berg. [lO bergs, several growlers. Berg. Do. Do. Do. Do. Do. Do. 3 bergs, several growlers. Berg, same as 258. Do. Do. 2 growlers, same'as25Si Berg. Do. 2 bergs. Small berg. Do. Do. Large berg. Small berg. Berg. Do. Do. Do. Do. 2 growlers. Do. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Ice patrol... 15 Sunoco 15 Brattingsborg 15 Ice patrol . .. . 16 do.. 16 Kapristan 16 Topdalsfjord 16 do . 16 do_ 16 do.. 16 Kingborn 16 do ... 16 Port Sydney 16 Graeia.- . .. 17 do 17 Montelare 19 Antonia 19 Lord Kelvin 19 do 19 do . 20 do 20 -do 20 Lord Kelvin 20 Empress of Scotland . . 20 do... 20 Welshman 20 Tiger. 20 . -do.. 20 do 20 . .do.. 20 Moveria 20 .. .-do.. . 20 do 20 20 do Aalsum 21 Ice patrol... .. ,. 21 do 21 do 21 do.... 21 Empress of Scotland 21 do 21 Arlington Court. 21 Tenbergen 21 do 21 do 21 21 21 do do Brecon 21 280 do 21 281 282 283 284 do.. .. . 22 Venus 22 do 22 Estonia 22 1 285 do... 22 286 Letitia 22 287 do 22 288 do 22 289 290 291 292 293 294 295 296 do 22 do 22 do. 22 Hastings County. 22 do. 22 Letitia .. . . 22 do 22 do 26 Table of ice and of other obstructions, 1926 — Continued No. Vessel reporting Position Nature of ice or obstruction 1 i Date Lati- tude, north Longi- tude, west May 22 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 Ice patrol . e / Around 49 33 49 24 49 22 49 16 49 04 48 50 47 22 47 29 44 02 47 46 48 33 48 04 42 24 42 24 42 42 42 51 48 55 42 15 42 34 42 37 43 54 48 04 48 14 47 34 47 25 48 38 48 25 48 28 42 12 41 51 41 48 41 50 40 54 41 23 42 04 42 05 45 00 42 28 42 25 42 40 42 37 42 39 40 56 48 15 43 22 48 23 48 17 48 19 48 22 48 30 48 27 47 30 47 34 48 03 48 13 48 07 48 09 48 20 47 24 40 44 44 24 47 39 47 45 47 42 47 53 47 54 47 49 47 22 47 38 47 31 47 38 41 35 41 36 41 26 41 53 41 54 o / ! Tail ; 26 bergs, scattered around Tail. 45 05 1 Berg. 22 Letitia . . . 22 22 \V^\do'"J^^V.'.V^''.'"".'"".'. 45 26 , Do. 48 25 Do. 22 do 45 36 Do. 22 do 46 05 1 Do. 22 Manchester County.. .. 47 00 Do. 23 Metagama 50 01 Do. 23 do 49 59 Do. 24 Thyra 48 42 4 bergs. 24 Metagama „ 49 07 Berg. 24 Montrose 49 27 1 Do. 26 Cameronia 49 20 50 20 50 20 50 01 50 00 47 23 50 32 51 05 51 09 44 45 47 27 44 44 46 21 47 00 44 50 46 26 46 20 50 10 48 33 48 26 48 23 47 00 48 23 49 38 49 48 47 50 50 19 50 30 50 33 51 35 51 36 47 56 45 14 43 02 50 38 51 06 51 50 46 57 51 02 51 06 50 58 51 04 50 08 51 53 52 24 .52 15 51 23 51 28 47 39 46 52 50 33 50 32 50 21 50 04 49 59 49 48 51 26 51 07 50 54 50 37 49 41 50 12 48 34 50 15 50 02 Berg, same as 297. 26 Clearpool . Growlers, same as 297. 26 do... Berg, same as 297. 26 Wanjasdga Do. 26 do Do. 26 Cameronia Berg. 27 Ice patrol A group of 5 bergs, same as 297. 27 do Berg, same as report No. 297. 27 do Do. 27 American Merchant Berg. 27 Zeeland Do. 27 California Do. 27 do Do. 27 . .do.. Do. 27 .\nsonia Do. 27 do. Do. 27 .. .do Do. 28 Ice patrol Group of 5 bergs, same as 315. 28 Chicago . Berg, probably same as 297. 28 Hamburg Berg, same as 327. 28 Seattle Spirit Do. 28 Inverurie Small vessel bottom up. 29 Ice patrol Berg, same as 327. 29 Western Plains .. . Berg, same as 315. 29 do 2 bergs, same as 315. 29 Unknown ship 4 bergs, 7 growlers. 29 Oscar II Same as 297. 29 do Do. 29 do Do. 29 do Same as 316. 29 do Same as 317. 30 Ice patrol Same as 327. 30 Empress of Scotland Small berg. 30 Berg, same as 318. 30 Cape Race (station) . . .. . 3 bergs. 30 do Berg. 30 ... do Large berg and growlers. 30 do Berg. 30 2 growlers. 30 do Berg. 30 do Large berg. 30 do Berg. 30 do 5 bergs. 30 do Berg, same as 345. 30 do Berg. 30 do Do. 30 . do Do. 30 do.. Do 31 Ice patrol .... . . Growler, same as 327 (melted). 31 2 bergs. 31 Berg. 31 .. . do Do. 31 do Berg and growlers. 31 do Berg. 31 .... do Do. 31 do Do. 31 do Growler. 31 do. Berg. 31 do Do. 31 do... Do. June 1 Stadisdyk Berg (position probably northward). 1 do Do. 1 George Washington . Small berg. 1 Winona County Berg. 1 do Do. 27 Table of ice and of other obstructions, 1926 — Continued No. Vessel reporting Position Nature of ice or oba Date Lati- tude, north Longi- tude, west traction 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 1 53 42 09 47 03 47 00 47 07 47 01 47 19 47 19 47 34 47 00 47 16 41 27 42 08 42 10 47 18 47 27 47 07 47 34 47 33 47 16 47 37 47 41 47 54 47 50 47' 50 41 18 41 31 42 00 42 02 f 47 16 { to I 47 41 47 10 47 04 47 07 41 00 41 15 42 29 42 34 42 30 41 51 42 00 41 06 47 30 47 18 47 14 47 12 42 38 42 47 42 44 41 57 40 57 46 50 47 32 47 50 47 12 47 18 47 24 47 26 47 15 47 25 42 58 42 49 40 57 42 55 42 59 43 06 42 55 42 58 42 46 47 35 47 04 47 58 47 35 47 31 47 58 47 59 o / 50 01 48 50 50 33 50 24 50 09 49 52 49 46 51 28 50 19 50 41 49 54 48 25 49 15 49 24 51 30 50 59 50 36 50 54 50 40 50 16 50 52 50 24 50 06 49 59 49 48 48 08 48 38 49 02 49 06 51 22 to 51 36 50 10 50 19 50 50 48 38 48 38 51 14 51 11 51 12 48 34 48 50 48 27 49 26 49 59 50 15 47 47 51 09 51 01 51 12 49 28 48 38 51 10 50 12 50 18 50 17 49 53 49 50 49 37 49 35 49 25 51 25 51 23 48 38 49 11 49 56 52 13 51 19 51 25 47 47 49 35 50 49 49 07 49 55 49 45 48 17 48 14 2 small bergs. Berg and 2 growlers. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Berg, same as 371. Small berg. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Berg, same as 371. Large berg. Do. Do. [e bergs. Berg. Do. Do. Berg, same as 371. Berg, same as 402. Berg, same as 337. Berg, same as 338. Small berg, same as 339. Berg, same as 403. Small berg. Berg, same as 402. Berg. Do. Do. Do. Do. Do. Do. Do. Berg and growlers, same Very large berg. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Berg, same as 402. Berg. Do. Do. Do. Do. Do. Berg and growler. Berg. Do. Do.. Do. Do. Do. Veendam Port Sydney - do . do - do . do - Berk - do do - Veendam do . do — do . do - do do do do -- -- do - 2 2 Bellflower 2 Drottingholm -- 2 do.- 2 Tiger 2 Bolingbroke. 2 do - - 2 do 3 Ice patrol 3 do.-- 3 Springbank.. 3 3 do 3 3 Lehigh . .. 4 4 Cape Race (station) 4 .do -- - 4 do 4 do 4 Westphalia . 4 do - - 4 do 4 5 as 402. 5 5 Cape Race (station) 5 do 5 do -- . - 5 -do 5 do 5 — do 5 do 5 . do 5 John W. Mackay 5 do 6 Ice patrol 6 6 do 6 Berk -- 6 . do 6 do- 6 . -do 7 7 Cape Race (station) 7 do 7 do 7 do -.. 7 do . -. 7 do 32036—27- 28 Table of ice and of other obstructions, 1926 — Continued Date No. Position Vessel reporting Nature of ice or obstruction 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 Cape Race (station). do do do do do Aurania do do do do do do Calumet Cape Race (station). Montroyal... Cleveland Deuteldijk Antonia do Cape Race (station)... do do do do do do do do.. Livenza do Cape Race (station)... do do do D rammensf j ord Nesstad Cape Race (station) .. . do... do Estonia do Delaware Cape Race (station)... do. Alaunia.. Unknown ship do do Caledonia.. Doric do do. Alaunia__ Nova Scotia.. do ....do... do do Canadian Transporter. Cape Race (station)... do ....do ....do do ....do ....do ....do ....do ....do ....do ....do ....do ....do 47 48 48 42 48 34 48 30 48 28 47 42 47 45 47 32 47 35 50 27 49 02 49 16 49 20 49 20 51 09 49 49 49 .37 49 35 48 03 ! 49 07 48 18 48 51 48 05 48 12 47 35 (47 50 \ to 148 42 47 28 40 17 34 34 47 41 47 34 47 02 47 27 47 45 out 3i;ai 47 37 47 46 47 33 47 33 47 32 42 49 42 50 47 41 47 35 47 57 47 25 46 06 43 08 47 14 46 45 45 19 47 45 47 53 47 28 47 30 47 22 47 09 47 21 47 47 48 00 48 07 48 14 48 13 49 12 47 50 47 51 47 51 48 10 48 17 48 25 47 32 46 45 47 23 47 47 48 14 48 20 47 09 47 23 48 37 47 35 47 30 47 21 46 55 47 00 47 14 48 18 48 21 49 31 48 18 to 51 15 49 51 56 07 50 46 48 48 48 48 57 55 50 54 50 29 eFrancii 49 28 48 37 49 24 49 28 49 33 49 18 49 08 47 31 48 52 50 03 51 40 48 38 50 10 48 37 52 50 48 00 51 07 51 15 51 23 52 30 50 34 50 00 50 16 49 13 48 44 48 35 49 06 49 16 49 21 47 13 52 15 52 04 51 54 51 17 50 57 50 17 52 53 51 21 50 16 49 09 48 50 50 00 50 04 51 31 51 40 48 25 50 00 52 35 52 22 51 42 Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Berg 160 feet high. Berg. Berg and growlers. Many bergs and pieces of ice. Low-lying berg. Red spherical buoy. Red and black bell buoy. Large berg, several growlers Low-lying berg. Wreckage of schooner. Berg. Do. 5 bergs. Berg. Do. Do. Do. Do. Do. Do. Large berg. Berg. Do. Do. Do. Do. Berg and growlers. Berg. Large berg. Do. Do. Small berg. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Berg, same as 497 Berg. Do. Do. Do. Do. Do. Do. Do. 29 Table of ice and of other obstructions, 1926 — Continued No. Vessel reporting Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction 623 524 526 527 528 529 530 531 532 533 534 535 Cape Race (station) 47 44 47 30 47 50 47 51 48 17 48 25 47 35 47 27 47 13 47 56 48 30 48 07 47 52 47 55 44 40 45 32 47 17 43 45 46 36 46 24 47 17 48 11 47 06 47 29 46 50 46 48 42 25 46 52 44 50 44 48 46 15 47 30 46 28 46 14 46 35 44 76 46 20 47 60 47 36 46 56 47 03 46 02 47 53 47 40 47 06 47 12 46 69 47 20 47 20 46 02 47 26 46 58 47 07 47 28 47 20 47 48 47 52 46 24 46 57 46 .58 47 37 46 30 47 07 47 34 42 26 47 48 47 52 48 43 48 56 47 12 48 39 47 39 46 48 48 50 49 07 46 45 50 55 50 37 47 13 52 16 51 01 50 57 51 11 51 07 51 30 49 60 46 65 49 38 50 04 49 26 45 36 48 04 50 40 51 11 52 56 53 10 60 14 49 22 51 27 48 04 50 15 50 40 49 07 48 05 45 55 46 30 53 06 49 59 51 45 53 05 54 00 45 40 63 10 48 33 49 50 51 36 50 54 47 02 51 00 50 54 50 37 51 24 51 32 51 30 50 50 47 20 51 40 51 21 50 47 49 51 49 44 50 40 50 48 52 28 51 65 51 22 49 56 62 46 60 55 48 43 45 28 50 40 50 48 50 30 50 00 50 50 49 58 50 57 52 36 50 10 49 30 52 45 Berg. 15 do Do. 15 do Do. 16 do Do. 16 do Do. 16 16 do do Do. Do. 16 do Do. 16 do. Do. 16 do.... Do. 17 Ascania Do. 17 Montrose..- Growlers. 17 ! 536 do Berg. 17 537 638 539 540 541 do . Do. 17 Svdland Do. 17 King Oruffydd. Small berg. 17 Transylvania.. Large berg. 17 Qreldon Small berg. 17 1 542 Transylvania. Berg. 17 543 544 545 546 547 548 649 550 551 552 553 554 655 666 557 558 559 560 561 562 563 564 565 666 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 do Do. 17 Letitia... Do. 17 17 do Montrose. Do. Small berg. 18 Valemore. Berg and growler. 18 18 19 do do United States Berg. Do. Small berg and growler. 20 Cape Race (station) Berg. 20 Denham . Small berg. 20 20 do Metagama. Large berg. Small berg. 21 Montroyal Ivarge berg. 21 do Berg. 21 do .. .. Growler. 21 Norefjord Berg. 21 21 Unknown ship , Trelissick Do. Growler. 21 Cape Race (station).. Berg. 21 do Do. 21 do Do. 21 do Do 21 Bleddyne Do. 21 Cape Race (station). Do. 21 do Do. 21 do Do. 22 do Do. 22 do Do. 22 do Do. 22 do Do. 22 do Do. 22 . .do . Do, 22 do Do. 22 . . do Do. 22 do . . Do. 22 do - .. .... Do. 23 Montcalm Do. 23 do Do. 23 Antonia. . Do. 23 do * Do. 23 583 do Do. 23 584 58.5 586 587 588 589 590 591 592 593 594 595 596 597 598 599 do . Do. 23 do Do. 23 do Do. 23 do Do. 23 Ulmus Growler. 23 Berg. 23 do...- Do. 23 do Do. 23 do 2 large bergs. 24 do . . Berg. 24 do. Do. 24 do.... Do. 24 do Do. 24 do Do. 24 do Do. 24' do Do. 30 Table of ice and of other obstructions, 1926 — Continued No. Vessel reporting Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction June 24 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 724 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 Cape Race (station) 47 24 47 31 47 11 47 30 48 31 48 40 48 27 48 24 48 31 46 49 47 15 47 02 47 39 47 10 47 39 48 09 47 30 47 53 46 49 47 10 48 05 48 06 47 40 46 52 47 50 47 39 48 18 48 16 47 50 47 48 47 26 45 56 46 07 47 45 47 57 48 19 48 52 49 04 47 50 41 50 51 30 49 40 50 46 51 24 51 59 50 46 51 28 51 32 51 08 62 37 47 25 47 40 49 35 49 38 49 35 44 44 60 39 49 47 52 01 49 38 49 05 48 63 51 19 52 02 49 55 49 52 50 01 48 49 49 55 49 55 50 37 48 05 48 08 60 12 49 26 52 17 51 48 50 49 49 20 51 45 Berg. 24 Zeeland Do. 24 do Do. 25 Cape Race (station). 2 bergs. 25 do - — Berg. 25 do... Do. 25 do Do. 25 do Do. 25 do. Do. 25 . . do — Do. 25 do Do. 25 do Do. 26 do Do. 27 Beemsterdijk. . . Small berg. 27 Cape Race (station). Berg. 27 do Do. 27 do Do. 27 do Do. 27 do Do. 27 do Do. 27 . .do Do. 28 Montrose ..... Do. 28 Cape Race (station) Do. 28 do Do. 28 do Do. 28 do Do. 28 do Do. 28 do Small patch of field ice. 28 do Berg. 28 do.. Do. 28 do Do. 28 do Do. 28 do. Do. 29 do Growlers. 30 do Berg. 30 do Numerous small bergs 30 . . .do Berg. 30 do 2 large bergs. 30 do Berg. 30 Ice patrol Fisherman's buoy with cage; destroyed. WEATHER— A BRIEF REVIEW OF THE 1926 ICE SEASON Edward H. Smith As we sit down to write a worth-while, instructive report on the subject of weather, as it concerned the ice patrol of 1926, and in a sense as it probably concerns future patrols, we believe it most important to survey first only the principal features which were responsible in characterizing the 1926 season as a whole. Under this category comes foremost the steepness of the barometric gradients and the consequent great intensity of the winds that blew so con- stantly from the daj^ we left Boston, March 25, until well along in April. It is impossible, of course, to place one's finger upon any definite date when a meteorological phenomenon such as we call "wintertime" conditions change to "summertime" conditions. This spring on the Grand Banks, however, we are convinced, that wintertime conditions prevailed longer than usual, and it was not until the latter part of April that we began to notice a slackening in the wind force, a dropping off in the frequency of storms, and a lessening in the tendency of great anticyclones to build up and spread eastward from the North American Continent. It also can be stated with con- siderable assurance that the atmospheric envelope was in a violent state of agitation from March 29 to April 20. During this period of 22 days the wind blew with gale force on 12 days, and there were only 2 days on which it did not attain a fresh to a strong breeze on the Beaufort scale. Before passing on from the remarks on winter- time meteorological conditions we should like to familiarize everyone with the general scheme of the air streams under which the ice regions come. THE TWO MAJOR WEATHER TYPES WHICH PREVAIL IN THE ICE REGIONS The ice season extending as it does from March to Juty bridges two main tj^pes of weather which standing at either end of the gamut we have termed wintertime and summertime conditions. This all important seasonal effect is of course superimposed upon the funda- mental planetary system of circulation and is directly due to the thermal seesaw which is continually in process between land and water masses. In the North Atlantic (and controlling the weather of the ice regions), we have three great centers of action, triangularly located and with the relative condition of each determining the consequent behavior of the air: (a) the Icelandic minimum; (6) the (31) 32 Azorean high; and (c) the continental effect of bordering land areas. Glancing at the normal isobaric map of the North Atlantic for the colder months of the year, the station normals of which are based upon average barometric records compiled over a long series of years, our eye is immediately caught by a huge elliptical-shaped depression near Iceland. And then we notice that in effect this depression is emphasized by the opposing anticyclonic conditions which prevail over the bordering land masses of the Atlantic basin. The geograph- ical position of the Grand Banks in the western North Atlantic on the southwestern side of this mammoth cyclonic wind system, it is plain to see, subjects the iceberg regions south of Newfoundland to an air stream flowing from west to east, the swiftness of which is gale force the major part of the early season. Such prevailing circulation is, however, often subjected to short interruptions when cyclonic storm centers usually of marked intensity come from the United States and cross the ice regions. Now, during the latter half of the ice season the unequal rale of solar warming between land and water causes the wintertime high pressure to transfer from the land and increase over the ocean, thereby placing the Grand Banks region on the northwest side of a huge clockwise wind system. Gradients also become much reduced in steepness from what are found in winter season, and the warm southerly winds blowing over the icy waters around the Grand Banks bring a fog sheet which often does not lift for weeks at a time. This comprises a general survey of the two main types of weather and incidently it emphasizes two of the greatest handicaps the patrol is forced to encounter, namely early season gales and later season fogs. If we return to a survey of the 1926 ice season we find no features of especial significance beyond the continuance of cyclone and anti- cyclone in alternate sequence following each other across the meteor- ological map from west to east, and in general with the progress of the season, gradients becoming gentler, winds weaker, and vortices traveling slower. An interruption in the regularity of undulations to which the trop- osphere was subjected by alternate "highs" and "lows," occurred May 27 to June 2, when a great anticyclone built up and spread over the entire Atlantic seaboard from Florida to Newfoundland. It is rare to have such an atmospheric distribution but it means clear visibility and northerly winds for the ice regions; really the best weather we get on patrol. DEVELOPMENT OF SUMMER TIME CONDITIONS Going into June we began to notice the gradual development of the summer time Azorean high pressure as the thermal seesaw swung the opposite way from that observed at the beginning of the ice season. 33 At this time southwesterly winds began to blow with greater fre- quency and longer duration along the Atlantic seaboard of North America, and the ice regions being in the periphery of this system came under the effects of the southwest air stream more and more. The first real evidences of a hot wave over the United States was perceived the latter part of June. ^^ Fig. 1. — March weather diagram WEATHER DIAGRAMS In order to secure an intelligent impression of the general weather conditions which prevailed in the ice regions during 1926 we have constructed circular diagrams which include by months the follo^ving 34 information: Each diagram represents a month's time and is di- vided into 30 or 31 equal sectors in accordance with the number of days. The outer margin gives the wind direction averaged for each 12-hour period and also the force in terms of Beaufort scale. The next adjacent ring contains information on the amount of fog and Fig. 2. — April weather diagram low visibility experienced during the month; the fog is filled in full black and the low visibihty in crosshatched shading. The third band in contains a continuous barograph record for the entire month and is drawn to scale. The numerals on the innermost ring signify the days of the month. 35 N \ Fig. 3.— May weather diagram Percentage (hours) Gales (number of days) 1 Winds (average force) Calms Month Fog Low- visibility (num- ber)' March: Actual— 0 31 23 42 32 33 12 55 0 3 5.0 0 April: Actual 1 9 3.8 0 May: Actual— 7 2 3.1 1 Pilot chart June: Actual—. .. 2 0 2.8 2 1 1 Based on 6 days in March. Gales per 12-hour periods. 3203&— 27— 4 ' Based on 12-hour periods. 36 Fog was noticeably less than normal during April, normal during May, and very deficient in June. The absence of fog in this latter month is partly attributed to the fact that the position of the patrol vessel was unusually far south in the Gulf Stream during the first Fig. 4. — June weather diagram half of the month and thus experienced clear weather. If she had been in the cold waters around the Tail of the Bank it is believed that almost constant fog would have been the order of the days. CYCLONE TRACKS Since the development and the passage of cyclones from the interior of the United States out across the ice regions is one of the most absorbing meteorological events with which we deal on patrol, per- 37 haps it will be of interest and instruction to describe the paths of some of the cyclones, rate of motion, and sequence in the procession which was observed. MARCH The weather conditions on March 25, our sailing day from Boston, consisted of a trough of low pressure stretched along the Ohio and St. Lawrence River Valleys and embracing a well marked center \V'^hich was progressing northeastward. It was rather interesting to watch the path of this disturbance which has been plotted on Figure 5, page 38, as track A. The center, during the night of March 26, curved to the right and followed a southeasterly path to the vicinity of Sable Island. At 8 a. m. on the 27th it was located again on the weather map off Sydney, Cape Breton, and thence it moved in the more frequently traveled route toward the northeast. The excursion to the southward of the usual cyclone path was attributed in this case to the presence of a deficiency of pressure over the Carolinas combined with the blocking influence of a high pressure area to the northward. The subsequent behavior of this disturbance is worth a word or two. It can be seen by Figure 5, page 38, that the center moved northeastward for two days when somewhere east of New- foundland it deepened and thus intensifying the gradient gave to the Grand Banks region strong westerly winds for several days. On March 31 an excess of air accumulated to the westward over the United States in sufficient proportions finally to remove all effects of our storm offshore into the ocean. (For a daily record of winds, pres- sures, and fog, reference may be made to the weather diagram, fig. 1, p. 33.) APRIL During the early part of the ice season the atmospheric envelope we repeat for emphasis, is usually in violent agitation; rocked inter- mittently, so to speak, as successive cyclonic vortices disturb the prevailing atmospheric pressure distribution. The normal pressure character for this time of year is one to which we have previously referred as wintertime, and is clearly identified by a dominating excess of pressure lying over the cold continental area as compared with the air mass over the warmer ocean. No sooner had March 31 marked the disappearance to the eastward of the storm center described above than it also ushered in a similar vortex in the troposphere, first noticed on our map for the eastern United States just south of Chicago, 111. The career of this cyclone across the country and out to sea, March 31 to April 3, has been traced as track B, Figure 5, page 38, The effect of its approach was first detected when at a distance of 500 miles from the ice patrol ship, the barometric pressure began to fall the afternoon of April 1. The northwesterly winds which had been blowing with great intensity and duration ceased about this 38 time and a breeze sprang up from the northeast. The barometer continued to fall until noon the 2d, when it recorded what proved to be the minimum for the entire patrol (28.90; see weather diagram for April), and the depression must have passed about over our position south of Newfoundland. The winds with the passing of the center almost immediately shifted to northwest and increased that night to gale force. While we were still within the effects of the storm described above, a region of new depression was observed over the lower Mississippi River Valley. The path followed by this dis- turbance from April 2 to 7 is shown as track D, Figure 5. This center traveled along a path located a little farther to the northward than that of its predecessor. It followed a straight line more or less CVLOMC TRACK€» MARCH 25-A.PRIL,30 Fig. 5. — March and April cyclone tracks up the St. Lawrence Valley until it arrived at the upper reaches of the gulf when it curved off to the right keeping over the water as much as possible, and slowly crossed southern Newfoundland on the 5th, 6th, and 7th. It is important to note that this cyclone, similar to several others which have been observed, deepened and intensified as it proceeded up the St. Lawrence River and Gulf. It deepened from a reported pressure in Mississippi of 29.76 to a minimum of 29.28 at Port aux Basque, Newfoundland, and it was at this point approximately 450 miles from the patrol ship that the first effects of the disturbance were felt. The wind shifted to southerly and the barometer fell but as the disturbance began to recede to the eastward it also began to occlude and the winds soon resumed their prevailing northwesterly direction. 39 While the foregoing storm was raging over Newfoundland another cyclone was growing down in Oklahoma. Its path from April 6 to 12 is lettered E on Figure 5. It followed the mean northeasterly- track, as can be seen on the figure, and on the evening of the 11th when 300 miles from the position of the patrol ship it made its first effects felt by the wind increasing to nearly gale force from the south. As the storm moved away out into the North Atlantic we were com- pletely enveloped in an anticyclone which was following on the rear of the "low," and for the next two days we experienced stiff north- westerly gales. A moderate depression was observed on the meteorological map for 8 a. m., April 10 as centered in eastern Texas. It traveled very slowly in an easterly direction until the 12th when near Atlanta, Ga., it abruptly turned and followed a track almost due south for about 300 miles then reversed itself and moved northeastward. This peculiar behavior was believed due to the presence of an anti- cyclone of considerable size and intensity to the northward. The distm'bance later spread southeastward over the Middle Atlantic States effectually blocking the normal cyclone path. Track H of a cyclone, April 24 to 27, lay farther north than the other tracks for the month and being so far removed from the Grand Banks region its passing influence could not be detected on the baro- graph record. Track I, however, the last one for the month, lay up the St. Lawrence Valley so that the center, when it crossed the gulf the night of the 29th, was about 540 miles from the patrol. At this distance it caused our pressure to fall slowly and the winds to shift temporarily from west to east. The rate of travel of this cyclone was about 25 to 30 miles per hour. The month closed with this disturbance central over Newfoundland. MAY On May 1 the cyclone that had moved along track I began to drift southeasterly toward the patrol ship and consequently left a graphic record of a sharp bend in our barograph curve for the 2d instant. (See weather diagram for May, fig. 3, p. 35.) The weather map which we compiled on board the morning of May 2 indicated another depression (29.70) forming to the westward over the Great Lakes region. First it followed an easterly path to the vicinity of Quebec where it hovered until May 3, then curved into northern Vermont and deepened to 29.30. April 4 it passed over the Gulf of St. Lawrence still intense (29.22), j^et that evening it suddenly and surprisingly began to fiU and by the following day it was very shallow and trough-like. May 6 it was almost squeezed out between two prominent areas of high pressure which merged and for several days prevented the regular procession of depressions which had been in effect prior to this. 40 It is interesting to observe that the easterly position of cyclone track B on Figure 6, was due without much doubt to the presence of the aforementioned anticyclone. Weather bulletins were received May 5, 6, and 7, containing information that a depression was form- ing in the region of Bermuda, but due to the lack of ship reports it was impossible to ascertain definitely the movement of the center. During the night of May 8 our barometer began to fall, which from past experience indicated the approach of a storm within a radius of about 500 miles. The next morning upon constructing the weather map the center was revealed near Port aux Basque; it probably had followed a northerly path from Bermuda as indicated on Figure 6. During the next few days the weather maps indicated a tendency of \ /^ /«;:::i' ^O^s^ ^^r" ^»*^--x-A- ■■""•-. ^^_8S!:3^^P / ^^ — '■ CYCLONE TRACKS MAY-I92fo -^'v-^ r £,/ %*V^ 4-5-6 Fig. 6.— May cyclone tracks the pressure to remain relatively low to the westward, depression centers being recorded from Nantucjset to Sydney. On May 11 a deep center appeared near Sydney and moved in a path across the Gulf of St. Lawrence and out to sea. The effects of this distribu- tion set up an indraft of southeasterly winds consisting of warm moisture-laden air pulled across the ice regions from out in the Atlantic. This condition incidently produced the longest period of fog which we experienced for the season. The two weeks from the 13th to the 27th marked a change in the previously noted tendency of the cyclones to travel consistently along northeasterly tracks Where prior to this period individual centers moved rapidly across the country we now saw several small vortices (families) following meandering paths as if they were the 41 prey to several factors no one of which exerted outstanding control. For example, on May 13 a slight shallow depression moved from Illinois eastward to the Potomac and the next day spread into a spacious depression with two centers. One traveled eastward while the other remained stationary until two days later it coalesced with a third depression which had been drifting slowly eastward from the Great Lakes. Contemporary with this modification in the weather we noticed that the wind velocities in general had gradually become less than they had been earlier in the season. Fig. 7. — June cyclone tracks May 25 to 30 an anticyclone of vast proportions expanded from the region of central Canada and spread over the entire eastern half of the United States and extended out to include the ice regions. It finally divided into two centers and soon afterward disintegrated completely. It is interesting to examine the flatness of the baro- graph curve and the presence of clear weather, both of which are recorded on Figure 3, page 35. JUNE The most important lesson contained in the cyclone tracks for June (fig. 7) is obtained by comparing the position of the average with the position of the average for the months of March and April. It is clearly indicated that a migration to the northward of the mean cyclone track took place in the course of two months. It is estimated as approximately 150 miles. The explanation for track C, Figure 7, 42 being much farther south than the others is to be found when refer- ence is made to the daily weather maps. An anticyclone of consid- erable strength spread southward out of the region north of the St. Lawrence River and probably tended to push cyclone C farther south than it would otherwise have traveled. The next most striking weather feature in June was the increased number of cyclone families which bred in central North America and persisted in occupying pretty much all of the region northward of a front that extended from the Great Lakes to east of New- foundland. PERSISTENCY OF A DEPRESSION IN THE REGION EAST OF NEWFOUNDLAND Many times during the spring of 1926 we observed that the region immediately east of Newfoundland, and often the Newfoundland area itself, was for days the seat of a deficiency of atmospheric pres- sure. This persisted so markedly that the phenomenon is regarded not simply as a peculiarity of one season but rather as a general characteristic of all years. As an illustration of the manner in which individual depressions (or a permanent general depression?) may persist in a given region we point to the meteorological maps from 8 a. m. April 15 to 8 a. m. of the 19th during which time the pressure in the Newfoundland theater was constantly lower than that sur- rounding it to the west and south. The fact that there are observa- tion stations on these three sides of Newfoundland permits one to construct an accurate isobaric map, but it docs not throw any infor- mation whatsoever on conditions in process in the quarter northeast of Newfoundland. It is easy to see then that we are unable to fLx the position of storm centers after they have reached this vicinity, and therefore when we continue to receive reports of low barometer read- ings from St. Johns it is a natural tendency to conclude the cyclone has paused in its northeasterly progress, but the truth of this opinion is open to question. It may be clearer to regard a series of monthly mean pressure maps of the entire North Atlantic, which over a series of years will reveal the presence of a mammoth depression central near Iceland. It is believed that the continual presence of a depres- sion observed east of Newfoundland on the ice patrol weather maps is in reality the western influence of the great Icelandic minimum accentuated by convergence while crossing Newfoundland of indi- vidual North American cyclone centers. THE STRUCTURE OF A STORM AND ITS PROBABLE PATH It may be instructive to devote a few very brief remarks to the new ideas in meteorology on the structure of cyclones (storm depres- sions) and their probable lanes of travel. Forecasters in the past 43 have usually been guided by the mean cyclone track, as compiled by the statistician, and the barometric tendency gained by simultaneous observations from scattered meteorological stations. Probably some of the most valuable recent contributions to the forecasting art are the investigations of Bjerknes into the structure of cyclones. De- tailed analysis of individual cyclones revealed the following two main types of classification: (a) Cyclones which have a definite warm sector separated from the cold part by definite surfaces of discontinuity. (&) Cyclones exhibiting no such individual parts at the surface of the earth. The former are young intensifying storm centers while the latter are old ones which tend toward retardation in their paths. When they are treated separately a real discovery was made that class A cyclones move in the direction of the air current in the warm sector and very nearl}'^ with the same speed as the velocity of the air in that sector. Since the direction of the wind is taken along the isobars, the direction of travel of the storm center shown in Figure 8, page 44, is AB. The isobars in the warm sector are drawn nearly straight because it is found in general practice that they are quite flat. The speed of the cyclone is found by multiplying the distance between the isobars by the sine of the latitude. The whole wind system is in motion and as a rule the direction of the isobar AB in the northern hemisphere will swing anticlockwise and the path of the center O will gradually curve to the left. Sometimes, however, when a small cyclone moves along the edge of a warm anticyclone the change is in the opposite direction. Bjerknes at the Geophysi- cal Institute, Bergen, has found that class B cyclones although not having distinct discontinuity surfaces such as class A exhibit on the earth's surface, do have weather characteristics which correspond to these latter and which do furnish similar information on the career of class B cyclones. The cyclone is said to be born when two air masses of differing densities come within proximity of each other; the thermal character of the two bodies is the usually accepted index. There follows a period of growth with a corresponding increase in intensity so long as the structure is fed by a sufficient supply of cold and warm cur- rents. Class A cyclones eventually begin to fill up or occlude as the lower limits of the warm sector lift off the earth's surface and shallow out. They are then known as class B cyclones, and the discon- tinuity surfaces are only to be found at increased heights in the troposphere. A great number of the storms which aft'ect the ice regions in early season are class A cyclones and it is quite often the case that we are able to observe the passage of the surface of discontinuity in many well- 44 developed disturbances. The first line of discontinuity to sweep across the observer's position is termed the warm front and this carries along with it the greatest abundance of precipitation. Coin- cident with the passage of the warm front the winds haul abruptly and also abate in force. The warm sector is characterized by warm moisture-laden air, overcast skies, reduced visibility, less intense winds and occasional rain showers. The second line of discontinuity is called the cold front and squall line. The direction of the wind at this place Fig. 8.— The structure of a cyclone changes quickly to the right, the temperature drops precipitously, and the skies clear. The cold front is often accompanied by rain or hail squalls and perhaps also thunder and lightning and a strengthen- ing of the wind. All of these are interesting to follow : The barograph curve, the wind velocity and direction, the air temperature, and the precipitation during the passage of some of the storms we experience on patrol. Often one can preceive how definitely, even in a crude way, the general structure of a cyclone can be traced. 45 COOPERATION WITH THE UNITED STATES WEATHER BUREAU As was done on previous patrols a meteorological map was con- structed twice daily on board ship, the data being obtained from the general synoptic reports broadcasted by the United States Weather Bureau from Arlington at 10 a. m. and 10 p. m. In addition to this the patrol ship was furnished with a daily forecast especially prepared by the Weather Bureau. All this information was broadcasted by phone to approaching steamers immediately following the ice broad- casts. The report on fog conditions was one of the most important features of this service from the standpoint of the steamship captain. The element of fog to the Grand Banks region, it is obvious, greatly increases the ever-present danger of collison with ice. Twice daily, at 8 a. m. and 8 p. m., a w^eather report was dis- patched to the United States Weather Bureau, Washington, D. C, and at the end of each cruise a more detailed report was forwarded b}' mail to Washington weather officials. ICE FORECASTING BY MEANS OF THE WEATHER One of the more important scientific problems that has con- fronted the ice patrol for some time is the desire to obtain advance information regarding the annual amount of ice to be expected south of Newfoundland. If the master of the Titanic had known, as we can clearly see to-day, that the year 1912 was one in which icebergs by the hundreds invaded the North Atlantic to low latitudes, he would probably have navigated his command farther south, and more cautiously, past the Arctic ice barrier. The amount of ice drifting out of the north into the open Atlantic is subject to great annual variations, for instance, in 1912 there were approximately' 1,200 bergs counted south of Newfoundland while in 1924 there were only a total of 11. Several investigations ^'^'^ have been made of the relation between the amounts of ice in the northeastern North Atlantic' and logical contributary factors, but only a few similar papers have dealt with the ice stream past Newfoundland.^- ^ All of the investigators, Schott, Mecking, Brenneck, Weisse, and Meinardus found that the wind was the most important factor which governs the southward drift of Polar ice. The ice patrol with the assistance of the British Meteorological Office and more recently, the United States Weather Bureau, has begim an investigation into the ' Meinardus, W.: Periodische Schwankungen der Eisdrift. Ann. Hydr., Hamburg, 1906; pp. 148-149 227-239, 278-285. ' Weise, W.: Polareis und atmospharische Schwankungen. Geo. Ann. Stockholm, 6 (1924); pp. 273-299. 3 Brennecke, W.: Beziehungen zwischen der Luftdruckverteilung und den Eisverhaltnisse des Ostgroen landisehen Meeres. Ann. Hydr., Hamburg, 1904; pp. 49-62. < Mecking, L.: Die Eisdrift aus dem Bereich der Baffin Bai usw. Verotf. Inst. Meersk, Berlin 7, 1906; p. 148. « Schott, G.: Uber die Grenzen des Trcibeises bei der Ncufundlandbank sowie uber eine Beziehung zwischen neufundlandischen und ostgronlandischen Treibeis. Ann. Hydr., Hamburg, 1904; pp. 305-309. 46 effect of the weather upon the distribution of icebergs. It is desired therefore under this section devoted to weather to give a brief account of the results so far of this research work. The period embraces 47 years, 1880-1926, a series of sufficient length to permit mathe- matical correlation, and in this respect it has an advantage over previous works. The results differ somewhat from those previously obtained by Mecking in that the chief importance is assigned to the variations of the pressure difference between Belle Isle, in Newfoundland, and Ivigtut in southern Greenland, during the period December to March. The pressure difference directly affects the amount of field ice, and Fig. 8a. — The atmospheric pressure map constructed by averaging the pressures for the months of December to March in the years 1881, 1891, 1895, 1900, 1902, and 1917. These years were all characterized by a lesser amount of Arctic ice drifting into the western North Atlantic thamisual. (See fig. 23.) it has been found that there is a very close relation between the amount of field ice and the number of bergs south of Newfoundland. The field ice tends to act as a fender along the shoreward side of the Labrador current, and thus more or less prevents the bergs from stranding as they are borne southward. The truth of this state- ment w^as curiously revealed during the 1924 patrol, when the un- usual absence of field ice left the season's crop of bergs to strand in northern waters. When the sea ice recedes northward, due to melting in May, the coast line becomes more and more exposed. Stranding takes place on a great scale, and the consequent supply of bergs to the Grand Banks is cut oft". The iceberg menace to steam- ships in the North Atlantic would be greatly diminished, or prac- 47 tic ally disappear, if sea ice did not hamper the North American coast line from February to March every year. The pressure dif- ference between Bergen and Stykkisolm during the period October to January was also found to be of importance. The use of pressure difference between various points furnishes the best data for forecasting purposes, because there is no room for the personal bias which may come in when charts are classified according to types. A classification of the charts of pressure anom- aly over the North Atlantic during the period December to March has, however, been made, and this distinctly reveals two types of pressure distribution— a plus type, in which an excess of pressure Fig. 8b.— The atmospheric pressure map constructed by averaging the pressures for the months Decem- ber to March in the years 1885, 1890, 1903, 1912, and 1921. These years are characterized by a greater amount of Arctic ice drifting into the western North Atlantic than usual. (See fig. 23, p. 76.) centered in the region of Iceland, more or less dominates the Atlantic north of the Azores (see fig. 8a, p. 46), and a minus type when reverse conditions prevail (see fig. 8b, p. 47). The plus type is subject to further classification into (1) and (2), depending upon a relatively great or moderate intensity of the excess pressure mass, both of which are reflected in a relatively very light, or light ice year, respectively, in the western North Atlantic. The minus type, although unmis- takably showing a greater .amount of ice than normal, does not permit subgrouping. In other words, the plus type of pressure conditions (fig. 8a) exhibit a higher correlation with poor ice years than do the minus type (fig. 8b) with correspondingly rich ice years. This indicates the presence of other factors, such as variations in 48 the air and water temperatures in the far north, or variations in precipitation, or perhaps an unnatural phenomenon, such as an ice jam in the Arctic Archipelago. Although the investigation is not yet completed at the present writing, the results already indicate a high degree of success for such a method of ice forecasting. Correlation coefficients have been calcu- lated between the following variables: (a) Number of bergs (on a scale of 0 to 10). (See fig. 23, p. 76.) (6) Amount of field ice (on a scale of 0 to 10). (c) Pressure difference (in millibars) between Belle Isle and Ivigtut, combined with a deviation of pressure from normal at Stykkisholm during the period December to March. The mean pressure difference is calculated from the combination: 2XDec. + 2X Jan. + 1 xFeb. + l xMarch and this mean is combined with the pressure deviation at Stykkisholm in the proportion of 6 to 1. {d) The pressure difference between Stykkisholm and Bergen during the period October to January, inclusive, December being given double weight. The correlation coefficients employed in the preparation of the forecast were as follows : Between (a) and (6) +0. 85 Between (a) and (c) — 0. 58 Between (a) and {d) — 0. 63 At the end of March a forecast of the number of bergs can be prepared by means of the regression equation: Bergs = 4.8 -0.08 (c)-0.12 (d) At the end of the field ice season, April 15, the number of bergs. May to July, can be predicted very closely by making use of the high correlation between field ice and bergs. Arrangements have been made with the United States Weather Bureau whereby that organization furnishes the ice patrol with the pressure data for the months October to March, inclusive, and upon which is based the forecast of bergs for the following spring season. The forecast for the ice season of 1926 was "a light ice year," (3.4 on scale 0-10), while as a matter of record it developed that we experienced very closely to ''a normal season 4.3." It is fair to add that we were handicapped in making a forecast due to the absence of pressure data from a very critical area, that of Greenland. This difficulty will probably not arise again as Greenland meteorological stations are no,w connected with Europe by means of radio. no, __^^-4A 4|3 ^ 42. AS 44 4i 42 5Z 51 oo 49 46 4.7 46 KiG. ».— A chart for use with the sonic depth apparatus showing the vilncily ot siniinl in llu' wnlcr loliinin around the Grand Bank 32030—27. (Face p. 4'J.) SOUNDINGS CARRIED OUT WITH THE SONIC DEPTH FINDER As a result of action on the part of the Interdepartmental Board on Ice Patrol at its regular meeting in the early part of 1924 one of the ice patrol ships, the Tampa, was equipped with a sonic depth finder of the United States Navy type. The main purpose of the board in having this apparatus installed was to test the practicability of locating icebergs by sonic means. A secondary object was to gain a more accurate knowledge of the bottom contour and consequently of the circulation in the ice regions. An account of the experimental work on icebergs in 1925 and the hydrographical soundings then taken are contained in the report of that year, Bulletin No. 13, page 45. No further work in connection with sound experiments on bergs was attempted in 1926. Arrangements, however, were made whereby a member of the United States Navy sound course at the New London school was detailed to the Tampa for the ice patrol. A program was drawn up to take as many soundings as practical to gain further material for a more accurate mapping of the bottom of the ice regions south of Newfoundland than is yet possible, and this work ought to be continued in the years to come. In accordance with the foregoing, a sounding was taken every hour, 8 a. m. to 10 p. m., while the lampa was on duty this year with the result that a total of 465 observations were made. In connection with this work a chart was constructed (fig. 9, p. 49) to include the ice regions south of Newfoundland showing by zones the velocity of sound after corrections had been made for the influences arising from pressure, temperature, and salinity. The distribution of salinity and temperature in the water mass in the ice regions is quite accurately known from the many oceanographic observations which have been compiled by the ice patrol. The correct velocity of sound in a water column of given temperature, salinity, and pressure is found by reference to very useful tables compiled by Heck and Service. (U. S. Coast and Geodetic Survey, Special Publication, No. 108.) The range of soundings made was from 23.5 fathoms to 2,850 fathoms. The list follows with date, hour, and latitude and longitude. (49) 50 SOUNDINGS AS RECORDED WITH THE SONIC DEPTH FINDER, 1926 Position 1 Position Time Time Date (sixtieth T ^■^rti Depth Date (sixtieth Longi- tude, west Depth meridian) Latitude, north tude, west meridian) Latitude, north o / 0 t Fathoms o , o , Fathoms Mar. 26 1600 42 35 65 05 45.5 Apr. 11 2200 43 14 54 03 2, 337. 3 26 1800 42 35 64 38 74.6 12 0800 43 13 53 46 2, 299. 0 26 2000 42 35 64 11 148.5 12 1000 43 13.5 55 20 2, 310. 3 27 0800 42 45 61 42 773.4 12 1200 43 r8 55 30 2,310.3 27 lOCO 42 45 61 22 956.1 12 14C0 43 09 55 42 1. 908. 5 27 1200 42 46 61 02 1, 301. 2 12 1600 43 07 55 56 1,929.0 27 14C0 42 43 60 40 1, 389. 9 12 1800 43 08 56 13 2, 047. 0 27 1600 42 43 60 21 1, 564. 9 12 2000 43 08 56 33 2,018.3 27 1800 42 43 59 53 1, 625. 9 12 2200 43 08 56 47 2, 047. 0 27 2000 42 44 59 31 2, 176. 6 13 08C0 43 20 58 34 1,771.2 27 22C0 42 44 59 08 2, 090. 9 13 09CO 43 22 58 47 1,.564.8 28 0800 42 54 57 22 2,411.0 13 0930 43 22 58 53 1, 564. 8 28 lOOO 42 56 57 03 2, 304. 6 13 1000 43 22 59 00 1,289.0 28 1200 42 57 56 40 2, 337. 3 13 1030 43 22.5 59 06 1, 386. 4 28 1400 42 56 55 58 1, 949. 5 13 1100 43 24 59 11 1,217.0 28 1600 42 55 55 55 1, 781. 4 13 1130 43 25 59 17 1, 172. 4 28 1800 42 55 55 50 2,035.6 13 1200 43 27 59 25 1,153.4 29 0800 42 55 52 50 1, 768. 3 13 1330 43 31 59 44 774. (^ 29 1000 43 02 52 41 1,544.8 24 0830 43 53 61 17 31. 29 1100 43 10 52 31 1, 532. 9 24 0900 43 51 61 10 36 29 1200 43 11 52 30 1, 520. 7 24 0930 43 50 60 54 25. 29 1300 43 13 52 29 1, 374. 9 24 1000 43 48 60 50 23. t. 29 1400 43 16 52 22 1, 237. 2 24 1030 43 46.5 60 45 30.1 29 1500 43 22 52 17 943.3 24 1100 43 45 60 46 32.2 29 1530 43 24 52 13.5 868.4 24 1200 43 39 60 20 42.6 29 1600 43 27 52 10 775.7 24 1300 43 38 60 11 55.3 Apr. 1 1400 42 05 52 37 2, 455. 6 24 1400 43 34 59 52 674.0 1600 42 18 52 19 2, 216. 0 24 1500 43 30 59 37 1, 302. 8 1800 42 21 52 00 2,009.0 24 1600 43 26 59 22 1,381.2 2000 42 30 51 39 1, 796. 5 24 1700 43 23 59 12 1.443.2 2200 42 33 51 35 1,541.0 24 1800 43 21 59 03 1, 838. 1 2 0800 42 42.5 51 20 1,084.7 24 1900 43 18 58 53 1, 689. 2 2 1000 42 48 50 57 709.5 24 2000 43 06 58 43 2,011.7 2 1200 42 54.5 50 34 166.0 24 2100 43 03 58 31 1,992.2 2 1400 42 56 50 08 85.0 24 2200 43 00 58 18 1,944.4 2 1600 42 56 49 43 944.3 25 0800 43 04 56 37 2, 072. 7 2 1800 42 57 49 31 685.4 25 0900 43 04 56 30 2, 072. 7 2 2000 43 07 49 27 685.4 25 1000 43 04 56 26 2, 099. 3 4 0930 43 29.5 49 33.5 43.0 25 1100 43 04 56 16 1,972.9 4 1000 43 29.5 49 27.5 48.6 25 1200 43 07 56 09 2,052.0 4 1030 43 29 49 22 69.0 25 1300 43 07 55 52 2, 052. 0 4 1100 43 29 49 15 85.3 25 1400 43 04 55 38 1,954.0 4 1130 43 28.5 49 09 120.7 25 1500 43 04 55 22 2,311.5 4 1200 43 32 49 07 572.8 25 1600 43 03 55 05 2, 248. 3 4 1300 43 41 49 03 544.7 25 1700 43 03 54 53 2, 225. 5 4 1400 43 50 48 58 143.0 25 1800 43 02 54 48 2, 225. 5 4 1500 43 58 48 54 120.7 25 1900 43 02 54 39 2, 225. 5 5 0800 43 47 49 16 402. 0 25 2000 43 00 54 30 2, 255. 9 5 1000 44 04 49 11.5 157.2 25 2100 42 59 54 21 2, 322. 7 5 1200 44 02 49 14 44.3 25 2200 42 58 54 12 2, 392. 7 5 1400 43 45 49 19 381.8 26 0800 43 02 53 14 2, 008. 0 5 1600 43 27 49 20 202.0 26 1000 42 55.5 52 59 2, 008. 0 5 1800 43 15 49 16 382.0 26 1100 42 58 52 58 2, 008. 0 8 1030 43 47 50 24 33.7 26 1200 43 02 52 50.5 2, 008. 0 8 1200 43 44.5 50 16 29.0 26 1300 43 07 52 46 1,842.1 8 1300 43 41 50 02 33.0 26 1400 43 11 52 39 1, 680. 8 8 1400 43 37 49 51 36.0 26 1600 43 18 52 34 1, 563. 0 8 1500 43 33.5 49 39 38.3 26 1630 43 21 52 31 1,518.4 8 1600 43 29 49 27 59.1 26 1700 42 23 52 29 1,436.4 8 1700 43 38 49 20 224.0 26 1730 43 25 52 26.5 1,273.0 8 1800 43 45 49 13 502.0 26 1800 43 28 52 24.5 1,220.6 9 0800 43 47 48 39 1,347.3 26 1830 43 29 52 23 1, 058. 8 9 0900 43 52 48 21.5 1, 676. 0 26 1900 43 31 52 21 954.2 9 1000 43 58 48 14 1, 789. 0 26 1930 43 33 52 18 940.7 9 1100 44 04 48 17.5 1, 768. 3 26 2000 43 34 52 18 940.7 9 1200 44 13 48 20 1,752. r 28 0800 43 53 51 20 41.3 9 1300 44 18 48 08 1, 894. 5 28 0900 43 43 51 18 37.8 9 14(0 44 14 48 01 1, 874. 7 28 1000 43 33 51 15 48.8 9 1500 44 11 47 50.5 2, 073. 4 28 1100 43 22 51 13 59.5 10 1200 43 15 48 21 1, 680. 0 28 1200 43 13 51 10 191.2 0800 42 55 51 19 321.3 28 1300 43 02.5 51 06.5 771.3 1000 42 55 51 26 723.3 28 1400 42 59 51 04 811.1 1200 43 00 51 58 1,403.8 28 1500 42 60 51 10 943.1 1400 43 02 52 25 1,626.0 28 1600 42 43 51 17 1,087.2 1600 43 06 52 52 1,809.0 28 1700 42 41 51 19 1,243.7 1800 43 08 53 22 1, 919. 6 28 1800 42 32 51 28 1,383.1 2000 43 13 53 46 2, 205. 2 28 1900 42 24 51 32 1,501.2 51 Soundings as recorded with the sonic depth finder, 1926 — Continued Position Time Position Time Date (sixtieth Longi- tude, west Depth Date (sixtieth Longi- tude, west Depth neridian) Latitude, north meridian) Latitude,! north 0 / o / Fathoms 0 , o / Fathoms Apr. 28 2000 42 22 51 34 1,582.3 May 4 1000 43 30 50 13 34.3 28 2100 42 17 51 39 1,723.9 4 1100 43 30 50 00 34.3 28 2200 42 08 51 46 1,759.9 4 1130 43 30 49 54 37.3 29 0800 41 27 51 02 2, 246. 9 4 1200 43 30 49 47 36.3 29 0900 41 24 50 49 2, 442. 6 4 1230 43 30 49 41 37.3 29 1000 41 20 50 37 2, 276. 1 4 1300 43 30 49 35 36.3 29 1100 41 13 50 25 2, 276. 1 4 • 1315 43 30 49 31 37.3 29 1200 41 06 50 16 2, 044. 8 4 1330 43 30 49 27 50.2 29 1300 41 06 50 16 2, 044. 8 4 1345 43 30 49 24 48.6 29 1500 41 21 50 16 1,921.4 4 1400 43 30 49 21 52.7 29 1600 41 27 50 16 2,012.8 4 1415 43 30 49 18 70.5 29 1700 41 34.5 50 16 2,012.8 4 1430 43 30 49 14 125.9 29 1800 41 45.5 50 16 2, 012. 8 4 1445 43 30 49 12 211.3 29 1900 41 47 50 17 1,964.5 4 1500 43 31 49 10 422.4 29 2000 41 56 50 17 1, 878. 6 4 1600 43 34 49 07 281. 5 29 2100 42 06 50 17 1,742.4 4 1700 43 40 49 05 414.8 29 2200 42 08 50 17 1,701.5 4 1730 1 43 42 49 04 441.4 29 2240 42 14 50 17 1,627.3 4 1800 i 43 43 49 02 441.4 29 2300 42 17 50 17 1, 596. 0 4 1900 43 44 48 59 402.2 29 2320 42 20 50 17 1,426.4 5 1000 43 37 48 06 1. 871. 7 29 2340 42 23 50 17 1,432.8 5 1100 43 38 48 02 1,916.8 30 0000 42 25 50 17 1,432.8 5 1200 43 32 48 14 1, 770. 1 30 0020 42 27.5 50 17 1,322.3 5 1300 43 28 48 25 1, 602. 3 30 0040 42 29 50 17 1, 290. 3 5 1400 43 26 48 28 1, 602. 3 30 0800 42 38 49 45 1,136.6 5 1500 43 24 48 .H2 1,497.3 30 0900 42 41 49 39 1, 170. 5 5 1600 43 21 48 41 1,393.5 30 1000 42 38 49 36 1, 200. 0 5 1700 43 16 48 54 1, 032. 2 30 1100 42 34 49 29 1,344.9 5 1800 43 07 49 02 1, 003. 9 30 1200 42 30 49 24 1, 407. 1 5 1900 43 01 49 12 800.4 30 1300 42 28 49 20 1,437.2 6 2000 43 02 49 26 687.0 30 1400 42 26 49 16 1,480.4 27 0800 42 30.5 50 14 1, 634. 1 30 1500 42 22 49 10 1, 522. 2 27 1000 42 20 50 11 1,634.1 30 1600 42 17 49 05 1,576.3 27 1100 42 19 ,50 15 1, 650. 3 30 1700 42 12. 5 48 56 1,602.3 27 1200 42 17 50 26 1.634.1 30 1800 42 11 48 20 1, 618. 6 27 1300 42 12 50 32 1, 721. 0 30 1900 42. 10 48 49 1,639.5 27 1400 42 19 50 42 1, 618. 0 30 2000 42 10 48 46 1, 639. 5 27 1500 42 25 50 53 1, 516. 2 May 1 0800 41 49 48 14 1,912.4 28 0800 42 13 50 15 1, 814. 7 0900 41 43 48 U 1,982.7 28 0900 42 13 50 13 1,814.7 1000 41 37 47 59 1, 846. 5 28 1000 42 13 50 12 1,814.7 1100 41 30 47 47 2, 033. 3 28 1100 42 14 50 09 1,775.5 1200 41 27 47 44 2, 147. 5 28 1200 42 15 50 13 1, 814. 7 1300 41 22 47 35 2, 130. 2 28 1300 42 15 50 13 1,814.7 1400 41 16 47 25 2, 170. 2 28 1400 42 16 50 16 1, 795. 1 1500 41 09 47 15 2, 182. 0 28 1500 42 13 50 01 1, 835. 5 1600 41 08 47 11 2, 225. 9 28 1600 42 10 49 48 1, 856. 3 1700 41 15 47 14 2, 205. 4 28 1700 42 06.5 49 32.5 1, 775. 5 1800 41 25 47 16 2, 175. 6 28 1800 42 03.5 49 18 1, 646. 2 1900 41 35 47 18 2, 145. 0 28 1900 42 00 49 02 1,715.4 2000 41 44 47 20 2, 175. 6 28 2000 41 57 48 48 1, 752. 5 2100 41 53 47 23 2, 175. 6 28 2100 41 54 48 38 1, 771. 2 2200 42 03 47 25 2, 175. 6 28 2200 41 52 48 26 1,85L8 2 0800 42 56 47 37 1, 805. 5 29 0800 41 28.5 48 23 1,851.8 2 0900 42 57 47 41 1, 945. 1 29 0900 41 26.5 48 23 1,83L0 2 1000 42 58 47 45 1, 846. 5 29 1000 41 25.5 48 23 1.83L0 2 1100 42 59 47 50 1,846.5 29 1100 41 24 48 23 1,831.0 2 1200 43 00 47 54 1, 825. 7 29 1200 41 23 48 21 1, 810. 7 2 1300 43 00 47 57 1,876.0 29 1300 41 21 48 21 1, 790. 7 2 1400 43 01 48 01 1, 876. 0 29 1400 41 20 48 20 1,83L0 2 1500 43 02 48 05 1, 746. 5 29 1600 41 18 48 19 1,83L0 2 1600 43 02 48 09 1, 746. 5 29 1800 41 16 48 18 1.856.3 2 1700 43 03 48 12 1, 705. 7 29 2000 41 13.5 48 16. 5 1,992.2 2 1800 43 03 48 14 1, 705. 7 30 0800 41 16 47 54 1, 899. 6 2 1900 43 04 48 15 1, 669. 1 30 1000 41 13 47 52 1,899.6 2 2000 43 05 48 22 1, 602. 3 30 1200 41 05 48 10 1, 835. 5 3 0800 42 45 49 37 1, 145. 1 30 1400 40 56 47 56 1, 835. 5 3 0900 42 47 49 40 1, 136. 6 30 1600 40 59 47 50 1, 733. 7 3 1000 42 49 49 43 1, 233. 5 30 1800 40 58 47 49 1, 790. 7 3 1100 42 51 49 43.5 1, 105. 5 30 2000 40 53 47 47 1, 790. 7 3 1130 42 54 49 45 1,098.0 31 0800 40 47 47 42 1,899.6 3 1200 42 52.5 49 44 1,091.8 31 1000 40 45 47 40 1, 921. 6 3 1230 42 56 49 46 1,008.4 31 1200 40 44 47 38 1,899.6 3 1300 42 57 49 46 990.0 31 1400 40 53 47 45 1,8.%. 3 3 1330 42 52 49 46.5 926.6 31 KKXJ 41 06 48 02 1,83,5.5 3 1400 42 59 49 47 896.9 i 31 1800 41 21 48 17.5 1,921.6 4 0800 43 25 50 17 35.6 31 2000 41 33 48 32 1, 83.5. 5 4 0900 1 43 26. 5 50 18 38.1 1 31 2200 41 35 48 37 1, 877. 5 52 Soundings as recorded with the sonic depth finder, 1926 — Continued Time Position Time Position Date (sixtieth Latitude, north Longi- Depth Date (sLxtieth Latitude, north Longi- Depth meridian) tude, west meridian) tude, west 0 / o / Fathoms / o , Fathoms June 2 0800 41 15 48 30 1,046.2 June 27 ICOO 41 10 50 20 2,311.0 2 1000 41 15 48 30 1, 646. 2 27 1200 41 22 50 20 1,926.3 2 1200 41 18 48 32 1, 662. 9 27 14U0 41 36 50 20 2. 126. 3 2 1400 41 24 48 25 1, 697. 5 27 1600 41 56 50 19 2, 021. 6 2 1600 41 16 48 32 1, 613. 7 27 1800 42 19 50 18 1.738.0 2 1800 41 11 48 37 1, 662. 9 27 2C00 42 29 50 17 1, 343. S 2 2000 41 44 48 33 1, 613. 7 27 2030 42 35 50 17 1,116.2 2 22C0 41 42 48 34 1, 646. 2 27 2045 42 38 50 17 1,079.0 3 0800 41 20 48 39 1, 835. 5 27 2100 42 4C.5 50 17 1,041.7 3 ICOO 41 40 48 43 1, 752. 5 . 27 2115 42 44 50 17 1, 003. 0 3 1200 41 35 48 46 1, 752. 5 27 2120 42 45 .50 17 938.9 3 1400 41 25 48 44 1, 810. 7 27 2128 42 46 .10 17 659. 6 3 1600 41 15 48 40 1, 697. 5 28 0000 42 49.5 50 03 246.9 3 1800 41 04 48 38 1, 662. 9 28 0030 42 51 49 55 250.0 3 2000 41 02 48 35 1, 697. 5 28 0100 42 53 49 47 448.6 3 2200 41 00 48 30 1, 697. 5 28 0105 42 52 49 44 806.0 4 1200 41 06.5 48 26 1, 680. 0 28 0800 43 02 49 23 701.0 5 08C0 40 57 48 36 1, 733. 7 28 0830 43 08 49 23 782.2 5 1000 40 57 48 39 1, 752. 5 28 1000 43 24 49 10 686.2 6 0800 41 23 47 50 1, 795. 1 28 1100 43 34 49 02 1, 298. 0 6 1000 41 28 47 36 2,067.7 28 1115 43 36 49 00 1, 308. 1 6 1200 41 40 47 27 2, 094. 2 28 1130 43 39 48 59 1. 147. 7 6 140U 41 40 47 27 2, 094. 2 28 1145 43 41.5 48 59 1,037.8 6 1600 41 36 47 30 2, 094. 2 28 1200 43 43 49 00 824.1 6 1800 41 32 47 50 1,944.4 28 1210 43 44 49 00 741.1 7 1800 41 56 48 49 1,815.1 28 1215 43 45 49 00 660.8 7 2000 41 55 49 09 1,815.1 28 1330 43 45 48 .53 1, 113. 4 8 1000 41 31 48 54 1,907.9 28 1400 43 45 48 44 1,264.5 8 1200 41 40 49 C9 1,815.1 28 1430 43 45 48 37 1, 537. 6 8 1400 41 52 49 21 1,815.1 28 1500 43 45 48 32 1, 646. 2 8 1600 41 41 49 25 1,613.7 28 1600 43 45 48 25 1,697.5 8 1800 41 35 49 38 1, 69C. 6 28 1700 43 45 48 09 1, 835. 5 8 2CG0 41 30 49 36 1,791.0 28 1800 43 45 48 04 1,877.5 9 0800 41 42 49 10 1, 795. 1 28 1900 43 44 47 51 1.972.9 9 1200 41 52 49 50 1, 775. 5 28 2000 43 44 47 39 2,052.0 9 1400 41 41 49 59 1, 733. 7 28 2100 43 41 47 41 . 2,052.0 9 1600 41 44 50 25 2, 067. 7 28 2200 43 32 47 49 1,899.6 9 1800 42 07 50 22 1,944.4 29 0800 42 18 48 49 1, 752. 5 9 2000 41 58 50 31 2, 067. 7 29 1000 42 09 48 52 1, 752. 5 9 2200 41 57 50 29 2, 046. 8 29 1200 41 52 48 29 1,873.0 10 1000 41 53 52 05 2, 300. 2 29 1300 41 49 48 24 1, 899. 6 23 1300 44 27 63 16 48.4 29 1400 41 40.5 48 11 2, 042. 0 23 1400 44 23 63 03 87.3 29 1500 41 31 47 58 2, 042. 0 23 1600 44 16 62 36 97.6 29 1600 41 30 47 55 2,094.2 23 1800 44 09 62 08 108.6 29 1700 41 24 47 47.5 2, 121. 1 23 2000 44 02 61 46 77.2 29 1800 41 15 47 35 2, 067. 7 23 2200 43 53 61 14 .35.0 29 1900 41 06 47 21.5 2, 016. 7 24 0800 43 01 59 28 1,733 7 29 2000 41 04 47 17 2,067.7 24 1000 42 49 59 23 2, 094. 2 ?9 2100 40 52 47 13 1. 949. 2 24 1200 42 37 59 13 2, 273. 9 29 2200 40 39 47 09 1,926.3 24 1400 42 26 59 02 2, 372. 9 30 0800 40 41 49 25 2,218.0 24 1600 42 12 58 50 2, 524. 7 30 0900 40 41 49 43 2, 159. 4 24 1800 41 59 58 32 2, 005. 0 30 1000 40 42 50 02 2,026.5 24 2000 41 57 58 02 2, 524. 7 30 1100 40 44 50 21 1,958.7 24 220J 42 CO 57 35 2, 524. 7 30 1200 40 46 50 38 2, 057. 0 25 0800 42 02 54 07 2, 524. 7 30 1300 40 47 50 56 2, 193. 8 25 1000 42 04 54 35 2, 564. 5 30 1400 40 48 51 08 2, 498. 7 25 12u0 42 05 54 CI 2, 564. 5 30 1500 40 50 51 30 2, 748. 3 25 1400 42 05 53 27 2, 659. 8 30 1600 40 51 51 44.5 2, 802. 1 25 1600 42 06 52 55 2, 748. 3 30 1700 40 52 51 55 2,850.0 25 1800 42 06 52 51 2,311.5 30 1800 40 54 52 12 1,900.5 26 0700 43 06 52 39 1, 671. 8 30 2000 40 56 62 42 2, 753. 0 26 0800 43 15 52 27 1,326.3 30 2100 40 55 • 53 05 2, 753. 0 26 0820 43 18 52 24 1, 079. 0 30 2200 40 56 53 19 2, 710. 0 26 083(1 43 19 52 22 1, 003. 0 July 1 0900 41 15 55 50 2, 794. 9 26 0840 43 20 52 20 902.3 1000 41 22 56 03.5 2, 617. 7 26 0850 43 22 52 19 804. 0 1100 41 27.5 56 15 2, 577. 0 26 0900 43 23 52 16 837.0 1200 41 34 56 27.5 2, 577. 0 26 0910 43 25 52 14. 5 801.9 1300 41 38 56 44 2. 577. 0 26 0920 43 26 52 13 701.0 1400 41 40 56 57 2, 537. 0 26 0930 43 27.5 52 11 632.3 1500 41 42 57 10 2, 617. 8 26 0939 43 29 52 10 496. 4 1600 41 43 57 25 2, 577. 0 26 1200 43 16.5 51 49 632. 3 1700 41 45 57 40 2, 617. 8 26 1400 43 00 51 23 620.2 1800 41 47 57 55 2, 537, 0 26 1445 42 57 5] 14 931.4 1900 41 48 58 15 2, 537. 0 26 1600 42 50 51 19 1, 003. 0 2000 41 50 58 30 2,617.8 26 1800 42 39 51 27. 5 1, 422. 7 2100 41 52.5 58 45 2, 577. 0 26 2000 42 22 51 40. 5 1, 776. 3 2200 41 54 59 00 2, 537. 0 27 0800 41 17 50 53 2, 449. 7 ICE OBSERVATION Edward H. Smith When the patrol ship, on her first approach to the ice regions, had arrived in the vicinity of the Grand Bank, a request was dispatched to the Canadian Government Radio Station at Cape Race (VAZ) for a summary of the state of the ice up to date. A detailed reply was received giving the position and character of all the ice that had been reported by passing ships, and this is incorporated in the bulletin for this year, heading the list of ice as contained in Table of ice and other obstructions, 1926 (p. 21). The number of bergs south of the forty-eighth parallel is also recorded by months in the table of ice- berg anomalies, 1906-1926 (p. 76). The monthly number has been determined by a compilation of all ice reported by passing ships, as well as that sighted by the patrol, care being taken to avoid listing a berg in this area more than once during any one month. JANUARY No ice was reported in the western North Atlantic to the best of our knowledge during January. A normal January reports three bergs south of Newfoundland. FEBRUARY The first ice report was reported to Cape Race on February 8 (see Table of ice and other obstructions, p. 21), this being slush ice en- countered by a ship on the extreme northern part of the Grand Bank near the 100-fathom curve. Eleven other reports were received at various dates throughout the month, all referring to Arctic field ice on the northeastern part of the Bank, except for one report of several small bergs just south of the forty-eighth parallel on February 20. No doubt these were the remains of one or two large bergs, which had survived the summer of 1925, and, being caught in the fields, were naturally the first of the glacial ice to put in an appearance in 1926. It seems reasonable to conclude that only three bergs came south of the forty-eighth parallel during the month of February. Normal conditions would be 12 bergs during February. MARCH Thirty-eight reports were received and distributed throughout the month, of ice in the western North Atlantic south of the forty-eighth parallel. Nearly all of these referred to Arctic field ice or to growlers; (53) 54 only 13 were of the presence of icebergs. Eight of the latter were of bergs classified as large, and one of these was reported three times. The most dangerous bergs reported during the month were a group of four large and three small, reported three different times, as drifting southward more or less together, from the northwestern part of the Bank. The latest report which was probably the direct cause of inaugurating the ice patrol, was contained in the United States Hydrographic Office broadcast of March 20. This dispatch mentioned the positions of four large and three small bergs in the vicinity of Fig. 10. — February ice map. The position of the first Arctic ice for the season of 1926; the first steamer report from Cape Race was February 8 latitude 45° 15', longitude 46° 20'. This is about 70 miles onshore of the 100-fathom contour of the Grand Bank, where they might be expected to drift eastward and southward to the northern borders of the Gulf Stream, just where the latter is deflected offshore almost due south of Flemish Cap. No doubt this fate actually befell them as none of these bergs were sighted b}^ the patrol or reported later by passing ships. Probably they finally disintegrated in the warm offshore Atlantic waters, as they drifted northeastward, away from the steamer lanes. Another large berg drifted southward to latitude 45°, about 30 miles seaward of the slope where it was sighted on 55 March 26. Since no further reports were received, we may conclude that it, too, was caught by the inshore invasion of the warm current and eventually carried offshore to the eastward. It might be added that very few ships frequent the regions where the early season ice is most liable to drift (the patrol at the time is watching the southern end of the field ice), so it is difficult to trace the berg movements in as great detail as is possible a month or two later. Four large bergs were reported on the 27th between the 50 and 100 fathom curves on 5o So AS A5 16.. "W^-^. ^^^^ ^29 6^^ ^ 23 MAROM-I^Z6. 4-9 s>& ,£,0 ^9 ^^ 4-7 ^b .4.5 A^ 43 -12 .5b 4.7 46 AB 44- AZ 4o Fig. 11.— March ice map. Position and kind of Arctic ice sighted and reported in the western North Atlantic for March, 1926. 1UMM\^ represents field ice. A represents an iceberg the northeastern part of the Bank, this closing the list of bergs re- ported south of the forty-seventh parallel during the month of March. One of the characteristic drifts of icebergs early in the season (before the early part of April) carries them farther offshore to the eastward than is usual later in the year, as explained in previous annual reports. (See Bulletin No. 12.) The fact that the first bergs are usually observed relatively far off shore between the Grand Bank and Flemish Cap has been ascribed 56 to the size and extent of the flat ice both as it tends to prevent the bergs from working in shoreward while they are drifting southward past the coasts of Labrador and Newfoundland, and secondly, because of the prevailing westerly gales which in early season exert a tremendous driving force on the fields, within such packs of which the bergs are more or less bound to be caught and deviated. We confidently reiterate a statement made a year or more ago, "The iceberg menace to steamships in the North Atlantic would be greatly diminished or practically disappear, if sea ice did not hamper the Labrador and Newfoundland shelves from February to April every year." The bergs arriving as they characteristically do between the Bank and the Cap, are borne southward on the northern edge of the Gulf Stream and thenceforth their history is quite consistently to drift off to the northeast, paralleling the steamer tracks and rapidly disintegrating. Field ice during March was present nearly all the time with its main mass hugging closely to the northeastern sector of the Bank as bounded between the 50 and 100 fathom contours. No field ice, it is worth mentioning, was found inshore of the 50-fathom curve, thus leaving the water over the Banks quite open the entire month. This is decidedly less field ice than usual, for in normal years, during this period, the flat ice spreads out to a considerable area over the Newfoundland shelf. The fields on the eastern side were continually being blown offshore by the prevailing westerlies and just as con- stantly were they being melted as they drifted out into the deep water off the shelf. Many reports on the seaward side of this ice mentioned the presence of growlers scattered here and there over a considerable frontage. The growlers evidently were nothing more than those parts of the Arctic pans which had become rafted and frozen together, and being of a mass bulkier than the flat ice was able to survive it by a matter of days only. Some of the flat ice succeeded in drifting southward to an extreme point as noted on March 23 in latitude 43° 45', longitude 48° 07'. Summarizing for the month, we estimate that there were a total of 15 separate and distinct bergs south of the forty-eighth parallel during the period, and this is about one-half the number of bergs that usually drift south during the month of March. The field ice was confined to the northern part of the Banks, along the edge of the slope, and driven southward by the winds to the southerly position as noted on the 23d instant. The amount this year is considered below that present* in a normal year, but more than prevailed in either 1924 or 1925. APRIL The reports for the month of April began to come in on the second day when a berg was sighted by a ship well to the eastward of the 57 Banks on the inshore edge of the Gulf Stream. This berg was not reported again, and inasmuch as our records for previous seasons indicate quite consistently that ice in such a position drifts north- eastward more or less parallel with the steamer tracks, we felt con- fident such a history occurred in this case. On the 8th three small 50 5^ 3o A5 4£> APR.lL--l^;^e. — ^ Mi 1^ 3±> 5^ 53 5^ ^1 vSo '^') ^& ^^ "'fc> '^- 50 49 ^1 ^£. 44 43 43 41 -^S ^ 4^ Fig. 12.— April ice map. Position and kind of Arctic ice sighted and reported in the western North Atlantic for April, 1926. mii^ r^resents field ice. A represents an Iceberg bergs were reported on forty-fourth parallel, 40 miles offshore of the continental shelf and the next day the patrol located this group, it having drifted northeastward at the rate of 0.7 knot per hour. The bergs were really so small that they were nearly the size of growlers and it is believed they became entirely melted by the 12th. This 58 position on the forty-fourth parallel, it might be added, was the farthest south recorded for any berg during April. Looking north- ward on the map for April, we note that four bergs were reported the 14th on the western edge of Flemish Cap. Two bergs were just inside the 100-fathom curve to the westward on the Grand Bank and seven bergs were scattered on an east and west line between the Bank and the Cap. A berg was reported on the 16th close in to the Bank slope, and of all the glacial ice recorded to date this berg was regarded from its position as being most liable to drift southward and menace the southern routes. This fear proved groundless as nothing more was heard of its career. A berg was reported offshore on the 10th, and again on the 14th, in each instance located without much doubt in the northern edge of the Gulf Stream drift. A second report from this locality of a small berg probably referred to the one pre- viously mentioned on the 10th; its new position would accord with the oceanographic circulation and indicated a rate of drift of 0.7 knot per hour. Three bergs between the forty-fifth and forty-sixth parallels about 50 miles eastward of the slope were reported on the 21st and it is believed that they were the same as two previously recorded on the 16th, which would account for a drift almost due south at the rate of 0.4 knot per hour. Clear weather set in the 22d on the northern routes and for a period of the next three or four days a considerable number of bergs were reported which greatly augumented the list for April. For example the most populous distribution existed on the 100-fathom curve in latitude 47° where one ship sighted 26 bergs and an extensive ice field. These bergs with the addition of a few scattered ones were continually being reported by passing vessels the 23d to 26th instant. On the 28th and 29th three or four bergs of this aforementioned original group were reported south to the extreme limit for the month, excepting three small bergs on the 8th, on the east edge of the Bank in latitude 44° 45'. One berg only was reported in on the shelf, but its position was well to the northward in latitude 47° 20' longitude 50° 45'. It is worth remarking that records show only about one-eighth or one-ninth of the total number of bergs south of Newfoundland ever succeed in drifting south of the Tail of the Grand Bank. We ought not to fail to mention the behavior and distribution of the field ice for April. It was present during the entire month on the northeastern slope of the Banks north of the forty-sixth parallel, but due to the fact that there were few ships passing through this zone the presence of the fields were not recorded often. Whenever a ship crossed this vicinity, however, we were quite certain to receive an ice report. The patrol recorded what proved to be the southern- most invasion of the Arctic sea ice for the current year, the field 59 being sighted in the form of an attenuated tongue stretched south- ward along the edge of the slope to latitude 43° 23' on April 5. Its movement between the 4th and 5th was at the rate of 1 knot per hour parallel to the slope, while three days after, during the interim of which a westerly gale had prevailed, no vestiges were to be found except an occasional growler here and there well offshore of the slope. On the 29th we received a report from the master of the sealing steamer Terra Nova (Captain Kean), containing a general account of field ice conditions northward along the east coast of Newfoundland. He stated having found the main pack about 40 miles north of Funk Island in the early part of March where also were loacted the seals. Northerly winds prevailed, driving the ice into the rivers and bays along the coast, more or less blocking the entire coast line southward to Bonavista Bay. Captain Kean had com- pleted the catch by the 20th and was leaving the western edge of the pack, then about 100 miles east-northeast of Cape Race. The field ice this year, he stated, was much nearer land than last year and there did not appear to be a great quantity of bergs. Field ice was reported off and on pretty nearly throughout the entire month's span and its eastern limits, to the northward, coincided very closely with the forty-seventh meridian. The last few days of the month (the 28th and 29th), field ice emerged again southward to within 80 miles of its farthest southern point described April 5. On April 29 a patch was reported in latitude 44° 30', longitude 48°. Summarizing for the month we estimate that there were a total of 58 bergs south of the forty-eighth parallel, the ilormal number being 78; this is approximately 33 per cent less than the average. MAY The reader will recall that during April a group of three bergs had been reported in an extreme southerly position on the east side of the Banks, latitude 44°, on the 8th instant. No bergs had been reported so far south as this throughout the month untU the last few days, the 28th and 29th, when a group of three bergs were sighted by a passing steamer between the forty-fourth and forty-fifth parallels in the deep water just off the slope. The first report for the month of May, which indicated that the bergs were on the move to the southward, was that of the 2d instant when a berg was sighted in latitude 44° 10' on the east side of the Banks. The patrol ship at the time was a few miles southeast, hove to in a northwesterly gale but the position of this berg was regarded with considerable interest as it was the second one for the year, apparently, which was in a critical position to drift southward of the Tail. Accordingly as soon as the gale abated we commenced efforts to locate it and so on from the 3d to 11th instant we carried on a search estimating the probable drift from day 32036—27 5 60 to day. The work, however, was greatly handicapped by continual encounters with fog and low visibility which no doubt prevented the patrol from making contact with this iceberg. Throughout this period of eight days reports of bergs to the northward were continually being received and also information regarding the position of isolated fields of ice on the eastern side of the Bank, but none southward of the forty-sixth parallel. Other patches of field ice were reported between 50t 50 :30 •30 45 ^^^ ;S- «*^ >V .^^* -^ j)--y 50 49. 46 Fig. 13.— May ice map. Position and kind of Arctic ice sighted and reported in the western North Atlantic for the month of May, 1926 the Grand Banks and Flemish Cap. On the 5th, 8th, 9th, and 12th days in May bergs were reported in groups as large as three to five in number all the way from the forty-fifth parallel southward to latitude 43° 30' just eastward of the edge of the Bank. The reports were not in great detail on account of fog enveloping this entire area, but it was not difficult to observe in general that the bergs were commencing to get farther south and were drifting in their usual path toward the Tail of the Bank. A respite from foggy weather came at last on 61 May 13 and 14, and these two days of excellent visibility permitted the patrol ship to locate a total of 21 bergs which were scattered along: the eastern side of the Bank from the forty-third parallel northward to latitude 44° 15'. This was really the first period of serious scouting AS ao A9 AA ^3 A-^ <^ •*♦».. s\ J50 ^9 A^ A5 ^54 Ah 42 Fig. 14. -Bergs sighted by the patrol May 13-14. These were the vanguard of a greater number than usual which drifted south of the Bank in May which the patrol had been able to accompHsh so far this year and these dates of the 13th and 14th may be accepted quite confidently as marking the initial invasion of glacial ice, during 1926, into rela- tively low latitudes. Moreover, it was beheved that a berg located on the very tip of the Tail of the Bank on both of these dates, was one 62 and the same as reported in a dispatch of the 22d instant and as previously discussed. It remained grounded in this spot; depth of water 43 fathoms, for the next four or five days. The clearing of the fog on the 13th and 14th instant was due to the northward spread of the summer time North Atlantic high pres- sure area, which accordingly caused a shift of the wind from the prevailing southerly direction to the northwest quadrant. Not only was this clear weather a great boon to the patrol, enabling it to accurately fix the position of the southerly bergs, but also it per- mitted steamships to the northward which were crossing the con- tinental slope, east and west bound from Canadian ports, to sight numerous bergs in those regions. There was a total of approxi- mately 102 reports concerning the position of bergs north of the forty-fifth parallel submitted by passing steamers to the patrol vessel in order that we might collect and rebroadcast such information to other ships. In fact, during this period of nine days there were received about two-thirds of the reports for the entire month, all of which concerned the location of bergs distributed from the forty-fifth parallel northward to the forty-eighth parallel. The area containing the most abundant amount of ice was between the forty-sixth and forty-eighth parallels on the eastern side of the Bank. Nearly all the aforementioned ships were using track E, and the distribution of bergs as shown from the map indicated this populous belt extended northeast and southwest from just inshore of Flemish Cap south- westward in over the Bank to an extremely western position of longitude 50° 20'. The duration of clear weather was comparatively short, for on the 15th instant about noon the fog shut in again, with earnestness. This illustrates the general behavior of weather conditions during the spring of the year and with which the patrol is obliged to contend. Prevailing atmospheric circulation supplies a more or less constant indraft of warm moisture-laden winds which blow from the southerly quarter and the Gulf Stream. These winds, reaching the relatively cold water which surrounds the Banks, are cooled and their moisture is precipitated mostly in the form of fog interspersed with rain. Occasional interruptions come in the form of high-pressure atmosphere phenomena which usually bring clear weather for a short time only, so that the patrol has come to expect on the average a period of four to seven days of thick weather followed by two or three days of clear visibility and then a resumption of fog. Before the fog rolled in on the 15th the patrol vessel had time to identify one of the southerly bergs as observed the day previously which was then drifting 1.5 knots per hour southwestward past the Tail. Here then was a potential menace which was probably drifting to the westward, and from the current map probably on to the southwest slope; 63 but a small deviation in the current might tend to transport this ice offshore, where it was liable to be turned to the eastward and eventu- ally^ appear in a very unsavory position immediately northward of the steamer lanes. The current map, which had been compiled on board April 29 to May 5 (fig. 49, p. 109), about tw^o weeks previ- ously, indicated, however, that the probable tendency for this ice was inshore to ground on the Bank. Fog, as we have just remarked left nothing else for us to do but wait patiently near the Tail of the Bank and somewhat to the south- ward, blind to the movement of the 21 bergs, but hoping any day to get an opportunity for clear weather and another search. The fog continued to prevail for five days, but on the expiration of the third, we decided to remain inactive no longer. It was thought that failing to follow this ice by means of actual contact each day, the next best proposition lay in compiling on board, as soon as possible, a map showing the current in this critical region which was now infested with several bergs. The ice patrol ship, therefore, May 18 to 20, w^as occupied in making a current survey of these fog-bound waters south and southwest of the Tail— the so-called critical area. The fog cleared on the 20th instant and also the same day the oceanographic work was completed and the course and velocity of the currents were mapped. As a result of this work is discussed under the section of oceanography it will not be mentioned in detail here except tb remark that the Labrador current flowed westward from the Tail to latitude 42° 34', longitude 51°, and from this point one branch swept westward flooding the slope of the Bank, while offshore a branch bent sharply back 113° through lati- tude 41° 55', longitude 50°. A natural inquiry for the reader to make is, "What was the subsequent behavior of the large group of 21 bergs which was located just north of the Tail on May 14?" Since none of this ice was sighted in the critical area southwest of the Tail during the oceanographic survey, it is believed several of the bergs were detained around the slopes of the Bank, and that most of them drifted offshore into the northeast set, with practically no ice following tracks southward past the Tail. It is most likely that the inshore edge of the warm counter current which we have just described on the current map, transported the majority of these bergs northeastward finalh' to melt them away from the steamer lanes. It is unfortunate that the patrol ship had no opportunity during the month to search this locality in order to corroborate such a belief. During the period May 15 to 20, reports from ships traversing the regions to the northward were not so numerous as earlier in the month yet it ought to be remembered that these waters were en- 64 shrouded in fog as well as where the patrol ship was further south. In spite of the low visibility on the northern routes, however, the bergs continued to be reported, which is pretty good evidence that they must have been quite plentiful, and many of the reports men- tioned passing ice close aboard. Just about nightfall on the 20th of May the steamship Tiger reported the position of 10 icebergs to the patrol, on the forty-third parallel, and about 25 miles east of the Tail. The patrol at the time was only a short distance to the southward finishing the last of the oceanographic stations and inasmuch as this ice was in a position from which it was liable to drift farther south the patrol laid plans to locate these bergs the next morning. Fortunately the 21st, 22d, ^nd 23d of May were days of clear weather and this permitted us to determine the position of 26 bergs distributed around the Tail and as far north as 43° 20'. The distribution of this group is shown on the accompanying sketch. There were no large bergs found and it was quite striking to observe that they were all about the same size and fairly well collected together. It is also worth remarking that none of these bergs were identified as any of the former group sighted on the 13th and 14th instant, nor would such a coincidence agree at all with the set and velocity of the currents which had been flowing in this interim of about one week. Several of the bergs were carefully watched as to geographical position and it was quite plainly observed that those farther offshore of the slope were being turned or retarded in the dead water which from the current map existed there. This movement is further illustrated on Figure 15, page 65. A regard of the current map together with the positions of the bergs convinced patrol officials that this ice constituted a serious menace to the present North Atlantic lane routes and it was believed that within the space of 7 to 10 days many of the bergs would be on, or uncomfortably near, the steamship tracks. It was deemed of utmost importance, with such information at hand, to advise Washington immediately to shift the tracks farther south. Reports regarding the position of bergs to the northward continued to be received by the patrol, and after May 15 the shift from track E to Cape Race track, caused numerous bergs to be sighted in the more northerly latitudes of 48° and 49° and also longitudes farther west, viz, 50° and 51°. (See fig. 13, p. 60.) The patrol was engaged in eft'ecting the relief between its two ships the 24th and 25th and on the 26th instant, when we had returned to the vicinity of the southern bergs, south of the Tail (see fig. 15, p. 65) a dense fog was encountered. A steamer passing close to us on this day reported having narrowly missed a berg and growler, and a brief light up during the afternoon permitted us to sight what was believed to be the southernmost ice. It was foggy at this time, it must 65 be remembered, and no great area could be searched nor could the bergs be definitely located, so under such conditions there was bound naturally to be a feeling (reahzing as we did the direction and velocity of the current), that there was a very good possibilit\^ of scattered bergs drifting in widely distant positions. The problem seemed to be without solution, however, as long as fog continued to envelop these waters. Clear weather came on the 27th instant and the patrol was able to get in touch with some of the bergs of the group last plotted in positions May 21 to 23. (See fig. lo.) A group of five bergs were kept in sight for two days, the 27th and 2Sth instants, and were subsequently reported by passing steamers on AAl 51 So -4-9 44 ^3 A2. wCi'. ^3 .^v^^ x^^ 42- v52 3f v50 ^^ 46 Fig. 15.— Bergs sighted by the patrol May 22 and 23. This was not the same group located May^l3-14. (See flg. 14, p. 61.) May 29, June 1, 2, and 3. Figure 16 is inserted on page 66 in order that the reader may follow the relative positions and career of this ice. The northern bergs of the group were, according to the current map, on the inshore edge of the offshore current but the three southern bergs, that is, those farthest offshore, were in the current proper, drifting 100° at rate of 0.5 knot per hour. This agreed very well with the current as calculated there May 18 to 20, and it showed, furthermore, the manner in which the offshore bergs in the stronger current outdistanced those only a matter of 5 miles or so farther inshore. Here is an excellent example of the appreciable difference possible in the movement of the water between two places located relatively 66 close together in this critical area south of the Tail. While we were lying near the bergs on the 28th instant observing their behavior, a report of a berg in latitude 41° 50', longitude 48° 23' was received and this being only 20 miles north of the westbound track and also the southernmost ice, the patrol immediately headed toward the position at full speed. Twice during the afternoon the same ice was reported by other vessels in about the same position at which we arrived near nightfall. The berg was not very large and was thought to be one of that group originally sighted on May 14 just north of the Tail for its position could under such conditions be attributed to the course and velocity of the current. We followed this berg for three days, the 29th, 30th, and the 31st (see fig. 17, p. 67), and inas- much as it was unusually far south position for ice, during these three days of disintegration it merits more than passing interest. -^r -*9 42 o.fe^f- ~v^**- -^ az -SL 49 Fig. 16. — The behavior of a group of five bergs May 26 to June 3, drifting on the northern edge of the Gulf Stream south of the Grand Bank At 5.30 a. m. on the 29th we sighted the berg bearing 210°, distance 4 miles, and approached nearby. It was approximately 150 feet long and 60 feet high. A light sea was running from the northeast, the sky was overcast the entire day, and the temperature of the water was 46°, with the air 47°. We fired 18 to 20 shots with the 6-pounder after gun which brought down considerable ice. In the afternoon two mines containing about 238 pounds of T. N. T. were exploded beneath the surface while suspended by a rope from the berg. The mines tore off several large growlers, but did not cause any great amount of damage. On May 30 during the 4 to 8 a. m. watch a northeasterly swell began to make up which continued quite "lumpy" all day. We came up close to the berg about 2.45 in the afternoon and it was apparent to everyone on board that it had been reduced to one-half its size of yesterday. Many growlers were calving off 67 and the rate of disintegration was rapid. The sea-water temperature did not change from that of the 29th until about 8 o'clock in the afternoon when it rose to 55° as we drifted across the "cold wall." The sky was overcast similar to that of the preceding day. Constant ^5 A\ .^>^^Ay;^-^^o«>fi. Watek.Tej-iP. 4^*f: I 13 KT- Z:^fp/^9 .^iooKi Wc^tei^Temp -^y'F l£:i-i^Ay370'NW. l^f^^^^I^^^c^KT: '^>^^ vv^z^r^^^ '^ v^-^ • /*=: \ 41 ^6 Fig. 17.— The drift and position of final disintegration of a berg followed by the patrol, May 28-31, 1926 touch was kept with the berg during the night and on May 31, at 8 o'clock in the morning, it was no larger than a good size ship's boat. The water temperature had remained constant and the northeast swell continued. The rapid rate of disintegration described herewith is attributable mainly to the appreciable swell and sea which in the 32036—27 6 68 24 hours entirely effaced the berg as a menace to navigation. This is one of the most rapid cases of disintegration of which the patrol has an account and it brings out one fact quite forcibly, namely, that bergs which attain extremely far south drifts such as near the Azores Islands or near the British Isles can only be accomplished when the berg is floating in a comparatively calm sea. A summary for the month indicated the following outstanding features: Field ice was not reported south of Newfoundland after the 6th of May. There was this month, however, a great increase over April in the number of bergs reported in the northwestern North Atlantic. The first group of bergs, 21 in number, to arrive at the Tail of the Grand Bank (the gateway to the Atlantic), were sighted by the patrol on the 13th and 14th instant. A great increase in the number occurred during these few days of clear weather when ships on northern routes were also able to sight them. Fog enshrouded the regions from the 15th to 21st but the latter day of which we had a clearing and 26 more bergs were found around the Tail. These it appears quite safe to state were not the same as those sighted the 13th and 14th instants. The 15th to 24th many more bergs sighted between the forty-eighth and forty-ninth parallels by ships which now had commenced to use the Cape Race tracks. May 22 to 31 the patrol kept in touch with the southern and eastern fringe of ice and tracked "strays" to extremely low latitudes, across the west- bound steamer lane. It is difficult to estimate the number of icebergs south of Newfound- land during the month of May due to the great duplication of reports, but to the best of our belief we state that there were a total of 168, which is 10 per cent more than normal. As for the area south of the Grand Banks we estimate a total of 36 bergs, which is 100 per cent more than normal. This is a great increase in numbers over what was in these regions at any time earlier this year or during any part of 1925 or 1924. The sudden and great increase in numbers, which came with a rush during the month of May, is more or less in agree- ment with the general character of the atmospheric circulation which prevailed December to March, 1925-26. Conditions were unfavor- able towards a normal distribution of ice from October to January, but from January onward atmospheric conditions changed to a diametrically opposite character, which undoubtedly is reflected in a correspondingly sudden increase in numbers of bergs around the Grand Banks for May. JUNE The preceding month, May, indicated a total of 168 bergs south of Newfoundland, and 36 south of the Tail of the Bank. The latter figure is twice the normal number and consequently the patrol looked forward with no small amount of conviction that an abnormal num- til) ber of bergs would probably continue during June just northward of the steamer tracks. The first five days were spent following and standing by two bergs- both of which drifted across the westbound tracks between meridians 48 and 49, and consequently formed a distinct menace to steamships during this period. 3o .4. ^7 i+- ^^7" ■^ 13 ■" ^.', ■^:i!t^ .,b^ JUME:-i9^e, ,~>;,'-^ii> ^ ^3- 49 46 ^1 45 45 41 40 SS 54 s;> 3Z. v?! 50 .^9 -aa ^7 'H. AS Fig. 18. — June ice map. Position and kind of Arctic ice sighted and reported in the western North Atlantic for June, 1926 The sketch shown herewith gives a good idea of the rate and direction of their drift. It is a drift which is noteworthy for the fact that it lies alnwst at right angles to the general direction of the Gulf Stream (or what we have conceived or believed to be the prevailing direction of flow) in that particular region. Three oceanographic stations taken somewhat to the northward during the period covered, June 1 to 5, indicated no appreciable set, at least in no way com- 70 mensurate with the drift rate of the ice, viz., 1 to 1.4 knots per hour If we compare the behavior of these two bergs as to their progressive movement southward between the forty-eighth and forty-ninth meridians, with a distribution of icebergs south of Newfoundland 1900-1926 (see fig. 25), we immediately note the tendency of the ice to attain an extremely far south position takes place between these two meridians of longitudes almost without exception. On June 4 two boats were lowered from the Tampa and directed to wire drag berg B, in order that data might be compiled by the ice patrol re- garding the draft, volume, etc., characteristic of Arctic icebergs. At A^ 4.e> AZ A\ •^1 ^9 4Z A^ Fig. 19.— The drift of bergs A and B across the westbound steamship lanes June 1 to 6, 1926, inclusive the same time that the small boats were working on this job measure- ments as to the exposed surface of the ice were made on the Tampa by means of sextant and range finder. The wire dragging operations, unfortunately, were unsuccessful due to the parting of the span which consisted of a condemned sounding machine wire. The above water dimensions were found, however, to be 382 feet long, and an average height above water of 42 feet. This was at 4 p. m. on June 4, latitude 41° 06.5' north, longitude 48° 27' west. At 6 p. m. a large square tower on the right-hand side of the berg fell off causing that end to rise, setting up new strains which resulted in cleaving the berg 71 sharpW in twain. The face of the cleavage was as flat as if had been carefully planed to such a surface. Naturally, this increased tremen- dously the rate of disintegration. The temperture of the water and the state of the sea and weather remained quite the same (see p. 36) for the next five days as that recorded on June 4. At 6 p. m. June 5^ 24 hours after the disruption described above, the growler formed by the tower sliding into the sea, had entirely disappeared because of melting. The two small bergs formed June 4 were by the 5th a small berg and a grow^ler in size. At 4 a. m. June 6, latitude 40° 56', longitude 48° 33', only 10 hours later, every bit of ice had melted. If we had not actually observed this with careful note, we would have been quite skeptical, I am sure. Such an enormous mass of ice such as we measured on June 4 completely disappearing is hard to reconcile with such an extraordinary survival as recorded of a piece of ice June 25 sighted in latitude 30° 20' north, longitude 62° 32' west (see U. S. Hydrographic Office Weekl}^ Bulletin for December 8, 1926.) The ice regions north of the temperature wall on June 4, which had enjoyed clear weather since May 28, were blanketed in fog which prevailed over these waters until June 13, a period of eight days. After remaining near bergs A and B (see fig. 19) until they had com- pletely melted, the natural procedure was to scout and get in touch with other bergs of the group of 26 seen south of the Tail, May 22 and 23. These bergs, being in the colder waters north of the temperature wall, was thought to be in various, but less menacing positions in this region. We attempted scouting but were rebuffed by the fog pall from June 6 to 13. When we did search these waters (the 14th to 17th instant) northward along the east side of the Bank to the forty-fifth parallel no ice was to be found. Passing steamers located a group of three bergs west-southwest of the Tail which from several consecutive reports indicated they were drifting northwest in a branch of the inshore current, up on to the southwest slope of the Bank. A small piece of ice was reported on the 12th and again on the 19 th, not far offshore southwest of the Tail in the dead water, and another berg was seen on the tip of the Tail on the 13 th and far- ther northwest on the Bank on the 17th. This was the last report of ice in the region of the Tail for June, so one can appreciate with w^hat suddenness the relativel}^ large group of bergs in positions south of the Tail disappeared from these waters during this month. Bergs on the northern part of the Bank, on the contrary, continued to be reported with little abatement during the entire month. There were many reports which referred to the same bergs, this fact being quite apparent to anyone charged with keeping a careful check on the total number of bergs. The tendency of drift of these bergs was quite in accordance with what has been observed in previous years, namely, to ground and drag along the bottom and break up 72 on the northern slopes of the Grand Bank. Then as the season grew older, the latter part of the month, an increasing number of bergs were reported in positions along the east coast of Newfound- land, and in the deep-water gully which leads around Cape Race. Such a tendency as described is well shown on Figure 18, as is also the comparatively large number of bergs which collected and stranded on the northern part of the Bank. A report from the steamship Empress of France on June 30 indicated a decrease in numbers even here. 0 M m mi m m m jul m ^p oir m m Fig. 20.— Distribution of icebergs south of Newfoundland, 1926. The full black curved line represents th? actual distribution, while the dotted line is the normal distribution The absence of berg reports between parallels 43 and 46 on the eastern side of the Grand Bank was quite noticeable if we but glance at Figure 18. The three or four which were sighted in this locality drifted eastward on the inner edge of the Gulf Stream and did not get south of the Tail. The underlying cause for such a dispersal is contained in a current map especially compiled by the Tampa just prior to the discontinuance of the patrol on the 30th instant. Summarizing, we state that there was a total of 85 bergs south of the forty-eighth parallel, about 10 per cent more than normal, and of this number there were 12 south of the Tail of the Grand Bank, all for the month of June. The most outstanding feature was the rapid decrease in numbers of bergs drifting southward of Newfound- land during June. The waters, after the 17th instant, were entirely free of bergs that could possibly, from currents, and experience 73 of previous years, drift southward and jeopardize trans- Atlantic navigation. Tile distribution of icebergs south of Newfoundland by months during 1926 was: January 0 February 3 March /_ 15 April. Mav- June_ 58 168 85 July August September October 3 November 1 December 0 r ^JuNC 17 ■• iCtBEK-G DRIFTS ^ '* ^i 48 ^1 44 -59 S6 57 Sfa 35 54 5i 52 51 so 49 46. 4] 4b 45 44 Ah 42 Fig. 21.— Iceberg drifts recorded during the season of 1926 This is shown graphically by a full black line, Figure 20, page 72. The normal distribution is shown as a dotted line. The bergs that the patrol were able to track in drifts during the ice season are recorded on Figure 21. A compilation has been made of all the drifts of icebergs around the Grand Bank that the ice patrol has been able to follow, and this chart is shown here. 74 Fig. 22.— Chart of compiled drifts of icebergs, 1914-1926 SUMMARY OF ICEBERG RECORDS IN THE NORTH- WESTERN NORTH ATLANTIC, 1880-1926 In connection with the ice forecasting work described in the " Weather " section (pp. 31-48) it has been fpund necessary to collect the very best data from all sources on the amounts of ice from year to year and month to month. For the period 1880 to 1900 advantage was taken of the figures compiled by Mecking and also those of Schott, these investigators having based their comparative estimates of these years on records of the Deutsche Seewarte, the United States Hydrographic Office, the United States Weather Bureau, the United States Signal Service. We made an actual count of the number of icebergs south of Newfoundland by months for the period 1900-1926, and the records consulted in this task were those of the International Ice Patrol, and the United States Hydrographic Office. For the sake of record a table of the actual iceberg count is appended herewith, followed by a table of iceberg anomalies : NUMBER OF ICEBERGS SOUTH OF NEWFOUNDLAND (48TH PAR- ALLEL) IN WESTERN NORTH ATLANTIC Year 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919, 1920 1921 1922 1923 1924 1925 1926 Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 10 0 0 5 32 33 6 1 1 1 0 0 1 0 0 4 13 29 22 6 5 1 2 5 3 0 1 1 13 5 16 1 0 1 0 0 0 2 400 166 151 52 23 7 0 0 0 1 0 0 12 63 82 89 14 3 2 0 0 0 3 2 168 373 109 100 50 9 8 8 0 15 14 11 77 49 133 87 18 16 0 0 0 0 0 1 11 162 248 138 64 11 0 0 0 3 1 0 / 39 82 51 2 2 20 15 3 0 0 55 147 134 321 181 121 45 19 1 0 0 0 0 0 34 10 3 3 0 0 0 0 0 0 8 41 112 72 77 21 40 3 0 8 14 1 0 34 395 345 159 63 19 0 0 3 0 2 4 37 109 292 71 14 4 7 0 6 4 1 41 32 27 419 71 22 46 52 13 1 6 14 72 67 96 97 71 28 17 5 0 1 0 0 0 0 0 25 29 0 0 0 0 0 0 0 0 13 3 3 9 10 0 0 0 0 0 0 0 12 23 26 37 27 34 22 1 14 3 3 4 5 25 75 56 26 36 69 2 12 4 6 43 20 5 211 86 18 5 18 19 10 4 17 5 43 210 198 175 53 24 4 10 1 6 0 3 35 71 245 83 21 11 6 27 21 0 0 3 28 65 83 42 10 3 2 0 0 0 3 0 6 2. 0 0 0 0 0 0 0 " i 0 3 S 8 58, 22 13 0 0 0 0 0 0 3 15 58 168 85 4 6 2 3 1 0 An- nual 89 88 41 802 265 845 405 638 222 1,024 50 396 1,019 550 731 468 54 38 199 317 445 746 523 236 11 109 345 (75> 76 TABLE OF ICEBERG ANOMALIES Year Jan. Feb. Mar. Apr. May- June July Aug. Sept. Oct. Nov. Dec. An- nual Normals 3 10 136 83 ISO 68 25 13 9 4 3 2 1386 1900-- +7 -2 0 -3 -3 0 +11 -3 -2 -3 -3 -3 -2 -1 _2 +11 -3 -3 -3 0 +3 +14 -3 -3 0 -3 -3 -10 -10 -10 -8 -10 -8 + 1 -9 -10 +45 -10 -2 -10 -6 +31 +62 -10 -10 -10 -6 +33 -5 -10 — 7 -36 -36 -35 +364 -78 -79 -82 +83 -98 -117 -117 +21 -48 -21 +3 + 118 -48 +191 -120 -58 +215 + 162 +289 -33 -105 -127 -104 -55 +81 +68 +115 -47 -130 -72 +38 -35 -39 -63 -16 +21 +32 +19 +70 -17 +113 -65 +9 +91 +3 +3 +3 -39 -59 -31 -12 +18 + 107 +15 -26 -08 -46 +17 -19 -3 -9 -2 -11 +25 +39 -23 +96 -22 -4 +38 -11 -3 +3 -25 -15 +2 +1 +28 -4 -15 -25 -12 -21 -12 -7 -12 -6 -10 -4 +3 -2 -11 +32 -13 +27 +6 -9 +33 +4 -13 -13 +21 +23 -8 +11 -2 -10 -13 -13 —7 -8 -4 -9 -9 -7 -1 -9 -9 + 11 +10 -9 -6 -9 -2 +43 -4 -9 -9 +13 +60 +9 -5 -3 -7 -9 -9 -3 -3 -3 -4 -4 +4 -4 -4 +11 -3 -4 -4 -4 -4 +9 -4 -4 -4 -3 -2 +15 +6 +23 -4 -4 -4 -1 -3 -1 -3 -3 -3 -3 -3 -3 0 -3 -3 +5 0 +3 -2 -2 -3 -3 + 11 +9 +7 -2 +18 -3 -3 -3 -2 -2 +3 -2 -1 -2 +13 -2 +1 -2 -2 -2 + 12 -2 +2 +4 -2 _2 -2 + 1 +2 +2 +4 -2 -2 -2 -297 1901 -298 1902 -345 1903-- +416 1901 -24 ! -20 + 132 J +290 +41 , -34 -25 +79 -29 : -44 + 111 1 +51 -36 , -49 +5 1 +29 -2 +312 -121 1905 . .. .. +459 1906.. + 19 1907 +252 1908 . -164 1909. . +638 1910 -336 1911 + 10 1912... +6.33 1913 1914 +1 -4 +31 -36 -23 +26 -56 +13 -83 -80 +lfr' +345 1915... +82 1916 -332 1917 -348 1918.. _. 1919... -24 : -60 -31 ' -58 -16 -78 +7 '+127 -1 -12 -8 ! -18 -30 -81 -31 -75 -21 —25 -187 -69 1920 +59 1921 . +360 1922... . + 137 1923 -1.50 1924.. _ -375 1925... . . -277 1926-.. -41 1 Based on March, 1903, with weight of 150 instead of 400. The character of the iceberg seasons 1880-1926 is represented by the following table based on a value of 0 to 10: Year 1880 1890 1900 1910 1920 0 1 2 3 4 5 6 4.7 2.4 6.1 4.7 6.4 7.4 4.0 8.6 3.1 4.0 4.4 6.1 3.0 3.8 3.0 3.0 2.5 7.3 4.1 7.4 4.7 2.8 4.6 8.6 5. 7 6.8 5.4 2.8 5.1 6.8 5.9 4.1 2.0 3.3 4.3 This table is represented graphica lly by Figure 23. 9 m -i- X l T x .^ 7 V X ^ it iX I ^^^t ii ^ d ^IX Ii IJ/^ /^ 5 Z^^Z \ ^ t\ 7\32^^^ i XlMttX "^^ ^\ 4 ^I JZ^^ ^ ^^I lit y ^4^ ^ 2 ^ V t\t ^ ^/ ^/ 3 ^L. t \ V- t^'^ ^^ A7 o 1 * C ^ ^ ^ Fig. 23.— The iceberg character of the years 1880-1926, based on a scale 0 to 10. Mean value 4.8 We may now take the iceberg count for the period 1900-1926 and by computing the average of each series of months obtain the normal number of bergs for the western North Atlantic for each one of the 12 months. . ''C. -K\ "-K-' ^' '' *. • 'yvK V',^<^"..\^^/.- •.-. ■ •'■•>■ 1' . ^• '^ I I I *-^ v5- ■^ =t=M= EEEi; ■49 .48 r I I I I I t" GENERAL- CHART . SHOwir-i& OISTRIBUTION OF ICEBERG-S SOUTH OF NEWFOUNDLAND I900-I926. F,o. 25.-Distribution o( icebergs south of Newfoundland. 190(K1926, compiled from steamer reports and ice-patrol reports contained" in the weekly Hydrographic Bulletins of the United States Hydrographic Offlco 32036—27. (Face p. 77.) 77 Normal number of icebergs south of the forty-eighth parallel {menace to the Cape Race tracks) January 3 j April. Fehruarj' 10 j May. March 36 ! June. 83 130 68 Julv 25 August 13 September 9 October... November. December. Normal number of icebergs south of the Grand Bank (menace to the United States to Europe tracks) January.. February March — 01 April 9 1 1 May 18 4 1 June 13 July August September. 3! October 2 j November. - 1 December.-- Fi<;. 24.— The normal monthly distribution of icebergs in the western North Atlantic— (o) south of Newfoundland (48th parallel); (&) South of the Grand Bank. The black area represents the span of the normal ice season as interpreted by the ice patrol The monthly distribution throughout a normal year is represented by the two curves on Figure 24. The space between the two dotted vertical lines embraces the normal ice season, March to July. It can be seen from the foregoing that there are really no ice-free months on the Cape Race tracks, while there are only four such months on the United States to Europe tracks. In the course of the research work which has been carried on by the International Ice Patrol there has been plotted on a chart the position of those icebergs reported by steamships during the period 1900-1926. This material has been taken from the file of United States Hydrographic OfRce publications, principally the Hydro- graphic Bulletin. OCEANOGRAPHY Oceanographic station data and dynamic calculations, 1926 ht at head of column 9 represents the value, density in situ. V at head of column 10 represents the value, specific volume in situ. V-Vi at head of column 11 represents the value, anomaly of specific volume in situ. E at head of column 12 represents the value, height in dynamic meters. E-Ei at head of column 13 represents the value, anomaly of dynamic height. Date Lati- Longi- a depth 01 a = Meters 01 = Pressure in decibars Sta- tion tude tude of depth Tem- Sa- water pera- ture linity 0/00 «t V V-Vi E E-Ei o / o / °C 654... Mar. 28 42 55 55 50 4,300 0 1.8 33.06 26.45 0. 97423 159 0 0 25 1.4 33.02 26.45 . 97423 170 24. 35438 . 03973 50 1.2 33.11 26.53 . 97392 150 48. 70488 . 07838 125 HA '33. 58 26.84 . 97331 123 121.72601 .18009 250 2.8 34.36 27.45 . 97218 66 243. 31914 .29915 450 4.2 34.87 27.67 . 97110 48 437. 65714 .42367 750 4.1 34.91 27.73 . 96973 44 728. 78164 . 56215 hbb... Mar. 29 42 47 53 00 4,040 0 2.2 33.46 26.75 .97394 130 0 0 25 3.3 33.48 26.66 . 97392 139 24. 34825 .02360 50 5.2 33.84 26.75 . 97371 129 48. 69363 .06713 125 '■7.2 "34. 50 27.02 . 97315 107 121.70088 . 15576 250 6.3 34.78 27.35 . 97229 77' 243. 29088 . 27089 450 4.9 34.94 27.65 .97112 50 437. 63188 . 39839 750 4.1 34.94 27.74 . 96972 21 728. 75788 . 53839 556... ...do 43 10 52 31 2,550 0 25 1.0 0.8 33. 75 33.72 27.06 27.05 . 97365 . 97355 99 102 0 24. 34050 0 . 02585 50 0.5 33.74 27.08 . 97341 99 48. 67745 .05095 125 2.0 34.22 27.37 . 97281 79 121. 66075 . 11563 250 4.0 34.74 27.60 .97204 42 243. 21288 . 19289 450 3.8 34.81 27.68 .97109 37 437. 52588 .29239 750 4.0 34.93 27.76 . 96970 41 728. 64438 . 42489 557... Apr. 8 43 47 50 24 60 0 0.8 32.78 26.29 . 97438 174 0 0 13 0.5 32.78 26.30 . 97431 12. 92305 26 0.3 32.76 26.30 . 97426 25. 58879 39 0.5 32.78 26.30 . 97417 38. 25365 50 52 C26.30 26.30 . 97414 . 97413 "172' 48. 96941 50. 91769 ".'34291 "b'.l' '32.' 78" 558... Apr. 26 42 56 52 59 3,000 0 0.6 33.37 26.78 . 97392 "128' 0 6 25 0.6 33.39 26.80 . 97399 146 24. 34638 . 03173 50 0.6 33.69 27.04 .97344 102 48. 68676 . 06026 125 2.2 24.31 27.42 . 97276 68 121'. 66926 .12414 250 2.5 34.58 27.62 . 97201 49 243. 21739 . 19740 450 3.3 34.78 27.70 . 97106 44 437. 52439 .29090 750 3.5 34.88 27.76 . 96969 40 728. 65189 . 43240 559... ...do.... 43 14 52 35 1,963 0 2.4 33.17 26.49 . 97419 155 0 0 25 1.8 33. 59 26. 88 . 97371 118 24. 34875 . 03410 50 1.0 33.72 27.03 . 97345 103 48. 68825 .06175 125 2.4 34.31 1 27.40 . 97278 70 121.68188 . 13676 250 4.0 34.73 ! 27.58 . 97215 63 243. 22376 . 20377 450 3.3 34.77 27.68 . 97108 46 437. 53676 . 30327 750 3.6 34.88 : 27.77 . 96968 39 728. 65076 . 43127 560... ...do.... 43 33 52 10 995 0 1.4 33.14 1 26.54 . 97414 150 0 0 25 1.5 33. 17 26. 56 . 97402 149 24. 35200 . 03735 50 0.4 33. 22 26. 68 . 97378 136 48. 69950 .07300 125 -0.6 33. 59 27. 01 . 97314 106 121.70900 .16388 250 0.4 33.96 1 27.26 .97235 83 243. 30213 . 28214 450 2.2 34.52 , 27.59 .97116 54 437. 65313 .41964 750 3.1 34.74 27.68 . 96977 48 728. 79263 . 57214 561... Apr. 28 43 01 51 04 784 0 0.0 33.18 26.66 . 97403 139 0 0 25 "0.3 33.18 26.67 . 97391 138 24. 34925 . 03460 50 »1.3 33.28 26.79 . 97368 126 48. 69413 . 06763 125 0.25 33.75 ; 27.10 . 97306 98 121. 69688 . 15176 250 2.3 34.35 1 27.44 . 97218 66 243. 27438 . 25439 450 2.45 34.61 1 27.64 .97111 49 437. 60338 . 36989 750 3.3 34.78 27.69 . 96976 47 728. 73388 . 51439 * Differs from observed, having been corrected for smooth curves of temperature, salinity, and density. ' Interpolated. (78) 79 Oceanographic station data and dynamic calculations, 1926 — Continued Date Lati- Longi- a depth ai a = Meters ai = Pressure in decibars Sta- tion tude tude of depth Tem- Sa- water pera- ture linity 0/00 5t V v-v, E E-Ei 0 , 0 / °C o62... Apr. 28 42 41 51 19 2.244 0 3.2 33.47 26.66 . 97403 139 0 0 25 2.8 33.50 26.72 . 97386 133 24. 34863 .02398 50 1.3 33. 58 26.90 . 97357 115 48. 69151 . 06501 125 3.6 34.47 27.42 . 97276 68 121.74889 . 20377 250 3.9 34.71 27.58 . 97205 53 243. 29952 . 27953 450 3.85 34.86 27.71 .97105 43 437. 60952 .37603 750 3.5 35.01 27.80 . 96965 36 728. 71452 . 49503 563... ...do.... 42 22 51 34 3.322 0 3.0 33.10 26.38 . 97430 166 0 0 25 2.2 33.18 26.51 . 97406 143 24. 35446 . 03981 50 0.7 33.69 27.02 . 97346 94 48. 69850 .07200 125 3.35 34.47 27.44 . 97274 66 121.68100 .13588 250 3.45 34.72 27.63 . 97200 48 243. 22725 . 20726 450 3.9 34.89 27.72 .97104 42 437. 53125 . 29776 750 3.8 34.95 27.78 . 96967 38 728. 63775 . 41826 564... ...do.... 42 04 51 4S 3.657 0 25 3.2 0.8 33.25 33.73 26.48 27.06 . 97420 . 97355 156 102 0 24. 34688 0 1 .03223 50 1.3 34.07 27.29 . 97321 79 48. 68138 .05488 125 2.3 34.45 27.43 . 97274 66 121. 65451 . 10839 250 4.7 34.93 27.67 . 97199 47 243. 20014 . 18015 450 4.3 34.95 27.73 .97104 42 437. 50314 . 26965 750 3.95 34.96 27.78 . 96968 39 728.61114 . 39165 565... Apr. 29 41 47 52 02 3,800 0 2.5 33.07 26.42 . 97426 152 0 0 25 5.0 33.69 26.65 . 97393 140 24. 35338 . 03773 50 4.5 33.90 26.92 . 97355 113 48. 69588 .06938 125 7.6 34.63 27.07 .97311 103 121.69563 . 15051 250 7.1 34.91 27.21 . 97243 91 243. 29188 . 27189 450 "6.1 ''34. 92 27.50 . 97128 56 437. 66288 . 42939 750 4.2 34.94 27.73 . 96973 44 728. 81438 .59489 566... ...do 41 06 50 10 3,800 0 16.0 36.17 26.65 . 97403 139 0 0 25 15.7 36.10 26. 66 . 97391 138 24. 34938 . 03473 50 15.0 35.95 26.69 . 97378 136 48. 69551 . 06901 125 13.2 35.61 26.84 . 97333 125 121.81214 . 16702 250 10.9 35.33 27.08 . 97258 106 243. 33839 .31840 450 "8.5 35.15 27.35 . 97145 83 437. 74139 . 50790 750 M.6 34.99 27.73 . 96975 46 728. 95139 . 73190 567... ...do 41 27 50 14 3,860 0 15.4 36.05 26.69 . 97400 136 0 0 25 15.4 36.04 26.69 . 97389 136 24. 34863 . 03398 50 15.3 36.02 26.70 . 97377 135 48. 69438 .06788 125 13.6 35.75 26.86 . 97332 124 121.71036 . 16524 250 10.9 35.36 27.10 . 97256 104 243. 32786 . 30787 450 t^O 35.11 27.38 . 97141 79 437. 72486 . 49137 750 ''4.4 "34.94 27.72 . 96975 46 728. 90036 .68087 568... ...do 41 48 50 13 3, 790 0 6.4 33.73 26.52 . 97416 152 0 0 1 25 6.6 34.18 26.85 . 97374 121 24. 34875 . 03410 50 11.0 35.23 26.97 . 97352 110 48. 68950 .06300 125 9.9 35.03 27.01 . 97316 108 121.69375 .14863 250 6.0 34.44 27.12 . 97251 99 243. 29813 . 27814 450 4.8 34.78 27.54 .97123 61 437. 67213 .43864 750 »3.8 "'34.90 27.75 .96971 42 728. 81313 .59364 569.. .'...do 42 08 50 14 3,352 0 3.8 33.16 26.36 . 97432 168 0 0 25 2.7 33.37 26.62 . 97396 143 24. 35350 . 03885 50 0.9 33.53 26.89 . 97358 116 48. 69775 . 07125 125 0.7 34.06 27.33 . 97283 75 121. 68850 . 14338 250 3.5 34.59 27.53 .97211 59 243. 24788 . 22789 450 4.0 34.85 27.68 .97109 47 437. 56788 . 33439 750 3.6 34.89 27.75 . 96971 42 728. 68788 .46839 570... ...do 42 29 50 14 2,560 0 1.2 33.16 26.57 .97412 148 0 0 25 1.2 33.37 26.74 .97384 131 24. 34950 . 03485 50 3.2 33.73 26.87 . 97360 118 48. 69250 .06600 125 2.7 34.12 27.22 . 97294 86 121.68675 . 14163 250 3.7 34. 58 27.51 . 97213 61 243. 37713 . 25714 450 3.4 34.78 27.69 . 97108 46 437. 69713 .46464 750 3.2 "34.87 27.77 . 96969 40 728. 81363 . 59914 571... Apr. 30 42 41 49 39 2,194 0 0.4 33.17 26.63 . 97406 142 0 0 25 0.2 33.24 26.70 . 97388 135 24. 34925 .03460 50 2.3 33. 65 26. 89 . 97358 116 48. 69250 .06600 125 3.4 34.21 27.23 . 97293 85 121.68663 .14151 250 2.1 34.42 27.52 .97212 60 243.25126 .23127 450 3.4 34.76 27. 67 .97110 48 437. 57326 . 33977 750 ''3.2 "34.68 27.76 . 96970 41 728. 69326 . 47377 " Diflers from observed having been corrected for smooth curves of temperature, salinity, and density. 80 Oceano^raphic station data and dynamic calculations, 1926 — Continued Date Lati- Longi- a depth ai a = Meters Ol = Pressure in decibars Sta- tion tude tude of depth Tem- Sa- 1 water pera- ture linity 0/00 s, V V-Vi E E-Ei o , 1 o , "C 572... Apr. 30 42 28 49 22 2,971 0 4.0 33.32 26.47 . 97421 157 0 0 25 3.7 33.72 26.82 . 97377 124 24.34975 i .03510 i 50 2.7 33.76 26.94 . 97353 111 48. 69100 1 . 0C4.50 125 3.1 34.13 27.20 .97296 88 121.68288 j .13776 250 3.9 34. 64 27. 53 .97211 59 243. 24976 1 . 22977 450 4.3 34.88 27.67 .97110 48 437. 57076 . 33727 750 '■3.5 '■34.90 27.77 . 96969 40 728. 68926 1 . 46977 573... ...do 42 10 48 49 3,291 0 3.4 33. 07 26.32 . 97435 171 0 ,0 25 3.0 33.30 26.54 . 97403 150 24.3.5475 1 .04010 50 1.6 33. 54 26.85 . 97362 120 48. 70038 1 . 0738S 125 4.8 34.23 27.11 . 97306 98 121.7088 .15576 250 3.5 34.38 27.36 . 97227 75 243. 40901 1 . 38902 450 3.1 '■34.66 27.62 .97113 51 437. 74901 ! . 51552 750 3.8 "34.89 27.75 . 96971 42 7^28. 87501 . 65552 574... May 1 41 49 48 14 3,657 0 5.0 33.45 26.46 . 97422 158 0 0 25 4.6 33.81 26.80 . 97379 126 24. 35013 I . 03548 [ 50 8.8 34.75 26.97 . 97352 110 48.69151 1 .06501 j 125 9.3 34.99 27.08 .97311 103 131.69014 1 .14502 1 250 3.3 34.30 27.33 . 97229 77 243. 27814 1 . 25815 450 ''3.4 ''34.67 27.59 .97116 54 437. 62314 ', . 38965 750 4.3 '■34.91 27.73 . 96973 44 728. 75664 .53715 675... ...do 41 28 47 44 3,167 0 14.8 35.94 26.74 . 97395 131 0 0 25 14.6 35. 92 26.76 . 97383 130 24. 34725 . 03260 50 14.4 35.89 26.80 . 97368 126 48.69113 .06463 125 13.3 35. 72 26. 90 . 97327 121 121. 70176 . 15664 1 250 10.7 35.32 27.10 . 97256 104 243.31614 1 .29615 1 450 7.1 35. 05 27.38 . 97140 78 437. 71214 . 47865 750 4.7 34. 95 27.70 . 96978 49 728. 88914 . 66965 576... ...do 41 07 ' 47 12 3,230 0 16.7 36.17 26.50 .97418 154 0 0 25 16.3 36.13 26. 52 . 97405 152 24. 35288 . 03823 50 15.9 36.10 26.62 . 97385 143 48. 69963 . 07313 125 14.1 35.84 26.83 . 97334 126 121. 71926 .17414 250 ni.b '-35.48 27.07 . 97259 107 243. 33989 . 31990 j 450 i>S.l ''35.11 27.36 . 97143 81 437. 74189 .50840 750 ''5.0 34. 99 27.69 . 96979 50 728. 92489 . 70540 577 May 3 42 57 49 46 760 0 0.0 33.14 26.63 . 97406 142 0 0 25 -0.2 33.14 26.64 . 97394 141 24. 3.5000 . 03535 50 -0.1 33.14 26. 64 . 97382 140 48. 09700 . 07020 125 -0.1 33. 29 26.76 . 97338 130 121.71700 .17188 250 0.4 33.98 27.28 . 97234 82 243. 32450 . 30451 450 2.6 34. 58 27.60 .97115 53 437. 67350 . 4 1001 750 '-3.5 6 34.79 27.69 . 96976 47 728. 81000 . 59051 578... May 4 43 44 48 58 548 0 0.5 33.23 26.67 . 97402 138 0 0 25 0.4 33.26 26.68 . 97390 137 24.34888 ; .03423 50 0.2 33.26 26.68 . 97388 136 48. 69476 . 06826 125 0.6 34.02 27.30 . 97287 79 121. 69414 . 13902 250 0.9 34.37 27. 56 . 97207 55 243. 2.5289 .23290 450 2.45 34. .'iO 27. 60 .97115 53 437. 77489 . 54140 750 3.25 34. 75 27. 67 . 96977 48 728. 91289 . 69340 579... May 5 43 43 i 48 42 2,560 0 2.7 33. 50 26.73 . 97396 132 0 0 25 2.7 33. 51 26.73 . 97385 132 24. 34763 . 03298 50 3.0 33.61 26. 79 . 97368 126 48. 69176 . 06520 125 M.2 1' 34.35 27.27 . 97291 83 121. 68889 . 14377 250 5.1 34.89 27.59 . 97206 54 243. 25577 . 23578 450 4.3 34.86 27. 66 .97110 48 437. 57177 . 33828 750 3.9 34. 89 27.72 . 96974 45 728. 69777 . 47828 580... ...do 43 40 48 20 3,108 0 3.4 33. 52 26.68 . 97401 137 0 0 25 3.0 33. 53 26. 73 . 97385 132 24. 34800 . 03335 50 0.3 1 33.35 26.78 . 97369 127 48. 69225 .06575 125 1. 15 33. 90 27. 17 .97300 92 121. 69350 . 14838 250 5. 35l 34. 88 27. 55 . 97210 58 243. 26225 .24226 450 4.7 34.91 27.63 .97113 51 437. 58525 . 35216 750 3.8 34.88 27.73 . 96973 44 728. 71425 . 49476 581... ...dO..-- 43 37 48 02 3,657 0 12.2 35.40 26.87 . 97383 119 0 0 25 12.0 35.37 26.88 . 97371 118 24. 34425 .02960 50 11.9 1 35.38 26.92 . 97356 114 48. 68538 . 05888 125 10. 9 35. 38 27. 10 . 97308 100 121. 68438 . 13926 250 7.3 ''34.91 27. 32 . 97233 81 243. 27251 . 25252 450 4. 4 1 34. 80 27. 60 .97116 54 437. 62151 . 38802 750 4.5 34. 94 27.70 . 90975 46 728. 75801 . 53852 * Differs from observed having been corrected for smooth curves of temperature, salinity, and density. 81 Oceanographic station data and dynamic calculations, 1926 — Continued Date a. ai a = Meters ni = Pressure in decibars sta- Lati- Longi- depth tion tude tude of depth Tem- Sa- water pera- ture linity 0/00 «t V V-Vi E E-E) o / o / °C 582... May 6 42 55 49 43 729 0 0.8 33.33 26.73 . 97396 132 0 0 25 0.0 33.34 26.79 . 97380 127 24. 34700 . 03235 50 -0.2 33.39 26.90 . 97357 115 48. 68913 . 06263 125 0.7 34.02 27.29 . 97289 81 121. 681.38 . 13626 250 2.6 34.46 27.50 . 97214 62 243. 24576 . 22577 450 2.7 34.58 27.58 .97117 55 437. 57676 . 34327 750 3.3 34.76 27.68 . 96976 47 728. 61626 . ,39677 5S3... May 7 43 50 50 20 58 0 2.4 32.69 26. 10 12 24 2.1 1.4 32. 71 32.77 26.14 ''26.20 36 1.4 32.74 26.22 48 1.3 32.82 26.29 584... May 14 42 53 49 42 850 0 0.8 35. 16 26. 61 '."97408" "Vu ""6 0 25 -0.4 33.22 26.72 . 97386 133 24. 34925 .03460 50 -1.0 34.46 » 26.80 . 97367 125 48. 69338 .06688 125 0.5 33. 68 27.03 .97312 104 121.69801 . 1.5289 250 0.65 34.02 27.30 . 97232 80 243. 28801 . 26802 450 2.5 34. 57 27.61 .97114 52 437. 63401 . 40052 750 3.1 34.81 27.72 . 96972 43 728. 76301 . 54352 585... May 18 43 OS 51 34 914 0 1.9 32.98 26.38 . 97430 166 0 0 25 -0.2 33.17 26.66 . 97392 1,39 24. 3.5275 . 03810 50 -0.9 33.34 26.82 . 97365 123 48. 69738 . 07088 125 1.0 34.16 27.39 . 97278 70 121.68851 . 14339 250 ''2.0 34. .54 27.62 . 97201 49 243. 23664 . 21665 450 2.5 '-34.75 27.74 .97101 39 437. 53664 . 30315 750 3.2 34. 85 27.78 . 96966 37 728. 48714 . 26765 586... ...do 42 58 51 50 1,280 0 3.8 33.19 26.39 . 97429 165 0 0 1 25 3.5 33.21 26.43 .97414 161 24. 35.528 . 04073 1 50 2.0 33.53 26.82 . 97365 123 48. 70276 . 07626 125 3.5 34.27 27.27 . 97290 82 121. 69839 . 15327 250 3.4 34. 58 27.53 .97211 59 243. 26152 .24153 450 3.7 34.84 27.70 .97107 45 437. 57952 . 34603 750 3.4 34.90 27.78 . 96966 37 728. 67402 . 454,53 587... May 19 1 42 49 52 05 2,560 0 5.2 33.03 26.11 . 97455 191 0 0 [ 25 4.9 32.99 26.12 . 97443 190 24. 36225 . 04760 50 3.3 33.21 26. 46 . 97399 157 48. 717,50 .09100 1 125 2.0 33.91 27.12 . 97305 97 121. 73150 . 18638 250 3.8 34. 51 27.45 . 97218 66 243. 30838 . 28839 450 3.7 34.73 27.62 . 97104 .52 437. 64038 .40689 1 ' 750 4.1 34.92 27.73 . 96973 44 728. 78088 . .56139 588... ...do i 42 30 i 52 00 2,925 0 5.8 33.14 26.13 . 97452 188 0 0 25 3.0 33.24 26.50 . 97407 144 24. 35738 . 04273 50 2.6 33.51 26. 75 . 97371 129 48. 70463 . 07813 125 2.8 34.34 27.39 . 97279 71 121. 69763 . 15251 250 i'3.8 34.82 27.66 . 97199 47 243. 35888 . 33889 450 4.1 34.91 27.72 . 97105 43 437. 66288 . 42939 i 750 4.2 35.01 27.78 . 96968 39 728. 77238 . 55289 589... ...do i 42 13 1 51 43 3,500 0 5.8 33.09 26.08 . 97458 194 0 0 25 3.0 33. 35 26. 58 . 97400 147 24. 35725 . 04250 50 1.2 33.47 26.82 . 97365 123 48. 70288 . 07638 125 1.3 33.98 27.22 . 97295 87 121. 70038 . 25526 250 2.8 34.50 27.52 .97211 59 243. 26663 . 24664 450 3.9 34.75 27.62 .97114 52 437. 59162 . 3.5813 750 4. 1 34.94 27.75 . 96971 42 728. 69913 . 47964 590... ...do ; 42 12 51 11 2, 743 0 12.0 34.71 26.38 . 97430 166 0 0 25 12,5 34.81 26.37 . 97419 166 24. 35613 . 04148 i .50 14.0 35.78 26. 80 . 97368 126 48. 70451 . 07801 1 125 M0.9 3.5. 44 27.15 . 97302 94 121. 70614 . 16102 250 '6.4 34.84 27.39 . 97227 75 243. 28739 . 26740 450 "4.4 34.85 27.64 .97115 53 437. 62939 .39590 750 M.l 34.94 27. 75 . 96971 42 728. 75839 .53890 591... ...do 42 33 51 17 2,377 0 6.2 33.38 26.27 . 9744U 176 0 0 25 7.9 34.19 26.67 . 97391 138 24. 35388 . 03923 50 9.3 34.82 26.95 . 97353 HI 48. 69688 . 07038 125 10.0 35.15 27.18 .97300 92 121. 69176 . 14664 250 6.7 34.90 27.40 . 97225 73 243. 26989 .24990 450 4.6 34.89 27.65 .97112 50 437. 60689 .37340 750 3.9 34.92 27.75 . 96971 42 728. 73179 .51190 ' Differs from observed having been corrected for smooth curves of temperature, salinity, and density. 82 Oceanographic station data and dynamic calculations, 1926 — Continued Date Lati- Longi- a depth fli a = Meters ai = Pressure in decibars Sta- tion tude tude of depth Tem- Sa- water pera- ture linity 0/00 fit V V-Vi E E-Ei o , 0 / °C 592... May 19 42 48 51 28 1,645 0 5.3 33.31 26.32 . 97436 171 0 0 25 4.9 33.32 26.37 . 97420 167 24. 35688 .04223 50 4.8 34.04 26.95 . 97352 110 48. 70338 .07688 125 4.6 34.36 27.23 .97294 86 121.69563 . 15051 250 4.4 '34.50 27.37 . 97226 74 243. 02063 .00064 450 4.1 34.67 27.53 . 97123 61 437. 36963 . 13614 750 3.8 34.89 27.74 . 96972 43 728. 51213 .29264 593... May 20 42 55 51 07 1,463 0 1.6 32.93 26.36 . 97432 168 0 0 25 0.1 32. ,94 26.46 . 97411 158 24. 35538 .04073 50 -0.8 33.21 26.71 . 97376 133 48. 70363 . 07713 125 0.1 33.71 27.08 . 97308 100 121. 70976 .16464 250 1.5 34.15 27.35 . 97227 75 243. 29414 .27415 450 i'2.6 34.53 27.56 .97119 57 437. 64016 . 40667 1 750 3.4 34.84 27.74 . 96971 42 728. 77514 . 66565 594... —do 42 45 50 35 1,737 0 2.0 33.08 26.45 . 97423 169 0 0 25 1.4 33.11 26.52 . 97405 162 24. 35350 .03885 60 -0.9 33.35 26.82 . 97365 123 48. 69975 . 07325 125 -0.8 33.64 27.06 . 97310 102 121. 70288 . 15776 250 2.3 34.11 27.32 . 97234 82 243. 29288 . 27289 450 2.9 34.57 27.57 . 97119 67 437. 64588 .41239 750 3.3 34.84 27.74 . 96970 41 728. 77938 . 55989 595... ...do 42 23 50 33 2,560 0 2.0 32.92 26.33 . 97434 170 0 0 25 1.8 32.98 26.41 . 97416 153 24. 35624 .04159 50 0.4 33.31 26.74 . 97372 130 48. 69974 . 07324 125 1.8 34.39 27.63 . 97266 58 121. 68900 .14388 250 3.4 34.73 27.65 . 97198 46 243. 22900 .21901 450 3.6 34.82 27.72 .97104 42 437. 53100 . 29761 750 3.6 34.90 27.77 . 96968 39 728. 63900 . 41961 596... ...do 42 05 50 21 3,340 0 4.6 33.02 26.17 . 97450 186 0 '0 25 0.6 33.16 26.60 . 97398 145 24. 36600 .04135 50 0.7 33.49 26.87 . 97360 118 48. 70074 .07424 125 3.4 34.36 27.34 . 97284 76 121. 69226 . 14713 250 4.6 34.74 27.53 . 97212 60 243. 26475 . 24476 450 4.8 34.93 27.66 .97112 50 437. 58875 . 35526 750 4.5 35.00 27.75 . 96970 41 728. 71175 . 49226 597... June 2 41 24 48 25 3.160 0 16.7 36.09 26.44 .97424 160 0 0 25 16.4 36.10 26.52 . 97406 152 24. 35288 .03823 50 15.9 36.04 26.59 . 97388 146 48. 70201 . 07551 125 13.7 35.76 26.85 . 97332 124 121. 72201 . 17689 250 11.1 36.27 26.99 . 97266 114 243. 34576 . 32577 450 8.1 34.95 27.24 .97154 92 437. 76576 . 53227 750 4.6 34.90 27.65 . 96981 52 728. 96826 . 74877 598... —do 41 12 48 39 3,150 0 16.7 36.10 26.45 . 97423 159 0 0 25 16.2 36.08 26.56 . 97402 149 24. 35300 .03835 50 15.4 36.04 26.59 .97388 146 48. 70175 .07525 125 13.9 35.82 26.86 .97331 123 121.72138 .17628 250 11.5 35.38 27.00 . 97265 113 243. 34388 .32389 450 7.9 34.89 27.26 . 97153 91 437. 76188 .62839 750 4.5 34.87 27.65 . 96981 52 728. 96288 . 74339 599... June 3 41 25 48 45 3,790 0 16.4 36.17 26.57 . 97412 148 0 0 25 16.6 36.13 26.58 . 97400 147 24. 35160 . 03685 50 16.9 36.08 26.61 . 97386 144 48. 69975 . 07325 125 13.8 36.80 26.85 . 97332 124 121. 71900 .17388 250 12.0 35.48 26.98 . 97267 116 243. 33713 . 31714 450 8.2 35.04 27.30 . 97149 77 437. 76313 .61964 750 6.3 36.00 27.66 . 96981 62 728. 94813 .72864 600... June 16 4? 42 50 18 1,828 0 8.0 32.64 25.35 . 97527 263 0 0 25 7.6 33.65 26.44 . 97413 160 24. 36750 .05285 60 5.1 33.48 26.48 .97382 140 48. 71688 .09038 125 1.8 33.82 27.08 .97309 101 121. 72602 .18090 250 2.7 34.03 27.38 .97224 72 243. 30917 .28918 460 6.2 34.68 27.42 . 97122 60 437. 65517 .42168 760 4.6 34.95 27.70 . 96977 48 728. 80367 .58418 601... ...do 42 32 50 18 2,194 0 9.8 33.88 26.13 . 97453 189 0 0 25 10.2 33.97 26.13 .97442 189 24. 36188 .04723 50 10.6 35.18 26.30 . 97415 173 48. 71901 . 09251 126 10.75 35.19 27.00 . 97317 109 121.74351 . 19839 260 7.8 34.85 27.21 . 97239 87 243. 34101 . 32102 450 4.9 34.69 27.46 . 97131 69 437. 71101 . 47762 750 4.3 34.98 27. 76 .96971 42 728. 86401 .64452 ' Differs from observed, having been corrected for smooth curves of temperature salinity, and density. H'S Oceanographic station data and dynamic calculations, 1926- — Continued Date Lati- Longi- a depth fli a = Meters 01 = Pressure in decibars sta- 1 tion tude tude of deptb Tem- Sa- water pera- ture linity 0/00 «t V V-V, E E-E, o / o / °C 602... June 16 42 22 50 17 2,590 0 10.2 33.26 25.57 . 97512 248 0 0 25 10.5 33.48 25.70 .97483 230 24. 37438 . 05973 50 10.8 33.91 25.98 . 97446 204 48. 74051 .11401 125 5.3 34.43 27.30 . 97297 89 121.76915 . 22403 250 3.5 34.68 27.60 .97211 59 243. 33665 . 31666 450 4.1 34. 83 27. 66 .97111 49 437. 65765 . 42416 750 4.5 34. 94 27. 70 . 96975 46 728. 78665 . 56716 603... ...do 42 11.5 50 18 2,800 0 9.0 32. 94 25. 52 . 97511 247 0 0 25 7.9 32. 97 25. 70 . 97483 230 24. 37425 . 05960 50 1.5 33. 18 26. 57 . 97389 147 48. 73325 . 10665 125 0.8 33.91 27.25 . 97291 83 121. 73825 . 19313 250 4.4 34.59 I 27.45 . 97208 56 243. 30013 . 28014 450 M.S '■34.85 27.69 . 97108 46 437.61613 . 37264 750 4.1 34. 94 27. 77 . 96970 41 728. 73313 .51364 604... June 19 43 50 50 25 62 0 7.7 32. 78 25. 60 .97504 240 June 25 42 06 52 50 4,700 13 26 39 52 0 6.9 6.3 1.5 1.4 18.9 32. 81 25. 73 32. 81 25. 80 33. 07 26. 48 33.08 ; 26.50 36.02 ; 25.85 605... '.'97480" "216" '"6" 6 25 18.4 36.03 25.98 . 97457 204 24. 36712 . 05247 50 17.4 36.04 26.23 . 97422 180 48. 72700 . 10050 125 17.5 35.80 26.71 . 97345 137 121.76380 .21868 250 (■ILO 35.50 27.18 . 97248 96 243. 38190 .36191 450 '7.5 35.20 27.53 . 97126 64 437. 75590 . 52241 750 4.6 34.84 27.61 . 96985 56 728. 92240 .70291 606... ...do 42 25 52 59 4,571 0 17.4 35.68 25.95 . 97470 206 0 0 25 16.6 35. 65 26.12 . 97443 190 24.36412 . 04947 50 14.2 35.71 26.71 . 97376 134 48. 71650 . 09000 125 11.8 35.45 27.00 . 97318 110 121. 72675 . 18163 250 '■8.9 I- 35. 10 27.23 . 97242 90 243. 32675 .30676 450 6.0 34. 83 27. 44 . 97133 71 437. 70175 . 46826 750 4.4 34.93 1 27.71 . 96976 47 728. 86525 . 64576 607... I June 26 42 43 53 07 4,023 0 11.7 32. 98 25. 10 . 97551 287 0 0 25 10.5 32.98 1 25.31 . 97520 267 24. 38388 .06923 50 9.6 33.16 25.60 . 97482 240 48. 75913 .13263 125 8.0 34.92 27.23 . 97295 87 121.80051 .25539 250 5.8 34.70 27.36 . 97228 76 243. 37739 . 35740 450 4.0 34.73 27.59 .97117 55 437. 72239 .48890 750 4.0 34.92 27.74 . 96972 43 728. 85589 . 63640 608...!.. .do 43 06 52 39 2,560 0 9.1 33.17 25.69 . 97495 231 0 0 25 '■7.5 33.14 25.90 . 97464 211 24. 36988 . 05523 50 2.1 33.59 26.86 . 97361 119 48. 72300 .09650 125 2.4 34.16 27.29 . 97289 81 121. 71675 . 17163 250 3.2 34.54 I 27.52 .97211 59 243. 27925 . 25926 450 3.9 34.77 27.63 .97113 51 437. 60325 . 36976 750 4.4 34.91 27.69 . 96978 49 728. 73975 . 52026 609... ...do..... 43 29 52 09 1,033 0 11.7 34.12 25.98 . 97468 204 0 0 25 9.4 34.09 "^26.36 . 97421 168 24.36112 . 04647 50 4.] 34.07 27.06 . 97343 101 48. 70662 . 08012 125 '3.5 34.33 27.32 . 97286 78 121.69250 . 14738 250 3.8 '■34. 54 27.46 . 97218 66 243. 25750 . 23751 450 4.1 '34. 65 27.52 .97124 62 437. 59950 . 36601 750 3.6 34.75 27.64 . 96980 51 728. 75550 . 53601 610... ...do 42 56 51 14 1,510 0 12.5 33.81 25.59 . 97505 241 0 0 1 25 f'12.3 35. 15 26.67 . 97391 138 24. 36200 . 04735 50 12.0 35.44 26.95 . 97354 112 48. 70512 .07862 125 10.4 35.28 27.12 . 97306 98 121. 70262 . 15750 250 5.9 34.64 27.30 . 97234 82 243. 29012 . 27013 450 3.6 34.68 27.59 .97117 55 437.64112 . 40763 1 750 4.4 34.90 27.68 . 96979 50 728. 78512 . 56563 611... ...do 42 39 51 27 2,304 0 11.4 33.22 25.34 . 97528 264 0 0 25 7.6 33.20 25.94 . 97460 207 24. 37350 .05885 50 5.4 34.19 27.01 . 97347 105 48. 72438 .09788 125 "4.0 34.73 27.31 . 97287 79 121.71213 . 16701 250 3.4 34.63 27.57 . 97206 54 243.27025 1 .25026 450 4.0 34.87 27.70 . 97107 45 437.58325 | .34976 i 750 4.0 34.91 27.72 . 96974 46 728. 70475 .48526 ' Differs from observed, having been corrected for smooth curves of temperature, salinity, and density. 84 Oceanographic station data and dynamic calculations, 19^6 — Continued Date Lati- Longi- a depth 01 a = Meters 01 = Pressure in decibars Sta- tion tude tude of depth Tem- Sa- water pera- ture linity 0/00 5t V ^•-Vl E E-E, o / 0 / "C 612... June 26 42 20 51 42 2,956 0 11.6 33.16 25.25 . 97537 273 0 0 25 8.9 33.19 25.74 . 97479 226 24. 37700 . 06235 50 1.7 33.64 26.93 . 97354 112 48.73112 .10462 125 2.0 34.22 27.37 . 97281 73 121. 71924 . 17412 250 3.4 34.69 27.61 . 97202 50 243.27112 .25113 450 4.0 34.89 27.72 . 97105 43 437. 57812 . 34463 750 4.0 34.91 27.73 . 96973 44 728. 69512 . 47563 613... —do 41 59 51 52 3,660 0 17.0 35.46 25. 88 . 97477 213 0 0 25 17.1 35.71 26.05 . 97450 197 24. 36588 . 05123 50 15.0 35.75 26.58 . 97389 147 48. 72076 . 09426 125 12.2 "35.56 j 27.01 . 97317 109 121. 73551 .19039 250 f'9.0 35.34 1 27.41 . 97225 73 243. 32426 . 30427 450 "6.0 35. 14 : 27. 685 .97110 48 437. 65926 . 42577 750 4.4 35. 00 1 27. 76 . 96971 42 728. 78076 . 56127 614... June 27 41 30 52 02 3,860 0 17.4 35. 79 : 26. 04 . 97462 198 0 0 25 17.0 35. 72 ' 26. 08 . 97447 194 24. 36362 . 04897 50 16.1 35.68 1 26.27 . 97418 176 48. 72174 . 09524 125 14.8 35.96 1 26.77 . 97340 132 121. 75599 . 21087 250 HI. 6 35. 47 27. 05 . 97260 108 243. 38099 .36100 450 8.0 34. 98 27. 28 .97151 89 437. 79199 . 55850 750 4.5 34. 89 27. 67 . 96980 51 728. 98849 .76900 615... ...do 41 09 50 20 3,765 0 15.8 35.07 ! 25.86 . 97479 215 0 0 25 n5.8 35.21 1 25.97 . 97458 205 24. 36712 . 05247 50 15.8 35.63 26.30 .97415 173 48. 72624 . 09974 125 13.8 35.76 1 26.83 . 97334 126 121.75712 . 21200 250 11.9 35.46 1 26.99 . 97266 114 243. 38212 . 36213 450 8.2 35.07 i 27.32 .97147 85 437. 79512 . 56^63 750 "4.5 34. 99 ! 27. 74 . 96973 44 728. 97512 . 75563 616... —do 41 32 50 19 3,700 0 18.7 35.79 [ 25.72 . 97492 228 0 0 25 18.4 35. 97 25. 93 . 97461 208 24. 36912 .05447 50 15.5 35.55 j 26.30 . 97415 173 48. 72862 . 10212 125 13.2 35. 64 26. 87 . 97330 122 121. 75800 .21288 250 11.0 35. 28 27. 01 . 97264 112 243. 37925 . 35926 450 5.3 34.69 ; 27.41 . 97135 73 437. 77825 .54476 750 3.3 34.71 27.65 .96980 51 728. 95075 . 73126 617... —do 41 56 50 19 3,430 0 13.6 33.32 1 25.00 . 97561 297 0 0 25 10.8 33.68 1 25.80 . 97474 221 24. 37938 .06473 50 2.4 33. 19 26. 51 .97394 152 48. 73788 .11138 125 9.2 35. 00 i 27. 10 . 97308 100 121.75113 . 20601 250 6.0 34.77 : 27.39 . 97225 73 243. 33425 . 31426 450 3.8 34.75 1 27.63 .97113 51 437. 67225 . 43876 750 4.4 35.00 27.76 . 96971 42 728. 79825 . 57876 618... —do 42 21 50 18 2,864 0 11.8 33.56 ' 2.5.55 . 97508 244 0 0 25 9.4 33.67 26.03 . 97452 199 24. 37000 . 05535 50 4.0 33.92 1 26.95 . 97353 111 48. 72062 .09412 125 4.2 34. 41 27. 32 . 97268 78 121.71024 . 16512 250 4.3 34.74 1 27.56 . 97208 56 243. 26899 .24900 450 4.6 34.95 1 27.70 . 97108 46 437. 58499 . 35150 750 4.0 34. 93 1 27. 75 . 96971 42 728. 70349 .48400 619... ...do 42 46 50 16 1,798 0 12.0 33.96 1 25.80 . 97485 221 0 0 25 9.8 34. 67 ! 26. 75 .97383 130 24. 35850 .04385 50 11.5 35.31 26.95 . 97353 111 48. 70050 .07400 125 10.1 35. 10 ; 27. 01 . 97316 108 121.70136 . 15624 250 *7.0 "34.78 27.26 . 97239 87 243. 29824 . 27825 450 4.3 34.81 1 27.62 .97114 52 437. 65124 . 41775 750 3.4 34.89 1 27.78 . 96967 38 728. 77274 . 55325 620... June 28 42 51 49 47.5 777 0 9.7 33.38 25.75 . 97489 225 0 0 25 8.5 33. 66 26. 16 . 97440 187 24. 36613 . 05148 50 2.4 33.54 26.79 . 97368 126 48. 71713 .09063 125 1.9 33.94 27.15 . 97302 94 121.71838 . 17326 250 3.4 34.37 27.36 . 97226 74 243. 42338 .40339 450 4.4 34.86 27.65 .97111 49 437. 76038 . 52689 750 3.8 "34.90 27.75 .96971 42 728. 88338 .66389 621... ...do 42 30 49 20 2,560 0 5.7 32.95 25.99 . 97467 203 0 0 25 6.6 33.94 26.66 ! . 97392 139 24. 35738 . 04273 50 11.2 35.29 , 26.99 [ . 97350 108 48. 70013 . 07363 125 7.9 34. 82 : 27. 17 ' . 97301 93 121. 69426 . 14914 250 .5.3 34.52 27.28 . 97236 84 243. 27989 .25990 450 '-3.9 34.64 27.53 .97123 61 437. 63889 .40540 750 4.2 34.82 27.65 ! .96980 51 728. 79339 .57390 " Differs from observed, having been corrected for smooth curves of temperature, salinity, and density" 85 Oceanographic statio)) data and dynamic calculations, 1926 — Continued Date a depth 0| a = Meters 01 = Pressure in decibars Sta- Lati- . Longi- 1 tion tude tude of depth Tem- Sa- water pera- ture linity 0/00 «t V V-V, E E-Ei o , ' a 1 "C fi22... June 28 43 45 49 00 1.060 0 .5.6 32.87 25. 95 . 97470 206 0 0 i 25 4.6 32.88 26.06 . 97449 196 24. 36488 . 05023 1 50 1.1 33.13 26.55 . 97391 149 48. 71988 . 09338 125 0.6 33.73 27.08 . 97308 100 121. 73200 . 18688 250 1.7 34.28 27.44 . 97218 66 243.31075 . 29076 4.50 3.0 34.72 27.68 . 97108 46 437. 63675 . 40326 750 ''■i.l 34.87 27.74 . 96971 42 728. 75.525 . 53576 fi23... ...do 43 45 48 33 2,590 0 9.0 32.92 25. 50 .97513 249 0 0 25 7.1 33.03 25. 87 . 97467 214 24. 37250 . 05785 .50 1.7 33. 85 27. 10 . 97339 97 48. 72325 . 09675 125 2.4 34. 48 27.52 . 97267 59 121. 700.50 1 . 1.5.538 2.50 M.5 34.90 27.67 . 97198 46 24.3.24112 .22113 450 4.0 34.92 27. 75 .97102 40 437.54112 . 30763 750 3.7 34.92 27.78 . 96967 38 728. 04462 . 42513 C24... ...do 43 45 48 04 3.125 0 8.2 32.98 25. 68 . 97496 232 0 0 25 4.9 33.36 26.41 .97416 163 24. 36400 .04935 50 2.3 34.06 27.22 . 97327 85 48. 70688 .08038 125 3.8 34.59 27.50 . 97269 61 121. 680.38 . 13,526 2.50 4.2 34.86 27.67 . 97198 46 243. 22226 . 20227 450 4.3 34.98 27.76 .97101 39 437. 52126 . 28777 750 3.8 34.96 27.80 . 96965 36 728. 62026 . 40077 e2o... ...do ! 43 45 47 40 3, 590 0 13.8 33.87 25.38 . 97525 261 0 0 25 13.7 34.17 25.63 . 97490 237 24. 37688 .06223 50 13.3 34.47 25. 94 . 97449 207 48. 74426 . 11776 125 9.4 35.00 27.07 .97311 103 121. 77926 . 23414 2.50 5.4 34.62 27.35 . 97229 77 243. 36676 . 34677 450 4.4 34.84 27.64 .97113 51 437. 70876 . 47527 7.50 4.0 34.94 27.76 . 96970 41 728. 83326 .61377 f.26... June 29.. 42 10 48 54 3.200 0 11.4 34.40 26.25 . 97442 178 0 0 25 11.4 34.49 26.33 . 97423 170 24. 35813 .04348 50 10.7 35. 22 27.02 . 97347 105 48. 70438 . 07788 125 8.1 34.86 27.17 . 97301 93 121.69738 . 1.5226 250 4.8 34. 67 27.45 .97219 67 243. 27238 . 2.5239 4.50 4.8 34.92 27.65 .97112 50 437. 60338 . 36989 750 3.7 34.85 27. 72 . 96974 45 728. 73088 .51139 f)27... ...do 41 50 48 25 3.660 0 11.1 33.28 25.43 . 97520 256 0 0 25 7.7 33.11 25. 85 . 97469 216 24. 37363 . 05898 50 5.5 33.84 26.72 . 97375 133 48.72913 . 01263 125 4.8 34. 56 27.36 . 97283 75 121. 72588 . 18076 2,50 3.9 34.71 27.59 . 97205 53 1 243. 28088 . 26087 450 3.9 .34. 85 27.70 .97107 45 ' 437. 59288 . 35939 7.50 3.9 34.92 27.75 . 96971 42 728. 70988 .49039 62S... ...do 41 30 47 55 3. 175 0 15.4 34. 17 25.26 . 97536 272 1 0 0 1 25 14.9 34.77 25.83 . 97471 218 24. 37588 .06123 50 9.0 34.50 26.75 . 97372 130 48. 73126 . 10476 125 10.9 3.5. 31 27.05 .97312 104 121. 73776 . 19264 250 6.8 34.83 27.33 . 97232 80 243. 32776 . 30777 450 M.8 » 34. 75 27.57 . 97120 58 437. 67976 . 44627 750 4.4 34.97 27.73 . 96974 45 728. 82076 . 60127 02y. . . ...do 41 04 47. 17 3. 245 0 16.6 35.28 25.84 . 97481 217 0 0 25 16.3 35. 54 26.11 . 97444 191 24. 36.563 . 0,5098 50 1,5.9 .36.09 26.62 . 97385 143 48. 71926 . 09276 125 14.6 35.95 26.81 . 97336 128 121. 73971 . 19459 250 11.6 35.36 26.96 . 97271 119 243.36911 . 34912 450 7.0 35.03 27.46 . 97133 71 4.37.77311 . 53962 750 4.9 34.96 27.67 . 96981 52 728.94411 . 72462 o:;o... ...do 1 40 39 47 OS 3,340 0 14.5 33.96 25.30 . 97532 268 0 0 25 15.1 34.92 25.91 .'97463 210 24. 37438 . 05973 50 14.0 3.5. 62 26. 68 . 97379 137 48. 72963 . 10313 125 13.3 35.70 26.89 . 97328 120 121. 74475 . 19963 2,50 11.2 3,5. 37 27.05 . 97260 108 243. 36225 . 34226 4.50 8.2 3,5. 15 27.38 .97141 79 437. 76325 . 52976 750 5.2 35.04 27.70 . 96978 49 728.94175 . 72226 ' Differs from observed, having been corrected for smooth curves of temperature, salinity, and density. 86 OCEANOGRAPHY Edward H. Smith It ought to be emphasized that the London convention which gave genesis to the idea of an ice patrol also laid particular stress upon the importance of collecting scientific data. It was believed that the patrol could give the most efficient economic service to shipping only when scientific methods were employed to support the practical work. Oceanographical investigations of the waters of the ice regions have, during the past 13 years of the service, gradually come to be recognized as contributing a clear and accurate insight into the behavior of floating ice. Such information is not only important for the patrol, but it likewise means greater safety for lives and ships on the North Atlantic. It is obvious that observations restricted solely to the surface do not furnish a true and complete picture of the circulation which is in process, and it is only by including the subsurface that we can hope to obtain a correct view of the inter- action between the water masses as a whole. The oceanographic information of which the patrol makes a com- plete analysis in arriving at conclusions regarding the behavior of ice, consists of the following: (a) Vertical distribution of salinity, temperature, and density. (6) Horizontal distribution of salinity, temperature, and density. (c) Horizontal distribution of potential (current maps). Ice scouting is the primary work of the patrol, and this means limiting the number of stations to the minimum and confining the observations to depths no greater than are essential for obtaining the true picture of the circulation. It is also necessary to remember that the more nearly simultaneous the observations can be, the more accurate picture is for the area covered. An ideal program, of course, includes a maximum number of stations distributed netlike over the area investigated and along lines running at right angles to the currents. Therefore, before commencing the observational work all available data as to the hydrographical nature of the ice regions should be carefully studied. This matter received the attention of the Interdepartmental Board on Ice Patrol as early as 1921, when a tentative program was formulated, which has been carried out more or less intensively ever since. The program was revised slightly in 1926 and is described here in some detail, because observations ought to be patterned along the same general lines for several years to come. A standardized program permits ready comparisons between a series of vears. 87 GENERAL PROGRAM OF WORK The oceanographic plan is based on five lines of stations which run more or less at right angles to the currents and to the general trend of the Grand Bank slopes along the following radials: Line A: Length 60 miles, 3 stations. Line B : Length 88 miles, 5 stations. Line C: Length 100 miles, 5 stations. Line D: Length 180 miles, 7 stations. Line E: Length 60 miles, 4 stations. 50 49 4-5 47 4fa 45" 44 43 Fig. 26. — The selected position of stations upon which are based the oceanographic surveys conducted by the ice patrol This distribution of stations permits a vertical examination of the water mass to be extended offshore from five different points along the slope of the Grand Bank, and it also allows us to determine the important physical variations taking place in the ice-infested waters. The distance between stations is set at 20 to 30 miles in order that all the principal features will be detected, and the stations are extended offshore from the Newfoundland shelf for a distance of 60 to 180 miles. The innermost stations are placed as far in on the continental slope as possible, and yet readings secured from the stand- ard maximum depth of observation, 750 meters, without the weights touching bottom. It is important to take temperature and salinitj 250 •450 450 observations from a sufficient number of levels of depth in order that the change in physical character of the water may be followed in detail. It is equally important that observations be extended down- ward to abyssal regions where uniformity of conditions tend to pre- vail. The greatest changes per unit increase in depth in an ocean are generally in the surface layers, and the deeper we penetrate the more homogeneous becomes the mass. A characteristic graph of the density which is based on the two funda- mentals, salinity and tem- perature, is shown in Fig- ure 27. The upper 25 meters is generally kept more or less homogeneous by the mixing effect of the waves, a feature illus- trated by the steepness of the density curve. The water column between 25 and 50 meters increases in density very rapidly, i.e., the water is very sta- ble, and this is shown by the horizontality of the curve at A. We find a secondary unevenness in the curve between the 125 and 200 meters depth, B, which is often observed and attributed to the limit of depth of the seasonal effect. Below this point the curve gradually and constantly approaches a straight line as homoge- neous abyssal water is entered. In accordance with this normal stratifi- cation, the ice patrol has adopted a minimum number of standard depths at which the observations for salinity and temperature are always taken, viz., 0, 25, 50, 125, 250, 450, and 750 meters. It has been found, however, that considerable circulation takes place even below 750 meters, if we proceed as far 120 miles offshore from the continental edge. Therefore it would seem desirable in future years to extend the observations at least to 1,200 meters. 750 Fig. 27.— An example of the distribution of density with ocean depth 89 HOW TO AVOID ERRORS IN OBSERVATIONS It is very eas}^ for one not thoroughly schooled in the art of collect- ing observations of the temperature and salinity of a water column to make all sorts of errors. Usually the mistake is not detected until some later date when, alas, it is too late to repeat observations and rectify the error. It behooves observers to exercise the greatest care in order that the degree of accuracy be raised as high as possible, and the reputation of the records correspondingly enhanced. The fol- lowing hints may be found useful by future investigators: (1) The water bottles should be in the finest working condition, and should be gone over and oiled frequently. (2) Guard carefully against a tendency for the bottle to close prematurely. (,3) Each bottle should be equipped with two thermometers. (4) Thermometers should be functioning properly and kept under close ob- servation. (5) If thermometers in the same bottle do not check, they should be examined. (6) The mercury column should be continuous from the bulb end when the bottles are lowered over the side. (7) The meter wheel should be checked occasionally for accuracy of measure- ment. (8) The wire should be guarded against kinks. (9) The wire should be oiled occasionallj-. (10) The wire should be vertical when the top messenger is released. (11) Never take station observations if wire has a slant of more than 35° with the sea surface. (12) Allow five minutes after lowering the instruments before releasing the first messenger. (13) Determine time interval for bottom bottle to be tripped at various depths and do not start hoisting until this interval has expired. (14) Do not capsize bottles when removing them from wire. (15) Read thermometers with great care and note registration in record book. (16) Each bottle should then be returned to its properly marked stall in the rack in order of sequence. (17) When last bottle is being hoisted on board, or before, plot the temperature readings of the various depths of observation on cross-section paper. If the values do not form a smooth curve characteristic for the time and place, repeat suspicious observations immediately before leaving station. Abilitj' to detect errors in temperature curves comes with experience. (18) Citrate bottles should be clearly marked to indicate the station number and the particular depth from which filled. (19) Stoppers on citrate bottles should be absolutely air-tight. (20) Coach oceanographic party in teamwork. (21) Determine salinity of water samples by running them through the electric salinity tester on board and in accordance with instructions for same. (22) Test salinity values on cross section for smooth curve. (23) Apply to stem temperature of deep-sea thermometers the proper correc- tion for auxiliary thermometer reading. (24) Obtain density values by entering temperature and salinitj- graph. (25) Test densities for smooth curve on cross-section paper. (See fig. 27, p. 88.) 90 A PROBLEM THAT HANDICAPS THE ICE PATROL One of the most important natural problems which has confronted the ice patrol has been the securing of advance information regarding the probable drift of ice after arrival at the gateway to the Atlantic (the vicinity of the Tail of the Grand Bank). If we glance at a general map of the northwestern North Atlantic we may trace the general course followed both by the current and by the ice stream southwards along the continental slope from Baffin Land to the Tail of the Grand Bank without great change in direction for a distance of 1,800 miles. But when the cold Arctic water is discharged past the Tail of the Bank it is no longer preserved by the general trend of the continental slope, but is forced to meet directly the easterly moving masses of, or associated with, the Gulf Stream. It is at this point that the course of the current, and likewise its freight of ice, is subjected to great variations in direction. Naturally it is extremely desirable for the patrol to be able to disseminate to shipping, whether the ice will be deflected northward again into the shallow shelf waters, or whether it will be swept southward across the North Atlantic Lane Routes, and so create a very grave menace to shipping. If the patrol had knowledge of the drift tracks which bergs would follow after arrival at the gateway to the Atlantic, much more detailed information could be furnished to approaching vessels, especially during the protracted periods when fog enshrouds this cold-water region. NEW METHODS IN OCEANOGRAPHY INTRODUCED ON ICE PATROL The interdepartmental board charged with the administration of ice patrol had for some time been following the modern methods pursued in oceanography, particularly those taught at the Geophys- ical Institute, Bergen, Norway. The board believed that these methods had a practical application to the ice patrol's unique problem, as described in the preceding paragraph. The new thought in this branch of oceanography was more or less widely introduced by Prof. V. Bjerknes and others ^ in a treatise on the dynamics. Since that time several Scandinavian oceanographers have attained such success in further applying Bjerknes' basic formula to oceanographic investigations that arrangements were made for me to attend the Geophysical Institute, Bergen, 1924-25, for a year's study with Prof. Helland-Hansen on the theory of free motion and for instruction in the various methods of illustration. The oceanographic records of the ice patrol, some 3,000 observations of temperature and salinity from various depths and places in the ice regions, were also treated at the Geophysical Institute by mathematical computation. It is hoped to have this research published. The first maps thus ever 1 Dynamic Meteorology and Hydrography. Carnegie Inst. Pub., Washington, 1910-11. 91 drawn of the circulation in the ice regions indicate a close agreement between the calculated currents (velocity and direction) and the actual drifts of bergs at the time and place. Dynamic oceanography provides an easy and efficient means for mapping currents over exten- sive ocean surfaces, which guarantees it wide employment in future hydrographical surveys. If properly employed on ice patrol, more- over, it promises some day to vindicate the belief of the members of the London Convention which established the ice patrol, viz. : Skilled navigators and scientists are confident, partly as a result of Arctic and Anarctic explorations of recent years, that a thorough study and observation of ice conditions and formation, and of the Labrador current and other currents, the natural laws governing the formation and the movements of ice in the North Atlantic maj' be determined, at least to the extent of permitting approximate forecasts, similar to recent meteorological forecasts, which will contribute to safer ocean navigation. If we steam the patrol vessel over the critical ice area, taking observations of the salinity and temperature at selected places, the data thus collected furnish the material for calculating the direction and velocity of the currents. - la:/ NE^FO\>t^aLM:D; - 45 .59 36 37 Sb 55 SA -Si, SZ Fig. 28.— Chart of oocanographic stations occupied in 1926 STATION WORK PERFORMED IN 1926 The 1926 ice season marked the first attempts to employ the scien- tific methods explained in United States Treasury Bulletin No. 14, 2 Smith, Edward H.: A Practical Method for Determining Ocean Currents. U. S. Treas. Dept. Bull. No. 14, 1925. • 32036—27 7 92 and the work was bent wholly towards contributing direct practical information on the behavior of those icebergs that drifted south of the Tail of the Grand Bank. In the course of the season a total of 76 stations were taken, all but three of which were occupied in the deep water off the slope to a depth of 750 meters. This number of stations is less than for 1923 or for 1924; but their value was conse- quently greatly enhanced by their being well distributed over the area to be surveyed, with each station in the set taken in rapid succession. We were handicapped during the early part of the season by the breaking down of the oceanographic winches on board both the Tampa and the Modoc, so that the first set of stations was not actually begun until April 29, after the patrol had been in progress more than a month. It was deemed best to make a general survey of the entire ice area at the beginning of the season and a second one at its close. During the progress of the season it was not found possible to make more than one survey and this was confined to a compara- tively small but important area off the southwest slope of the Bank. The critical ice area is of such great extent that it requires at least a total of 12 to 14 stations to delineate the courses of the currents with any accuracy. A satisfactory survey of the entire region around the Tail was afforded by Sets I and III with a total of 26 stations. SOME FEATURES REVEALED BY THE VERTICAL SECTIONS The vertical sections show the distribution of temperature, salinity, and specific volume for the following groups of stations : Section I: West-southwest slope, stations 558-560, figures 29 and 30. Section II: Southwest slope, stations 557-565, figures 31 and 32. Section III: South slope, stations 566-570, figures 33 and 34. Section IV: Southeast slope, stations 571-576, figures 35 and 36. Section V: East slope, stations 578-581, figures 37 and 38. Section VI: West-southwest, station 607-609, figures 39 and 40. Section VII: Southwest slope, station 610-614, figures 41 and 42. Section VIII: South slope, station 615-619, figures 43 and 44. Section IX: Southeast slope, station 620-630, figures 45 and 46. Section X: East slope, station 622-625, figures 47 and 48. Since vertical sections normal to the Grand Bank slopes have been taken and discussed repeatedly in former ice seasons, only brief com- ment on the principal features is called for. Section I: The striking thing about this profile, Figure 29, is the shelf of icy water (temperature below^ 0° C), that hugged the slope between i(>0' and 200 meters, and extended out about 20 miles from the edge. The density wall, as illustrated in Figure 30, was well developed at the time with its highest point approximately 45 miles seaward from the slope. 93 0 25 SO STATIC M sse, 559 56 o 125 ZSO- 450- 750- WEST S<5orH WeST Si-of=e- APf^lL. 26, 1^26. ST/VT'oaJ^ Fig. 29.— Distribution of temperature and salinity 3pe> 339 ^fcO i2e> 155 150 Z5 J 50 125 250 450 75TATIONECT«oM TT »44- .3^ .2,6 o56 .47 Fig. 32.— Distribution of specific volume 95 STT^/oMb 566 ^ECTlOrO TTT Fig. 33. — Distribution of temperature and salinity STATioMS. 56fa Sin 5f.6 .Sfe9 S/o 152 1^6 l46 SCT .Sl>& .ff*7 SECT/ONJ JH Fig. 34. — Distribution of specific volume 96 97 iolQ^ 98 0 >50 VZ'5 750 STAmo^s> A50 57b 579 580 561 33.Z 5„< 335i7i .1 lis? 54 55^ 12 z 531 EAST SLOPE- e»EcT)OK3 :sr 750 J4^>M89 0M66 "349/ h500 43 4.7 4.-4 ■ytj ■<.3489 '54Aft .3494 5,^ 3.8 4^ Fig. 37.— Distribution of temperature and salinity 99 0 576 ^9 S60 Se>l li's »32 1^7 »I9 1-57 «i^3^__9l3,2 /„,,5 136 ■>i:sfo oiy; on4 '^a «.4S 0^04. o4b Fig. 38. — Distribution of 3i)ucinc volume 3203G- 27- 100 Fig. 39. — Distribution of temperature and salinity 101 250. 450 ISO' WEST 50orH-\WEST SLOPE. JUNE. 26j^2t. SEOTIONJ 3zr Fig. 4C.— DiFtribution of specific \olunic 102 til feto SS'ZZ. 33"Sl,j ■S>T7^-n o/\rS SOOTK-wEsT SLOPE/ ^u JOf^E 26-27, I92fe. ^ECTiOlN V7T Fig. 41.— Distribution of temperature and salinity STAT/OA/S ;rH-^v£sT Slope- Fig. 42. — Distribution of specific volume 103 .il9 .417 itlf, MS- SMOOTH SUoPE- vJO/Oe. ^7, i')Z(o e>E:CT!OM VTTT Fig. 43. — Distribution of temperature and salinity 5ECTIOtS vnT Fig. 44.— Distribution of specific volume 104 ,lM-N 105 106 Section II: A cold surface layer 125 meters in tliickness spread out from the edge for a distance of 75 miles. The corresponding profile anomaly of specific volume, Figure 32, indicates a much steeper slope to the isosteres on the offshore side of the density wall than on the inshore. Section III: No water colder than 0° C. was found at the Tail on April 29, despite the fact that water colder than zero was then STp>rrfO/^S Fig. 47.— Distribution of temperature and salinity bathing the slope farther to the northwest. The coldest water at the Tail, 1°, then took the form of a closed core at a depth of 50 to 100 meters, situated about 45 miles off the slope. The warm salty water at the outer end of this section is unmistakably that of the Gulf Stream. The density wall, as shown by Figure 34, page 95, was then well devel- oped located near station 569, 45 miles offshore from the Tail. A com- parison of Figures 33 and 34, page 95, indicates that the density wall 107 was then approximately 25 miles inshore of the "cold" temperature wall. Section IV: No extremely cold water was found in this section, but the offshore stations 575 and 576 showed the effects of warm tropical water. The isosteres have a gentle, irregular slope from the inshore station, 571, out to the very end of the picture. ■^To>T/0/^S 0 7-5 \V> 750 450 75C. 348 (, , i^LZ 4Z \54- -r.Q "3472: «3492 »349S '^',., // 3-0 4^0 4.^ 44 EASjT S.LOPE- e>£CTior\! >1A$1 «34Q2 -349b o34H Fig. 48.— Distribution of specific volume Section V: The inner edge of the Gulf Stream was reached at station 581 while the inshore stations showed no water colder than 0° C. The density wall lay 25 miles inside of the "cold " temperature wall. (Cf. fig. 37 with fig. 38, pp. 98, 99.) Section VI: To our surprise a pool of relatively warm and fresh water was found at the offshore station on this section. It is difficult, to explain its source unless it had drifted out from the Grand Bank, curling around the end of the cold current which usually extends northwestward along the slope from the Tail, at that season. Doubt- 108 less the body of warm salty water which bathed the slope inshore on this section had its source in the inner edge of the Gulf Stream, the development of this invasion is plainly discernible on the horizontal charts of circulation. The increased number of isosteres in the profile of specific volume (fig. 40), over what were present in this locality six weeks earlier (fig. 30) represents the influence of increased solar warming of the surface layers. Section VII: A connection with the warm salty water observed in Figure 39, is to be observed in this section (fig. 41) at the slope stations. The high temperatures and salinities at the two outer stations plainly indicate that the northern edge of the Gulf Stream then lay approximately 75 miles off the southwest slope. The density wall (fig. 42) was 20 to 25 miles inshore of the cold wall. Section VIII : Again in this section we see a trace of tropical water along the southwest slope wedged in against the bank. The density wall at the Tail was about 30 miles inside of the temperature wall. Sections IX and X exhibit no unusual characteristics from those observed in earlier sections at the same places. DISCUSSION OF THE CIRCULATION IN THE HORIZONTAL PLANE The total of 76 stations have, for the purposes of horizontal illus- tration, been divided into three groups which are separated from one another by a space of at least two weeks in time. They have been arranged as follows: Set I: April 29 to May 5, a total of 25 stations embodied in Figures 49, 50, 51, 52. Set. II: May 18 to 20, a total of 13 stations embodied in Figures 53, 54, 55, 56. Set III: June 25 to 29, a total of 27 stations embodied in Figures 57, 58, 59, 60. SET I The 175 density values obtained from 25 stations, 558 to 583, taken April 29 to May 5, were subjected to mathematical computa- tions described in United States Treasury Department Bulletin No. 14, giving the values shown in the last four columns in the oceano- graphic station table, page 78. Since we assumed that the maximum depth of observation, 750 meters (or decibars), was a level isobaric plane, the dynamic values of 728+ given on the charts (figs. 49, 53, and 57) represent the height of the sea surface in dynamic meters at each station. (See Oceanographic station table, p. 78, for a detailed record of these data.) The dynamic heights have been plotted at the proper station positions on Figure 49, page 109, and contour lines delineating the topography of the sea surface were drawn in similar fashion to those which appear on an ordinary 109 isobaric weather map. The dynamic topographical map (fig. 49) is read also in the same manner as one reads a meteorological map. The oceanic situation around the Tail of the Grand Bank April 29 to May 5 may be described as follows: A "low" or hollow in the sea surface lay centered off the southwest slope of the Grand Bank with a trough, circumscribed by the contour of 728.70 dynamic meters, extended around the Tail to the northeastward more or less parallel- ing the 100-fathom curve. The sea surface was relatively high in over the Bank itself and at the outermost stations offshore. A liill of water, figuratively, lay centered about 65 miles southeastward of the Tail. Fig. 49.— Set I. Dynamic topographical map The circulation of the water, which will follow this dynamic topog- raphy of the surfaces is in general as on a weather map, anticlock- wise around the "lows" and clockwise around the "highs." Figure 50, page 110, indicates the direction of flow of the water by means of the arrows, and the numerals represent in knots per horn* the veloc- ity of the current at the particular place and time. The velocities were calculated upon the assumption that the water had no motion at a depth of 750 decibars (meters). Such, however, was not liter- ally the case, especially offshore in the Gulf Stream, but inasmuch as 750 decibars was the limit of depth to which our observations ex- tended, it is taken arbitrarily as the depth at which motion most nearly approached zero. Reference to Figure 50, page 110, shows 110 CUR.R.tNT5 ■/1.4KT |a4KT Oirf^ ^ i ^^ -^r -'""' Sb ,55 3^ 3» 52 51 JO A') 4© 47 -It. 4£ Fig. 50.— Set I. Direction and velocity of the currents DISTEI&UTION or TE:MPER.ATueE. APFJIU 29 -MAY 5,1926. ■J L.^EJ" .5S 54 56 Si 31 ao -»j -?e 47 ^fe Fig. 51. — Set I. Distribution of cold and warm water Ill that the cold current was running swiftest along the east side of the Bank at the rate of 1.4 knots per hour, but it decreased to 0.7 knot 60 miles farther south at the Tail. The inshore set (Labrador current) curled around the Tail and flowed northwestward parallel with the continental edge, a distance of 150 miles, as far as our observations extended in that direction. Reaching that locality, a great portion of the current eddied offshore and back to the east- ward, forming a vast anticj^'clonic vortex off the southwest slope. The most rapid rate of flow was 1 knot, located southwest of the Bank, as shown on Figure 50, page 110. The easterly moving water masses were split by a clockwise eddy when they reached a point v5Uf?FACE: PiiTRlBUTION OF LI&hTC&T WATEE, AF!i!L 29 - MAY 3. IJSfe SS 5J Sh 52- SO 4? 4t, 47 4t 45 Fig. 52.— Set I. Distribution of light and heavy water on the surface of the sea southeast of the Tail, but just to the northeast of this point the branches rejoined. The northeasterly coimterset was only 25 miles off the eastern edge of the Bank in latitude 44°, but it was weak — 0.2 of a knot per hour. The distribution of cold water, as shown by Figure 51, page 110, is good evidence wliich supports the general scheme of circulation calculated and portrayed on Figure 50, page 110. The cold water from the north was transported to the Tail and thence along the southwest slope of the Grand Bank as far as om- observations in that direction extended. The shape and position of the shaded area of water less than 1° C. (fig. 51, p. 110), clearly indicates that this cold water after being brought to the region of the southwest slope was 112 carried back to the eastward in the form of a counterset, separated from the westerly moving stream inshore by a strip of water about 10 miles in width and with a temperatm'e higher than 1°. The fourth sketch of this set of observations, April 29 to May 5 (fig. 52, p. Ill), illustrates the distribution on the surface around the Tail of the lightest water. The lightest water, which has been inclosed in a shaded area, extended parallel with the slope some 35 miles to the seaward of the 100-fathom contour and had heavier water on either side. Light water also was found in over the Bank itself. SET II A hollow in the sea surface, the center of which was 10 dynamic centimeters lower than at any other point around the Tail, is to be 'WwS* -5i £.2. 51 50 4? ^t Fig. 53.^Set II. Dynamic topographical map noted on Figure 53. The same trough of 728.70 dynamic meters that was recorded around the Tail of the Bank two weeks earlier is seen here stretched along the slope. The sea surface was relatively high in over the Bank and offshore at the outer stations, all of which conditions agree with those previously observed this season. The oceanic situation for May 18 to 20 (fig. 53) reveals the fact that an important change had taken place since the first week in May (fig. 49). These two figures show that the spacious vortex observed in the sea surface off the southwest slope April 29 to May 5 had been pushed up against the edge of the Bank by a force acting 113 r>^ ^..^'^ C U R- (2. £ f^ "T-S MAY ig-20, 1^26 S3 SZ 51 50 49 48 Fig. 54.— Set II. Direction and velocity of the currents r"^^ DlfeTeiBUTION OF temperature: MAY 16-20, I92£> S-^ 5b S2 ^1 5^^9 Fig. 55. — Set II. Distribution of cold and warm water 114 from offshore to the southwest, and this action, moreover, had tended to deepen the vortex by about 10 dynamic centimeters. The steepening of the sides of this hollow had correspondingly intensified the currents around the center so that velocities as high as 1.3 knots per hour are recorded on Figure 54. The distribution of critical temperatures on Figure 55 discloses a wedge of warm water had invaded the locality immediately off the southwest slope from off- shore. The western side of the picture shows cold inshore water of northern origin curling around the western extremity of this warm wedge to the southeastward, so that the birth of an anticyclonic ^^ SURFACE. OlSTK,ie>UTlON OF LIG-HTEL&T WATER. S-3 S> 52. Fig. 56. — Set II. Distribution of light and heavy water on the surface of the sea rotating eddy is clearly indicated off the southwest slope of the Bank. The lightest water on the surface lay in over the Bank and also offshore at the outer stations, a distribution very similar to that which prevailed two weeks earlier. SET III A study of the dynamic topographical map for the period June 25 to 29 shows that the hollow in the sea surface off the southwest slope of the Bank (figs. 49 and 53) had again expanded to about the same form as in early May, except for being slightly more elongate and curling a few miles further to the eastward. A trough extended southward paralleling the east slope of the Bank and at a distance out about 50 miles. The direction and velocity of the currents are shown on Figure 58 as also the drift of two bergs which were sighted 115 SA 53 5Z 31 50 49 47 4j, 45 Fig. 57.— Set III. Dynamic topographical map ^ ^ ,.7 JZ f^/fA \ ■^^':WiyM ^Zt/ N •■■■ •?-14 '1 4.5 44 45 4Z 41 cuRfeeNTO June: 25-23,1526,. 40 -54 3i 5Z 51 50 4? 4& 47 46 45 Fig. 58. — Set III. Direction and velocity of the currents 116 y DISTRIBUTION or temperature: June. 25-25,1926 Fig. 59. — Set III. Distribution of cold and warm water SUferACE Dl&TieiBUTION OF LI6HTE5T WATER. CSPEClFlC VOLUME.) JUNE ?S-29, IJ?2£>. S-S 5-i Sb 5i 51 50 49 45 47 4fo 45' Fig. 60. — Set III. Distribution of light and heavy water on the surface of the sea 117 in the area at the time. The behavior of the ice conforms as might be expected to the circulation as denoted on the map. The distribution of temperature as plotted on Figure 59 plainly shows that warm water previously mentioned on Figure 55 had worked its way to the north- westward along the Bank slope, while on the other hand cold water from the north curled offshore 150 miles or so westward of the Tail, finally to be carried along in a return stream to the eastward, 30 to 40 miles off the continental edge. A comparison of this map with the two earlier temperature charts. Figures 51 and 55, shows the development of this rotating movement of the warm and cold waters. The lightest surface water (fig. 60) was in the form of a band 25 to 30 miles in width and more or less paralleling the Bank contour about 60 miles offshore. The effect of solar warming of the surface layers during the latter part of June is clearly shown by the increase in values for the specific volumes from those collected for May. (Fig. 52.) SUMMARY The work this year marks the first attempt at dynamic calculation of ocean currents on board a surveying vessel immediately following the collection of the data and also the employing of such informa- tion at once for the benefit of passing ships. The three sets of obser- vations (figs. 49, 53, and 57) permit us to follow the changes that took place in the circulation around the Tail of the Bank from April 29 to June 30. First, we may regard the circulation as found by the earliest survey as more or less characteristic of the waters around the Tail of the Grand Bank. On or about May 15 warm salty water from offshore interrupted this scheme of circulation by pushing in toward the southwest slope and pinching off the flow of Arctic water that normally drifts clockwise around the Atlantic face of the Grand Bank. This movement characterizing the currents in May had slackened before the latter part of June, and the scheme of circula- tion had returned to what we regard as normal. Except for this unexplained interruption the cold current continually flowed around the Tail and to a variable^ distance (approximately 150 miles), along the southwest slope where it turned to the eastward, joining the warm current known as the Gulf Stream. This distribution and direction of the currents tended to form a great anticyclonic eddy off the south- west slope of the Grand Bank. RELIABILITY OF CURRENT MAPS One of the problems upon which we wished to gain information as a result of the season's work, was the rate of change in direction and velocity of ocean currents, to tell whether one survey a month would serve all practical purposes or whether rapid changes in the circula- tion would make more frequent surveys necessary. There have been 118 very little data collected from the ocean which throw much light on this subject. In case we argue from the atmosphere we know that isb- baric maps as much as 24 hours old contain little information on the situation for the present. The scheme of oceanic circulation around the Tail of the Bank this season altered quite noticeably within a space of two weeks and then resumed, broadly speaking, its original state, all within the priod of two months. It is hoped that the same plan of oceanographic work introduced in 1926 is continued for a few years so that we shall be in a position to say considerable more on the relia- bility of current maps with the elapse of time. DISSIMILARITY BETWEEN DENSITY AND COLD WALLS The observations in 1926 corroborate earlier ones to the effect that the density of the water around the Grand Bank is usually- higher along the zone of contact between the Labrador current and the Gulf Stream than on either side of the latter. But this density wall does not exactly coincide in location with the zone of most abrupt transi- tion from low to high temperature (the cold wall), but lies as a rule 25 to 35 miles inshore of the latter. Since the density wall unques- tionably marks the boundary between the easterly and westerly sets, this discovery means that the drop in the temperature of the surface water near the continental slope does not mark the change in the direction of the current. LIGHT WATER COLLECTS ON SURFACE OF THE SEA Evidence has been accumulating that there is a prevailing tendency for relatively light water to collect on the surface of the sea immedi- ately over the belt of the heaviest subsurface water, represented by the density wall; this has been observed in the profiles of every ice season since 1922, so it must be more than a coincidence. DRIFT OF BERGS CHECKED WITH CALCULATED CURRENTS We were handicapped this year by fog in comparing the drift of the bergs with the currents calculated and plotted, but the few examples obtained have been found to harmonize. (Fig. 21, p. 73.) The fact that there were few opportunities to make comparisons in the case of specific bergs ought not to be interpreted as detracting from the value of the three sets of illustrations represented by Figures 49, 53, and 57, all of which were continually consulted by those in charge of maneuvering the patrol ships. /W 119 320 » is <>CL-Q y''liJti!< z tvaOf 31 9 121 C _J rtAn!5>\ library: . j 14 of the patrol (se^ fig. 50, p. 90), during which time the waters of the entire eastern side of the Grand Banks were mapped. This timely information enabled the patrol to forward to Washington officials an intelligent and accurate recommendation regarding the safety of the trans-Atlantic tracks. The drift of the ice and the stream lines of the currents, as calculated from the station data, agreed very closely. The methods employed in determining the direction and velocity of the currents around the Grand Bank, which are described in Bulletin No. 14, 1925, appear very feasible and the results in 1927 certainly threw an intelligent light upon the probable movements of the ice, a subject which naturally is of inestimable value to those in charge of the patrol work. The patrol ships had on board practically the same outfits as carried in 1926 with the exception of a larger number of spare oceanographic instruments. The installation of new electric hoists for lowering and hoisting the water bottles was a great improvement which shortened the time spent at stations by almost one-half. The policy begun in 1926 of carrying out a survey of the bottom contour whenever opportunity afforded was continued by the Tampa in 1927, and about 435 sonic soundings were obtained in this manner. The sonic apparatus is also of invaluable assistance in locating the position of the patrol ships, and the ice sighted, during the protracted periods of cloudy and foggy weather around the Banks. The radio apparatus functioned quite satisfactorily this year with the exception of three days when the Tampa's main motor radio generator developed a ground. The trouble was located, however, and by working night and day the patrol ship was soon back on radio schedules. The breakdown, it should be added, did not affect the set which is used to communicate with passing vessels, as the spark set is on a separate generating circuit. About 450 steamships are known to have taken advantage of the service provided by the ice patrol this year, and no doubt there were many more, that also listened in for the daily broadcasts. We made a few inquiries as to how far the ice patrol reports were picked up, and what the general policy was among the steamers regarding listening in for the ice broadcasts. The replies indicated that radio contact with the patrol was usually made at a distance of about 450 miles east and west of the Grand Banks; also that the commercial radio operators were given standing orders to copy the broadcasts at all times when within this range, giving the messages priority over all other traffic. The following list is submitted in order that the reader may obtain an idea of the service which is being furnished the ships of many nations. The masters of these vessels have been thanked, by letter, by the chairman of the ice patrol board. 15 Belgian 4 1 Dutch 30 British 150 French 7 Canadian 36 ! German 12 Danish 17 ! Greek 2 Italian 17 Japanese 3 Norwegian 32 Portuguese 1 Spanish 3 Swedish 25 United States. 104 A summary of the work performed, the dissemination of the infor- mation, and other miscellaneous business handled by the patrol for 1927 follows: Washington official messages 424 Daily routine broadcasts 380 Special broadcasts (during fog) 8 Ice information to certain vessels, special 91 Special ice information requested 55 Position reports requested 6 Track information requested 2 Weather reports received 464 Water temperature reports received 5, 548 Ice reports received : Steamships 380 Cape Race radio station 107 Medical treatment by radio 3 Violation of steamship tracks reported 1 Radio compass bearings received 291 Words handled by radio 274, 407 As in previous years, the cooperation received from passing ships was generous and indicative of a sincere appreciation of the service which is being financially supported by international contribution. The commander of the ice patrol takes this opportunity to thank all those who assisted in making this past season's work so successful. TABLE OF ICE AND OTHER OBSTRUCTIONS— 1927 Date 26 No. Reported by- Cape Race (station). do do do do do ....do Oxonian Cape Race (station). Incemor e Cape Race (station). ....do.- ...-do ....do ....do.- .do. .do- do do do Stockholm Cape Race (station). do -do. -do- -do. .do- .do. -do. HelligOlav- -.. Cape Race (station). do HelligOlav. .do- Cape Race (station). do do do-.. do Vela - Cape Race (station) - do do do do do -do. -do- -do. -do. Position Lati- tude, north 47 02 48 02 48 04 47 43 47 42 Longi- tude, west 47 47 47 49 51 23 50 11 46 22 20 niiles East Bull Head 47 43 45 52 47 00 46 07 46 40 46 35 46 06 45 58 46 02 44 56 to 45 00 48 20 to 47 50 47 50 46 55 46 30 44 22 47 05 46 45 to 46 30 46 05 46 34 48 41 57 20 47 41 47 12 47 42 47 30 47 12 47 29 46 25 60 00 to 60 06 50 00 to 50 05 50 25 61 25 53 17 02 41 49 12 51 17 to 52 10 49 12 52 23 2 miles S. E. Renews Rock 47 31 to 47 14 46 55 47 48 to 47 36 47 23 5 miles East Cape Race 47 23 54 27 47 30 54 00 to 54 35 60 10 to 60 50 47 15 47 30 47 13 48 00 12 miles S. W. 47 00 47 00 48 30 46 36 46 47 47 35 47 05 47 58 to 46 50 46 30 46 20 46 30 (16) 46 56 45 22 46 00 I 45 30 to 1 45 40 44 52 to 44 46 46 25 46 50 46 12 48 10 Nature of ice or obstruction Berg. Do. Do. Small berg and growler. Growler. Berg. Small berg. Thick field ice. Large berg. Berg. Do. Small berg. Berg, same as 10. Do. Do. Patches of field ice. ■Field ice. Berg. Field ice. Berg and heavy slob ice. Large growlers. Small berg. •Slob ice in all directions. Small berg. Large berg, same as 20. Do. •Field ice and growlers. Field ice and small bergs. Berg. Field ice extending north and south Field ice. Field ice extending 10 miles north and south. Field ice, same as 31. 50 30 47 00 49 30 46 48 48 05 47 26 46 59 48 45 to 46 47 46 46 45 50 45 54 Heavy field ice, same as 16. Growlers and field ice. Drift ice. Small berg and northward field ice. Drift ice. Tall berg and light slob ice. 100 miles of field ice to the eastward. Large berg. Large berg and field ice. Do. Two small bergs and some growlers. Large berg. Do. kce field. Berg. Do. Dangerous growlers and small pieces. 17 Table of ice and other obstructions — 15^7^-Continued Date No. Mar. 20 20 20 22 22 22 22 22 22 22 22 22 22 23 24 24 24 25 27 27 23 27 28 28 28 29 29 29 29 29 29 30 30 30 30 30 30 31 31 31 31 31 31 Apr. 1 1 1 1 1 1 2 2 3 3 3 3 4 4 67 Reported by — Cape Race (station). do do— do do. do do... do do do do do do... do .do. .do- -do. .do. .do. .do. .do. .do. .do. do do Tyrifjord do do do do do Ice patrol (T). do do Scandia do Cairnvalonia. Estonia do do do do Cairnvalonia. Schenectady.. Chicago do Auronia Minnie Larrinage. Doric Phoebus Iroquois Cairnesk do Mount Royal. United States. Devon Bay State 108 I Gypsum King. Bergen sfjord Ice patrol (T) do... Cairnmona Cape Race (station). Gypsum King 115 Sachem. Position Lati- Longi- Nature of ice or obstruction tude, tude, north west 45 54 47 37 Large berg. 45 55 47 40 Do. 45 53 47 51 Growler. 45 31 47 13 Large berg. 45 34 47 03 Do. 45 35 46 39 Do. 46 47 43 19 Do. 45 51 45 41 Berg. 45 50 45 41 Large berg. 45 58 45 40 Do. 40 03 46 10 Growler. 45 52 46 53 Beri?. 45 58 47 02 1 Do. 40 47 44 31 Large berg. ( 46 23 47 59 \ to to [Field ice with large pieces. [46 15 47 53 45 47 43 48 Large berg. 45 14 46 25 Do. 45 18 45 42 Do. 44 56 45 49 1 berg; 2 growlers. 202° fro tu Cape Berg, same as 39. Ra ce 40 55 52 32 Derelict "Ann Belle Cameron " 44 00 49 00 Large berg, 2 growlers. f 46 23 47 47 1 \ to to J^Field ice, same as 65. I 46 44 47 21 ) 202° 1 : 1 miles.. Same as 70 and 39. 46 45 42 30 Berg. 44 40 48 10 Do 44 55 48 34 Small berg. 44 47 48 47 Growler. 44 50 48 48 Small berg. 44 45 48 50 Growler. 44 48 48 54 Do. 44 28 48 44 2 small bergs, same as 77. 44 21 48 26 2 small bergs, same as 79. 43 56 49 03 Growler, same as 72. 45 18 48 10 Large berg. 45 12 48 00 Do. 44 41 49 00 Medium berg. 46 35 47 30 Heavy field ice. 45 52 49 30 Medium berg. 45 45 49 23 Growler. 45 40 49 40 Large berg and growler. 45 40 49 47 Do. 45 30 46 35 Small berg. 44 18 48 50 1 berg and 1 growler. f 47 15 48 00 1 to to >Dense ice field. I 47 30 48 05 1 46 14 48 10 Large berg. 44 18 48 51 1 berg and 1 growler, same as 94. 39 33 48 59 Derelict Anna Belle Cameron, sam > .s 71. Growler. 46 05 49 32 42 05 50 28 Do. 40 09 52 51 Derelict about 30 feet long. 43 50 48 34 Berg. 43 36 48 50 Small berg. 41 02 46 20 Gas buoy. 42 53 49 11 Small berg. 43 08 49 08 Growler. 44 18 48 31 Berg. ( 47 29 48 00 1 to to >Heavy field ice, same as 6. I 46 22 47 10 J 43 36 48 52 Large growler, same as 102. 42 53 49 32 Berg, same as 105. 42 58 49 28 Growler, same as 100. 45 02 48 57 Large berg. 46 37 52 58 Large berg, drifting soutli. 44 41 48 38 Large berg. ( 47 30 52 35 1 \ to to >Field ice. I 46 14 51 15 1 18 Table of ice and other obstructions — 1927 — Continued Date Position No. Reported by- Apr. 6 116 (17 118 Sachem, America. do— 119 I Mexico. 120 121 do Canadian Victor. 122 i Sachem. 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 144a 145 146 147 148 149 150 151 1.52 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 do Independence Hall.. do America Mexico Baron Garioch Ice patrol (T) do Hellig Olav Balfour Cape Race (station) . Ala do .:.-.do - do Trolleholm. Ala do Trolleholm - Lord Antrim. Lord Devonshire. do Annavore Ice patrol Athenia Wolsum Athenia Lord Downshire.. Newfoundland Brandon.. Newfoundland... Sinasta Aurania -do. Yorck. _ Luossa Bengasi Brant County. Lucerna Cairnesk do Copemau Holly Park.-.. Regina Estonia Regina do Tampa S. S... Cape Race do-. Regina Cairnross.. Hjelmasen. 46 32 46 47 to 47 05 46 40 to 46 25 47 00 to 45 30 45 25 43 36 46 40 to 46 05 45 50 43 16 43 21 45 51 44 43 43 32 43 23 43 24 45 08 42 54 39 45 46 12 46 28 46 51 47 05 40 35 to 45 25 45 42 45 45 45 14 46 28 to 45 30 43 42 43 51 44 40 42 43 43 38 43 38 44 08 44 13 46 50 43 12 46 08 40 00 45 11 45 14 to 45 31 42 49 40 03 43 54 44 15 43 03 44 06 43 55 42 55 44 30 45 47 41 55 46 11 46 26 44 12 46 21 46 28 46 42 to 46 45 43 57 43 42 52 36 52 31 to 51 40 52 30 to 51 30 46 20 to 47 40 47 50 49 01 50 00 to 47 40 47 20 49 25 49 42 48 11 49 47 48 38 49 22 49 41 48 28 49 52 47 59 48 15 47 42 47 35 47 25 48 30 to 48 35 49 00 48 56 49 42 47 10 to 48 00 49 18 49 26 48 51 49 45 49 06 49 33 48 30 48 22 47 00 49 18 48 32 48 51 48 46 48 36 to 47 25 50 10 49 00 49 19 48 47 50 04 49 32 49 28 50 34 48 58 49 14 52 05 48 46 47 56 48 55 46 58 to 46 56 48 47 48 27 Nature of ice or obstruction Berg, same as 113. Heavy field ice, numerous bergs, and growlers. Heavy field ice. Field ice. 2 small bergs. Small berg. •Field ice to northward on Banks. Low berg. Berg, same as 121. Berg. Large berg. Large berg, same as 92. Large berg. Berg, same as 125. Berg, same as 124. 2 small growlers. Large berg. Derelict iVnua Belle Cameron. Light field ice. Ice field. Do. Do. Do. Large berg. Berg. Large berg. Field ice. 2 bergs. Growler. Large berg. Berg. Berg and growler, same as 144. 2 small bergs, same as 144. Large berg. 2 small bergs, same as 148. Field ice extending north and south. 2 growlers. Berg. Derelict .\nna Belle Cameron. Small berg. Open ice field. 1 growler. Derelict -\nna Belle Cameron. Berg and growlers. Berg. Growlers, same as 145. Berg. Do. 2 bergs, same as 145. Small growler. Berg. Heavy log. Berg. Small berg. Large berg. 2 growlers. Large berg. Field ice. Berg. Berg, same as 173. i 19 liable of ice and other obstructions — 1927 — Continued Date No. Apr. 16 175 16 176 16 177 16 178 16 179 16 180 16 181 16 , 1S2 184 185 IS 186 18 187 19 189 19 190 19 191 19 192 20 193 20 194 20 195 20 196 20 197 20 199 20 200 20 201 20 202 20 203 20 204 20 205 20 206 20 207 20 208 20 209 20 210 21 211 21 212 213 214 21 215 21 216 21 j 218 21 ' 219 21 220 21 221 21 1 222 I 21 223 21 224 21 225 21 . 226 21 ' 227 21 ' 228 22 I 229 22 230 22 231 23 ' 232 Reported by- Colonian- Metagama do ..-- Alchiha do — do -.- do Ice patrol (M). do Alphard Bayou Chico.. Ariano. .-. do do Ascania_ Montrose Delaware Montrose Samatario Bolingbroke.-- Sylvia Ravanger Ice patrol (M)- Montrose Motocarlin Alaunia Bolingbroke Ice i)atrol (M)-.- ....do Concordia Alaunia ....do.. Ascania City of Glasgow. .\scania City of Glasgow. Litiiania Bay State.- Montroval do.." do_... do.. do Montroyal... Fanad Head. do Lituania Parthenia. 23 234 23 235 23 236 23 237 23 238 23 239 do do.._ Fanad Head Burgerdijk Ice patrol (M). Marte Stavangerfjord. Marte Gorm Montreal Marte Nova Scotia... do _ do .....'do do.. Canadian Rancher. Position Lati- Longi- Nature of ice or obstruction tude, tude, north west ( 46 09 46 50 ) i to to V Field ice, same as 172. 1 46 59 47 17 1 43 42 48 27 Small berg, same as 173. 43 57 48 18 Large berg, same as 174. 46 28 47 14 Berg, same as 171. 45 52 48 55 Do. 45 49 48 59 Do. 46 21 46 58 2 growlers, same as 170. 43 52 48 09 Berg, same as 173. 43 36 48 23 Berg, same as 174. 44 30 47 58 Berg. 39 35 49 33 Derelict Anna Belle Cameron. 46 17 47 37 Small bergs. 46 22 ~ 47 46 Small bergs and growlers. 46 15 48 25 Large berg. 44 52 59 19 j] { to to meavy field ice (31 bergs to date) . 44 18 58 49 j] 47 13 47 15 1 Berg. 42 19 50 02 Heavy log, 30 feet long. 47 12 47 27 1 Field ice. 44 50 49 30 Berg. 46 38 47 39 Field ice, some heavy pieces. 44 25 60 00 Field ice, with many growlers. 46 44 47 40 Field ice and to the northward. 44 12 48 54 Berg. ( 47 12 47 27 \ to to I Field ice. 1 46 47 47 43 39 30 47 12 Derelict Cameron. 46 40 48 15 Berg. 46 16 48 26 Do. 44 42 49 13 Do. 44 50 49 30 Berg, same as 193. 43 30 49 31 Berg, same as 197. 46 28 48 37 Do. 46 22 48 53 Do. 46 10 48 14 Berg, same as 205. 46 49 47 10 Small berg. 46 07 48 21 Field ice. 46 36 47 40 Field ice (39 bergs) . 45 21 48 51 Small berg. 44 04 48 23 Berg. 46 40 48 10 Berg, same as 200. 46 32 47 58 Berg. 46 41 48 09 Do. 46 32 48 38 Berg, same as 205. 46 30 39 05 Berg. f 46 46 48 14 to to I Field ice. [ 46 38 47 45 46 10 47 51 Southern end of field ice. 46 12 48 12 Berg. 45 33 49 37 Small growlers. 46 00 47 50 1 to to ^Field ice, light and open. 45 50 48 10 1 45 55 47 50 Berg, same as 186. 46 00 48 20 Berg, same as 187. 46 58 47 33 Field ice, eastern edge. 40 36 50 58 Light buoy showing red flashes. 43 37 49 38 Berg, same as 197. 43 31 41 13 Large buoy superstructure. 44 21 49 08 Small growler. 44 38 47 38 ; Berg, same as 212. 46 40 48 30 Berg. 45 56 47 18 Do. 45 04 49 20 Berg, same as 211. 46 40 47 40 2 miles field ice, open and scattered. 46 40 47 40 Small berg and growlers. 46 50 49 00 Berg. 46 40 46 40 48 30 48 00 Berg, same as 231. Berg and growler. f 44 55 59 25 to I 44 29 to Isiob ice (from St. Lawrence). 59 05 il 20 Table of ice and other obdruclions — iS^r— Continued No. Reported by— 1 Position Nature of ice or obstruction Date Lati- tude, north Longi- tude, west Vpr. 23 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 ?6? Cape Race _. . 46 22 45 58 f 48 42 \ to [48 38 48 32 46 45 46 00 42 58 47 03 47 00 f 48 48 \ to 48 06 48 05 { to [ 47 50 42 58 45 38 42 33 46 08 46 33 44 55 47 27 46 59 46 38 45 46 f 48 40 \ to I 48 30 48 14 46 10 48 30 47 40 47 37 47 40 47 38 47 50 47 48 47 40 47 23 49 22 47 18 47 14 47 30 47 27 47 27 47 20 47 27 47 27 47 21 47 45 ( 48 00 \ to [49 00 47 40 46 57 41 56 f 48 56 \ to I 48 06 48 06 42 52 47 40 46 32 46 40 46 55 46 40 46 55 47 20 47 34 47 30 47 23 47 27 46 48 48 30 47 54 to 48 08 45 33 47 30 47 36 51 00 48 45 49 56 49 40 to 49 17 47 20 to 48 44 51 00 48 57 59 35 47 54 48 32 50 17 49 23 52 35 52 20 49 44 48 45 to 48 55 48 50 50 15 49 00 52 20 52 79 52 12 51 38 48 23 48 27 48 47 49 29 49 38 49 46 49 49 49 49 49 53 49 57 49 49 49 53 49 57 50 03 50 50 47 30 to 49 15 49 40 47 08 63 13 49 06 to 50 44 50 44 42 55 48 45 53 25 48 34 52 48 53 00 52 48 52 35 49 00 48 55 49 10 49 11 Berg. Berg and isolated patches field ice. ^Southern edge of an ice field Growler. Narrow ice field extending north south. Scattered field ice. Berg. 2 large bergs. Berg. Ice field. Field ice and several growlers. Berg, same as 246. Berg. Buoy, conical shape. Growler. Berg, several growlers. Berg and growlers. 2 and 2 small bergs. Large berg. Medium berg. Small berg. > Field ice. Edge of ice field. Growler. Heavy ice field. Berg and growlers. Do. Do. Do. Growler. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Growler, same as 277. Growler, same as 278. Growlers. 35 large bergs and numerous si ones. Field ice. Several large bergs, vicinity. Small berg and growler. Bell buoy. Heavy field ice. 14 bergs and growlers, same as 285. Wreckage, 20 feet long, 4 feet wide. Several growlers. 1 berg. 2 growlers. Large berg, same as 258. Several growlers in vicinity. 1 large berg, same as 258. Medium berg, aground. Berg. Do. Do. Do. 23 do.... 23 do . 23 do 23 do 23 Maidenhead . 25 Montclare... . 25 Salina 26 do. 26 Arna 26 do 26 Ice patrol 27 Southerland. 27 Sulina . 27 Seven Seas Trader 27 Albertic .. . 27 Clear poo] 27 Polan Hall 27 do 27 do 27 28 Ivar . . 29 do...;.... 29 ?m Letitia 29 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 Ivar _.. 30 Newfoundland 30 do 30 do . . 30 do 30 Manchester 30 do 30 do . 30 do.... 30 do 30 do 30 do . 30 do.... 30 do_. 30 do 30 do . 30 do 30 do_ 30 do . 30 Newfoundland m]\ May 1 Cape Race (station) 1 do 2 Suderoy 2 Samaria . 2 Caringowan 2 do... 3 Qallier 4 Panjalo 5 Minnendosa. . . 5 Regina 5 Cape Race (station) 5 do 5 Suderoy 5 do 5 ice patrol (T) 5 ...do. 5 ...do 5 ...do... 21 Table of ice and other obstructions — 1987 — Continued Date No. Position Reported by- 808 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 -do. 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 Huronian ^ Modavia Manchester Commerce- Ice patrol (T) Ikala. , Modavia Topsdalfjord. Albatros , Lituania , .do. Cairnglen. do do do do do Comino... do C adore - Oceanic Qracia Lord Downes Stockholm Cape Race (station). Schouwen... do do Ice patrol (M) Schouwen Dalworth Montcalm do do do... Moveria 344 I Nova Scotia. 345 I Canadian Commander. 346 I Cape Race (station) Estonia. do... do... do... do... do... do... do... do... do... Caronia. Cape Race (station). .do. .do. .do. 47 33 47 36 47 35 47 36 47 36 47 26 48 00 to 47 34 46 28 46 39 46 12 47 50 to 47 30 46 10 46 05 47 18 46 14 47 00 46 48 to 47 12 47 23 47 20 47 21 47 20 47 09 47 11 46 45 46 35 48 00 to 47 36 47 15 46 10 ii, 52 42 37 48 27 47 15 47 19 47 10 46 08 46 53 47 10 to 47 10 46 35 46 55 46 49 46 53 46 08 48 30 to 48 00 45 50 47 37 to 47 20 47 13 46 11 48 10 48 15 47 10 47 05 46 58 46 58 47 06 46 58 43 32 47 02 to 47 07 47 24 47 27 47 22 49 42 49 40 50 09 50 26 50 34 49 52 49 46 to 50 23 48 43 47 40 48 35 50 30 to 51 00 49 09 48 48 50 35 48 39 49 05 48 47 to 48 20 49 45 49 48 49 54 50 26 50 30 50 33 47 30 48 00 48 40 to 49 21 48 40 48 41 48 00 63 31 49 10 48 50 48 40 49 29 48 42 50 30 49 50 to 51 00 49 40 48 55 48 55 48 45 48 42 49 30 to 51 25 48 31 50 57 to 50 45 48 38 49 02 49 15 48 14 49 19 49 31 49 54 50 13 49 22 50 13 43 00 51 00 to 50 40 48 32 49 12 49 37 Nature of ice or obstruction Berg. Do. Do. Do. Do. Do. Field ice. Large berg. Large growler. Large berg. About 100 icebergs. Berg. Large berg. Several large and small bergs. Berg and growler. Large berg. Numerous growlers. Berg and growlers, same as 312. Berg. 2 bergs, same as 312. 1 berg, same as 312. Berg, same as 312. Detached ice, same as 312. 5 growlers. Berg. f Several hundred growlers. Several bergs. Berg. Large growler. Large black buoy. Numerous bergs and growlers . 1 growler. 3 growlers. 1 growler. Berg, same as 329. Berg. 15 bergs. Berg. Do. Growlers. Growler. Berg and growler, same as 336. [■50 bergs; 100 growlers. ' Berg, same as 336. ! I Numerous bergs and field ice, same as J 312. Growler. Do. Do. Berg. 1 Do. ! Do. 1 Do. Do. Growler. Do. Gas buoy "A-6." 16 bergs, same as 338. Berg. Do. 2 growlers. 22 Table of ice and other obstructions — 19S7 — Continued No. Reported by- Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction May 8 12 12 13 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 Cape Race (station). Lapland Missouri Cape Race (station) .. 39 30 46 24 46 11 45 27 41 09 46 28 46 11 45 54 46 56 46 49 46 46 46 08 47 20 47 19 46 15 45 20 43 41 45 54 46 42 46 38 46 28 41 57 47 41 46 18 46 41 46 45 46 40 46 54 46 40 46 45 47 15 47 30 47 52 45 55 48 30 47 21 46 40 47 00 46 47 46 56 46 52 47 13 47 11 47 48 47 51 47 46 47 55 47 55 48 06 50 24 42 15 47 35 40 38 47 42 46 37 47 18 47 31 47 41 47 39 47 38 48 36 47 29 47 28 47 23 47 33 47 20 47 21 47 18 48 05 47 51 46 42 47 38 47 40 47 33 47 34 47 34 39 03 47 59 47 30 56 17 53 26 47 39 47 30 47 50 48 10 49 14 49 51 47 57 47 20 52 24 48 56 44 50 42 06 47 50 49 56 50 14 63 12 49 53 51 18 53 12 52 54 50 16 52 51 52 49 52 38 53 00 51 48 51 25 50 40 55 30 49 20 49 02 50 09 49 47 49 33 49 40 49 11 48 33 48 19 50 51 51 00 50 43 50 41 50 26 50 22 50 12 45 14 50 00 45 44 44 39 53 14 50 32 50 36 50 36 50 43 50 48 51 02 50 57 50 52 50 49 50 43 50 44 49 44 49 36 49 00 48 37 48 06 50 42 50 45 50 32 59 33 50 26 Derelict Anna Belle Cameron. Growler. Do. Red buoy "F4." 13 13 13 14 13 """doll""-!""""""""- Oakworth Cape Race (station). Black gas buoy. Growler. Growler, same as 364. Growler. Do. 13 13 13 13 13 14 14 do Landaas Lord Kelvin 3 growlers. Berg. Growler. Do. 2 growlers. Berg and growler. Berg. 14 Cape Race (station) Can buoy. 14 14 14 -I"do"-""""--"""-I"II do Growler, same as 369. Berg. Do. 15 do Do. 15 Liberty. .. . . - . . Growler. 15 Berg. 15 do Do. 15 Andania Do. 16 Canadian Planter Do. 16 Andania Do. 16 16 16 16 16 16 16 do do Gorm do do do Cape Race (station) Do. Do. Do. Growlers and berg. Berg. 2 bergs, growlers. Tree. 16 . do Berg. 16 Growler. 17 Cape Race (station) - Berg. 17 399 do - Do. 17 400 401 402 403 404 405 408 407 408 409 410 411 412 413 414 415 416 do Do. 17 do Berg and growler. 17 do Growlers. 17 do Do. 17 do Do. 17 do Berg. 17 do Do. 17 do Do. 17 do Do. 17 17 do V . .... Do. Do. 17 do . - Do. 17 Lehigh Log. 17 Melita Berg. 19 Baron Sempill .. Spar. 19 Svir -- Berg. 18 Cape Race (station) Do. 18 1 417 do - - . Do. 19 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 do Do. 19 Melita Growler. 19 do - Berg. 19 do Do. 19 - -do Do. 21 21 Calgaric do Do. 3 bergs. 21 -do Berg. 21 do Do. 21 do Do. 21 Do. 21 . .do Do. 21 do 3 bergs, same as 9th. 21 do Berg. 21 Berg and growlers. 21 Calgaric - 22 bergs, same as 312. 21 - do 3 bergs, same as 312. 21 do. Berg, same as 312. 21 do Do. 21 do.- _ Do. 23 Table of ice and other ohslrxictions — 1927 — Continued No. ] Reported by— Position Nature of ice or obstruction Date Lati- tude, north Longi- tude, west Mav 21 438 439 47 42 47 37 47 43 47 35 47 39 47 49 47 50 47 51 47 54 48 00 46 40 48 31 48 20 48 25 48 22 48 15 48 18 48 13 48 26 48 10 48 12 46 40 47 33 47 20 47 32 47 26 47 24 47 12 48 26 f 48 12 { to \ 47 50 47 30 \ to I 47 30 47 35 47 40 47 25 46 42 46 37 46 52 46 21 46 43 46 05 46 19 43 46 46 39 f 48 11 \ to I 47 21 46 21 47 20 47 16 47 19 f 47 14 to 1 47 15 47 17 47 20 47 29 47 23 47 31 47 44 47 47 47 48 47 53 47 50 47 49 48 02 47 47 47 50 47 49 47 38 47 46 47 10 47 13 50 32 Berg, same as 312. 50 24 i Do. 50 27 Three growlers, same as 312. 60 19 ' Berg, same as 312. 50 08 1 Do. 49 52 Do. 49 49 Do. 49 29 Do. 49 37 Do. 49 32 Berg and growlers. 46 50 1 2 bertis. 21 do 21 i 440 do 21 1 441 do 21 442 do 21 443 444 446 do . . . 21 .do 21 . do 21 21 21 446 447 ii9, do do._ _.. -. .- Frode . 21 449 49 19 49 22 49 27 49 33 49 42 49 42 49 48 49 34 49 54 49 58 46 59 48 15 49 18 49 40 49 16 49 50 50 10 49 07 47 40 to 50 40 50 40 to 50 60 52 38 49 41 50 45 52 47 53 10 62 31 46 47 47 39 48 00 47 56 49 43 53 03 46 40 to 52 30 46 47 60 19 50 09 49 46 49 43 to 49 39 49 33 49 21 48 58 48 57 48 25 48 35 48 08 48 10 47 55 47 42 47 35 47 25 48 03 49 15 49 20 49 23 49 25 50 20 50 20 Growler. Berg and 4 growlers. Berg. Do. Do. Do. Do. 2 bergs. Berg and growlers. Do. 2 bergs. Berg and growler. Bergs. Do. 2 bergs. Berg and growlers. Huge berg and growlers. Berg. [25 bergs and 75 growlers. [•14 large bergs. 2 bergs. Berg. 25 bergs, many growlers, same as 4 Berg. Do. Do. Do. Berg and growlers. Growler. Berg and growler, same as 432. Whale belly up. Berg. [44 bergs, several growlers, same as Berg, same as 475. Berg. Growler. Berg. Several pieces of ice. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Berg and 3 growlers. Berg. Do. Berg, same as 467. Do. Do. Do. Berg. Do. 21 450 ... do .. 21 451 do 21 452 453 454 455 456 457 458 4.59 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 do .. 21 21 21 21 21 21 21 21 21 21 '!.'ido.-^ -.];.. ------I------ do. do "^-^!do""'^"!!-^-"!-""-l^-- 21 do ... 21 21 21 do do .... do 21 .... do 22 do 22 ....do 22 do 22 22 Hada Cape Race (station) 67. 22 23 do 23 23 Skipsea 23 Ice patrol (M) . . 23 47S .... do - 23 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 23 Cape race (station) . 23 do 467. 23 do 23 23 Asconia .. do 23 23 do do 23 do. 23 do 23 do ... 23 do _ 23 do - . 23 23 do. do... 23 23 do.. 24 do 24 do_ 24 24 do Beemsterdyk.. 24 Montroyal 24 do.. 24 do. 24 do . 24 Beemsterdyk 24 do 24 'I'able of ice and other obstructions — 1927 — Continued No. Reported by— Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction May 24 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 629 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 Megantic. 47 25 47 19 47 24 47 36 47 33 47 37 47 35 47 42 47 30 47 45 47 37 46 34 to 48 19 47 46 47 32 47 42 47 35 47 40 47 29 47 37 47 17 47 36 47 24 47 19 f 47 25 { to I 48 07 46 49 47 16 46 49 47 20 f 47 20 ■ to 47 45 47 45 { to I 48 12 47 29 47 35 47 32 47 36 47 17 47 22 f 47 16 \ to [ 47 31 46 37 46 47 f 47 30 \ to I 46 40 47 16 47 09 47 25 47 23 47 18 47 08 47 09 46 41 47 14 47 06 47 09 46 39 47 46 47 46 4n 33 47 17 47 22 4fi 31 46 43 46 46 f 47 03 \ to [ 47 18 46 46 50 41 50 27 50 28 50 26 50 16 50 18 50 12 50 15 49 57 50 09 49 51 53 09 to 50 08 52 41 52 30 49 26 49 32 49 32 49 50 50 00 50 00 50 03 50 24 50 24 50 41 to 48 32 52 36 49 04 52 33 50 40 50 30 to 49 25 49 25 to 48 37 48 00 47 37 47 34 47 31 52^ 35 52 29 50 25 to 49 37 52 36 52 33 52 40 to 53 00 47 20 49 44 48 46 48 54 49 04 49 27 49 59 52 58 50 14 49 48 49 34 49 51 52 41 49 09 52 40 52 35 52 29 52 42 52 41 51 15 50 34 to 49 46 47 12 Berg, same as 467. 24 do Do. 24 ._.-do.. Do. 24 do_..- Do. 24 do Do. 24 do Do. 24 do Do. 24 do Do. 24 do Do. 24 -do . Do. 24 do Do. 24 Cairngowan.. 1 Numerous bergs; growlers and small 24 Watuka - . - Berg. 24 do... Do. 24 Montroyal.- .. . Growler, same as 481. 24 do . Berg and pieces of ice, same as 481 24 do Berg, same as 481. 24 24 do do Growler, same as 481. 2 bergs, same as 481. 24 do Berg, same as 481. 24 do Do. 24 do ... Do. 24 24 do Megantic- - Do. [■31 bergs and growlers, same as 467 . 24 Beemsterdyk Berg. 24 Ice patrol (M) ... Do. 24 Montroyal. Do. 24 Modavea . 2 large bergs. 24 do. [22 bergs, same as 529 24 -do >12 bergs, same as 529. 25 Caledonia Large berg. 25 do Do. 25 -do. - Small berg. 25 do- Large berg. 25 Pajala Berg. 25 do Do. 25 Rindijk [Several large bergs, same as 534. 25 Montroyal- Berg. 25 do . Berg, same as 632. 25 Pajala.. [several growlers. 25 Brecon. - Berg. 25 Albertic-. Do. 25 . -do . Do. 25 ...-do-.- ... -- . Do. 25 do Berg and growler. 25 -do . Berg. 25 do .. -. . . Do. 2o Canadian Leader. 2 growlers. 25 Berwyn Berg. 25 do .- Do. 25 do Berg, same as 551. 25 Norefjord--- Berg. 25 Cape Race (station). Do. 25 do Berg and numerous growlers 25 do --- Berg. 25 do Do. 25 .do Do. 26 Canadian Leader. . - . Berg, same as 560. 26 do 2 bergs. 2C do . Berg. 26 do - 1 Numerous bergs and growlers, same 26 Golden Gate 1 as 34. Large berg. 25 Table of ice and other obstructions — 1927 — Continued No. Reported by- Position Nature of ice or obstruction Date Lati- tude, north Longi- tude, west May 26 26 568 569 570 571 572 572a 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 014 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 46 25 46 37 46 45 47 00 46 21 46 24 46 43 46 40 f 47 24 { to [ 47 02 48 25 46 50 46 54 46 45 46 27 46 40 46 05 47 33 45 42 46 04 47 09 47 03 47 -01 46 55 46 47 37 04 47 07 46 52 46 44 46 04 48 00 47 00 46 28 46 28 46 46 47 40 47 14 f 46 50 to 47 39 ( 46 53 { to 1 47 07 45 39 47 OS 46 54 46 48 46 35 46 55 45 33 46 52 46 01 46 02 46 54 47 00 47 03 47 12 47 08 47 13 47 19 46 28 46 05 46 39 47 40 47 28 47 28 47 18 47 21 47 IS 47 14 47 12 47 00 47 40 46 43 47 02 48 13 48 48 48 44 48 54 49 48 49 43 47 26 46 56 50 07 to 51 27 51 29 47 28 47 28 47 35 48 43 48 30 49 26 50 53 52 31 52 27 51 42 51 40 51 58 52 00 52 09 47 49 47 49 48 10 48 23 52 27 50 52 52 30 46 38 46 38 51 00 51 00 49 31 50 48 to 49 00 50 52 to 49 55 48 28 50 16 50 38 50 38 50 31 50 31 47 54 47 50 48 28 47 12 51 44 51 27 51 17 51 08 51 05 51 02 50 59 46 31 47 00 52 44 50 48 49 55 51 03 51 25 51 45 51 42 51 44 49 03 51 30 51 00 52 40 47 12 Berg. Do. Do. Do. Berg, same as 569. Berg, same as 570. Berg, same as 491 . Berg, same as 567. [53 bergs and numerous growlers. ^%o. Growler. Berg. Do. 3 bergs and 4 growlers. Berg. Do. Growler. Berg. Do. Berg and growler. Scattered pieces of ice. Berg. Do. Do. Growler. Do. Do. Berg, same as 585. Berg. Berg and growlers. Berg. Berg, same as 598. Berg. Berg and growlers. Berg. [•12 bergs, 10 growlers. I20 bergs on both sides, ("ape 1 track, same as 575. Berg. 5 bergs. Berg. Do. Do. Do. Do. Berg and 3 growlers. 2 growlers. Berg. Bergs. Growler, same as 575. Berg, same as 575. Bergs. Do. Do. 2 bergs and growlers. Berg and several growlers. Berg. Do. Berg and 2 growlers. ^%o. Do. Do. Do. Berg and several growlers. Berg. 3 bergs and several growlers. Berg and several growlers. 2 bergs. Berg. do 2f) do 26 do 26 Lord Downshire 26 do 26 26 Knggano - 26 Alaunia 26 26 Pennland 26 do ... 26 do :. 26 26 do Lord Downshire ....... 27 Penuland 27 Letitia. '>7 Concordia.. . . 27 Breedyk 27 Letitia ... 27 do . 27 07 do'"-" '."."- 27 .do 27 Moveria 27 do ... 27 27 27 Cape Race (station). . 27 . . do... 28 do . .. 28 28 do Breedyk 29 Brandon . 29 Blackheath. . ... 29 Blairholm. . . 29 Melita... 29 Yildum Race 29 Shouwen ........ 29 Blairholm 29 ..do 29 do 29 do 29 do... 29 Shouwen 30 Blair Logie 30 Greldon .. 30 Emily Caron 30 Montrose 30 do 30 do 30 do.. 30 do... . 30 do 30 do... 30 t Emily Caron.. . 30 ' Bellatrix 30 Hartbridge 30 Simmonburn 30 do 30 do.... . 30 do.... 30 t do 30 do 30 do-... . 30 30 do 30 do 30 do 30 do 26 Table of ice and other obstructions — 1927 — Continued Date No. May 30 637 30 638 30 639 30 640 30 641 30 642 30 643 30 644 30 645 30 646 30 647 30 648 30 649 30 650 31 651 31 652 31 653 31 654 31 655 31 656 31 657 31 658 31 659 31 660 31 661 31 662 31 663 31 664 31 665 31 666 31 667 31 668 June 1 669 1 670 1 671 2 672 2 673 2 674 2 675 2 676 2 677 2 678 2 679 2 680 2 681 2 682 2 683 2 684 2 685 3 686 3 687 3 688 3 689 3 690 3 691 3 692 3 693 3 694 Reported by- Cape Race (station). do_ do do do do_ do do Dubhe Montrose do.. do_ do Qreldon Stal Ice patrol (T) Nikola Mibanovic... Grene. Lumen. Winterswyk. Doric do Anglo Australia. do .do. Cape Race (station) . do _do- do.. do.. do.. do.. Poljana . Minnedosa. _do. Cape Race (station) . do do do Suderoey Andania Regina. Andania. .do. .do- Cape Race (station) . do do do Lituania... do do do London Commerce.. Cape Race (station) . do _ do _ do Position Lati- tude, north 46 39 47 40 47 28 47 28 47 18 47 21 47 18 47 14 47 30 47 18 47 18 47 38 47 46 46 01 45 00 45 28 45 20 47 50 to 47 50 44 63 46 05 47 47 to 47 21 47 30 to 47 03 47 39 47 46 to 47 24 47 50 41 04 41 44 47 47 to 47 11 46 10 46 25 46 11 48 04 45 13 47 49 to 47 13 46 41 47 06 47 03 46 41 46 40 48 05 47 42 47 26 to 47 16 47 48 to 47 13 47 16 to 47 05 46 02 47 21 47 22 46 39 47 35 47 46 47 44 47 38 47 17 42 48 47 23 47 16 47 11 47 04 Longi- tude, west 52 44 50 48 49 55 51 03 51 25 51 45 51 42 51 44 48 50 50 38 50 17 50 11 49 50 48 25 45 40 48 24 48 49 52 50 to 50 21 45 58 52 51 49 32 to 50 06 50 05 to 51 07 52 53 50 50 to 51 06 51 00 49 03 52 43 50 18 to 51 44 52 18 52 14 52 14 48 U 46 18 49 34 to 51 15 52 47 50 19 50 19 52 47 53 00 52 18 50 32 50 55 to 51 55 50 42 to 51 14 51 54 to 52 06 50 13 49 55 50 03 52 51 48 50 50 27 50 46 50 49 51 35 43 59 49 20 51 54 51 58 52 06 Nature of ice or obstruction Berg, same as 624. Berg and 2 growlers, same as 625. Berg, same as 626. Berg, same as 627. Berg, same as 628. Berg, same as 629. Berg, same as 630. Berg and several growlers, same as 631. Berg. 17 bergs. 2 growlers. Berg. 3 bergs. Berg. Do. Berg, same as 611. Berg, same as 605. Several bergs and growlers. Berg, same as 651. Berg. 6 bergs, 4 growlers. 30 bergs, many growlers Berg. Several bergs. Do. Derelict "Annabelle Cameron.'' Wreckage. Several bergs and growlers. Berg. Do. Do. Do. Do. 25 bergs and six growlers. Berg. Do. Do. Do. Berg and several^growlers. Berg. 6 bergs, several growlers. 7 bergs, several growlers. 23 bergs; several growlers; same as 65- 3 bergs. Do. Growler. 1 berg, 1 growler. Berg. Do. Do. Do. Growlers. Berg. Black buoy. Growlers. Berg; same as 680. Do. Do. 27 Table of ice and other obstructions — 1927 — Continued Date June 3 3 No. Reported by- Position Lati- tude, north Longi- tude, west Nature of ice or obstruction 697 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 Cape Race (station). do .do. Damholm Metagama.. do do do do do... do do do do do do do do Montroval do do do.. Metagama.- do ...:.do do Cape Race (station) . do do.-._ do.. - do do do_. do.... do do do do Ice patrol (T) Valcirusa do Ellerdale do Innerton do do _. do do Kentucky do do Tampa do do.. Ice patrol (T) do do do... do do do do do do do do do do do.... do do... do do do.. 46 37 47 00 47 50 to 46 50 46 22 47 56 47 38 47 39 47 32 47 33 47 34 47 44 47 23 46 50 46 37 46 52 47 16 47 29 47 08 47 13 47 04 46 43 46 40 46 39 46 22 46 49 44 51 46 47 46 35 48 06 48 28 47 33 47 59 48 02 48 05 48 15 47 23 47 30 47 27 46 30 46 24 46 28 45 42 45 48 45 57 46 58 47 00 46 49 46 53 46 55 46 51 46 55 46 56 46 59 46 58 47 18 47 19 47 19 47 19 47 27 52 41 47 49 49 30 to 52 55 46 26 50 09 50 10 50 19 50 14 50 15 50 15 50 34 50 36 50 37 50 47 50 56 50 57 50 58 51 17 51 44 51 31 52 34 50 11 51 11 51 35 51 37 51 42 48 56 49 51 49 50 60 03 50 08 50 25 50 32 52 10 52 27 52 40 52 30 52 32 49 00 52 32 52 21 50 35 49 56 51 12 50 18 50 12 50 06 49 39 51 26 51 35 51 13 47 27 47 38 47 42 47' 50 49 36 49 20 49 29 49 48 49 49 49 56 50 01 50 02 50 08 50 10 50 12 50 20 49 25 49 30 49 50 49 51 49 55 Berg. Do. 6 bergs, several growlers. Large berg. 1 medium berg. 1 growler. Do. 1 medium berg. 2 medium bergs. Do. 1 medium berg. 2 medium bergs. 1 medium berg. 2 medium bergs. 1 medium berg. 1 small berg. 1 large berg. 1 table berg. Berg. Do. Do. Do. Do. Berg and 2 growlers. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Small berg, same as 652. Berg. Do. Do. Do. Patch of field ice Berg. Do. 2 growlers. Large berg. Berg. Do. Growler. Do. Berg. Growler. Bere. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. 28 Table of ice and other obstructions — 1927 — Continued Date No. Reported by- Position Lati- tude, north Longi- tude, west Nature of ice or obstruction June 6 6 6 6 6 6 6 6 6 6 6 6 6 6 0 6 6 6 6 6 6 6 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 Ice patrol (T)_ ....do ....do ....do -_..do ....do -...do ...-do--.. -..do ....do ...-do ....do ....do Albertic Alaunia ....do 785 I Letitia 786 I do 787 North Anglia.. 788 I Ice patrol (T) . 789 i Alaunia 790 I do- 791 do... 792 do 793 794 795 796 797 798 -do. North Anglia. Letitia do do do 799 Balsam. 800 I do--. 801 ! Alaunia - 802 Letitia. 803 North .\nglia 804 I Cape Race (station) . 805 Calgaric 806 ' do 807 1 Veendam 808 I Calgaric 809 ; do 810 , do 811 i Veendam 812 ' do 813 ! do 814 do 815 i Calgaric 816 Veendam 817 ! Cape Race (station'). 818 do. 819 do 820 do--.. ---. 821 do 822 j Ice patrol (T) 823 do 824 : do.... 825 Cape Race (station) . 826 j Moveria 827 do 828 I do 829 ' do 830 ! Marburn. 831 -do- -do- 47 15 47 08 47 09 47 10 47 11 47 10 47 09 47 15 47 16 47 17 47 18 47 06 I 47 07 46 32 46 34 46 50 46 33 46 47 46 32 46 35 47 10 46 57 48 13 to 47 20 47 13 47 13 47 19 47 19 47 25 47 48 to 47 07 46 47 47 20 to 47 39 47 23 to 47 54 47 08 to 47 25 47 14 48 17 47 54 47 28 47 33 47 15 47 30 47 28 47 27 47 14 47 17 47 07 47 02 47 04 47 32 47 46 46 05 48 20 47 28 47 07 46 50 46 42 47 50 47 41 47 31 47 07 47 41 47 28 [47 23 \ to 47 17 50 00 50 05 50 05 50 08 50 10 50 14 50 18 50 14 50 14 50 09 50 06 49 49 49 53 52 15 52 18 52 24 52 12 52 18 52 18 52 20 51 05 50 56 50 50 50 28 50 16 to 49 56 51 07 51 00 50 44 50 42 50 43 50 12 to 52 06 52 50 49 56 to 48 30 50 34 to 49 16 51 11 to 49 46 58 22 49 07 50 10 49 23 50 55 51 12 51 12 49 19 49 21 50 09 50 28 52 11 51 37 52 16 51 25 50 44 50 30 50 10 52 23 51 55 52 55 52 28 50 04 50 18 50 52 51 35 48 16 48 34 48 55 to 49 20 Berg. Do. Do. Do. Do. Do. Do. Do, Do. Do. Do. Growler. Do. Berg. Berg, same as 782. Berg. Do. Do. Berg, same as 785. Berg. Do. Do. Do. Do. 15 bergs, numerous growlers. Berg. Do. Do. Do. Do. kl bergs, 4 growlers. Berg. \\Q bergs, numerous growlers. U9 bergs, numerous growlers. [Several bergs, many growlers. Black can buoy. Berg. Do. Berg and growler. Berg and 2 growlers. Berg. Do. 2 growlers. Berg, same as 807. Berg and 7 growlers, same as 809 Berg. Growler. Berg. Do. Berg, 5 growlers. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. 7 bergs, 4 growlers. 29 Table of ice and other obstructions — 1927 — Continued Date No. Reported by- Position Lati- tude, north Longi- tude, west Nature of ice or obstruction June 8 8 S 8 8 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 869 870 871 872 873 874 875 881 882 883 seo 891 892 893 894 895 899 Westpool. Sulinac California - - . Kumara -. California Siberian Prince. Cairnross do.... do do.... do do. Kia Ora do do do Kumara Cape Race (station). do.. do do do do : do do do... Kia Ora Antonia Arabic do do do do Megantic do do Montclare do do Arabic.- do do do do do do Megantic Leicester do Ice patrol do do do.. do... do... do do do do do Megantic. do.... do.... do.... do.... Arabic Cape Race (station) . 901 902 903 43 54 45 55 45 29 48 09 45 44 47 30 47 40 48 05 47 30 48 05 48 10 48 20 47 03 47 06 47 05 47 20 47 37 48 24 48 01 47 54 47 50 47 46 47 37 47 35 47 17 46 48 47 27 47 52 47 28 .do. .do. .do. 72092—27- 47 23 47 42 ■47 46 47 26 48 06 47 59 47 51 •47 54 47 43 47 45 47 40 47 41 47 50 47 56 48 07 47 55 47 49 47 23 47 23 47 24 47 23 47 24 47 25 47 26 47 21 47 15 47 14 47 20 48 10 48 01 47 55 47 54 47 56 46 52 47 35 to 47 32 47 20 to 47 13 47 52 47 47 47 31 48 22 46 21 48 30 51 10 47 32 48 25 51 11 50 20 51 11 50 10 50 10 50 00 49 48 49 43 49 20 48 30 52 00 48 45 49 34 49 47 49 54 50 19 50 25 50 33 51 23 51 50 47 50 47 57 49 58 50 01 50 03 50 05 50 12 50 22 50 56 51 23 49 44 49 59 50 15 47 56 49 17 49 09 48 46 48 30 48 56 48 57 49 41 47 55 48 20 50 01 49 55 49 54 49 52 49 50 49 49 49 42 49 41 49 41 49 24 49 11 49 54 49 55 49 49 49 48 50 14 51 58 49 12 to 49 17 49 48 to 50 10 47 58 52 03 49 20 Growler. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. 2 bergs. Berg. Berg and several growlers. Berg. Do. 3 bergs, 2 growlers. Berg. Do. Do. 2 growlers. Growler. Berg. Do. Do. 6 bergs within area of 10 miles. Berg. Do. Do. Do. Do. Do. Growler. Berg. Do. Growler. 1 berg, 1 growler. 8 bergs. Berg, several small pieces. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. K Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Berg; 2 growlers. ^6 bergs, numerous growlers. 5 bergs and growlers. Berg. Berg and growler. Berg. 30 Table of ice and other obstructions — 1927 — Continued No. Reported by- Position Date Lati- tude, north Longi- tude, west Nature of ice or obstruction 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 Cape Race (station) 47 31 48 02 47 10 47 16 47 11 47 14 47 29 47 16 47 18 47 35 47 16 47 16 47 20 46 51 47 24 47 56 47 47 47 38 47 30 47 39 47 39 47 38 47 13 47 14 47 16 47 16 47 12 46 49 47 04 47 17 47 14 47 19 47 57 47 47 39 56 46 49 46 57 47 13 47 17 47 14 47 19 47 47 47 57 f 48 00 \ to I 47 32 48 09 47 57 47 47 47 47 47 02 47 10 48 02 47 59 47 52 47 43 47 32 46 43 46 48 46 52 47 29 47 31 47 44 46 50 47 00 46 34 f 47 46 { to I 48 01 47 37 47 31 47 36 47 43 47 56 47 08 47 42 49 35 51 21 49 20 49 17 49 08 49 06 49 18 49 05 49 02 48 56 48 51 48 48 48 46 52 02 50 25 49 00 49 18 48 53 48 32 48 23 48 05 47 50 49 08 49 06 49 11 49 17 49 22 51 55 49 46 49 37 49 22 49 05 49 49 49 40 61 38 51 55 50 06 49 46 49 37 49 22 49 04 49 40 49 49 49 12 to 50 17 50 05 50 35 50 50 50 55 47 27 47 34 49 17 49 43 49 42 50 20 50 20 52 06 52 05 52 00 50 24 50 20 50 20 52 03 52 50 47 23 50 02 to 49 25 50 15 50 00 49 33 50 16 50 00 47 12 49 33 Berg. Do 9 do 10 Ice patrol (M) -- Do. 10 10 do do Do. Do. 10 do Do. 10 do Do. 10 do Growler. 10 do Do. 10 ...do . Berg. 10 ... do Do. 10 do Do. 10 do Do. 10 Canadian Planter Berg and growlers. 10 10 do Huronian .. . Large berg. Berg. 10 do -- Berg and growler. 10 Ice patrol (M) Berg. 10 do Do. 10 do Do. 10 . .do ... Do. 10 10 ""I.do". "'.""""""""" Do. Do. 10 - -do . Do. 10 do . Do. 10 10 11 do do... Empress of France . Do. Do. Do. 11 do Do. 11 do Do. 11 do Do. 11 11 do, Melmore Head . Do. Do. 11 11 do Cape Race (station) Do. Mast 60 feet long* 11 do Berg. 11 do.... Do. 11 do - Do. 11 do Do. 11 do Do. 11 do Do. 11 do Do. 11 do Do. 11 Gracia [several bergs and several growlers. 11 Berg. 11 do Do. 11 do Do. 11 .do Do. 11 Ice patrol (M) Do. 11 do Do. 11 1 954 11 ! 955 Canadian Commander _ .do Do. Do. 11 ] 956 do Do. 11 ! 957 .do . Do. 11 1 958 12 959 do Metagama Do. Do. 12 : 960 .do - Growler. 12 i 961 Canadian Explorer . Berg, same as 906. 13 962 Metagama. . Berg. 13 '• 963 Minnedosa Do. 13 { 964 ...do 2 growlers. 13 1 965 Andania . Berg. 13 936 967 968 .do Do. 13 Svir Berg and several growlers. 13 >S bergs. 13 j 969 Berg. 13 970 do Do. 13 ' 971 Do. 13 ' 972 .do Do. 13 973 do Do. 13 i 974 Robilante .. Do. 13 ! 975 Andania Do. 31 Table of ice and other obstructions — 1927 — Continued Date June 13 13 13 13 13 13 13 14 14 15 15 15 15 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 16 16 16 16 17 17 17 17 17 17 17 17 17 18 18 No. 976 977 978 ; 979 9S0 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 Reported by— 18 1019 18 1020 18 1021 18 1022 18 1023 1024 1025 1026 1027 102.S 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 Andania do. do. do _. do.. do Cape Race (station). do do Hilversum Blairdam do.. do- do do do... Hilversum Montrose. do do do. Melita...- do.... Ascania _ Ice patrol Transylvania ...do ...-do ....do-- Ascania Stavangerfjord ("ape Race (station) . Drottningholm ...-do ...-do Cape Race (station) . Pajala .\riano ....do Bosworth ....do Orca ....do.... Montnairn. Position Lati- tude, north Ice patrol (M). do Delaware Holtby. Cape Race (station) . do do Ice patrol do.-- do Vestalia Calgaric-. Holtby.. Pajala do Vestalia Cape Race (station). ...do.... West Harcuvar Cape Race (station). ....do ....do ....do Ala do... Strinda.. Antonia. do... 47 44 47 47 48 00 47 55 47 45 47 57 47 40 46 49 47 00 47 10 47 23 47 33 47 38 47 36 47 41 47 33 47 35 47 04 47 05 46 48 46 54 47 27 46 43 47 16 45 20 46 51 46 50 46 58 46 53 46 36 46 56 46 46 45 47 45 45 45 38 46 15 48 31 46 00 45 49 46 40 46 37 46 34 46 33 46 35 to 47 19 45 47 45 54 46 00 45 57 to 46 00 48 31 46 51 46 32 45 48 45 53 45 48 46 32 47 26 46 23 48 07 47 14 45 46 48 12 46 39 42 16 46 37 46 25 46 34 46 40 47 25 47 40 47 39 46 34 47 07 Longi- tude, west 49 35 49 32 49 39 49 34 49 12 49 13 48 43 51 58 52 00 46 50 49 59 49 48 48 58 49 00 49 00 48 35 48 16 51 09 52 08 51 55 52 48 50 55 52 25 50 27 43 30 52 36 52 53 52 23 52 41 52 14 47 12 52" 27 46 28 47 06 46 55 57 14 51 23 46 50 47 20 52 38 52 53 52 34 52 32 53 00 to 50 09 46 41 46 42 Nature of ice or obstruction 48 m 47 36 to 47 14 51 23 52 29 52 14 47 02 47 22 47 34 45 54 50 10 45 55 51 42 51 42 48 16 51 42 53 (X) 51 10 52 54 52 10 52 53 53 02 50 06 50 21 50 39 52 52 50 28 Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. 3 bergs. Berg. Do. Do. Berg and growler. Growler. 3 growlers. Berg. Do. Do. Do. Do. Dead whale, belly up. Berg and growler. Berg. Do. Do. Do. 2 growlers. 2 bergs, 2 growlers. Berg and growler. Berg. Berg and 2 growlers. Spar. Berg. Berg and growlers, same as 954. Berg, same as 955. 2 growlers. Small berg. Berg. 2 growlers. 5 bergs. Berg. Do. Berg and numerous growlers. J-Berg and 4 growlers. Berg. Do. Berg and growler. Do. 5 growlers. Berg. Berg and 2 growlers. Berg. Growlers. Berg. Berg and several growlers. Growler. Berg and several growlers. Berg. Gas and whistling buoy. Berg. Do. Do. Do. Do. 2 bergs. 2 bergs, several growlers. Growler. Berg. 32 Table of ice and other obstructions — 1927 — Continued Date No. June 20 1048 20 1049 20 1050 21 1051 21 1052 21 1053 21 1054 21 1055 21 1056 21 1057 22 1058 22 1059 22 1060 22 1061 22 1062 23 1063 Reported by— Antonia do_ do Canadian aviator Cape Rice (station).. Svitriod do Veendam B olingbroke do_- MontroyaL Bolingbroke Cape Race (station). Fannad Head Cape Race (station). Caronia Position Lati- tude, north 47^ 10 47 22 47 14 47 20 47 31 45 17 45 03 40 33 46 31 46 32 47 23 47 20 48 37 47 51 46 39 46 04 Longi- tude, west 50 01 50 07 49 44 50 02 49 58 46 11 46 30 57 13 51 48 52 15 50 20 50 05 50 24 50 08 53 02 51 52 Nature of ice or obstruction Berg. Do. Do. Do. Do. 3 bergs. Small berg. Light buoy (red) . Growler. Berg. Do. Berg, same as 105. 2 bergs. Berg. Do. Do. PLATE 111.— THERE IS NOW INSTALLED IN THE CONDENSER INTAKE PIPE OF BOTH ICE PATROL SHIPS A SEA-WATER THERMOGRAPH, WHICH REGIS- TERS CONTINUOUSLY THE TEMPERATURE OF THE SURFACE LAYER THROUGH WHICH THE VESSEL PASSES WEATHER Following the arrangement of reports in former years, there is set forth under this section a description of the general weather conditions that were experienced during the ice patrol of 1927. The remarks, which are grouped according to months, are devoted to tracing the general behavior of the high and low pressure systems in the atmos- phere as they traveled over the eastern United States and passed out to sea, across the ice regions. Accompanying the monthly remarks is a sketch showing the tracks of the more noteworthy disturbances, and also in other particular instances sketches have been appended. The weather diagram for each month gives at a glance the wind direction and force averaged for every 12 hours; the barograph curve; and the time and duration of fog and low visibility during the month. The geographical position, for which this is a meteorological record, although observed from the patrol ship cruising in the ice regions, can for all practical purposes and interpretations, be taken as latitude 43° 00' N., longitude 50° 00' W., the Tail of the Grand Banks. A general description of the two major types of weather which prevail in the ice regions, remarks on the structure of a storm, and iceberg forecasting by means of the weather are all contained in the ice patrol report for 1926 (Bull. No. 15), to which the reader's attention is invited. MARCH When the Tampa left Boston on March 22, a great mass of cold dry air was spreading east and southeast out of central Canada, across the North Atlantic States, the Maritime Provinces, and out on to the ocean. A center of low pressure retreated before this invasion leaving one vast area of high pressure enveloping the land and ocean to the northward of us. The Tampa, because of such a distribution of pressures, experienced continuous easterly winds on her passage to the ice regions. Along the southeastern border of this afore- mentioned air mass, from March 23 to 26, there traveled a low- pressure disturbance. It was first observed on the meteorological map for March 22 off the coast of the Carolinas, but after that it could not be followed so clearly, due to the scarcity of ship reports from this direction. Its path is shown fairly accurately, however, as track A on Figure 2, the center passing close to the Tampa on the morning of the 26th instant, when she was south of Sable Island. The first effects of this storm (a depression of the barograph, see fig. 1) were (33) 34 observed when the center was about 420 miles from our position. It was then travehng at the approximate rate of 20 miles per hour. Soon after it had passed we got a rapid shift in the winds to a north- westerly direction, which increased three hours later to force 10 of the Beaufort scale. A second large anticyclone spread across the country and out to ■sea from the 27th to the close of the month, thus furnishing the N Fig. 1. — March weather diagram. The inner circle gives the day of the month; the next band out contains the record of atmospheric pressm'e; the next outer one indicates the degree of visibility (crosshatched areas represent low visibility and black areas duration of fog); the outer margin shows the average direction and force of the wind, per 12-hour periods, noon and midnight Grand Banks with prevailing northeasterly winds and generally fair weather for the end of the month. Another disturbance from March 29 to April 3, took a path shown as track B on Figure 2. It followed a course farther north than most storms, due to an interposing anticyclone that was lying over the Atlantic States at the time. This situation tended to keep it at a distance from our vicinity, yet on reaching a point near St. Johns, Newfoundland, the depression deepened and thus intensifying, for 35 about eight hours, April 2, set up a considerable indraught of southerly winds. This brought heavy rains and some low visibility for a V Sy -r ^ v»^y^ <^ 1 v^ / / 1 ^ffi) — ■ s Y^ ^^AM-24 y^^^^ e ^-c-^ I "^IX Fig. 2. — March cyclone tracks Fig. 3.— Isobaric map for 8 a. m. March 26, 1927. The center of the distuibance, traveling at the rate of 20 miles per hour, passed directly over the position of the "Tampa," then just south of Sable Island (see p. 33) few hours, to the relatively cold Grand Banks regions. The weather for March, 1927, was much better than that for the same month in 1926. We experienced practically no fog and only 17 per cent hours 36 of low visibility in the nine days of March which we were at sea. There were four days out of the nine, however, during which the wind attained gale force. APRIL Disturbance C, Figure 5, was observed south of Chicago the evening of April 1 , from thence it moved easterly, passing out to sea- on the 3d instant. Several steamship reports from along the 40th Fig. 4.— April weather diagram parallel permitted us to locate this center on the 4th, then between our position and Bermuda. It was still moving in an easterly direc- tion, and probably prevented from following the usual northeasterly course by a large anticyclone centered over the Gulf of St. Lawrence. The presence of this ''high" moreover undoubtedly saved us from the discomforts of passing through another severe storm similar to the one experienced last month. The steamship Majestic, 200 miles southwest of our position on April 4, reported a very rough sea and a northeasterly gale. The path of this depression is shown as track C, Figure 5. 37 April 3 a new depression put in appearance over Iowa and during the next four days crossed the country, as shown on Figure 5, track D. An interesting feature in connection witli this cyclone is that it brought to the Newfoundland region, an area of low pressure which prevailed there for the succeeding 10 days. In fact, the general distribution of atmospheric pressure over the eastern United States and out over the ocean including the ice regions, did not materially alter for the nine-day period, April 7 to 16. Such a stagnation in the characteristic progress of "highs" and ''lows" is a rare phenomenon at this time of the year. The foregoing general conditions are shown on Figure 6. The patrol, cruising on the Grand Banks during this period, enjoyed excellent weather conditions. Fig. 5. — April cyclone tracks An interesting meteorological phenomenon took place April 16, when in a locality about 150 miles southeast of Sable Island there was witnessed the development of a disturbance (cyclone) of restricted but considerable intensity. It traveled almost due east along the northern edge of the Gulf Stream and the forty-second parallel, and on April 17, passed about 140 miles south of the ice patrol ship. We experienced easterly winds of increasing strength early the morning of the 17th, which gradually backed to north and attained gale force by nightfall. The lowest barometer reading at this time was 29.70, clearly indicating that the Modoc was in the cold northern sector of the storm, the center apparently passing at the rate of 15 to 20 Icnots per hour. The strongest wind was from the north and north-north- west, and some snow fell during the night hours. Conditions indi- 38 cated that the depression was deepening and intensifying as it traveled eastward. The winds backed still further during the 18th and finally later in the day, gradually abated in force as the disturbance moved out into the North Atlantic and all influence had disappeared. Track E, Figure 5, is an excellent example of the birth of a cyclonic vortex in the atmosphere, probably materially aided by the presence of warm and cold masses of water along the southern border of the Nova Scotian continental shelf. This particular cyclone had its birth over the northern edge of the warm and cold water where the current curves up in the great oceanic bight west of the Grand Banks. Track E is an example of developments that may take place in the atmos- FiG. 6.— The general distribution of atmospheric pressure from April 7-16, during the nine days of which there was an unseasonable stagnation in the movement of "highs" and "lows" phere over an ocean but where due to the scantiness of data, winds sometimes even of considerable intensity can not be explained by reference to the generalized weather map. The distribution of pressure following the events described above took the form of a huge high pressure area extending from Newfound- land southward over the Atlantic States to Florida. This mass of air,^ however, gradually shrank in extent until on the 19th it centered over the Carolinas and by the 20th it had retreated completely to join the more or less prevailing "high" in the direction of Bermuda. An expansive area of low pressure which had lain motionless since April 7 (for a period of about two weeks) over the Southwestern States^ began to move about the 20th and simultaneously with the removal of the high pressure described in the preceding paragraph. Its track F, Figure 5, from April 18 to 20, is shown crossing northward to Lak 39 Superior and thence eastward, later curving to the left, and finally occluding in the direction of Labrador. Another depression moved from near Cincinnati, Ohio, where it had first formed, north-northeast- ward toward Labrador, and finally off the map. It was noted this month that there appeared to be an excess of air over North America with the "highs" pushing the low-pressure cen- ters to the northward and easily filling them up. The tendency for the atmospheric high pressure, especially over Nova Scotia and New- foundland during April and the latter part of March, resulted in an abnormal percentage of northeasterly and easterly winds for the Grand Banks region. This condition was doubtless the underlying factor responsible for the iiotable westerly positions of the ice south of Newfoundland during April. A depression followed track G, on Figure 5, from 8 a. m. the 21st until 8 p. m. the 23d, when it disap- peared from the meteorological map in the region of Labrador. The next depression of consequence was centered just west of Lake Superior the morning of the 25th. It had advanced to Lake Huron by the morning of the 26th, and from thence it curved to the northeast- ward and finally on the 27tli assumed an elongated shape covering an area from Quebec southward of Nantucket. (See track H, Fig. 5.) A small portion of this area apparently broke away from the main system and drifted southeastward and thence eastward, passing south of the Grand Banks on the 28th instant. We experienced fresh east- erly winds in consequence and more fog than at any period this season. Newfoundland and the Grand Banks vicinity continued to have low atmospheric pressure for the remainder of the month. Summing up, we are particularly impressed with the prevalence of easterly and northerly winds this year. This was due primarily to an excess of air which persisted over the Canadian Maritime Provinces and Newfoundland, where in normal season, low pressure usually prevails. This distribution of pressure and the consequent system of winds tended to hold the field ice and bergs nearer the continental slope than they normally would otherwise have drifted. There were, however, only two days, the 17th and 18th, upon which the wind attained gale force. Fog was present 16 per cent of the month and low visibility and fog 22 per cent. MAY The first week in May was characterized by a relatively large num- ber, and frequency, of centers of low and high pressure. Families of cyclones, four and five in number, appeared on the meteorological map at time of observation instead of two or three as is normally the case, and as these several centers drifted across the ice regions the patrol experienced unsettled and changeable weather. The Modoc, return- ing to the patrol on the 9th instant, stated that similar weather condi- • 40 tions were experienced in Halifax; first a warm day followed by one which was cool. An unusually deep atmospheric depression was observed on the meteorological chart for the morning of May 9. The lowest barome- ter reading was recorded in Nebraska but the attending low-pressure system spread over a relatively large area of the central United States. This "low" moved eastward very slowly and assumed various shapes Fig. 7.— May weather diagram and positions but remained at all times over the continent. The period May 11 to 20, consequently, was characterized by general low atmospheric pressure over the United States east of the Mississippi River Valley and extended eastward over the Maritime Provinces and Newfoundland. (Fig. 9.) These summer-time conditions brought southerly winds, rain, and a protracted spell of wet weather to the northeastern part of the country, and the ice regions coming again under prevailing southwesterly winds received the first prolonged period of fog for the season. We had almost continuous fog and low 41 visibilit}^ in the cold waters around the Grand Banks from May 1 1 to 20. (See Weather diagram, Fig. 7.) Fig. 9.— The distribution of atmospheric pressure May 11-17; a type of distribution that is cominon during the warmer months of the year. During this period of seven days the rchitivoly cold waters of the Nova Scotian and Newfoundland Banks were enveloped in thick fog. The normal fog area under such conditions is shown as a shaded area on the figure The meteorological map for 8 a. m., May 21 recorded the first material change in pressure conditions since the 11th instant. The pressure increased very rapidly over the eastern half of the United 42 States and a ridge in the atmosphere extended southward from Hudson Bay to Bermuda. New meteorological conditions came not as a surprise to the patrol as we had experienced stormy weather all day of the 20th which pointed toward a forthcoming change. Early the morning of the 21st, the fog rolled away before a gentle northwesterly breeze, revealing in all directions a hard, clear cut horizon. This was the patrol's first opportunity to scout for ice since May 9, 12 days previous. High pressure and clear weather prevailed from May 21 to May 27, upon the latter day of which fog and mist again shut in. A disturbance of unusual intensity for this time of season marked the days of the 25th and 26th. The storm developed from a moderate depression over Montreal on the morning of May 22. The next day it moved eastward to the Gulf of St. Lawrence and deepened to a minimum of 29.66 recorded at Harrington, Quebec. It finally paused in its northeasterly progress because Cape Race and ships to the east- ward on the 24th instant reported pressures of 29.35 and 29.29. The patrol ship, 150 miles to the southward, recorded a pressure of 29.50, but no stormy conditions existed and the winds continued light from the westward. Early the morning of the 25th, however, our baro- graph began to rise rapidly and the wind increased correspondingly in force from a northwesterly direction. At 8 a. m. it was blowing with gale force and a ship northeast of Cape Race, about 300 miles from the patrol, reported a barometer reading of 28.60. Situated on the rear of this disturbance we experienced one of the strongest gales and roughest seas for the season of 1927. Conditions slowly grew better on the 26th, and the wind shifted to light southeasterly airs with low visibility ensuing. That the stormy conditions of the past few days had not ceased was apparent by glancing at the meteorological map for 8 p. m. of the 26th where we found depicted another well-developed but less deep depression than that of the 25th. It became centered east of Newfoundland where it remained from the 24th until the 26th and then another equally well-developed depression arrived from the westward and remained in the vicinity of Newfoundland until the 29th. It was plain to see that for some cause the atmosphere from May 26 to 31 had become unseasonably agitated. The outstanding feature for the month was the changeable weather during the first nine days, followed by two weeks stagnation of ''highs" and "lows," providing for the Grand Banks almost continuous fog and summer-time directions of wind. The latter part of the month was featured by increased activity in the atmosphere as high and low pressure centers followed each other across the map. We experienced only two days upon which the wind blew with gale force and we experienced 43 per cent hours of fog and 55 per cent hours of fog and low visibility. 43 JUNE On June 1 a low pressure centered near Nova Scotia elongated its shape to the eastward causing easterly winds to blow around the Grand Banks. As this depression moved northeastward the wind hauled to the southward, but the "low" hovered in the vicinity of Newfoundland until the 4tli instant, when it was displaced by a large anticyclone. The fog caused by the southerly winds during the first Fig. 10.— June weather diagram three days in June lifted on the 4th, giving the patrol an opportunity to scout for ice during the succeeding four days. It was unusually clear June 7, when the anticyclone completely surrounded the Grand Banks, and on that day we sighted several bergs the exceptionally long'distance of 20 miles away. A disturbance was noticed on the meteorological map for June 3, it being centered over the Mississippi River Valley, and its path across the country and over the ice regions is shown on Figure 11, marked 44 "A." This "low" was of more than ordinary significance in that its passage was simultaneous with the stranding of a French fishing vessel on the southern coast of Newfoundland, 3 miles west of Cape Race. Its untimely appearance unfortunately caused strong south- erly winds which quickly broke this vessel up on the rocky shore, thus making her a total loss. The passing of this storm brought the wind around to the westward and we again enjoyed clear visibility. It was apparent from the examination of the file of daily meteoro- logical maps that there was tendency for low pressure to spread over a large portion of the northern tier of the United States. In fact a depression stretched all the w^ay across the northern part of the coun- try with a "high" resting over the ocean in the region of Bermuda. Fig. 11.— June cyclone tracks Thus the stage was all set for the normal summer-time distribution of pressure, prevailing southerly wdnds, and much fogginess. Such con- ditions actually persisted from the 7th to the 14th instant, a situation similar to that which prevailed May 11 to 17 (see p. 41). On the 12th instant a high-pressure area was observed to be accumulating over the western plains and consequently we looked forward to a respite of clear weather. The Modoc on June 13 was called eastward to the fortieth meridian, nearly mid-Atlantic, by a medical case and returning to the Grand Banks encountered a strong westerly gale. On the 14th the wind blew so forcibly that it was necessary to reduce speed to bare steerage- way. The great wind velocity was due to a disturbance northeast of Newfoundland, which deepened and intensified. No sooner had 45 the gale of the 14th abated than another disturbance was located about 250 miles south-southeast of Sable Island. It had been lost on the Weather Bureau's synoptic map, when it passed out to sea off the Virginia coast the 15th, but the ice patrol was able to plot its position quite accurately from a number of ship reports scattered over a large area. The winds accompanying this disturbance backed through the northeast, showing that the storm was passing to the southward of us and by the 17th the wind had weakened to a moderate breeze from the northwest, with fine weather again. The path of the cyclone is shown as track B on the weather map for the month. (See fig. 11.) An anticyclone of expansive proportions followed closely in the rear of this disturbance, bringing northwesterly winds, high pressure and fine weather, the 18th, 19th, and 20th, but on the 21st, and 22d a general lowering of the barograph ushered in summer-time conditions, a shift of wind to the southern quadrant, and plenty of fog for the ice regions. The first week of June was characterized by a large anticyclone and clear weather favorable for ice scouting. The second week low pressure over northeastern North America and high pressure in the region of Bermuda, gave southerly winds to the Grand Bank and much fog. The third and last week the patrol was in the ice regions we experienced two disturbances, one of which followed a track south of the Banks. There were two days during the month when the wind attained gale force. There was 33 per cent hours of fog and 43 per cent hours of fog and low visibility. SUMMARY The season's summary reveals the following facts: Probably the most outstanding meteorological event of March, at least for the patrol, w^as the passage of a severe storm center directly across the position of the Tampa southeast of Sable Island; the barometer record- ing a minimum of 28.96 inches. April 7 to 16 witnessed a general stagnation in the usual march of the "highs" and "lows," but the most important weather characteristic of April was the prevalence of anticylco.:ic conditions over Nova Scotia and Newfoundland, .resulting in an abnormal percentage of easterly and northeasterly winds. May saw families of cyclones, and changeable weather up until the 8th, followed by a period of 11 days when a summer-time distribution of atmospheric pressure brought the first really long spell of fog. Gales and strong winds ushered out the month. June 7 to 14 there was a resumption of lov/ pressure over North America and a return of the blanket of fog to the cold waters around the Grand Bank. The normal monthly percentages of fog based on 7 consecutive years of patrol records are: April, 24 per cent; May, 28 per cent; and June, 38 per cent. There was only one-half the usual amount of fog during 72092—27 4 46 April this year; May, however, there was about double the normal amount, and June proved to be just about normal. A table showing montlily records of fog, fog and low visibility, gales, and calms for the 1927 ice season is shown below: Month April May June .' 1 Based on 12-hour periods. Percentage (hours) Fog Low visibility Gales (number of days) Winds (average force) 3.6 3.3 3.7 Calms (num- ber)! so- -70- 60 50 40 I- Z y 0 b^ 30 u a. ^0 10 oL I APRIL MAV June: Fig. 12. -The monthly percentages of fog around the tail of the Grand Bank during the ice season of 1927, and as compared with normal Figure 12 shows the monthly percentages of fog which was observed by the patrol around the Tail of the Grand Banks during the ice season of 1927. The percentage of fog that envelops the ice regions is always a subject of vital interest, since, obviously, fog and low visibility greatly magnify the danger of collision with icebergs. COOPERATION WITH THE UNITED STATES WEATHER BUREAU Following the procedure on previous patrols a meteorological map was constructed twice daily on board ship, the data being obtained from the general synoptic reports broadcasted by the United States 47 Weather Bureau from the naval radio station at Arlington at 10 a. m. and 10 p. m. Occasionally the weather experienced by the patrol vessel did not accord with the Weather Bureau's data when plotted on a base map. In such cases it was necessary to collect reports from as many ships as possible and well scattered within a radius of 500 miles of our position. This work often revealed the presence of disturbances that had formed or developed over the sea, the position of these storms being unknown to the Weather Bureau, at least when it had sent out its routine data. Twice daily, as in former years, at 8 a. m. and 8 p. m., a report was dispatched to the United States Weather Bureau, Washington, D. C, and at the end of each cruise a more detailed report was for- warded b}^ mail to the Washington weather officials. ICE FORECASTING BY MEANS OF THE WEATHER Last year's annual report (Bull. No. 15, pp. 45-48) contained an account of a scientific investigation carried on at Harvard University Fig. 13. — The anomaly of atmospheric pressure over the northwestern North Atlantic for the month of October, 1926. Isobars drawn every 2 millibars. Conditions when reflected the following spring spell less ice than normal and later at the British Meteorological Office, London, into the pos- sible relationship, between the varying amounts of Arctic ice from year to year and meteorological events occurring in the northern regions some months previously. It appears logical to believe that the prevailing direction of winds over the Labrador-Greenland region, when expressed in terms of departures from normal, and considered in monthly periods, would be reflected sometime later in the varia- tions from normal in the amounts of ice. It has been found best throughout the investigation to work with differences from means, .and this fact should be kept in mind by the reader. 48 The first factor, consisting of the atmospheric pressure differences be- tween two points taken across the line of drift of the ice on its journey to the southward, is being furnished by the United States Weather ^0^ ^ ^^ J^ ^^jf^^^^ 0'^iA_ ^ -^ 1 -y^X-^ ^ Fig. 14. — November, 1926, anomaly of atmospheric pressure. Condi- 1^ t ions when reflected the following spring indicate more ice than normal Bui'eau in the form of monthly mean pressure records from^meteor- ological stations scattered around the shores of the North Atlantic. Observation points even in Greenland are now connected with the \ \ {/M^ ™ 5 /// wM 1 0* ^li w^> \\>^ Fig. 15. — December, 1926, anomaly of atmospheric pressure. Conditions when reflected the following spring indicate a normal ice season outside world by radio, a fact of great importance to the success of this particular ice forecasting problem. Maps showing the anomaly isobars, one map for each of the months, October, 1926, to Alarch, 49 1927 (see figs. 13 to 18, inclusive), will give the reader a pretty fair picture of events leading up to the ice season of 1927. It is plain to Fig. 16. — January, 1927, anomaly of atmospheric pressure. Conditions when reflected the fallowing spring indicate more ice than normal see, for example, that during October, 1926, meteorological condi- tions were less favorable than they usually are for Arctic ice to drift southward into the Atlantic. December, 1926, the winds were more ?|S4 \r^ ^jX >5^ ^5j^^ Fig. 17.— February, 1927, anomaly of atmospheric pressure. Conditions when reflected the following spring indicate more ice than normal or less neutral, but November, January, February, and March were more favorable than ordinarily to a greater abundance of ice appearing in the spring of 1927 than is normal. 50 A more accurate method of measuring the value of the meteor- ological factor was found by our investigation to be an equation Bergs = 4.8-0.08(c)-0.12((?) where the number of bergs is expressed as a value 0-10; c represents the pressure difference in millibars between Belle Isle and Ivigtut; d represents the pressure difference between Stykkisholm and Bergen. (For details of the values see Bull. No. 15, p. 48.) Fig. 18. — March, 1927, anomaly of atmospheric pressure. Conditions when reflected in the spring spell more ice than normal A forecast was made in a letter, March 11, 1927, to the chairman of ice patrol board, that about 396 bergs would drift south of New- foundland during 1927, or field ice and bergs somewhat in excess of that during a normal year. As a matter of fact we now know after a careful check that the number of bergs for the danger season, March to July, was 367, and about 390 for the entire year, and thus the forecast was quite accurate. (See iceberg table, p. 16.) The number of bergs may vary within wide hmits; for example, in 1912 there were 1,200 and in 1924 only 11. The forecast in 1927 was 'pur- posely kept from publication because it is desired to test the work with a few more trials, but it all is most encouraging and the service will be continued for 1928. DEPTH SURVEY CARRIED OUT WITH THE SONIC DEPTH FINDER Work was continued during 1927 with that part of the scientific program which related to surveying the bottom contour in the ice regions whenever opportunity offered. The work really has two principal objects, (1) to contribute more cartographical information than is now on record of these little frequented regions, and (2) to learn more regarding the currents through a more detailed knowledge of the sea floor, because as we well know, the configuration of a sea basin casts an important influence upon the moving masses in it. The sonic depth finder apparatus was operated this season by a member of the Coast Guard, a chief petty officer, who received an eight weeks' course of instruction at the Navy sound school, United States Navy submarine base, New London, Conn. The apparatus functioned quite satisfactorily throughout the entire patrol. The calculations of the time interval used in multiplication to obtain the depth, were facilitated by a graphic means of division, the curves being constructed of a scale sufficiently large to permit interpolation to 2 in the third decimal place of the time factor. The velocity of sound in the water column, at the particular spot, was obtained by referring to the chart that was especially constructed for this region last year (Bull. No. 15, fig. 9, p. 49), in which correc- tions have been made for the influences arising because of pressure, salinity, and temperature. The geographical positions of the sound- ing were not accepted until they had been tested by several astronomical sights, and frequently supplemented by radio compass bearings from Cape Race. There was a total of 435 soundings recorded this year which range from as shallow as 30 fathoms to as deep as 2,312 fathoms. A report and record of the data has been submitted to both the United States Hydrographic Office and the United States Coast and Geodetic Survey, in order that revision may be made in the proper charts. One of the most important advantages that has been gained from the sonic apparatus by the patrol has been of a navigational nature. The distribution of the ice, and consequently the activities of the patrol, take place in general along the Atlantic faces of the Grand Bank, a region notorious for its fogs. In consequence the patrol vessels experience considerable difficulty in obtaining frequent and accurate astronomical "fixes." The depth of water, rapidly and easily taken by means of the sonic apparatus, however, quickly locates our distance in or out with respect to the bottom grade, while a radio bearing from the only station in the ice regions. Cape Race, fixes our position along the slope. (51) ICE OBSERVATION It has been customary for a number of years to devote a section of the annual report to remarks on the behavior and distribution, in time and place, of all Arctic ice south of Newfoundland (the forty-eighth parallel of latitude). A certain amount of statistical work on this subject in addition to current reports, has been carried on by the ice patrol, especially that covering the amount of ice from year to year and from month to month. A complete report for those students interested in this aspect of the subject is contained in Ice Patrol Bulletin No. 15 (for 1926), pages 75 to 77. The ice observation for the season 1927 follows: JANUARY There was a total of four icebergs reported by steamers for the month of January, All of these bergs were distributed along a line 50 ^s- Fig. 19.— January ice map. The position of the first Arctic ice for the year 1927. -A- represents an iceberg. There were four bergs south of the forty-eighth parallel during the month between St. Johns, Newfoundland, and Flemish Cap. This informa- tion was obtained from Cape Race radio station by the ice patrol ship upon its initial arrival in the ice regions. Conditions were con- sidered average, as a normal January records three bergs. (See Iceberg Tables pp. 75-76, Bull. No. 15.) (52) 53 FEBRUARY Field ice put in its first appearance on February 10, when reported in a position between Cape Race and Sable Island. This ice w^as doubtless of St. Lawrence origin, it having been blown offshore to the outer edge of the shelf. The first flat ice of Arctic origin was sighted on the 19th instant, from latitude 48° 20' longitude 50° 00' to latitude 47° 50' longitude 50° 05', the extreme northern part of the Bank, about 100 miles due east of St. Johns. There were seven other reports relating to the position of field ice during the month, nS ^r f>r )0 r^^-ZS ^--1^^^' ^^^' X5^ ^25 x^ |25. 49 46 47 4b +S- 60 50 iS 57 -5-6 Fig. 20.— February ice map. \\l\ V V represents field ice. There was a total of 10 bergs south of the forty-eighth parallel during the month the southernmost field being found in latitude 46° 00', on the eastern slope of the Grand Banks. This southerly position indicated an mvasion of nearly 120 miles, all which took place during the latter part of the month. A total of 10 separate and distinct bergs, it is estimated, drifted south of the forty-eighth parallel during February; the most of these moved south along the usual path parallel with the eastern slope of the Grand Bank. There were two exceptions when two bergs drifted toward Cape Race close in near the shore. The southernmost berg during February was reported on the 13th instant, 54 then just below the forty-sixth parallel between Flemish Cap and the Grand Banks. The normal number of bergs for February is 10, just what was observed. MARCH There was'' a total of 7 field-ice reports and 38 reports of icebergs received during the month, some of which, of course, referred to the same ice. No field ice, however, was sighted south of the forty-sixth parallel, a fact which showed the ice had not increased in abundance so AS 3o 49 45 ^-] 46 ^S -44. -Ji 4-^ 4l Fig. 21.— March ice map. There were 26 bergs south of the forty-eighth parallel during the month sufficient to extend its boundary southward of a point observed in February. About half of the bergs drifted southeastward between Flemish Cap and the Grand Banks, and out on to the northern edge of the Atlantic water. The patrol sighted its first ice for the year on the 29th instant in the form of a small growler, latitude 44° 00', longitude 49° 00'. The next day we made contact with the two southernmost bergs 44° 26', 48° 40'. The patrol remained with the inshore berg (they being about 10 miles apart) for the last two days of March, during which time a drift of 1.4 knots per hour was recorded 55 to the southward, more or less parallel with the general trend of the Bank. It was noticed that the ice consisted of small bergs, which plainly showed the effects of last summer's disintegration in high latitudes; and, also, this is a characteristic form for the early season. An interesting incident was the case of a large berg which remained grounded about 7 miles southwest of Cape Race, in plain sight of the station, from the 6th day throughout the remainder of the month. It is estimated that there was a total of 26 bergs in the North Atlantic, south of Newfoundland, for the month. A normal March records 36 bergs south of the forty-eighth parallel and 4 south of the Tail, but this year none of the ice succeeded in drifting as far south as the Tail. APRIL The small berg which we had been standing by the last few days of March grounded on the 2nd instant in latitude 43° 31', longi- tude 49° 28', at a point where the contour of the Grand Bank projects abruptly out to the eastward. The drift covering March 29 to April 2 is shown on Figure 22. The neighboring berg, which on Alarch 29 had been 10 miles farther offshore, drifted south faster in the current and was by this time no longer in sight, nor did we see it again in spite of a search covering the day of April 3. Its drift must have been offshore to the eastward as well as to the southward, where undoubtedly it was caught in the warm counter current. A small growler was reported on the afternoon of the 2d instant about 50 miles due south of the Tail. This was the southernmost position that ice had attained thus far this year, and we believe it to have been the same growler as one sighted by the patrol on March 30, 30 miles north of the Tail. The patrol found a small berg and growler on the 4th about 35 miles almost due east of the Tail. We remained drifting'near this ice the remainder of that day. It was moving southward at the rate of 1 to 1.5 knots per hour. A strong wind blew from the north during the night, and although we had been able to keep in sight of the growler, at daylight, the 5th, the berg was nowhere to be seen. Search was carried on for the entire day without success and we were forced to conclude that the berg had been set southeast, or east, into the warm offshore current. Since no ice was reported later to the southward, this behavior was somewhat substantiated. Two small bergs were sighted April 7, the smaller in on the Bank and the larger about 10 miles east on the 100-fathom contour and about 25 miles north of the Tail. Fog shut in for the next two days, and when the patrol was next able to search, the larger of the two bergs was found southeast of the Tail, drifting in the heart of the current to the westward. We followed it as it swung to the north- west and later to the north, at about 0.9 knot per hour. Finally, 56 on the 13 th, it entered water of practically no current in on the shoal of the Tail of the Bank itself. We remained near this berg untU the morning of the 15th. It had calved several growlers, melted somewhat, and naturally was slowly becoming smaller. The water Fig. 22.— The drift of 3 bergs into the shallow water on the eastern side of the Grand Bank during April. Warm water from offshore pressing against the slope at this point is believed responsible for the deviation in the normal path of the ice was relatively cool, 35° where it floated, and therefore not especially favorable for fast disintegration. From the 10th to the 15th bergs were reported in positions scattered all along the slope from the Tail northward to the twenty-seventh parallel. A relatively great number of bergs, beginning with the 20th, were reported on the northern part of the Bank, as steamers began using tracks E bound for the Gulf of St. Lawrence. 57 The Modoc, on the 15th, searched around the Tail of the Bank to make sure no bergs had entered this area unobserved. AprU 16 the scouting was extended northward along the east side of the Bank and we sighted a large berg and growler near nightfall. The berg was surrounded by warm water, temperature 50° F., but inshore to the westward from its position we could plainly see the boundary line where the cold slope water began. The surface temperature for April 9 to 24 (fig. 54, p. 95) shows the relative positions of these two 55 f 50 I M ^.|m' ../" •%? x-< ^"^7 ° ,<> 9 c^.o ;,A s?^ 49 45 44 4i 41 55 S4 5b 5Z 5\ 5o 49 -'fe 47 4fa 45 44 41, Fig. 23.— April ice map. There was a total of 93 bergs south of the forty-eighth parallel during the month temperatured waters. During the next 24 hours this berg drifted a total of 17 miles and then a strong northerly gale broke it up rapidly into many growlers. The 18th, 19th, and 20th were days of excellent visibility and the patrol ship took good advantage of the opportunity to search the eastern slope of the Grand Bank from the Tail to the forty-fifth parallel of latitude. Only three bergs were found in this zone; all of them had been carried by the cold current inshore on to the shelf, 15 to 40 miles inside of the edge of the Bank. 58 The- fourth berg to drift south of the Tail was reported by a steamer on the 25th about 100 miles west of the Tail on the south- west slope. The patrol stood by it for the next tln-ee days when it had completely melted away. It did not drift dm-ing this period over 15 miles from the position first sighted. This ice was thought to be one and the same last seen by the patrol on April 21 then in on the Bank about 50 miles to the northward. The last day of the month the steamer Newfoundland, on her regular run between St. Johns and Liverpool, reported passing a total of 35 large bergs and numerous small ones on the extreme northern edge of the Grand Bank. This suddenly boosted the num- ber of bergs south of the forty-eighth parallel for the month above normal. The position of this ice was somewhat to the westward of its usual path along the eastern slope of the Bank and therefore we expected that most of the bergs would eventually drift to southwest- ward, toward Cape Race. Field ice was reported twenty times and on one day, xlpril 7, it stretched in a broken line with few interruptions from near Cape Race to the east edge of the Bank in latitude 46° 00'. The farthest south position was recorded on the 13th instant when an open field was sighted in latitude 45° 14' on the eastern side of the Bank. A field also projected out of the Gulf of St. Lawrence, its southern limits being reported 25 miles north of Sable Island on April 19. One of the most striking points in connection with the ice distribu- tion for the month of April is plainly to be discerned by glancing at the ice map for the period. (Fig. 23, p. 57.) Practically all the ice sighted and reported for the month was confined to the limits of the continental shelf. This was due to the prevalence of high atmospheric pressure over Canada and Newfoundland giving a consequent pre- dominance of northeasterly winds combined mth the oceanic fact that warm Atlantic water pressed closer to the continental slopes during April than is normal for the season. These two factors also interfered with the normal southward distribution of the Arctic ice. There was a total of 189 ice reports relating to the positions of 93 bergs during the month of April south of Newfoundland (the forty- eighth parallel). Only 4 bergs, however, drifted south of the Tail of the Bank. A normal month provides for 83 bergs south of the forty-eighth parallel and 9 south of the Tail, therefore icebergs dur- ing April were slightly in excess of normal, but the southward distribution was not. MAY The 1st to the 5th days of May provided on the whole a very good visibility, affording the patrol an opportunity to search northward along the eastern slope of the Grand Bank. No ice was seen or reported, however, during this interval south of the forty-seventh 59 parallel. On the 6th and 7th days of May the Tampa sighted approx- imately 100 bergs, most of which were found in an area bounded by parallels 47° 50" and 47° 30" and meridians 50° 30" and 51°, an area of about 36,000 square miles situated about 150 miles northeast of Cape Race. This great quantity of ice apparently was drifting southward eventually to ground on the northern part of the Bank; many of the bergs it was expected would succeed in drifting toward Cape Race while a much less number would probably follow the 50 and 100 fathom contours down the east side of the Bank. The fact that over 100 icebergs were in these regions on the northern slope of the Bank was considered an event of especial importance, par- ticularly in view of the fact that the Cape Race tracks, leading directly thi'ough this area, would become effective May 15 and thus endanger those steamers bound to and from St. Lawrence ports. May 7 to 11 was spent near the southernmost known berg on the east side of the Bank near the forty-sixth parallel in 40 fathoms of water. The berg apparently was agrovmd, or else there was no current at that place, because it did not change its position materially for four days. The patrol during this time broadcasted warnings every six hours regarding the unusual quantity of ice then present on the northern part of the Bank. May 11 to 16, the fog settled over the cold, ice-infested waters on the northern part of the Bank, cutting off all opportunity to observe the behavior and drift of the bergs. It was with surprise that we received a report of a growler on May 15, in latitude 41° 57', longi- tude 49° 53', but the steamer which made the report added her inability to secure "sights" for the past two days and this naturally made the position very uncertain. In view of subsequent events, the presence of ice in this locality, approximately 60 miles south of the Tail, is deemed very unlikely. The patrol ship during the foggy spell, 11th to 16th, employed its time almost exclusively in making a survey of the circulation along the eastern slope of the Grand Bank and southward around the Tail (see p. 80). May 21 was the first clear day for a fortnight and so we searched northward along the east side of the bank, and as guided by the boundary between the two currents, which now it had been possible to delineate on the current map just compiled. A considerable amount of ice was reported on the 21st instant. For example, the steamship Calgaric sighted about 38 bergs on the Cape Race tracks between longitude 49° 40' and 50° 30'. These were thought to be part of the same large group last seen by the ice patrol on May 6. May 23 to 27 were days of clear visibility and accordingly the patrol ship searched northward from the forty-fifth parallel all the way to the twenty-seventh parallel. A total of six bergs were sighted, which comprised the southernmost group on the eastern side of the Bank. The farthest south berg on the 23d instant was 60 recorded in latitude 46° 19', longitude 47° 56'. The fact that there were so many bergs east of Newfoundland on the Grand Banks and that there were none south of the forty-fifth parallel was a truly remarkable condition. We made a report on this subject to the commander of the ice patrol on May 23, and, as it well describes the foregoing situation, it is included herewith : I would like at this time particularly to invite your attention to the important events that have featured the ice patrol of 1927 and, as guided by the present conditions, to outline the probable general character and ice behavior for the remainder of the season. As a result of research work abroad and at Harvard University carried out by the ice patrol, a prediction was made in March that approximately 396 bergs would drift south of Newfoundland in 1927. The termination of the field-ice season (usually the first half of May) now permits us to make a more accurate statement regarding the number of icebergs. The final forecast is close to 360 bergs, or a year quite similar to 1926, and one that is normal in number. To date there has been recorded a total of 224 icebergs south of Newfoundland, so that about two-thirds of the forecasted number have already put in an appearance. Both the ice and its time in season, therefore, are running along in harmony so far with predictions. The first third of the season of 1927 was characterized by an unusual predomi- nance of northeasterly winds, and this fact, combined with the presence of great masses of warm xA.tlantic water close in to the Grand Banks' slopes, interfered very markedly with the normal southward distribution of the icebergs. These facts were made the subject of a dispatch to headquarters on May 4 last. It is remarkable that nearly all the bergs this year have been confined to the nortliern part of the Banks and the coastal shelf, and only five bergs have drifted south of the Tail. None of these, moreover, have at any time endangered the United States-Europe steamship tracks. The second third of the ice season, in which we are now well advanced, is distinguished for the cessation of the Labrador current southward around the Tail of the Bank, where normally it flows at 0.5 knot per hour at this time of year. A current survey covering about 40,000 square miles of area, equal to the size of the State of Pennsylvania, was carried out by the Modoc May 10-21, and the results of this work are shown on the current map of water around Grand Banks, May 11-21, 1927. The direction and velocity of the circulation have been calculated in accordance with methods contained in Coast Guard Bulletin No. 14 and includes the resultant movement of the mass in which an iceberg would normally float. It can be seen from the above current map that the warm offshore current presses unusually far inshore against the continental slopes. The current runs northward even, on the east side of the Bank in latitude 43° 50', right in to the 100-fathom depth. Thus the warm current has tended to dam the icy current from the north (the Labrador) and has caused its main branch to be deflected south of Flemish Cap. The original of this chart is at present of invaluable assistance in guiding the patrol ship in its scouting work for icebergs. Naturally a subject of special interest at this time is to learn, if possible, the behavior of the ice and the course of events during the last third of the season. Considering the present ice situation, viz, about 70 bergs and growlers on the northern part of the Grand Banks, plus 100 more bergs expected, and the position of the two ocean currents, leads to the belief that few, if any, bergs will succeed in drifting south of the Tail of the Grand Banks. In other words, present con- ditions indicate that the ice menace for the United States-Europe tracks will 61 continue to dwindle throughout the remainder of May and June. The Cape Race steamship tracks (used by St. Lawrence ships), however, where they cross the continental shelf, may expect to be hampered with about 100 more bergs and probably lasting well into August. 4^ 30 ^ gP^3l 21 '-id. '^Z\ 48 ^ 45 4^ 4S 47 46 44 Fig. 24. — The northeastern Grand Bank promontory showing the drift of a number of bergs observed by the patrol May 24-31. The drifts were temporarily accelerated by a northerly gale which blew on the 25th and 26th instants The summary is as follows: First third of season: (o) Normal number of bergs but held up in northern waters. Second third of season: (6) Inshore invasion of warm northeasterly countercurrent to the ice. Last third of season: Probable accentuation of (o) and (6). A northwesterly gale blew on the 25th and 26th of May and its influence tended to accelerate the southward drift of bergs then on 72092—27 5 62 the northeastern side of the Bank. Drifts averaging 1.2 knots per hour (30 miles per day) were observed and are shown herewith in Figure 24. The southernmost iceberg, reported elsewhere on May 23, eluded our search on the 26th after the gale had subsided. The next day the wind changed to the south quadrant and low visibiHty and fog postponed further scouting operations. A berg was reported twice on the last day of the month in latitude 44° 53', longitude 45° 38', 50 45 >-^1 A-^^ 45 44 43 4Ji, M 55 5^ 53 5X 5/ 50 4? 48 47 ^6 ^5 f 4 4^ Fig. 25.— May ice map. There was a total of 153 bergs south of forty-eighth par- allel during the month and such a drift to the eastward from the position of the berg last seen on the 23d would indicate that this was one and the same berg. The patrol ship sighted a total of five bergs on the 26th of May, strung out along the northeastern contour of the Bank and drifting^ southward more or less parallel to the general trend of the slope. Foggy weather again intervened on the 27th, 29th, and 30th, and, not being able to search for ice, we ran two lines of oceanographic stations normal to the slope just north of the forth-sixth parallel. On the 31st it cleared again and the patrol searched to the westward near 63 the slope in this same vicinity and two bergs were found fairly close inshore near the 100-fathom contour. It was believed that these two bergs were part of a group of six last seen on the 26th instant, and Figure 24 shows quite clearly their direction and rate of move- ment. The fact that they were observed to be drifting southward at 1.2 knots per hour agrees, moreover, almost exactly with the calcu- lated rate determined by the density observations. We drifted near the inshore and southernmost berg the night of the 31st at the rate of 1 knot per hour to the southward, and thus ended the month. Summarizing for May, we estimate a total of 153 bergs were south of Newfoundland (forty-eighth parallel), or 23 more than for a normal year. The most striking feature with reference to the distri- bution of the bergs was the complete absence of any ice during the entire month around the Tail of the Bank where the presence of 18 bergs is normal. The southernmost berg for the month, if we disre- gard the report on May 15, which was considered erroneous, was the berg observed on the 31st instant in latitude 45° 04', longitude 49° 54' or, no in other w^ords, no berg was sighted within 200 miles of the United States-Europe steamship lanes during the month of May. This all tended, of course, to concentrate the ice on the northern part of the Banks where it gravely endangered steamships bound to and from St. Lawrence ports following the Cape Race tracks. JUNE The first two days in June were foggy, but in spite of this fact we sighted a small berg on the northeastern slope of the Bank. The next two days we spent on the current survey, but on the 4th instant we again sighted the berg last seen on the 1st. It had drifted south very little during the interval of three days and now was just south of the forty-fifth parallel. As the berg was apparently in the dead water on the Bank and consequently showed slight indications of drifting far from this spot, we left it again scouting northward for ice, and during the next three days searched the continental slope all the way to the forth-seventh parallel and westward to Cape Race. June 5, a Sunday, we sighted four bergs on the slope on the northeastern edge of the Bank and the next day located a total of 30 bergs dis- tributed along the northern slope, the greatest number being found near latitude 47° 50'. This area has been inclosed on Figure 26 and labeled accordingly. The Modoc assumed patrol duty on the 8th instant and immediately stood eastward, intending at first to search between the forty-seventh and forty-eighth parallels, just north of the area which the Tampa had recently covered. Fog and low visibility, however, modified these plans to a considerable extent, and so we were obliged to steer a straight course offshore to the edge of the slope. A few bergs, 64 nevertheless, were sighted along the 47° 30' parallel, the work being further assisted by the steamship Arahic which passed during the afternoon of June 9 about 5 miles north of us. It was estimated that to date there were a total of 65 bergs present for the month south of Newfoundland (forty-eighth parallel), but nearly all of the ice was north of the forty-sixth parallel and distributed in various positions <5^S^^ 33 JA «Ji ^0 ^9 -18 ^7 46 4^ 44 43 Fig. 26.— June ice map. There were approximately 95 bergs south of the forty-eighth parallel during the month along the northern slopes of the Grand Banks. It appeared to exhibit no appreciable drift; if anything, it was working slowly to the southward farther in toward shallow water and, of course, break- up at a seasonal rate. Those bergs which were on the extreme northeastern side of the Bank, however, were being carried to the southward in a path more or less following the trend of the slope. 65 The direction and velocity of the circulation are clearly shown in considerable detail on the current map for the period, Figure 50, page 90. The southernmost ice was the small berg previously mentioned in the first part of our remarks, just south of the forty-fifth parallel on the east side of the Bank. It was reported again and for the last time on the 8th instant, reduced now to the size of the growler in latitude 43° 54', longitude 48° 22'. It evidently had drifted off the slope and been caught in the warm countercurrent which pressed into the westward at this particular point. (See the ice map for June, fig. 26.) Only four bergs succeeded in drifting south of the forty-sixth parallel prior to the 8th instant and all but one of these was deflected off to the eastward, south of Flemish Cap. On June 10, when just north of the forty-seventh parallel and bound off the slope on a line of oceanographic stations, we sighted 12 icebergs scattered between the 50-fathom and 100-fathom curves. The southerly current in this zone was calculated to be 0.3 to 0.2 knot per hour. (See fig. 50.) Two of the same bergs were sighted again on the 11th, they having drifted southward to the forty-seventh parallel and followed the general trend of the slope, a drift which accords very closely with the current as calculated and drawn on the current map. (See fig. 50, p. 90.) We were absent from the patrol grounds from the 13th to the 17th instant, but upon our return at the latter date a total of five bergs and several small pieces of ice were sighted in the vicinity of latitude 46° 00', longitude 47° 00', as shown on the ice map for the month. (Fig. 26.) This was believed to be the same ice as that last seen by the patrol on the 9th and 10th, then on the northern part of the bank. These bergs were reported again by a steamer on the 21st near the forty-fifth parallel and somewhat to the eastward, following a path in general conformity to the stream lines of the current. Few bergs were sighted on the northern tracks during this period, despite the fact that it was clear weather in that locality. We kept a careful record of the ships on the Cape Race tracks for a period of four days and estimated there were a total of 15 bergs the latter part of the month in this region. This would indicate that three-fourths of the number sighted up to June 9, or 50 bergs, had melted during the interim of two weeks, a sum which appears rather high. Probably some of the missing number might be found upon further search southward in the shoal water of the Bank, a locality which is seldom crossed by passing vessels. We estimate there were a total of 95 bergs south of Newfoundland during the month, or 27 more than the average. The bergs remained concentrated on the northern part of the Banks, a condition which was also noted during May. Only one berg drifted south of the 66 forty-fifth parallel, and that one only to latitude 43° 54', longitude 48° 20', on the east side of the Bank, where it melted. When we left the ice regions, June 25, there were approximately 20 bergs on the northern slopes of the Grand Bank and 3 bergs near the forty- iifth parallel drifting to the eastward on the northern edge of the Gulf Stream. SUMMARY We now come to the summary of the season of 1927, the spring and early summer of which were characterized by a number of bergs JAH m m APR m m jul Mt ^ ^\x m/ Dfc Fig. 27. — The distribution of icebergs south of Newfoundland, by months, during 1927. The full black line represents the actual observed numbers, while the dotted line represents the number which drifts south in a normal year slightly in excess of normal, follows : January 4 April February 10 May March 26 June The distribution by months was as 93 July 5 October 0 153 August 3 November 0 95 September 0 December 0 The foregoing table is shown graphically by Figure 27 appended herewith. The most striking fact in connection with the behavior of the icebergs in the North Atlantic during the spring of 1927 was their incomplete normal southward distribution. The bergs not being disposed as they usually are, consequently became concentrated from May 10 to June 15 in great numbers on the northern part of the Grand Bank where they constituted a distinct menace to steam- ships plying the Cape Race tracks. The uneven geographical dis- tribution was attributed to the predominance of easterly and north- easterly winds during March and April combined with the inshore invasion of the warm Atlantic countercurrent. 67 The fact that only two bergs drifted as far south as the Tail of the Bank places the season of 1927 comparable with those in 1924 and 1925, two years noted for the absence of ice near the regular steam- ship tracks. The United States-Europe steamship lane routes dur- ing 1927, in fact, were at no time endangered on this score, and the conditions can best be presented by referring to Figure 28, which shows that during April there was only one berg that drifted as far south as the Tail of the Grand Bank, it being on April 13, its southern- most point, 90 miles to the north. During May the closest an ice- berg approached the steamship lanes was on the 31st instant, when it was 210 miles away. June 8, the nearest that any berg drifted \ .. v*e.ST-&ooMP sTe&naMcP tkack EAST-e>ooi*c ^ifTj::T><^ir~TiraZ!^ SO 49 4» 47 46 Fig. 28. — The nearest positions which bergs attained to the United States-Europe steamship tracks during 1927. Also, there is shown all the bergs that the ice patrol was able to follow in their drift during the month, was 140 miles to the northwest of the United States-Europe lanes. As in former years, the ice patrol kept track and recorded the drift of as many bergs as possible during the season, and the paths followed are shown on Figure 28. A record of all the icebergs that the patrol has been able to chart and follow since 1914 is shown as Figure 29. As a result of the observations concerning the courses which bergs have followed near the southern end of their transport, we are including this year a map (fig. 30, p. 69) which shows diagrammatically the general berg paths and the most likely offshoots. Icebergs approaching the northern slope of the Grand Bank take any one of three paths a, b, 68 or c, depending upon the oceanographic and meteorologic conditions and the position of the ice geographically. Path c has six most probable points of departure. A berg embarking on path c may follow any one of the branched arrows e, f, g, h, and i. In early season — that is, in February and March — bergs characteristically Fig. 29.— The drift tracks that bergs have followed since 1914 around the Grand Bank, as compiled from all records of the international ice patrol follow branch d, but later in April, May, and June the ice follows any of the other branches farther to the south. Path i is, of course, the most dangerous for the steamships, as the ice there slowly crosses the United States-Europe steamship routes. Branch i, moreover, invariably lies between meridians 49 and 47, but fortunately it is a very small percentage of the total number of bergs taking path c that ultimately reach southward along branch i. 69 In order that the reader may have an idea of the comparative value of the year 1927 with respect to the number of icebergs that 42 52 51 50 -^9 4-a 47 ^ ^5 -»4 4S Fig. 30.— The main paths that icebergs are most liable to follow in the western North Atlantic when advancing southwards toward temperate latitudes. Branches d, e, f, g, h, and i are variations in the drift, once a berg has embarked along path c. This illustration is purely diagrammatic but it contains information where bergs are most liable to be met drifted south of Newfoundland, there is appended below a graph of the iceberg character of the years 1880 to 1927, inclusive, arranged on a basis of 0-10. For a detailed count of the icebergs from 1900 IT" " \- ii y^ ii - -1 ^^ ^ t iX- ^-v^t ^V - :l'i7X I X tx A /\ Il^t X ^ L\ , ^-V ^-^ iXLAZZt ± ^ ^. _N r^. ^^ -SZ^^LA ^- -A zt V rj^ ^^ jv r Z ^ v-' u / - -^^ 3 ^L it '^L " - ^ / - X^^ ^'^ ^ 17 oi23^5fo7ajo ^z^>'iSG739'^ izA^is^bvaOo 12.34s6.7a90 1 z a 4 s b 1 £ « ^ ? 5r Fig. 31. — The iceberg character of the years 1880-1927 based on a scale of 0-10 mean value 4.8 to 1926, and also the departures in numbers from normal, please refer to Ice Patrol Bulletin No. 15, for 1926, pages 75 and 76. The iceberg character of 1927 is 4.8. OCEANOGRAPHY The fact that practically all the icebergs that drifted south of Newfoundland in 1927 remained to break up on the northern part of the Grand Banks, and that at no time during the season did ice threaten the United States-Europe steamship lane routes, gave the patrol more than ordinary opportunity to conduct frequent surveys of the ocean along the junction of the Gulf Stream and the Labrador "\ ^■, .- ■"" .i»o • M .M6 .(04 •■ .• • M2 .tU.W .1A1.7A;.l*.T^.1il to7 • tol '^^^. '"'"-w .M5 .1.1 ;.k.^^. ?5 -• (ta-^'C „ •^" .T T ;/■ m-'-" •'* .M7-™ •.,'" -Jl "lA M (» ■•Fiw-K'-''» - OT 'IK •"' .7.2 .,B ,i. J* •■ai o» •■»' •■"° ">,■'"' 55 M 53 52 ^1 3-0 49 48 47 4t 45 -M. •»= Fig. 32.— Oceanographic stations during 1927 current. We were thus able, during 1927, to follow more closely than ever before the processes that are continually altering the movement and behavior of the water masses in this interesting area around the ocean slopes of the Grand Banks. The state of the cir- culation resulting from the juxtaposition of the Gulf Stream and Labrador current, we have grounds to believe, is in successive months or weeks, never exactly the same, nevertheless there is an unmis- takable tendency for the two antithetically charactered masses to (70) A. 71 occupy positions which are more or less characteristic for the Grand Banks area. It is natural to speculate whether daily synoptic data for the ocean depths would show short-lived movements, similar to those that form in the atmosphere. The ice patrol, however, is almost exclusively concerned in the extent to which major changes, in the circulation cause a deviation in the iceberg drifts. And this, information, we find for all practical purposes, is contained in the current surveys, obtained monthly or bimonthly. In carrying on the scientific investigations, the ice patrol follows a program laid down by the ice patrol board which deals with its general policies and plans. First, our principal concern during the particular ice season is tracing the developments in the circulation from March to July, as governing the drift of bergs approaching the southern end of their transit. For example, the observations taken by the patrol in the first part of April, 1927, indicated the scheme of circulation around the Tail of the Bank depicted on Figure 34 p. 75. And the correctness of this picture is evidenced by the fact that on April 10 to 15 a berg drifted southward, swung around the Tail, and stranded in on the Bank, in conformity with the stream lines that had been calculated. In order to be prepared for future bergs in April, a second investigation of the waters was made April 21 to 25, which showed that the general scheme of circulation had slightly altered. (Fig. 38, p. 78.) No more bergs, it happened, drifted so far south as the Tail, but if they had there were data on board which would have been ample to predict their probable paths. Information on the ever-changing positions of the currents, it is plain to see, is of great value to the patrol in conducting its ice service to shipping. The other aspect of the oceanographic work is one with a longer view, which, after a few more years' mapping of the currents, sees much information resulting from a comparison of the maps from year to year. We believe that there are particular features which are more or less characteristic of all years; types that are easily subject to classification. Already, for instance, we are convinced, as a result of current data collected even over a short period of years, that an area of approximately 1,000 square miles, located on the southwest slope of the Grand Bank, is normally the seat of an anticlockwise rotating eddy. This phenomenon (and it is important from our viewpoint) explains why bergs passing close by the Tail so often drift inshore and remain to melt in the shoal water on the Bank. There- fore, the greater the number of systematic surveys of the circulation, the better we are able to understand what formerly seemed a chance disposition of the ice. There were five dynamic surveys made of the waters of the ice re- gions in 1927. The positions at which observations are usually made (C. G. Bull. No. 15, p. 87) were not adhered to closely in 1927, be- LIBRARY)^ 72 •cause experience now permits certain modifications in the program. Twice during 1927, for example, we were able to gain a good idea of the currents from a map based upon only 20 stations scattered net- like over the region around the Tail of the Bank. The other three surveys, however, dealt with a larger area situated along the eastern slope of the Bank, and consequently they embrace more stations than the earlier investigations. (See fig. 32, p. 70.) But the general plan of sections placed at right angles to the currents underlies all of the observational work. The choice of the particular area to be surveyed, it should be remarked, is often dependent upon the relative position of the ice and the patrol vessel, because we wish never to be far distant from the southernmost bergs. A short description of the methods employed to determine the currents is given herewith. First we decide on the ocean area in which it is most desired to learn the direction and the velocity of the circulation. Usually the waters between the United States-Europe steamship tracks and the Tail of the Grand Bank are of first con- sideration, because it is there the course of the cold current and its freight of ice are subjected to the greatest variations in direction. When respite from ice scouting occurs, the patrol ship cruises over this zone; stopping and taking stations every 15 to 20 miles, the points of observation being distributed equidistant over an area which often approximates in size the State of Pennsylvania. A thoroughly drilled oceanographic team of four to six men starts work when the vessel becomes stopped at the observation point. As soon as the ship is "dead" in the water, a heavy weight attached to a small wire rope is lowered over the side and an instrument called a water bottle is securely clamped to the wire at the rail. The meter wheel, which records the length of wire run out, is next set at zero, the winch brake released, and the line allowed to unreel rapidly off the drum. Six or seven water bottles are successively attached to the wire at those levels at which we desire observations, until we reach a depth of 750 meters, the limit to which the ice patrol has carried the work. A water bottle, it should be explained, is an ingenious mechanical instrument which, at the will of the observer, captures a sample of the sea water in which it is immersed and simultaneously registers the temperature by means of attached thermometers. When all the water bottles are suspended on the wire at the proper depths, a weight, called a messenger, is placed on the wire and, sliding down, trips the first bottle. This causes the instrument to auto- matically make a record and also release a second messenger which in turn slides down to the second bottle, and so the operation is carried on to the last bottle of the series. The wire is then reeled in, the thermometers read, and the samples of the water from the respective depths are bottled, the total elapsed time at a station being from 20 to 30 minutes. 73 The bottled water is next siphoned into the test cells of tlie electric salinometer, an instrument which conveniently measures the total solid salts of the sample per thousand grams of water. (See C. G. Bull. No. 12, pp. 136-147; and Bull. No. 15. p. 125.) There were over 1,000 samples of sea water tested for salinity by this instrument during the patrol of 1927. The next step is to convert temperature and salinity values into terms of specific gravity, and from these latter the currents are calculated. The final result of the current surveys are such sketches and maps as Figures 33 to 52. Such cur- rent maps, moreover, have proved of great value to those in direct charge of the patrol, as they reveal information on the probable movements of the ice. The installation in 1927 of new electric oceanographic winches to lower and hoist the instruments materially shortened the time spent at stations, and thus allowed a greater number to be taken. A total of 208 stations, nearly double the number of any previous season, were located around the Atlantic faces of the Grand Bank. The surveys were made in the following order: The first part of April the so-called critical area around the Tail of the Bank was surveyed. Two weeks later observations were repeated in the same region to determine what changes, if any, had taken place. The first part of May the Modoc investigated the water mass lying along the east side of the Bank from the forty-sixth parallel southward around the Tail and for a distance of 150 miles to the westward along the southwest slope. Three weeks later the currents were traced along the east side of the Bank by the Tampa for a distance of 120 miles north and south of a point on the slope where the warm offshore water pressed in. The final investigation for 1927 was conducted by the Modoc the second two weeks in June, and embraced the entire eastern slope of the Grand Bank from its northern reaches to the Tail and eastward to Flemish Cap. This was the most exten- sive survey ever conducted by an ice patrol vessel, and presented to those in charge of the work a most detailed picture of the ice and current conditions near the close of June. It was upon the informa- tion contained on the current map for this period that the strong recommendation to discontinue the patrol June 25 was based. DISCUSSION OF THE CIRCULATION IN 1927 The total of 208 stations has, for the purposes of illustration and discussion, been divided into five groups or sets, arranged chrono- logically for the periods observed. Each set contains four maps — one dynamic topographic of the sea surface, one showing the direction and velocity of the currents as calculated, one representing the distribution of the cold and warm water, and one showing the relative positions of the fresher and Salter masses. 74 Set I. April 6 to 10, 20 stations. (Figs. 33, 34, 35, and 36.) Set II. April 21 to 25, 21 stations. (Figs. 37, 38, 39, and 40.) Set III. May 10 to 18, 59 stations. (Figs. 41, 42, 43, and 44.) Set IV. May 29 to June 3, 31 stations. (Figs. 45, 46, 47, and 48.) Set V. June 9 to 25, 68 stations. (Figs. 49, 50, 51, and 52.) The dynamic maps. Figures, 33, 37, 41, 45, and 49, show the topog- raphy of the sea surface compared to the 750 decibar (meters) surface, the assumption being that this plane was level. The num- bers, viz, 728.80, 75, 728.70, etc., represent the height of the surface of the sea in dynamic meters above the 750 decibar base plane. j^U^ ^W r' \ \ /, / 726.60 .4fc 45 128.70 72S-50 -725.00- 40 55 .52 S\ SO .*5> -46 -47 4-fo Fig. 33. — Set I. Dynamic topographic map drawn from observations made at stations 631-651, April 6-10, 1927. This map is read the same as an ordinary isotaric weather map , Such maps are quite similar to the ordinary isobaric weather maps, and, for all practical purposes, the dynamic contours represent the stream lines of the currents, as explained in Coast Guard Bulletin No. 14. SET I The oceanic situation April 6 to 10 may be described as consisting of an ellipitical depression in the sea surface centered over the south- west slope of the Grand Bank. From this center a trough extended to the eastward around the Tail, more or less paralleling the contour of the slope, and separating water of higher elevation, which lay in on the Bank, from that offshore to the southward. Figure 33 shows that the sea surface was highest at a point about 100 miles southwest 75 of the Tail, thus recording a slope of about 30 centimeters in a dis- tance of 35 miles. Calculation of velocities shows that a rapid current of 1.4 knots per hour flowed toward the east at the outer stations along the southwest slope, and an equally strong set to the southward took place along the east side of the Bank about 45 miles north of the Tail. The current arrows on Figure 34 clearly show the manner in which the current hugged the 100-fathom con- tour to the Tail, where it split, one branch flowing for a short distance to the westward and then bending to the northwest to overflow the shaUow part of the shelf. The outer branch turned abruptly 3^ 5Z ^\ 50 4-9 4e Fig. 34.— Set I. The direction and velocity of the currents, April 6-10, 1927. April 12-15 is also shown The drift of an iceberg back to the eastward at the fiftieth meridian and joined the more voluminous masses of the Gulf Stream. Particular interest is attached to two features of the circulation which were in process when this picture was recorded: (1) a tendency on the part of the Gulf Stream, as shown in the shape of the current arrows, to force itself in toward the slope of the Bank; (2) the anticlockwise eddy seated over the southwest slope of the Bank, which appears to have received its life from the inner current on the north and also from the outer cur- rent on the south. In such a case it had a mechanical source rather than a hydrostatic cause. Its presence, however, was accountable for the only berg that reached the Tail in 1927, to be carried to the northwest, inshore, where it eventually melted. (See fig. 34.) 76 1^^ X4 53 St- Si So 4? 4i 47 4fc Fig. 35.— Set I. The distribution of cold and warm water at the 50-meter level, April 6-10, 1927 JV) Si SZ J-\ 5o 49 4J 47 Fig. 36.— Set I. The distribution of salinity at the 50-meter level, April 6-10, 1927 77 The distribution of cold and warm water April 6 to 10, at a depth of 50 meters, is sho^\^l on Figure 35. We now see that the southerly drift along the east side of the Bank of 1.4 knots per hour must have been Labrador current because of its extremely low temperature. The much warmer water, greater than 10° C, which lay about 35 miles seaward of the continental edge was "Gulf Stream." The distribution of the salinity at the 50-meter level, as contained on Figure 36, supports the conclusions drawn from the foregoing figures of the set. SET II After an elapse of two weeks we repeated the survey of the area just discussed in order to determine what changes, if any, had taken Sb SZ 5/ So A9 'JO 17 ■"*> Fig. 37. — Set II. Dynamic topographic map drawn from observations made at stations 652-673, April 21-25, 1927. This map is read the same as an ordinary isotaric weather map place in the scheme of circulation around the Tail of the Bank. We found the shallow depression in the sea surface still persisting in about the same position it had had two weeks previously over the southwest slope. A second depression, centere^fl about 50 miles southeast of the Tail, was almost completely cut off from the Grand Bank by a ridge of relatively high contour, which had developed since the preceding survey, and was thrust from west to east, past the Tail between the forty-third and forty-second parallels. The surface of the sea on the eastern side of the Bank, between the forty-third and forty-fourth parallels, was elevated, the dynamic contour of 728.85 72092—27 6 78 dynamic meters projecting in to the 100-fathom curve. The current velocities on Figure 38, when compared with those of two weeks previous (fig. 34) show a considerable slackening, except south of the Tail, where the outer current bent back toward the southwest at the very rapid rate of 1.7 knots per hour. There is also evidence that the outer current as a whole had pressed in more closely toward the slopes of the Grand Bank, especially on the east side of the latter, between the forty-fourth and forty-third parallels, where the cold water was probably dammed from following its usual path along the continental edge. The dynamic calculations in this instance are further sup- ported by the drift of a large iceberg (fig. 38) first sighted by a steamer V--W Vt^ !■< ; r "■ l^./ "^l)---. }/ / i 0 3 :^<.-; 44. fS 'H «3 4^ fl 6'9 5d S2. SI SO ^9 -ffi -*7 ft Fig. 38— Set II. The direction and velocity of the currents, April 21-25, 1927. Numbers 66-70 repre- sent a line of oceanographic stations taken by the "Michael Saro," 1910. See p. 80 on April 14 and then by the patrol on the 16th, and again for the last time on the 17th. Obviously its track agrees closely with the direc- tion of the currents as calculated. It is also interesting that on April 16, a calm smooth day, we could plainly see tide rips about 2 miles westward of this berg. This must have been near the boundary of two currents (fig. 38), because later in crossing this zone we experi- enced an abrupt drop in the temperature. Figure 39, when compared with Figure 35, shows that the tempera- ture of the water around the Grand Bank grew much warmer during the month of April, except offshore from the southwest slope, where it had cooled somewhat. The distribution of salinity (fig. 40) in general corroborates the temperature chart for the same period. 79 y •— ~«' TW^ , ...'■ \ ''"-' -\ \^,';ju / Fig. 39.— Set II. The distribution of cold and warm water at the 50-meter level, April 21-25, 1927 "XT" "^^ X/ / f' \ /V •A •\ / ^ ', \ / \, \ / / \'>5? ii I - I ^ 4-Z 4-1 S4 5i ^i 5-1 5o 4? 44 4-7 4«. Fio. 40.— Set II. The distribution of salinity at the 50-meter level, April 21-25, 1927 80 The indentation south of the Tail of warm Atlantic water into the mixed zone and its comiterflow toward the southwest, as shown on Figure 38, p. 78, brings to mind a similar condition foimd by the Michael Sars on a section across this region in 1910. (Murray and Hjort, The Depths of the Ocean, p. 99.) As a result of the observations of this expedition, the impression is often held that the Gulf Stream south of Newfoundland is split by a cold southwesterly current, but as such a phenomenon has seldom been observed the true condition has remained obscure. The ice patrol observed a similar location of the two currents south of the Grand Bank in 1923, but evidence in the form of surface temperature charts proved the cold current to be temporary and caused by the great irregularity and distortion of the boundary between coastal and oceanic masses. A multitude of curling tongues and votices is a natural accompaniment along the border of two opposing ocean flows, and our present-day ability to plot the stream lines of the currents reveals hitherto unsuspected phenomena concerning the behavior of the water particles. The fact that the course of the northern edge of the Gulf Stream south of the Grand Bank is found so extremely sinuous, turning and bending back so sharply upon itself, strikingly emphasizes the great mobility of water in the open sea. SET III This set of observations, taken May 10 to 18, extends the view from the neighborhood of the Tail, where the two former surveys stopped, to the circulation along the entu'e eastern side of the Bank. This is the first time that a dynamic survey has ever been made of this particular region. The axis of the depression previously observed off to the southwest of the Grand Bank was moved so much closer in to the continental edge, as shown by Figure 41, that the rising slope to be expected inshore of it no longer falls within the picture. Con- sequently no westerly current appears there, though such a set no doubt existed some few miles in on this part of the Bank. At the same time the extreme tip of the projection of high surface previously extending from west to east in the offing of the Tail had flattened out and the low pool to the southeastward had also shifted correspond- ingly to the westward. A second trough in the sea surface, as em- braced by the dynamic contour of 728.70 dynamic meters, is seen on Figure 41 projecting offshore from the shelf for about 80 miles between the forty-third and forty-fourth parallels, and this formation is probably a development of the shoaler depression seen in the same general location on Figure 37. The ridgelike elevation to the north of it persists in extending southwestward, even abutting the 50-fathom curve of the Bank. 81 S4- Si> 5Z .51 v50 49 4S ^7 46 45 4A 4^ Fig. 41. — Set III. Dynamic topographic map drawn from observations made at stations 678-737, May 10-18, 1927. This map is read the same as an ordinary isotaric weather map 7^ KJ I ■■ . I I I I 'I ■ £ ,o5 / -o.E/ y (oa Y; .f^1' 1^^ 4/ ^ =^4 ^ 47 4S 4+ 4i « SI 50 4.- ^ J .< z o4.0 34.94 27.76 . 96969 40 ! 728.8081 .58852 668 Apr. 25 43 05 51 35 620 0 4.4 33.00 26.18 . 97449 185 0 0 25 4.2 33.12 26.30 . 97426 173 24.35938 .04473 50 4.2 33.30 26.44 . 97401 159 , 48.71276 . 08626 125 4.2 34.01 27.00 . 97316 108 ! 121. 73164 . 18652 250 4.2 34.61 27.40 . 97223 71 243. 31852 . 29853 450 4.6 34.86 27.63 .97114 52 437. 65552 . 42203 750 4.0 35.06 27.85 . 96961 32 728. 76812 . 44863 669 ...do 42 56 51 00 1,080 0 5.2 33.22 26.26 .97441 177 0 0 25 4.4 33.64 26.68 . 97390 137 24. 35263 . 03798 50 8.1 34.49 26.88 . 97360 118 48. 69738 .07088 125 9.0 34.87 27.03 . 97314 106 121.70013 . 15501 250 7.2 34.75 27.22 . 97242 90 243. 29763 .27764 450 4.8 34.64 27.13 .97133 71 437. 62263 .43914 750 4.0 34.83 27.67 . 96979 50 728. 84063 .62114 670 ...do 42 51 50 16 800 0 0.4 33.21 26.66 . 97403 139 0 0 25 0.4 33.23 26.68 . 97390 137 24. 34913 . 03448 50 -0.2 33.27 26.74 . 97372 130 48. 69438 .06788 125 0.2 33. 62 27.00 .97314 106 121. 70201 .15689 250 1.0 33.83 27.12 . 97249 97 243. 30451 .28452 450 2.2 34.24 27.37 . 97137 75 437. 69051 . 45702 750 2.6 34.73 27.75 . 9G967 38 728. 84651 . 62702 671 —do 42 35 50 19 2,270 0 2.6 33.43 26.68 . 97401 137 0 10 25 3.9 33.64 26.74 .97384 131 24. 34813 . 03348 50 7.0 34.48 27.03 . 97346 104 48. 68937 .06287 125 6.4 1 34. 67 27.21 . 97297 89 121. 68051 . 13539 250 5.3 34.61 27.35 . 97229 77 243. 2C026 . 25027 450 4.6 34.57 27.44 . 97132 70 437. 62126 . 38777 750 3.8 34.68 27.58 . 96987 58 728. 79876 .57927 672 ...do..— 42 17 50 18 2,845 0 10.6 34.79 26.70 .97399 134 0 0 25 11.2 35.07 26.81 . 97378 125 24 34713 .03248 50 11.4 35. 15 26.84 .97364 122 48. 68988 .06338 125 11.6 35.26 26.89 .97338 120 121.71313 . 16801 250 8.6 34.86 27.00 . 97256 104 243. 32438 .20439 450 5.1 34.78 27.51 . 97126 64 437. 90638 . 67289 750 4.2 34.82 27.65 .96980 51 729. 06538 .84589 > Interpolated. 104 Oceanographic station data and dynamic calculations, 1927 — (Jontinued Date Lati- tude Longi- tude a depth of Ol depth a = Meters ai= Pressure in decibars Station Tem- Sa- water pera- ture linity 0/00 «< V V-Vi E E-Ei 0 r o / "C. 673 Apr. 25 41 57 50 18 3,720 0 4.0 33.45 26.58 0. 97411 147 0 0 25 3.2 33.30 26.58 . 97400 147 24. 35138 . 03673 50 1.2 33.38 26.75 . 97371 129 48. 69775 . 07125 125 4.4 34.36 27.33 . 97285 77 121. 69375 . 14863 250 5.8 34.28 27.42 . 97222 72 243. 26075 .24076 450 4.7 34.84 27.60 .97117 55 437. 59975 . 36626 750 4.0 34.86 27.70 . 96976 47 728. 73925 . 51976 674 Apr. 29 42 46 49 61 2,090 0 5.0 33.72 26. 67 . 97402 138 0 0 25 4.6 33.08 26.69 . 97389 136 24. 34888 . 03423 50 4.6 33.90 26.87 . 97360 118 4& 69251 . 06601 125 3.9 34.20 27.18 . 97299 91 121. 68964 . 14452 250 3.8 34.59 27.50 . 97214 62 243. 26027 . 24028 450 3.6 34.80 27.69 . 97108 46 437. 58227 . 35878 750 3.6 134.84 27.72 . 96973 44 728. 70377 .48428 675 —do 42 56 49 54 238 0 25 7.6 7.6 34.15 34.18 26.68 26.71 . 97401 . 97386 0 0 50 9.4 34.72 26.85 . 97363 "m" "48."6920i" '.'06551 125 225 7.1 5.0 34.70 34.50 27.19 27.30 . 97299 . 97244 250 4.1 34.44 27.35 . 97228 ""76" "243."27576' "."25577 676 ...do 43 08 50 01 54 0 1.4 33.21 26.60 . 97409 145 0 0 13 1.1 33.11 26.65 . 97398 140 12. 66246 . 01849 26 6.0 34.05 26.82 . 97377 124 25. 32284 39 5.7 33.96 26.92 . 97359 113 37. 98078 50 52 26.95 26.95 .97353 . 97352 111 111 48. 68984 .... '.'06334 '5.4' '34.12' 677 ...do 43 16 50 16 59 0 0.4 33.11 26.58 .97411 147 6 15 0.4 33.21 26.66 . 97396 139 14. 59553 .00639 30 0.0 33.19 26.67 . 97388 137 29. 19433 .01708 45 0.0 33.27 26.73 . 97375 131 43.80156 . 03721 50 0.0 33.30 26.78 . 97369 127 48. 68016 . 05366 60 0 1 33 36 26.80 . 97353 116 678 May 10 46 04 48 38 79 0 0.8 32,99 26.46 . 97422 158 """6 0 20 0.6 33.00 26.48 .97411 156 19. 48330 .03135 40 0.4 33.02 26.51 . 97398 152 38. 96150 . 05940 50 -1.0 26.56 . 97390 148 48, 70360 . 07710 60 -0.2 '33.' 12" 26.62 . 97380 143 58. 44030 . 08985 80 -1.1 33.13 26.75 . 97358 130 77. 91590 . 11890 ...do 46 00 48 21 119 100 0 . 97331 . 97431 112 167 97. 38490 0 . 14315 679 "\.l' '32.'92' '26." 37' 0 25 0.0 32.92 26.45 . 97423 170 24. 35538 . 04072 50 -1.2 33.08 26.63 . 97406 164 48. 70475 . 07825 75 -1.4 33.24 26.76 . 97394 163 73. 04762 . 11209 100 -L4 33.32 26.82 . 97388 169 97. 38550 . 14375 ...do 46 66 48 00 183 » 125 0 26.84 26. 23 . 97386 . 97444 178 180 121. 71962 0 . 17451 680 "ae' "32." 69' 0 30 -0.6 33.00 26.54 .97400 149 29. 22660 . 04935 60 -1.6 33.28 26.80 . 97363 126 58. 44105 . 09060 90 -1.7 33.37 26.87 . 97342 118 87. 64680 . 12720 120 -1.4 33.56 27.02 . 97324 114 116.84670 . 16225 125 -0.4 27.02 . 97313 105 121. 71262 .17750 150 -1.4 li'ss' 27.04 . 97299 102 146. 03912 . 19338 681 ...do 45 52 47 41 1,097 0 1.4 32.78 26.25 .97442 178 0 0 25 -0.8 33.27 26.74 . 97384 131 24. 35325 . 03860 50 -1.0 33.54 26.99 . 97349 107 48. 70487 .07838 125 2.4 34.42 27.47 . 97272 64 121. 68775 . 14263 250 3.2 34.73 27.66 . 97198 46 243. 23150 .21151 450 3.2 34.80 27.72 . 97104 42 437. 53350 .30001 750 3.1 34.87 27.78 . 96966 37 728. 63850 . 41901 682 ...do 45 48 47 20 1,463 0 1.6 33.51 26.83 . 97387 123 0 0 25 0.1 33.57 26. 97 . 97363 110 24. 34375 . 02910 50 0.9 33.86 27.15 . 97334 92 48. 68087 .05438 125 2.1 34.47 27.56 . 97263 55 121. 65475 . 10963 250 3.0 34.70 27.66 . 97195 43 243. 19100 . 17101 450 3.1 34.78 27.71 . 97105 43 437. 49100 . 25751 750 3.6 34.85 27.73 . 96972 43 728. 60650 . 38701 683 May 11 45 42 46 46 1,645 0 0.3 33.55 26.94 . 97376 112 0 0 25 0.6 33.70 27.04 . 97356 103 24. 34150 . 02685 50 1.6 33.98 27.20 . 97329 87 48. 67712 .05063 125 1.7 3149 27.61 . 97257 49 121. 64687 . 13201 250 3.0 34.81 27.76 . 97189 37 243. 17562 .15564 450 3.2 34.90 27.78 . 97098 36 437. 46262 . 22914 750 3.4 34.91 27.79 . 96966 37 728. 55863 .33914 ■ Interpolated. I Exterpolated. 105 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of depth 0 = Meters a\ = Pressure in decibars Station Tem- Sa- water pera- ture linity 0/00 «< V V-Vi E E-Ei o / 0 / "C. 684 May 11.. 45 18 46 45 2,743 0 4.2 33.71 26.76 0. 97393 129 0 0 25 3.4 33.76 26.87 . 97372 119 24. 34562 .03098 50 3.7 33.81 26.89 . 97358 116 48. 68687 . 06038 125 3.8 34.41 27.35 . 97283 75 121. 67725 . 13213 1 250 3.9 34.71 27.58 . 97206 54 243. 23287 . 21289 450 3.6 34.89 27.75 . 97102 40 437. 54087 . 30739 1 750 3.4 34.90 27.78 . 96967 38 728. 64437 . 42489 685 ...do 1 44 52 46 43 3,657 0 9.4 34.85 26.95 . 97375 111 0 0 1 25 9.6 34.80 26.88 . 97371 118 24. 34325 . 02860 I 50 9.5 34.74 26.85 . 97373 131 48. 68ti25 . 06975 125 9.2 34.83 26.96 . 97321 113 121. 69650 . 15138 250 4.9 34.46 27.25 . 97238 86 243. 29588 .27589 450 4.4 34. SO 27.58 .97118 56 437. 65188 . 41839 750 4.2 34.94 27.72 . 9f 974 45 728. 78988 . 57039 686 ...do..... 44 28 46 43 3,725 0 13.6 35.80 26.90 .97380 116 0 0 25 13.7 3.5. 78 26.87 . 97372 119 24. 54400 . 03123 50 13.8 35.76 26. 83 . 973(15 123 48.68613 .06151 125 13.2 35.77 26.97 . 97320 112 121. 69451 . 14939 250 10.8 35.41 27.15 . 97251 99 243. 30451 .28452 450 5.8 35.03 27.62 .97116 54 437. 69661 .4(302 750 5.0 34.98 27. 68 . 9. 980 51 728. 87201 . 65252 687 ...do 44 35 47 17 3,650 0 14.0 35.72 26. 75 . 97394 130 0 0 25 14.0 35.86 26.86 . 97373 120 24. 34588 .03123 50 14.1 35.86 26.84 . 97364 122 48. 68801 . 06151 125 13.5 35.87 26.98 . 97320 112 121. 69451 . 14939 250 10.9 35.38 27.10 . 97256 104 243. 30451 . 28452 450 5.3 34.67 27.40 . 97136 74 437. 69651 . 46302 750 5.0 34.96 27.66 .9.981 62 728. 87201 . 65252 688 May 12 44 40 47 50 3,475 0 9.0 34.54 26.76 . 97394 130 0 0 25 9.1 34.56 26.77 . 97382 129 24. 34700 .03235 50 9.2 134.60 26.79 . 97369 127 48. 69098 . 06448 125 19.1 34.68 26.87 . 97329 1:1 121. 70263 . 1.5751 250 1 7.5 34.61 27.06 . 97258 106 243. 31951 . 29952 450 5.1 34.63 27.36 .97140 78 437. 71751 .48482 750 4.8 34.95 27.67 . 96981 52 728. 89901 . 67952 688 —do 44 42 48 08 2,652 0 8.3 34.53 26.88 . 97382 118 0 0 25 8.2 34.53 26.89 . 97370 117 24. 34400 .02935 50 8.1 34.52 26.90 . 97358 116 48. 68500 . 06850 125 6.2 134.31 27.00 . 97316 108 121. 68775 . 14263 250 5.8 34.57 27.25 . 97238 86 243. 28400 .26401 450 4.9 34.89 27.60 .97117 55 437. 6i,900 . 40561 750 4.0 34.92 27.74 . 96972 43 728. 77250 . 55301 690 ...do 44 46 48 24 2,377 0 3.6 33.44 26.60 . 97409 145 0 0 25 3.6 33.60 26.73 . 97385 132 24. 34925 . 03460 50 3.5 33.96 27.03 . 97345 103 48. 69050 .06400 125 3.3 34.33 27.32 . 97286 78 121. 67713 . 13201 250 3 2 34.81 27.70 . 97194 42 243.22713 . 20714 450 3.0 .34.93 27.83 . 97093 31 437.51413 . 28064 750 2.7 34.91 27.85 . 96959 30 728. 59213 . 37264 691 do 44 49 48 37 320 0 3.0 33.47 26. 68 . 97401 137 0 0 25 3.0 33.65 26. 82 . 97377 124 24. 34725 . 03260 50 2.9 33.97 27.05 . 97.<44 102 48. 68738 .01 .088 125 4.0 1 34. 42 27.34 . 97284 76 121. 67288 . 1:>776 250 4.3 34.74 27.55 . 97209 57 243. 2 lUl . 21102 450 4.0 134.84 27.67 .97110 48 437. 5.5001 .3lo52 . 750 3.5 34,90 27.75 . 9f.970 41 728. 67001 . 45062 692 ...do 44 52 48 51 201 0 0.6 32.90 26.41 . 97427 163 0 0 25 0.4 32.92 26.43 .97414 11 24. 35513 .04048 50 -1.6 33. 30 26.82 . 97o64 1^2 48.681.12 .07588 125 0.7 33.70 27.03 . 97.-. 13 105 97. 35512 . 16114 200 1.8 33.90 27.12 . 97271 97 146. 00487 . 2;i677 240 2.4 34.16 27.27 .97239 84 194. 63987 . 313u7 250 27.28 .97234 82 243. 26262 .32092 693 ...do 43 53 49 09 238 0 "8.1" "34." 50" 26.84 .97386 122 0 0 25 8.2 34.50 26.87 . 97^72 119 24. 34475 . 03010 50 7.4 34.38 26. 89 . 97359 117 48. 68lil2 .05963 100 5.6 34.42 27.11 . 97317 98 97. 35612 . 11338 150 6.4 34.47 27. 2^ .972S2 85 146. 004s7 . 15914 200 5.2 34.50 27.27 . 97258 84 194. 63987 . 20131. 250 27.31 .97233 81 243. 26262 . 24264 Interpolated. 106 Oceanographic station data and dynamic calculations, 1927 — Continued Longi- a depth ai 0= Meters ai= = Pressure in decibars station i^^te 1 \^; tude of depth Tem- Sa- water pera- ture linity 0/00 h V V-Vi E E-Ei 0 / o , °C. 694 May 12 43 51 48 55 347 0 4.3 33.23 26.37 0. 97431 167 0 0 1 25 7.8 34.39 26.83 . 97376 123 24. 35087 .03623 50 7.4 34.38 26.89 . 97359 117 48. 69275 . 06625 125 6.0 ' 34. 33 27.04 . 97313 105 121. 69475 . 14963 250 5.6 '34.53 27.25 .97238 86 243. 28912 . 26914 450 5.3 34.61 27.35 . 97141 79 437. 66812 .43464 750 5.0 34.94 27.64 .96983 54 728. 85412 . 63464 695 May 13 43 49 48 42 2,524 0 11.0 35.20 26.95 . 97375 111 0 0 25 10.2 35.21 27.10 . 97351 98 24. 34075 . 02610 50 10.0 35.24 27.15 . 97335 93 48. 67650 . 05000 125 8.4 35.01 27.22 . 97296 88 121. 66312 . 11801 250 6.2 34.74 27.33 . 97231 79 243. 26750 . 24751 450 4.1 > 34. 63 27. 50 . 97126 64 437. 62450 . 39101 750 3.9 34.92 27.75 . 96971 42 728. 77000 . 55051 696 --do 43 48 48 22 2,926 0 10.2 34.83 26.80 . 97390 126 0 0 25 10.4 34.87 26.80 . 97379 126 24. 34612 . 03148 50 10.6 35.05 26.90 . 97358 106 48. 68815 . 06165 125 6.6 34.55 27.11 . 97307 99 121. 68752 . 14241 250 4.9 34.64 27.40 . 97224 72 243. 26940 .24941 450 4.2 34.83 27.62 .97114 52 437. 60740 . 37391 750 4.1 34.95 27.75 . 96971 42 728. 73490 .51541 697 ...do 43 45 48 00 3,651 0 6.0 35.50 26.39 . 97429 165 0 0 25 5.8 33.72 26.58 . 97400 147 24. 35362 . 03898 50 4.7 33.96 26.89 . 97358 116 48. 69837 .07188 125 4.0 34.62 27.45 .97273 65 121. 68500 .13988 250 4.5 34.91 27.66 . 97198 46 243. 22937 i . 20939 450 4.4 34.98 27.73 . 97104 42 437. 53137 . 29789 750 4.0 34.97 27.78 . 96968 39 728. 63937 . 41989 698 ...do 43 42 47 37 3,654 0 8.5 34.16 26.55 . 97413 149 0 0 25 9.9 34.71 26.76 . 97383 130 24. 34950 . 03485 50 8.9 '34.60 26.84 .97364 122 48. 69287 . 06638 125 8.0 134.59 26.97 . 97320 112 121. 69937 .15426 250 7.6 34.72 27.13 . 97251 99 243. 30625 . 28626 450 3.3 34.54 27.50 . 97125 63 437. 68225 .44876 750 4.8 34.93 27.65 . 96980 51 728. 83975 . 62026 699 ...do 43 10 47 50 3,292 0 3.8 33.66 26.76 . 97394 130 0 0 25 3.6 33.64 26.76 .97383 130 24. 34712 .03248 50 2.8 ' 33. 70 26.87 . 97360 118 48. 69000 . 06350 125 2.4 34.21 27.34 . 97284 76 121. 68150 .13638 250 '3.4 34.66 27.59 .97204 52 243. 36150 .34151 450 4.0 34.92 27.74 . 97103 41 437. 66850 . 43501 750 3.8 134.93 27.77 . 96968 39 728. 77500 . 55551 700 -May 14 42 15 48 44 3,152 0 6.4 133.85 26.62 . 97407 143 0 0 25 6.2 33.85 26.64 .97394 141 24. 35013 .03548 50 5.0 33.88 26.82 . 97365 123 48. 69500 .06850 125 4.7 34.36 27.22 . 97295 87 121. 69250 . 14738 250 4.3 34.78 27.58 . 97206 54 243. 25562 .23564 450 3.8 34.75 27.62 .97114 52 437. 57562 . 34214 750 3.6 34.96 27.80 . 96965 36 728. 694125 .47464 701 ...do 42 26 48.59 3,949 0 4.2 33.54 26. 63 . 97406 142 0 0 25 2.8 33.51 26.73 . 97385 132 24. 34887 .03423 50 2.0 33.61 26.88 . 97359 117 48. 69187 . 06538 125 4.1 34.42 27.30 . 97288 80 121. 68450 . 13938 250 14.0 34. 61 27.48 . 97216 64 243. 24950 . 22951 450 4.1 34.70 27.56 . 97120 58 437. 58550 .35201 750 3.8 34.94 27.78 . 96968 39 728. 71750 . 49801 702 ...do..-. 42 34 49 08 2,560 0 6.6 33.92 26.64 . 97405 141 0 0 25 8.2 34.48 26.87 .97371 119 24.34713 . 03248 50 8.7 34.67 26.92 . 973.56 114 48. 68812 .06163 125 7.9 34.86 27.20 . 97298 90 121. 68337 . 13826 250 '6.2 134.88 27.43 . 97221 69 243. 25775 . 23776 450 5.3 34.90 27.58 .97119 57 437. 59775 . 36426 750 4.2 34.96 27.75 . 96971 42 728. 73275 .51326 703 ...do...._ 42 42 49 18 2,359 0 6.8 33.78 26.52 . 97416 152 0 0 25 5.8 33.93 26.74 . 97384 131 24. 35000 .03535 50 3.9 34.01 27.03 . 97345 103 48.69112 . 06463 125 3.6 34.08 27.15 . 97302 94 121.68375 .13863 250 14.4 134.68 27.50 . 97214 62 243. 25625 .23626 450 4.4 34.85 27.64 .97112 50 437. 58225 .34876 750 4.0 34.94 27.77 . 96969 40 728. 70375 . 48426 704 ...do.... 42 49 49 28 1,832 0 6.5 33.91 26.65 .97404 140 0 0 25 6.2 33.93 26.70 . 97388 135 24. 35000 .03535 50 5.2 34.00 26.88 . 97359 117 48. 69337 . 06687 125 5.8 34.53 27.23 . 97295 87 121. 68862 . 14350 250 5.5 34.86 27.52 .97213 61 243.25612 .23613 450 4.6 134 88 27.65 .97112 50 437. 58112 ,34763 750 4.2 34.94 27.74 . 96972 43 728.70112 .48763 1 Interpolated. 107 Oceanographic station data and dynamic calculations, 1927 — Continued Date a depth of depth a = Meters Ol = Pressure in deeibars Station Lati- Longi- tude tude Tem- Sa- water pera- ture linity 0/00 S| V V-Vi E E-E o / o / °C. 705 May 14 42 56 49 37 640 0 2.0 33.32 26.65 9. 97404 140 0 0 25 0.4 33. 34 26.79 . 97380 127 24. 34800 . 03335 50 2.9 33.52 26.90 1 . 97357 115 48.69012 . 0G362 125 5.9 34. 51 27. 20 1 .97298 90 121.68574 . 14062 250 5.3 34.68 j 27.40 . 97224 72 243. 26199 .24200 450 4.6 34.85 27.62 .97115 53 437. 60099 . 36750 750 4.0 34.91 27.73 . 96973 44 728. 73299 . 51350 706 ...do...- 43 03 49 47 160 0 3.1 33.36 1 26.58 .97411 147 0 0 40 3.4 33. S4 26.94 . 97357 111 38. 95360 .05150 80 4.5 34.19 27.11 . 97326 98 77. 89020 . 09320 1 120 4.0 34.25 27.13 1 . 97306 96 116.81660 .13215 125 4.0 27.15 . 97302 94 121.68180 . 13668 160 3.8 li'si 27.28 . 97274 82 155.73260 . 16831 707 May 15 42 29 49 56 2.743 0 5.2 33.12 26.18 . 97449 185 0 0 25 2.4 33. 33 26. 62 . 97396 143 24. 35562 . 04097 50 2.2 33. 72 26. 95 . 97352 110 48.69912 . 07262 125 3.4 '34.13 27.17 .97300 92 121.69362 .14850 250 5.4 34.70 27.40 . 9722:j 71 243. 27050 . 25051 450 4.2 34.78 27.61 .97115 53 437. 60850 .37501 750 4.0 34.88 27.73 . 96973 44 728. 74050 . 52101 708 ...do 42 15 50 04 2,926 0 4.4 33.60 26.65 .97404 140 0 0 25 4.2 33.64 ! 26.70 . 97388 135 24. 34900 . 03435 50 5.0 33.86 26.79 . 97368 126 48. 69400 .06750 125 5.3 34.57 27.32 .97296 94 121.69300 . 14788 250 5.6 34.94 27.57 . 97208 56 243. 25800 . 23801 450 4.4 34.90 i 27.68 .97109 47 437. 57500 .34151 750 4.0 34.99 1 27.79 . 96967 38 728. 68900 . 46951 709 ...do..-. 42 00 50 10 3,712 0 7.7 33.41 26.09 . 97457 193 0 0 25 7.4 34.31 26.83 . 97376 123 24.35412 . 03947 50 10.3 34.99 26.91 . 97357 115 48. 69574 .06924 125 6.7 34.59 27.15 . 97303 95 121.69324 . 14812 250 5.2 34.57 27.33 .97231 79 243. 276;}6 . 25637 450 4.6 34.88 27. '65 .97112 50 437. 61936 . 38587 750 4.3 35.05 27.80 . 96967 38 728. 73786 .51837 :710 ...do..-. 42 01 50 40 3,719 0 6.6 33.41 26.25 . 97442 178 0 0 25 6.4 33.51 26.35 . 97421 168 24.35787 . 03422 50 4.7 33.86 26.82 . 97366 124 48.70624 . 07974 125 3.3 34. 22 27. 25 .97292 84 121.70299 .15787 250 3.7 34.61 I 27.52 .97212 60 243. 26799 .24800 450 3.9 34.78 27.73 .97104 42 437. 58399 . 35050 750 4.2 34.96 27.75 . 96971 42 728. 69649 . 47700 711 ...do.... 42 02 51 07 3,840 0 6.6 32. 90 25.84 . 97481 127 ; 0 0 25 3.8 33.32 26.49 . 97408 155 24.36112 . 04647 50 3.6 33.85 26.93 .97354 112 48. 70637 . 07987 125 7.0 34.74 27.23 .97295 87 121.69974 .15462 250 5.4 34.78 27.47 . 97218 66 243. 27037 . 25038 450 4.2 34.74 27.58 .97118 56 437. 60637 .37288 750 4.0 34.98 27.78 . 96968 39 728. 73537 .51588 712 ...do 42 24 51 10 2,404 0 8.8 33.49 25.99 . 97467 203 0 0 25 8.2 33.85 26.36 . 97421 168 24. 36100 . 04635 50 10.6 34.96 26.83 .97365 123 48.71025 . 08375 125 11.6 35.32 26.93 . 97324 116 121.71862 .17350 250 9.0 35.13 27.23 . 97262 110 243. 32237 .30238 450 5.0 34.69 27.45 . 97131 69 437. 69537 . 46188 750 4.2 34.88 27.68 . 96978 40 728. 85887 . 63938 713 May 16 42 21 51 44 3,349 0 9.0 33.71 26. 12 . 97454 190 0 0 25 10.8 34.18 26.57 . 97401 148 24. 35687 . 04222 50 11.8 35.24 26.83 . 97305 123 48. 70262 .07612 125 11.7 35.31 26. 90 . 97327 119 121.71212 .16700 250 9.4 34.96 27.03 . 97261 109 243. 32962 . 30963 450 5.0 34.54 27.33 . 97143 81 437. 73362 .50013 750 4.3 34.94 27.72 . 96975 46 728. 91062 .69113 714 ...do 42 44 51 55 2,743 0 8.4 33.22 25. 84 . 97481 217 0 0 25 7.0 33.66 26.25 . 97431 178 24. 3C400 .04935 50 9.0 34.23 26.53 . 97393 151 48.71700 .09050 125 10.0 35.10 27.05 .97312 104 121.73137 . 18625 250 17.4 34. 90 27.33 .97232 80 243. 32137 . 30138 450 5.1 34.81 27.53 .97124 62 437. 67737 . 44388 750 4.3 34.94 27.72 . 9C975 46 728. 82587 , .60638 •715 ...do.... 42 59 51 46 2,194 0 6.8 32.88 25.80 .97485 221 0 0 25 6.2 33.26 26.17 . 97439 186 24. 36550 1 .0.5085 50 10.0 34.85 26.85 . 97363 121 48.71.575 .08925 125 5.8 34.32 27.06 .97311 103 121.71850 .173.38 250 7.2 34.85 27.28 .97236 84 243.31047 .29048 450 4.8 34.79 27.55 .97122 60 437. 66387 .43038 750 4.0 34.88 1 27.71 .96975 46 728. 81387 1 .59438 ■1 In ten Dolated. 108 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of Qi depth 0= Meters ai= Pressure in decibars station Tem- Sa- water pera- linity s, V v-v,, E E-E: ture 0/00 o / o , °C. 716 May 16_. 43 06 51 35 768 0 6.3 32 72 25.74 . 97490 226 0 0 25 5.0 33.30 26.35 .97421 168 24. 36387 . 04922- 50 9.2 34.74 26.90 . 97358 116 1 48.71124 .08474 125 7.1 34.57 27.03 . 97314 106 121.71324 . 16812: 250 4.7 34.52 27.35 .97229 77 243. 30261 . 28262.' 450 4.0 34.77 27.62 .97114 52 437. 64561 .41212 750 3.8 34.87 27.73 . 96973 44 728. 77611 . 55662: 717 ...do 43 15 51 24 549 0 5.8 32 59 25.70 . 97494 230 0 0 60 3.4 33.19 26.42 . 97399 162 58.46790 . 11745 120 7.6 1 34. 36 26.86 . 97332 122 116.88720 .20275 180 7.2 34.68 27.15 . 97279 98 175. 27050 . 26911 240 5.7 34.75 27.41 . 97227 71 233. 62230 i . 31861 —do 43 08 50 48 129 250 0 27.42 26.03 . 96222 . 97463 70 199 243. 34475 1 . 32476 718 "\.Y '32 86" 0 0 25 3.6 33.02 26.27 . 97429 176 24.36150 .04685. 50 > 1.8 33.24 26.60 . 97386 144 48. 71337 . 08687 75 0.8 33. 38 26. 78 . 97358 127 73.05637 i .12083 100 3.4 33. 96 27. 03 . 97324 105 97. 39162 ! . 14987 ...do 42 58 50 58 1,079 125 0 2 27. 13 25.78 .97304 . 97487 49 223 121. 72012 ' . 17500^ 719 5' 2' '3261" 0 iO 25 5.0 32 80 1 25. 95 . 97459 206 24. 36825 . 05360- 50 2.2 33.12 1 26.47 . 97398 156 48. 72537 .09887 125 5.9 34. 62 27. 29 .97290 82 121. 73337 .18825 250 5.2 34.73 ! 27.46 . 97219 67 243. 30149 . 28150 450 4.2 34.81 27.63 .97113 51 437. 63349 . 4000O 750 3.7 34.85 27.72 . 96973 44 728. 76249 . 54300' 720 .-do 42 45 51 11 1,280 0 5.2 32 36 25.59 . 97505 241 0 0 25 5.0 32 44 25.68 . 97485 232 24. 37375 . 05901 50 3.0 S2 45 25.88 . 97454 212 48.74112 .11462- 125 5.4 34.32 27.11 . 97306 98 121.77612 .23100. 250 5.0 34. 52 27.32 . 97232 80 243. 36237 .34238. 450 4.1 34. 79 i 27. 63 .97113 51 437. 70737 . 47388 750 3.9 34. 79 ! 27. 66 . 96980 51 728. 84687 . 62738 721 May 17 42 40 50 40 2,103 0 5.4 32 42 1 25. 61 . 97503 239 0 0 25 3.9 32. 79 ! 26. 06 .97449 196 24. 36900 . 05435 50 1.4 33.21 1 26.60 . 97386 144 48. 72337 . 09687" 125 6.2 34. 50 , 27. 15 . 97303 95 121. 73174 . 18662- 250 5.0 34. 67 i 27. 43 . 97221 69 243.30924 .28925. 450 4.2 34.86 1 27.67 .97110 48 437. 64024 . 40675 . 750 3.9 34. 90 ! 27. 73 . 96973 44 728. 76474 . 54525' 722 _..do 42 53 50 14 367 0 4.2 33. 40 26. 51 .97417 153 0 0 50 4.0 33. 99 27. 00 .97348 106 48. 69125 . 06475- 100 5.0 34. 2S 27. 12 . 97312 93 97.35625 1 .11450 150 6.3 34. 56 1 27. 18 .97288 91 146. 00625 t . 16051 200 5.6 34. 56 1 27. 27 . 97259 85 194. 64300 ; . 20451 ..-do 42 45 49 53 2.081 250 0 2 27. 30 26.50 .97234 . 97418 82 154 243. 26625 . 24626 723 ""6."2' "33.68' 0 0 25 5.1 33.84 1 26.76 . 97383 141 24.35012 .03547 50 4.8 34. 29 27. 16 . 97333 91 48. 68962 1 . 06312 125 5.6 34. 55 1 27. 27 .97242 84 121.67399 I .12887 250 5.3 34.83 i 27.52 . 97213 61 243.26461 .24462- 450 4.4 34.93 i 27.70 . 97107 45 437. 58461 .35112- 750 4.0 34. 90 ! 27. 73 . 96973 44 728. 70461 . 48512: 724 ...do 42 26 50 20 2,834 0 5. 8 1 32. 52 25.63 . 97501 237 0 0 25 3.3 32 76 26.08 . 97447 194 24. 36850 . 05385 50 2 2 33.14 26.48 . 97397 155 48. 72400 .09750 125 8.2 34.89 27.16 . 97302 94 121. 73615 .19103 250 5.5 34.75 27.43 . 97221 69 243. 31302 .29303 450 4.2 34.86 27.67 .97110 48 437. 64402 .41053 750 3.7 34.84 27.71 . 96974 45 728. 77002 .55053. 725 ...do 42 20 50 48 2,871 0 7.6 32. 98 1 25. 77 . 97488 224 0 0 25 6.8 33.34 26.16 .97440 187 24. 36600 . 05135 50 10.8 35.07 26.88 . 97360 118 48. 71600 . 089505 125 7.8 34.67 27.06 . 97312 1(M 121. 71800 .17288 250 5.6 34.71 27.39 . 97225 73 243. 30362 . 28363. 450 3.8 34.75 27.62 . 97114 52 437. 64262 .40913 750 3.7 34.86 27.72 . 96973 44 728. 77312 .55363 726 ...do 42 10 50 29 3,292 0 8.4 33.41 25.98 . 97468 224 0 0 25 5.2 33.60 26.56 . 97402 149 24. 35875 .04410 50 3.8 33.70 26.80 . 97367 125 48. 70487 .07837 125 5.0 34.34 27.17 .97300 92 121. 70499 . 1598r 250 6.0 34.57 27.23 .97240 88 243. 29249 .27250. 450 4.6 34.84 27.61 .97116 54 437. 64849 . 41500 750 4.0 34.91 27.73 . 96973 44 728. 78199 . 56250. I Interpolated. • E.xinterpolated, 109 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude a ai depth a = Meters ai = Pressure in decibars Station Longi- tude depth of Tem- Sa- water pera- ture linity 0/00 5< V V-Vi E E-Ei 0 / 0 / °C. 727 May 19 41 47 49 30 3,657 0 11.2 33.64 25.70 0. 97494 230 0 0 25 7.9 33.85 26.41 . 97416 163 24. 36375 .04910 50 12.6 35.26 26.69 . 97378 136 48. 71300 .08650 125 11.6 35.31 26.92 . 97325 117 121. 72662 . 18150 250 8.6 34.90 27.18 . 97246 94 243. 33349 . 31350 450 5.2 34.80 27.47 .97131 69 437. 71049 .47700 750 4.4 34.96 27.73 . 96974 45 728. 86799 . 64850 728 —do 42 15 49 20 3,152 0 8.6 33.79 26.25 . 97442 178 0 0 25 5.4 33.76 26.67 . 97391 138 24. 35412 . 03947 50 4.6 33.94 26.90 . 97357 115 48. 69762 .07112 125 4.9 34.55 27.35 .97283 75 121. 68762 .14250 250 4.7 34.73 27.52 .97212 61 243. 24762 .32763 450 4.4 34.91 27.68 . 97109 47 437. 56962 . 33613 750 4.0 34.94 27.76 . 96970 41 728. 68812 . 46863 729 ...do 42 44 48 44 2,853 0 4.2 33.32 26.44 .97424 160 0 0 25 1.2 33.36 26.73 . 97385 132 24.35112 .03647 50 1.6 33.70 26.98 . 97350 108 48. 69299 .06649 125 5.0 34.41 27.22 .97295 87 121. 68486 . 13974 250 5.2 134.64 27.38 .97226 74 243. 26048 .24049 450 5.0 34.80 27.54 .97123 61 437. 60948 . 37599 750 4.6 34.84 27.59 . 96987 58 728. 77448 . 38999 730 —do 42 55 48 22 3,291 0 3.6 33.11 26.34 . 97433 169 0 0 25 2.3 33.86 27.05 . 973.53 102 24. 34850 . 03385 50 1.0 33.80 27.10 . 97339 97 48. 68625 . 05975 125 7.0 34.68 27.18 . 97299 91 121. 67550 . 13038 250 5.4 34.74 27.44 . 97220 68 243. 24988 .22989 450 4.9 34.96 27.65 .97112 50 437. 58188 .34838 750 3.6 34.88 27.75 . 96970 41 728. 70488 . 48539 731 May -20 43 04 48 39 3,265 0 3.2 33.42 26.62 . 97407 143 0 0 25 3.2 133.55 26.79 . 97380 127 24. 34713 . 03248 50 4.0 33.89 26. 92 . 97355 113 48. 68901 . 06251 125 5.7 34.50 27.22 . 97295 87 121. 68276 .13764 250 4.6 134.60 27.42 .97222 70 243. 25589 .23590 450 3.8 34.80 27.66 .97111 49 437. 58889 .35540 750 3.5 34.91 27.78 . 96967 38 728. 70589 .48640 732 ...do 43 12 48 55 2,194 0 6.2 33.50 26.36 . 97432 168 0 0 25 5.6 33.84 26.71 . 97387 134 24. 35238 . 03773 50 5.9 34.08 26.86 . 97362 120 48. 69601 . 06951 125 5.0 34.38 27.20 . 97298 90 121. 69351 .14839 250 4.0 34.58 27.50 . 97214 62 243. 26351 . 24352 450 3.6 34.87 27.73 . 97104 42 437. 58151 . 34802 1 750 3.4 34.84 27.74 . 96970 41 728. 69251 . 47302 733 ...do 43 18 49 06 , 1.326 0 8.0 34.10 26.73 . 97396 132 0 0 25 4.6 33.77 26.76 .97383 130 24. 34738 .03273 50 4.4 33.93 26.91 . 97356 114 48. 66476 . 03826 125 4.2 34.45 27.35 .97283 75 121. 65439 . 10927 1 250 4.0 34.68 27.50 . 97215 63 243. 21564 . 19565 ] 450 3.8 34.84 27.70 . 97107 45 437. 53764 . 30415 1 750 3.6 34.88 27.75 . 96970 41 728. 64864 . 42915 734 —do 43 24 49 17 1 420 0 7.2 33.74 26.42 . 97426 162 0 0 70 3.6 33.95 27.01 . 97340 107 68. 16810 . 09415 140 3.0 34.25 27.30 . 97281 80 136. 28545 210 4.6 27.45 .97237 67 204. 36675 280 3.8 '34.I5" 27.55 . 97195 57 272. 41759 350 3.5 34.73 27.63 .97157 50 340.44115 '."29191 420 3.4 34.76 27.67 . 97122 42 408. 43880 . 33966 450 27.69 . 97107 45 437. 57315 735 .-do 43 33 49 36 57 0 "To" 33.10 26.30 . 97437 173 0 0 10 3.8 33.22 26.41 . 97422 162 9.74295 1 .01675 25 2.2 33.13 26.46 .97411 158 24.35542 1 .04077 40 0.7 33.17 26.61 . 97389 143 38.96542 .06332 50 12.5 26.62 .97384 142 48.70407 1 .07757 55 26.63 . 97381 141 53.57319 ! .08465 736 !...do 43 35 49 48 44 0 "z.¥ '33."68" 26.30 . 96437 173 0 0 10 3.8 33.07 26.29 . 97433 173 9.7435 .01730 20 3.4 33.11 26.35 . 97423 168 19.4863 .03435 30 2.2 33.09 26.44 .97410 159 29.2279 i .05065 40 2.1 33.05 26.43 . 97406 160 38.9687 1 .06660 737 ...do 43 46 50 00 59 0 5.2 33.10 26.17 . 97450 186 0 0 14 4.8 33.07 26.18 . 97442 184 13.64244 1 28 2.1 33.11 26.47 . 97408 156 27.28194 ! 42 1.3 33.24 26.64 . 97385 140 40.91745 1 56 6.2 33.21 26.62 . 97382 142 54. 55114 Interpolated. 72092—27 8 110 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- Longi- a depth ai 0= Meters ai = Pressure in decibars Station tude tude of depth Tem- Sa- water pera- linity h V V-Vi E E-Ei ture 0/00 o , o , °C. 738 May 29 45 33 48 09 64 0 2.6 33.36 26.63 0. 97406 142 0 0 25 2.9 33.74 26.91 . 97368 115 24. 34675 . 03210 50 0.6 1 33. 75 27.08 . 97341 99 48. 68538 .05888 125 1.6 34.26 27.42 . 97276 68 121. 66675 . 12163 250 2.6 134.61 27.63 . 97200 48 243. 21425 . 19426 450 3.1 34.81 27.75 . 97101 39 347. 51525 . 28176 750 3.2 34.89 27.79 . 96965 36 728. 61425 . 39476 739 ...do 45 33 48 24 0 1.6 33.17 26.55 . 97413 151 0 0 25 1.0 33.46 26.82 . 97377 124 24. 34875 . 0341O 50 1.4 33.74 27.02 . 97346 104 48. 68913 . 06263 125 0.6 1 34. 64 27.35 . 97282 74 121. 67463 . 12951 250 2.3 1 34. 55 27.61 .97202 50 243.22713 . 20714 450 3.2 1 34. 81 27.74 . 97102 40 437.53113 .29764 750 3.4 1 34. 92 27.80 . 96965 36 728. 63163 . 41214 740 ...do 45 33 48139 625 0 1.8 32.91 26.33 . 97434 170 0 0 25 -1.2 32.92 26.38 .97419 166 24. 35663 . 04198 50 -1.2 33.54 26.99 . 97349 107 48. 70263 . 07613 125 -1.0 33.69 27.11 . 97305 97 121. 69788 . 15276 250 -0.6 33.85 27.22 . 97239 87 243. 28788 . 26789 450 2.4 34.59 27.53 .97112 50 437. 63888 . 40539 741 ...do 45 33 48~54 84 0 2 8 32 88 26. 23 . 97444 180 0 0 20 2.4 32182 26^23 '. 97435 180 19. 48790 . 03595 40 0.2 32.87 26.39 . 97410 164 38. 97240 . 07030 50 1 26. 47 . 97398 156 48. 71280 . 08630 60 -i.l' '33." 12" 26.65 . 97377 140 58. 45155 . 10110 80 -1.5 33.18 26.71 . 97362 134 77. 92545 . 12845 125 •27.11 . 97305 97 121. 72553 . 18041 724 ...do 45 33 49 10 57 0 "¥.l' "32.'99" 26.32 . 97435 171 0 0 16 2.4 32.97 26.35 . 97455 168 15. 58880 32 2.0 33.10 26.47 . 97407 157 31. 17536 48 -1.6 33.33 26. 83 . 97365 122 46. 75712 50 > 26. 84 . 97363 121 48. 70440 ".'07796 • 64 -i.l" "33."37' 26.87 . 97354 119 62. 33459 743 ...do 45 14 49 28 63 0 3.0 33.06 26.35 . 97432 168 0 6 15 2.8 33.01 26.33 . 97427 170 14. 61442 . 02528 30 -0.6 33.17 26.67 . 97388 137 29. 22555 .04830 45 -0.8 33.43 26.89 . 97360 116 43. 83165 . 0673O 50 1 26. 90 . 97357 115 48. 69957 . 07307 60 -i.'o" "33.'56' 26.95 . 97348 111 58. 43482 .08437 744 ...do 45 10 49 15 54 0 2.6 32.87 26.22 . 97445 181 0 0 16 2.6 33.01 26.40 . 97421 164 15. 58928 32 -0.8 33.12 26.64 . 97390 140 31. 17416 48 -1.4 33.33 26.83 . 97365 122 46. 74756 50 26.84 . 97363 121 48. 70184 "."07534 64 -i.h' '33.'43' 26.92 . 97350 115 62. 33175 745 May 30 45 06 49 00 201 0 2.8 32.79 26.16 . 97451 187 0 6 15 2.5 32.86 26.24 . 97436 179 14. 61652 . 02738 30 -LO 33.10 26.63 . 97392 141 29. 22862 . 05137 45 -1.6 33.26 26.86 . 97363 119 43. 83525 .07090 50 60 26.86 26.86 . 97361 . 97358 119 121 48. 70335 58. 43930 . 07685 -i.'s" l3."32' .08885 746 —do..... 45 02 48 47 210 0 2.4 31.41 26. 69 . 97400 136 0 0 25 2.0 33.37 26.72 . 97386 133 24. 34825 .03360 50 1.4 33.81 27.08 . 97341 104 48. 68912 . 06262 125 1.8 34. 45 27. 48- . 97371 163 121. 66862 . 12350 250 3.0 34.78 27.72 . 97192 40 243. 20799 . 28800 450 3.2 34.86 27.77 . 97099 37 437. 49899 . 26550 750 3.3 34.89 27. 79 . 96965 36 728. 59499 . 37550 747; .... ...do 44 58 48 34 732 0 3.2 33.28 26.51 . 97417 153 0 0 25 1.6 33.65 26.94 . 97365 112 24. 34775 . 03310 50 0.9 34.23 27.41 . 97304 62 48. 68137 .05487 125 2.2 34.52 27.59 . 97260 52 121. 61699 . 07187 250 3.2 34.80 27.70 . 97194 42 243. 15074 .03075 450 2.9 34.75 27.72 . 97104 42 437. 44874 . 11525 750 3.6 34.88 27.75 . 96970 41 728. 55974 . 34025 748 ...do 44 55 48 18 2,011 0 3.8 32.26 25.65 . 97499 235 0 0 25 3.1 33.49 26.69 . 97399 146 24. 36100 . 04635. 50 2.8 33.94 27.08 . 97341 99 48. 70225 . 09575, 125 2.7 34.58 27.60 . 97259 51 121. 67725 . 13213 250 3.4 34.82 27.72 . 97192 40 243. 20912 . 18913 450 2.9 34.77 27.73 . 97103 41 437. 50412 . 27O63 750 3.6 34.88 27.75 . 96970 41 720. 61362 .39413 i[nterpolated. Ill Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of depth 0= Meters 01 = Pressure in decibars Station Tem- Sa- water pera- linity ii V V-Vi E E-Ei ture 0/00 o / o , °C. 749 May 30 44 50 47 59 2,377 0 3.0 32.73 26.09 0.97457 193 0 0 25 1.7 32.75 26.21 . 97435 182 24. 36510 .04685 50 -1.0 33.30 26.79 . 97368 126 48.71187 . 08537 125 0.6 33.90 27.20 . 97296 88 121. 71462 . 16590 250 4.0 34.66 27.53 .97211 59 243. 28149 . 26150 450 4.4 34.86 27.65 .97111 49 437. 60349 . 37000 750 4.2 34.95 27.75 . 96971 42 728. 72649 . 50700 750 ...do..... 44 41 47 40 2,925 0 9.9 33.93 26.29 . 97438 174 0 0 25 9.6 33.95 26.22 . 97434 181 24. 35900 .04435 50 9.2 34.29 26.55 . 97391 149 48. 71212 . 08562 125 6. 6 34. 58 27.16 . 97302 94 121. 72199 . 17687 250 5.1 34.74 27.48 . 97217 65 243. 29636 . 27637 450 4.0 34.82 27.66 .97110 48 437. 62336 . 38987 750 4.4 34.96 27.73 . 96974 45 728. 74936 . 52987 751 ...do 45 19 47 53 2,743 0 4.0 32.71 25.99 . 97467 203 0 0 Z, 25 6.0 33.73 26.58 .97400 149 24. 5837 .04372 50 3.8 33.89 26.95 . 97352 110 48. 70237 . 07857 125 3.4 34.38 27.37 . 97281 73 121. 68974 .14462 250 4.6 34.80 27.58 . 97207 55 243. 24474 . 22475 450 4.5 34.82 27.61 .97116 54 437. 56674 . 33425 750 4.4 34.88 27.67 . 96980 51 728. 71174 . 49225 752 June 1 ...do..... 44 24 44 23 49 04 48 48 55 1,316 0 13 26 39 50 52 0 3.2 3.7 0.2 -0.4 32.85 32.92 33.14 33.23 26.17 26.27 26.64 26.72 26.73 26.73 26.37 "la 70271' 50. 65017 0 -o.'s" 2.8 '33.'25' 33.06 753 "."97431" "167" 0 25 2.2 33.11 26.47 .97410 157 24. 35512 .04047 50 1.7 34.24 26.61 . 97385 143 48. 70449 . 07799 125 -0.3 34.76 27.14 . 97302 94 121.71211 . 16699 250 2.2 34.53 27.60 . 97203 51 243. 27773 . 25774 450 3.0 '34.77 27.72 . 97104 42 437. 58473 .35124 750 3.3 134.87 27.76 . 96966 37 728. 68973 . 47024 754 ...do 44 22 48 36 3,332 0 2.6 33.11 26.43 . 97425 161 0 0 Z. 25 2.4 33.37 26.66 . 97392 139 24. 35212 . 03747 50 1.2 33.61 26.93 .97354 112 48. 69537 . 06887 125 0.8 34.32 27.54 . 97264 56 121. 67712 .13200 250 2.6 34.70 27.70 . 97194 42 243. 21337 . 18338 450 3.1 34.83 27.76 . 97100 38 437. 50237 .27388 750 3.3 34.86 27.78 . 96966 37 728. 60637 .38688 755 ...do 44 22 48 20 3,423 0 3. 2 ; 32. 93 26.24 .97443 179 0 0 25 2. 7 33. 19 26.49 . 97408 155 24. 35638 . 04173 50 1. 6 1 33. 50 26.82 . 97365 123 48. 70301 . 07651 125 1.0 34.09 27.34 . 97284 76 121. 69639 . 15127 250 •2.5 34.50 27.55 . 97208 56 243. 25389 . 23390 450 4.6 134.86 27.63 .97114 52 437. 57589 . 34240 750 4.3 :'34.91 27.70 . 96977 48 728. 71239 . 49290 766 ...do 44 24 47 58 3,474 0 25 13.8 14.0 35.53 35.54 26.65 26.62 . 97404 . 97396 240 143 0 0 24.35000 1 .03535 50 14.4 35.84 26.77 . 97371 120 48. 69588 .06938 125 11.2 35.22 26.80 . 97336 128 121.71101 . 16589 250 7.8 34.93 27.22 . 97242 90 243. 32226 .30227 450 5.4 34.87 27.54 . 97123 61 437. 68726 . 45377 750 4.4 34.81 27.61 .96984 65 728. 84776 .62827 757 ...do 44 10 47 52 3,656 0 12.2 34.98 26.55 . 97413 149 0 !o 25 12.0 35.00 26. 61 . 97397 144 24. 35125 .03660 50 13.2 35.55 26.80 . 97368 126 48. 69687 . 07037 125 13.4 35.99 27.09 . 97310 102 121.70112 .15600 250 11.3 35. 73 27.29 . 97238 86 243. 29362 .27363 450 6.7 34.95 27.44 .97134 72 437. 66562 . 43213 750 5.9 35.07 27.64 . 96989 55 728. 84262 .62313 758 ...do 43 51 47 47 3,809 0 9.2 33.90 26.24 . 97443 179 0 0 25 12.6 35.44 26.42 .97415 162 24. 35725 .04260 50 35.83 26.63 . 97384 142 48. 70712 .08062 125 "\i.l' 35.96 26.81 . 97336 128 121. 72712 .18200 250 8.5 34.75 27.02 . 97262 110 243. 35087 .33088 450 6.5 34.94 27.41 .97137 75 437. 74987 .51638 750 5.0 34.87 27.59 . 96988 59 728. 93737 .71788 759 June 2 43 47 47 44 3,729 0 7.8 33.73 26.33 . 97434 170 0 0 25 8.6 34.13 26.52 . 97405 152 24. 35487 .04022 50 13.8 35.63 26.73 . 97374 132 48. 70224 . 07574 125 15.0 36.05 26.80 . 97337 129 121. 71886 . 17374 250 10.9 35.09 26.88 . 97276 124 243. 35198 .33199 450 6.0 34.63 27.28 . 97149 87 437. 77698 .54349 750 5.0 34.64 27.41 .97005 76 728. 00798 .78849 ' Interpolated^ 112 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- Longi- a depth a\ a = Meters Oi = Pressure in decibars St&tioD tude tude of depth Tem- Sa- water pera- ture linity 0/00 «« V V-Vi E E-Ei o / o , °C. 760 June 2 43 41 48 18 3,017 0 7.4 33.60 26,28 0. 97439 176 0 0 36 6.6 33.72 26.49 . 97408 165 24.35587 .04122 50 4.8 33.95 26.89 . 97358 116 48. 70162 .07512 125 4.9 34.41 27.20 .97297 89 121. 69724 . 15212 250 4.4 34.70 27.52 . 97212 60 243. 26536 .24537 450 4.2 34.89 27.69 . 97108 46 437. 58536 . 35187 750 4.0 34.92 27.74 . 96972 43 728. 70536 .48587 761 ...do.-.. 43 36 48 42 2,005 0 2.6 32.77 26.15 . 97451 187 0 0 25 1.4 32.88 26.33 . 97423 170 24. 35925 .04460 50 -0.8 33.29 26.78 . 97369 127 48. 70825 .08175 125 -1.4 33.41 26.90 . 97324 116 121.71812 .17300 250 0.4 33.91 27.23 . 97237 85 243. 31999 .30000 450 3.9 34.73 27.60 . 97116 54 437. 67299 . 43950 750 4.4 1 34. 92 27.70 . 96977 48 728. 81249 .59300 762 ...do...- 43 37 48 56 1,463 0 3.2 32.80 26.13 . 97453 189 0 0 25 0.6 33.12 26.58 .97400 147 24. 35662 .04197 50 -1.4 33.29 26.79 . 97368 126 48. 70262 . 07612 125 -1.4 33.39 26.88 . 97326 118 121. 71287 . 16775 250 -0.2 33.83 27.20 . 97240 88 243. 31662 .29663 450 '3.8 ' 34. 68 27.57 .97119 57 437. 67562 . 44213 750 14.0 134.89 27.72 . 96974 45 728. 81512 . 59563 763 ...do.... 43 37 49 09 457 0 3.6 32.69 26.01 . 97465 201 0 0 25 1.8 32.79 32.79 . 97432 179 24. 36212 .04747 50 -1.0 33.29 33.29 . 97369 127 48. 71224 .08574 125 -1.2 33.46 33.46 . 97321 113 121. 72099 .17587 250 2.0 34.17 34.17 . 97225 73 243.31229 .29230 450 3.0 34.72 34.72 . 97107 45 437. 64429 . 41080 750 3.4 1 34. 87 1 34. 87 . 96971 42 728. 76129 . 54180 764 ...do...- 43 37 49 23 366 0 3.2 32.83 26.15 . 97451 187 0 0 25 2.5 33.89 26.26 . 97430 177 24. 36012 .04547 50 -1.2 33.19 26.72 . 97374 132 48. 71062 .08412 125 -1.3 33.41 26.89 . 97325 117 121. 72274 . 17762 250 0.6 33.76 27.10 . 97251 99 243. 33274 . 31725 450 3.4 34.38 27.37 . 97137 75 437. 72074 .48725 750 3.5 34.77 27.68 . 96977 48 728. 89174 . 67225 765 ...do.... 43 36 49 23 66 0 4.8 33.03 26.15 . 97451 0 10 15 4.2 32.95 26.16 . 97443 14.61705 ! 30 1.6 32.97 26.42 .97412 29. 23117 45 -0.4 33.10 26.61 . 97387 43. 84109 50 60 26.63 26.69 . 97383 . 97373 48. 71034 58. 44804 '."08384 "ao" "33."22" 766 June 3 43 56 48 54 1,097 0 3.2 32.82 26.15 . 97451 "187" 0 0 25 2.6 32.87 26.24 . 97432 179 24.36037 ! .04572 50 -0.6 33.13 26.65 . 97381 139 48.71199 .08549 125 -0.1 33.45 26.89 . 97325 117 121. 72674 . 18162 250 1.5 34.23 27.41 . 97221 69 243. 31799 .29800 450 3.2 34.78 27.71 . 97105 43 437. 64399 . 41050 750 3.4 34.82 27.72 . 96973 44 728. 76099 .54050 767 ...do...- 43 69 48 30 3,294 0 4.0 32.87 26.12 . 97454 190 0 0 25 2.8 32.89 26.24 . 97432 179 24. 36075 .04610 50 -1.3 33.21 26.73 . 97373 131 48.71137 .08487 125 -1.1 33.48 26.93 . 97321 113 121. 72152 .17640 250 -M.6 34.24 27.41 . 97221 69 243. 31027 .29028 450 3.9 34.80 27.66 .97111 49 437. 64227 .40878 750 4.0 34.91 27.73 . 96973 44 728. 76827 .54878 768 ...do.... 44 05 48 40 2,081 0 2.4 33.09 26.43 . 97425 161 0 0 25 1.8 33.11 26.50 . 97407 154 24.35400 . 03935 50 1.6 33.50 26.83 . 97374 132 48.71137 .08487 125 0.8 33.86 27.17 .97299 91 121. 68549 .14037 250 2.0 34.43 27.53 . 97210 58 243. 25361 . 23362 450 3.1 34.66 27.61 .97114 52 437. 57761 . 34412 750 3.9 34.69 27.65 . 96980 51 728. 71861 . 49912 769 ...do.... 44 11 48 52 1,126 0 3.2 32.88 26.19 . 97448 184 0 0 25 2.2 32.95 26.34 . 97422 169 24. 35875 .04410 50 2.0 33.39 26.71 . 97375 133 48. 70637 . 07987 125 1.1 33.94 27.21 .97295 87 121. 70762 1 . 16250 250 2.6 34.44 27.49 . 97214 62 243. 27574 . 25575 450 3.2 34.62 27.59 .97116 54 437. 60574 . 37225 750 3.4 34.70 27.64 . 96980 51 728. 74974 .53025 770 June 9 47 18 49 18 83 0 3.4 32.43 25.82 . 97483 0 0 0 20 3.2 32.45 25.86 . 97470 215 19. 49530 .04345 40 2.8 32.84 26.19 . 97429 183 38. 98520 . 08310 60 -1.2 33.08 26.63 . 97379 142 58. 46600 . 11555 80 -1.4 33.22 26.75 . 97358 130 77. 93970 . 14270 90 1 1 26. 80 . 97350 126 87. 67510 . 15550 Interpolated. 113 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of depth a = Meters ai = Pressure in decibars Station Tem- Sa- water pera- ture linity 0/00 «< V V-V, E E-Ei 0 t o / •c. 771 June 10 47 24 49 00 98 0 18 36 54 72 3.4 3.2 0.8 0.6 -L4 32.49 32.52 32.78 133.12 33.14 25.87 25.91 26.30 26.58 26.68 0.97478 . 97466 . 97421 . 97386 . 97362 0 17. 54496 35. 08479 52. 61742 70. 14474 0 90 -1.3 33.22 26.74 . 97355 ""131" 87. 66927 '.'14967 ...do.... 47 31 48 43 155 100 0 26.75 26.00 . 97349 . 97466 130 202 97. 40447 . 16272 772 "z.l' "si'es" 0 0 25 -1.6 33.18 26.73 . 97385 132 24. 35638 .04173 50 -1.3 33.37 26.87 . 97360 118 48. 69950 .07300 100 -1.0 33.46 26.92 . 97333 114 97. 37275 .13100 150 0.0 33. 81 27.17 .97287 90 146. 02775 . 18201 773 ...do.... 47 37 48 25 210 0 3.4 32.70 26.04 . 97462 198 0 ;o 1 25 -1.6 33.17 26.71 . 97387 134 24.35613 I .04148 [ 50 -1.4 33.41 26.89 .97358 116 48. 69925 .07275 100 -0.6 33.67 27.08 . 97319 100 97. 36850 . 12675 150 0.2 33.91 27.24 .97280 93 146. 01825 . 17251 200 0.8 34.03 27.29 . 97255 81 194. 65200 . 21351 774 ...do.... 47 44 48 06 292 0 4.0 33.11 26.31 . 97436 172 0 0 25 3.3 33.13 26.38 . 97419 166 24. 35687 .04222 50 1.6 33.48 26.76 . 97370 128 48. 70549 . 07899 100 1.2 34.14 27.36 .97292 73 97. 37099 .12924 175 2.0 34.40 1 27. 51 . 97245 59 170. 32236 200 250 275 27.53 1 27.50 27.59 .97232 . 97207 . 97192 58 55 51 194. 63198 243. 24173 267. 54160 ".'14349 . 22174 "2"4" "34.' 52" 775 _-.do 47 51 47 47 383 0 25 3.6 -0.8 32.73 33.01 26.04 26.55 . 97462 . 97402 198 149 0 24. 35800 6 .04335 75 -1.4 33.51 26.98 . 97339 108 73. 04325 . 10771 150 1.4 34.22 27.41 .97264 67 146. 01937 . 17363 250 1.6 34. 59 27.69 . 97195 43 243. 24887 .22888 375 1.8 34.64 26. 98 . 97135 39 364. 70512 776 -.do..-. 48 03 47 32 909 0 4.6 33.72 26.72 . 96397 133 0 0 25 4.2 34.07 27.05 . 97355 102 24.34400 .02935 50 2.2 34.04 27.21 .97328 86 48. 67937 .05287 125 2.0 34.46 27.56 .97263 55 121. 65099 . 10587 250 2.6 34.60 27.61 . 97202 50 243. 19161 . 17162 375 450 1 27.66 27.70 .97141 .97106 45 44 364. 65598 437. 49860 "'2.8' '34." 73" '."26511 750 3.3 34.83 27.73 . 96972 43 728. 61560 .39611 777 June 11 47 59 46 57 1,097 0 4.2 33.61 26.68 . 97401 137 0 0 => 25 3.0 34.10 27.18 .97343 90 24. 34300 .02835 50 2.1 34.29 27.42 .97308 66 48. 67437 .04787 125 2.4 34.54 27.59 .97260 52 121. 63737 .09225 250 3.0 34.76 27.71 . 97195 43 243. 16674 . 14675 450 3.1 34.83 27.75 .97101 39 437. 46274 .22925 750 3.2 34.87 27.77 . 96967 38 728. 56474 .34525 778 -.do.... 47 64 46 22 1,152 0 5.8 34.29 27.04 .97367 103 0 0 25 5.0 34.39 27.21 . 97340 87 24. 33837 .02372 50 14.1 34.47 27.37 . 97313 71 48. 66999 .04349 125 3.0 34.59 27.57 .97262 54 121. 63561 .09049 250 3.2 34.82 27.73 . 97191 39 243. 16873 . 14874 375 450 I 27.73 27.74 . 97135 . 97103 39 41 364. 62248 437.46173 "3.1" '34." 85" '."22824 750 13.6 34.89 27.76 .96969 40 728. 56973 .35024 779 --.do 47 49 45 50 380 0 6.0 34.17 26.92 . 97372 114 0 0 i 25 5.0 34.16 27.02 . 97358 105 24. 34200 .02735 75 3.4 34.38 27.37 . 97302 71 73. 00700 . 07146 150 3.0 34.56 27.55 . 97252 55 145. 96475 . 11901 250 3.2 34.80 27.72 . 97192 40 243. 18675 . 16676 375 3.4 34.85 27.75 . 97134 38 364. 64050 780 --.do 47 30 46 08 769 0 5.5 1 33.75 26.65 .97404 140 0 0 25 5.2 33.98 26.86 . 97373 120 24.34712 .03247 50 14.6 34.13 27.05 . 97343 101 48. 68662 .06012 125 3.0 34.47 27.47 . 97272 64 121.66724 . 12212 250 3.1 34.70 27.65 . 97196 44 243. 20974 . 18975 375 450 1 27.67 27.69 .97142 . 97107 46 45 364. 67099 437. 51436 "3.'4' '34.' 79' '."28087 750 3.3 34.85 27.75 . 96970 41 728. 62986 .41037 781 --.do 47 20 46 29 760 0 6.6 34.05 26.75 . 97394 130 0 0 -M 25 6.0 34.08 26.85 . 97374 121 24. 34600 .03135 50 4.8 34.28 27.15 .97334 92 48. 68450 .05800 125 3.2 34.63 27.58 .97261 53 121.65767 .11257 250 3.2 34.78 27.70 .97194 42 243. 19200 .17201 450 3.4 34.86 27.75 . 97101 39 437. 48700 .25351 750 3.3 34.85 27.75 . 96970 41 728. 59350 . 37401 ■Interpolated. 114 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of depth a = Meters 01 = Pressure in decibars Station Tem- Sa- water pera- ture linity 0/00 h V V-V, E E-Ei o / o / °C. 782. June 11 47 11 46 49 887 0 5.4 33.90 26.77 0. 97393 129 0 0 25 4.3 34.11 27.06 . 97355 102 24. 34350 1 . 02885 50 3.0 34.27 27.32 . 97318 76 48.67762 ! .05112 125 2.8 34.65 27.55 .97264 56 121. 64487 < . 09975 200 250 27.64 27.66 . 97221 . 97198 47 46 194. 57674 . 13825 "3.1" "u.ii 243. 18149 . 16150 450 3.2 34.80 27.72 .97104 42 437. 48349 . 25000 750 3.3 34.86 27.76 . 96969 40 728. 59299 ' . 37350 783 ...do..-. 47 05 47 16 262 0 4.0 33.28 26.44 . 97424 160 0 0 25 1.0 33.12 26.55 . 97402 149 24.35325 .03860 50 0.2 33.43 26.85 . 97362 120 48. 69875 . 07225 100 -0.4 33.73 27.12 .97315 96 97. 36800 . 12625 150 1.4 34.16 27.36 .97269 72 146. 01400 . 16826 200 2.4 34.49 27.57 .97228 54 194. 63825 . 19976 784 ...do.... 47 00 47 41 182 0 3.6 32.81 26.10 . 97456 192 0 0 25 13.2 33.01 26.29 .97427 174 24. 36037 . 04572 50 1 1.8 1 33.04 26.44 . 97401 159 48. 71387 , . 08737 75 -0.2 33.07 26.59 . 97376 145 73. 06099 . 12545 90 100 26.69 26.74 . 97360 . 97350 136 131 87. 66619 97. 40169 . 14659 -1.2 '33." 22" . 15994 125 -1.4 33.44 26.91 .97323 115 121. 73581 .19069 150 175 26.96 27.00 .97306 .97292 109 83 146. 06443 170. 38918 . 21869 -i."6" '33." 55' 785 ...do.... 46 54 48 04 128 0 3.8 32.62 25.93 . 97472 208 0 0 30 1.2 32.90 26.36 . 97417 166 29. 23335 . 05610 60 -1.4 33.13 26.67 . 97375 138 58. 45215 . 10170 90 -1.0 33.43 26.90 . 97340 116 87. 65940 . 13980 120 -0.3 33.66 27.06 .97312 102 116.85720 June 12 46 49 48 26 96 125 0 27.06 25.77 . 97310 . 97488 "224" 121. 72275 0 786 "i'\' "32."49' 6 23 3.6 32.59 25.93 . 97462 208 22. 41925 46 -0.6 32.88 26.44 .97403 159 44. 82872 69 -1.4 33.07 26.62 . 97376 143 67. 22830 90 92 26.79 26.80 . 97351 . 97349 127 126 87. 67463 89. 62163 '."15503 -i."2' "33.' 30' 787 ...do.... 46 15 48 27 93 0 4.6 32.51 25.82 . 97483 219 0 o" 23 4.0 32.62 25.91 .97464 210 22. 41890 46 2.0 32.71 26.16 . 97430 186 44. 83171 69 1.3 33.19 26.72 . 97366 133 67. 23325 90 92 26.76 26.76 . 97353 . 97352 129 129 87. 67874 89. 62579 '.'15914 "l.\ '33.' 26' 788 ...do.... 46 20 47 59 115 0 4.0 32.27 25.64 . 97500 236 0 0 28 2.0 32.85 26.27 .97427 175 27. 28988 56 -1.1 33.15 26.68 . 97376 136 54. 56230 84 10.1 33.21 26.69 . 97362 136 81. 82562 190 1100 112 26.69 26.69 26.69 . 97360 . 97355 . 97351 136 136 138 87. 66728 97. 40303 109. 08539 .'14768 .16128 '"6.' 7" 33.' 25 789 ...do...- 46 26 47 30 205 0 3.4 33.00 26.33 . 97434 170 0 6 50 -1.4 33.30 26.81 . 97366 124 48. 70000 .07350 100 -1.3 33.53 26.99 . 97327 108 97.37325 . 13150 150 0.9 34.03 27.29 . 97276 79 146. 02400 . 17826 200 1.1 34.11 27.34 . 97250 76 194. 65550 . 21701 ...do.... 46 26 46 57 914 1250 0 27.35 26.65 .97227 .97404 75 140 243. 27475 0 .25476 790 ""i's" '33. 66 0 25 4.0 33.84 26.88 . 97371 118 24. 34687 . 03222 50 2.8 34.27 27.33 . 97317 75 48. 68287 .05637 125 2.5 34.59 27.62 . 97257 49 121.64812 .10300 250 3.0 34.78 27.72 . 97192 40 243. 17874 . 15875 450 3.2 134. 81 27.73 .97103 41 437. 47374 .24025 750 3.4 34.84 27.73 . 96972 43 728. 58624 . 36675 791 ...do 46 31 46 21 404 0 6.2 34.23 26.94 . 97376 112 0 0 25 5.8 34.32 27.05 . 97355 102 24. 34137 .02672 50 4.8 34.42 27.25 .97324 82 48. 67624 .04974 100 3.3 34.64 27.58 . 97272 53 97. 32524 .08349 200 3.4 34.83 1 27.73 . 97213 39 194. 56774 .12925 1275 300 27.75 27.76 . 97178 . 97167 38 38 267. 46436 291. 75748 "z.h' "34.'87' '.'16724 ...do.... 46 36 45 52 276 400 1450 0 27.77 27.77 26.75 . 97121 .97099 .97394 37 37 130 388. 90147 437. 45648 0 .20448 .22299 792 "Y.l' 34.20 0 25 6.2 34.23 26.94 .97365 112 24. 34487 .03022 50 4.8 34.54 26.62 .97315 73 48. 67987 . 05337 100 3.2 34.57 26.79 . 97277 58 97. 32787 . 08612 176 3.4 34.76 26.92 .97230 45 170. 26799 1250 275 26.93 26.94 .97196 .97185 44 45 243. 17774 267. 47536 '."15775 "z.h' 'si'ii" 1 Interpolated. 115 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of ai depth a = Meters 0 = 1 Pressure in decibars station Tem- Sa- water pera- ture linity 0/00 h V V-Vi E E-Ei o / 0 / "C. 7«3 June 13 46 40 45 23 255 0 8.2 34. 50 26. 87 0. 97383 119 0 0 25 7.6 34.59 27.03 . 97357 104 24.34250 . 02785 50 5.2 34.61 [ 27.36 . 97314 72 48. 67637 .04987 100 3.3 34. 63 27. 57 .97273 54 97.32312 .08137 175 3.4 34. 81 27. 76 .97223 38 170. 25912 250 3.6 34. 94 27. 79 . 97186 34 243. 16248 '.'14249 794 ...do..- 46 15 45 11 3,062 0 7.6 34.49 i 26.95 . 97375 111 0 0 25 7.5 34.51 ; 26.98 . 97362 109 24. 34212 . 02747 50 6.4 34.55 27.17 . 97332 90 48. 67887 . 05237 125 5.2 34.63 27.37 . 97281 73 121. 65873 . 11361 250 4.0 34.77 27.62 .97202 50 243. 21060 .19061 450 3.4 34.82 27.72 .97104 42 437.51660 .28311 750 3.6 34.84 27.72 . 96973 44 728. 63210 . 41261 795 ...do...- 45 49 45 00 3,383 0 6.6 33.18 26.06 .97460 196 0 0 25 5.0 33.41 26.43 . 97414 161 24. 35925 .04460 50 4.8 34.24 27.11 . 97338 96 48. 70325 . 07675 125 14.3 34.45 27.33 .97285 77 121. 68688 . 14176 250 5.6 34.85 27.50 . 97215 63 1 243.24938 .36439 450 3.8 34.89 27.73 .97104 42 437. 56838 . 46989 750 3.9 34.91 27.74 . 96972 43 728.68238 .58789 •796 ...do..-- 46 25 45 11 3,566 0 5.2 33.07 26.14 .97452 188 0 0 25 17.0 33.39 26.17 . 97439 186 24. 36137 .04672 50 7.3 33.81 26.47 . 97399 157 48.71612 . 08962 125 4.8 34.42 27.25 . 97292 84 I 121.72525 . 18013 250 5.6 34.86 27.51 . 97214 62 ' 243.29276 .27276 450 3.5 34.74 27.65 .97111 49 ' 437.61776 .38426 750 3.4 34.86 27.75 .96970 41 728. 73925 . 61976 797 ...do.... 45 11 45 32 3,658 0 6.4 33.14 26.06 . 97460 196 1 0 0 25 5.0 33.31 26.35 . 97421 168 1 24.36012 .04547 50 4.5 33.71 26.73 . 97373 131 48. 70937 .08287 125 2.1 34.24 27.37 .97281 73 121. 70462 . 15950 250 15.1 34.90 27.60 .97205 53 243. 25837 .23838 450 4.2 34.93 27.73 .97104 42 437.56737 . 33388 750 14.1 34.95 27.75 . 96971 42 , 728.67987 . 46038 798 June 14 45 39 40 19 4,663 0 15.6 35.98 26.00 .97409 145 0 0 25 15.4 35.97 26.63 . 97395 142 24. 35050 .03585 50 15.0 35. 96 26.72 . 97376 133 48. 69675 . 07025 125 14.1 35.88 20.86 . 97331 123 121.71150 . 16638 325 12.3 35.63 27.03 .97231 113 ; 316.27350 625 8.2 35.03 27.28 . 97076 92 j 607.73400 750 16.5 27.53 . 96996 67 : 729.02900 "."soosi 925 5.0 '34.'92" 27.63 . 06909 57 1 898.69687 799 June 17 45 09 45 50 3,670 0 7.0 34.10 26.73 .97396 132 0 6" 25 6.9 34.13 26.76 . 97383 130 24.34737 .03272 50 5.0 34.36 27.18 . 97331 89 , 48.68662 .06010 125 4.3 34.66 27.50 . 97269 61 121.66162 .11650 250 3.7 34.79 27.67 . 97198 46 243. 26599 .24600 450 3.8 34.84 27.70 .97107 45 437. 57099 .33750 750 3.7 34.80 27.74 . 96971 42 728. 68799 . 46850 800 ...do.... 45 03 46 09 3,658 0 5.8 33.72 26.58 .97411 147 0 0 25 5.7 33.73 ■26.61 . 96397 144 24.36100 .03635 50 4.5 33.93 26.90 . 96367 115 48. 69525 .06875 125 4.0 34.44 27.36 . 97282 74 ; 121.68487 . 13975 250 3.5 34.61 27.64 .97210 ' 58 243. 24237 .22238 450 3.9 34.80 27.65 .97111 49 437. 56337 .32988 750 13.8 34.82 27.70 . 96976 47 728. 69387 .47438 801 ...do..- 45 18 46 18 3,566 0 6.1 33.89 26.68 . 97401 137 0 0 25 5.8 33.85 26. 69 . 97389 136 24. 34875 . 03410 50 4.8 34.01 26.93 .97364 112 48. 69162 .06512 125 3.2 34.47 27.46 .97273 65 121. 67674 . 13162 250 3.5 134.67 27.59 .97205 53 243. 22549 .20650 450 3.7 34.83 27.68 .97109 47 437. 53949 .30600 750 3.8 34.86 27.71 . 96975 46 728. 66549 .44600 ■802 ...do.... 45 30 46 36 1,829 0 5.9 3.3.63 26.50 . 97418 154 0 0 25 5.4 33.79 26.69 . 97389 136 24. 35087 .03522 50 14.4 134.C5 27.00 . 97348 106 48. 69299 .06649 125 3.2 34.53 27.50 .97269 61 121.67467 .12925 250 3.7 34.80 27.07 . 97198 46 243. 21626 .21626 450 3.8 134.86 27.71 .97104 42 437. 52025 .28676 750 3.9 34.89 27.73 . 96973 44 728. 63875 . 41926 «03 June 18 45 44 46 27 1,463 0 6.4 34.08 26.79 . 97391 127 0 0 25 5.8 34.10 26. 89 . 97370 117 24. 34512 .03047 50 5.0 34.32 27.15 . 97334 92 48. 68312 .05662 125 3.6 34.56 27.49 . 97270 62 121. 65962 .11450 250 3.7 34.69 27.58 . 97206 64 243. 20712 . 18713 450 3.8 34.82 27.68 . 97109 47 437. 52212 .28863 760 3.9 34.91 27.74 .96972 43 728.64362 .42413 ^ Interpolated. 116 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- Longi- a depth 01 a = Meters 01 = Pressure in decibars station tude tude of depth Tem- Sa- water pera- ture linity 0/00 «. V V-Vi E E-Ei o , 0 / °C. 804 June 18 45 57 46 18 1,518 0 7.8 33.93 26.48 0. 97420 156 0 0 25 7.2 34.93 26.57 . 97401 148 24. 35262 . 03797 50 6.2 34.47 27.13 . 97337 95 48. 69487 . 06837 125 14.4 34.66 27.50 . 97269 61 121. 67212 .12700 250 4.6 34.80 27.58 . 97207 55 243. 21962 . 19963 450 3.6 34.81 27.69 . 97108 46 437. 53462 .30113 750 3.5 34.84 27. 73 . 96972 43 728. 65462 . 43513 805 ...do 45 55 46 41 1,481 0 6.2 34.04 26.79 . 97391 127 0 0 25 6.0 33.99 26.78 . 97381 128 24. 34650 . 03185 50 5.8 34.20 26.97 . 97352 110 48. 68812 . 06162 125 4.4 34.65 27.48 .97271 63 121.67175 . 12663 250 4.2 34.86 27.67 .97198 46 243. 21488 . 19489 450 3.8 34.83 27.69 .97108 46 437. 52088 .28739 750 3.6 34.84 27.72 . 96973 44 728. 64238 .42289 806 ...do 45 51 47 15 1,463 0 5.2 33. 46 26.45 . 97423 159 0 0 25 4.7 33.63 26.64 . 97394 141 24. 35087 . 03622 50 1.8 34.03 27.23 . 97326 84 48. 69087 .06437 125 .3.6 34.59 27.52 . 97267 59 121. 66325 . 11813 250 3.7 34.78 27. 65 . 97199 47 243. 20450 .18451 450 3.6 34.84 27.72 .97105 43 437. 50850 . 27501 750 3.4 34.83 27.73 . 96972 43 728. 62400 . 40451 807 —do 45 31 47 23 1,829 0 6.5 33.44 26.27 . 97440 176 0 0 25 6.0 33.57 26.45 . 97412 159 24. 35650 . 04185 50 1.1 33.78 27.07 . 97342 100 48. 70075 . 07425 125 2.7 34.42 27.46 .97273 65 121.68138 . 13626 250 3.6 34.77 27.66 . 97199 47 243. 22638 . 20639 450 3.5 34.87 27.75 .97102 40 437. 52738 .29389 750 3.4 34.88 27.76 . 96969 40 728. 63388 .41439 808 —do 45 15 47 10 3,352 0 6.2 33.26 26. 17 . 97450 186 0 0 25 6.1 33.33 26.25 .97431 178 24. 36013 .04548 50 4.3 33.41 26.51 . 97394 152 48. 71325 . 08675 125 2.4 34.14 27.26 . 97292 84 121. 72050 . 17538 250 2.9 34.66 27.63 . 97200 48 243. 27800 . 25801 450 3.4 34.79 27.69 . 97107 45 437. 58500 .35151 750 3.5 34.86 27.74 .96971 42 728. 70200 . 48251 809 ...do 45 10 47 40 2,670 0 9.2 33.47 25.90 . 97475 211 0 0 25 9.0 33.55 26.00 . 97455 202 24. 36625 . 05160 50 7.6 33.65 26.29 . 97416 174 48.72512 . 09862 125 5.6 34.45 27.08 .97312 104 121. 72812 . 18300 250 4.6 34.62 27.44 . 97220 68 243. 31062 .29063 450 4.3 34.73 27.55 .97121 59 437. 65162 .318ia 750 3.8 34.87 27.72 . 96974 45 728. 79412 . 57463 810 June 19 45 17 48 00 2,195 0 6.0 33.21 26.16 . 97450 186 0 0 25 5.8 33.20 26.18 . 97438 185 24. 36100 1 . 04635 50 1.8 33.66 26.93 .97354 112 48. 71000 .08350 125 1.6 34.33 27.48 . 97271 63 121. 69438 . 14926 250 2.5 34.63 27.65 .97198 46 243. 23751 . 21752 450 3.6 134.83 27.69 .97108 46 437. 54351 . 31002 750 3.7 '34.89 27.73 . 96972 43 728. 66351 .44402 811 ...do 45 21 48 13 1,097 0 5.8 33.56 26.46 .97422 158 0 0 25 5.7 33.53 26. 46 .97411 158 24. 35412 .03947 50 1.0 33. 74 27.05 .97343 101 48. 69837 . 07187 125 1.4 34.21 27.40 . 97277 69 121. 68087 . 13575 250 3.6 34.78. 27.66 . 97198 46 243. 22762 . 2076a 450 4.0 34.85 27.68 .97109 47 437. 53462 .30113 750 4.1 34.88 27.70 . 96976 47 728. 66212 . 44263 812 - ...do 45 25 48 27 973 0 5.0 33.25 26.38 . 97430 166 0 [0 25 4.9 33.50 26. .52 .97405 152 24.35437 ! .03972 50 3.0 34.00 27.10 . 97339 97 48. 69737 . 07087 125 2.8 34.47 27.49 . 97270 62 121. 67575 . 1306a 250 3.0 34.66 27.62 . 97201 49 243. 22013 . 20014 450 3.3 34.75 27.67 . 97109 47 437. 52513 .29164 750 3.4 34.81 27.71 . 96974 45 728. 64963 . 43014, 813 ...do 45 28 48 40 812 0 3.9 32.89 26.14 . 97452 188 0 0 25 3.6 33.07 26.31 . 97425 172 24. 35962 .04497 50 -1.4 33.30 26.81 . 97366 124 48. 70849 .08199- 125 1 0.8 33.43 27.17 . 97299 91 121. 70787 . 16275 250 3.2 34.37 27.38 .97224 72 243. 28475 .26476 450 1 3.2 34.57 27.55 .97120 58 437. 62875 . 39526 750 3.4 34.74 27.67 . 96978 49 728. 77575 . 55626 814 ...do 45 32 48 50 77 0 4.9 32.61 25.91 . 97474 210 0 0 19 3.1 32.72 26.07 . 97450 195 18. 51778 38 -0.3 33.18 26.68 . 97383 136 37. 02692 50 57 .97369 . 97363 127 124 48. 71204 55. 52766 '."08554 -i."i" "33.12" '26." 81" 76 -1.2 33.42 26.90 . 97346 115 74.02502 » Interpolated. 117 Oceanographic station data and dynamic calculations, 1927 — Continued Date a Ol depth a = Meters a\ = Pressure in decibars Station Lati- tude Lonpi- \ depth tude i of Tem- Sa- water pera- ture linity 0/00 &t V V-Vi E E-Ei o , o / "C. 815 June W 44 43 49 04 400 0 4.4 32.81 26.02 0. 97464 200 0 0 25 4.3 32.85 26.07 .97448 195 24. 36400 . 04935 50 -1.1 133.09 26.63 . 97383 141 48. 71787 . 09137 100 -1.2 33.41 26.89 . 97325 106 97. 39487 .15312 • 175 -0.6 83.67 27.08 . 97284 99 170.37325 275 1.2 34.08 27.31 . 97219 79 267.62475 400 2.2 34.44 27. 53 .97143 59 389.10100 .40401 ...do 44 40 48 49 897 450 0 127.58 26.25 .97117 . 97442 55 178 437.61600 1 .38251 816 "l'.i' '33.'28" 0 0 25 5.6 33.58 26.50 . 97407 154 24. 35612 i . 04147 50 4.6 34.29 27.17 .97332 90 48. 69849 1 . 07199 125 1.6 134.44 27.57 . 97262 54 121. 67124 . 12612 250 2.4 134.67 27.69 . 97195 43 243. 20C87 . 18688 450 3.0 34.73 27.70 .97106 44 457. 50787 . 27438 750 3.4 34.81 27.71 . 96974 45 728. 62787 .40838 817 —do 44 39 48 36 2,012 0 6.8 33.10 25.97 .97409 205 0 0 25 6.6 33.28 26.14 . 97441 188 24. 36375 .04910 50 0.0 33.46 26.89 . 97358 116 48.71374 1 .08724 125 4.4 34.43 27.30 . 97288 80 121. 70599 ; . 16087 250 4.2 34.80 27.60 .97204 52 243. 26349 . 24350 450 4.1 34.86 27.68 .97109 47 437. 57649 . 34300 750 4.0 34.92 27.74 . 96972 43 728. 69798 . 47849 818 June 20 44 35 48 12 3,383 0 6.8 33.08 25.95 . 97470 206 0 0 25 6.2 33.21 26. 13 . 97432 179 24. 36275 .04810 50 5.2 133.99 26.87 . 97360 118 48. 71300 .08650 125 4.7 34.43 27.27 . 97291 83 121. 70713 . 16201 250 4.6 34.78 27.57 . 97208 56 243.26901 1 .24902 450 4.0 34.83 27.67 .97110 48 437. 58701 : . 35352 750 4.2 34.94 27.73 . 96973 44 728.71151 1 .49202 819 --do.... 44 02 48 18 3,018 0 11.1 33.58 25. 67 . 97497 233 0 0 25 11.0 34.22 26.18 . 97438 185 24. 36687 . 05222 50 9.2 34.69 26.86 . 97362 120 48. 71687 . 09037 125 7.5 34.73 27.15 . 97303 95 121. 71625 .17113 250 6.0 34.82 27.43 . 97221 79 243. 30375 . 28376 450 4.7 34.90 27.65 .97112 50 437. 63675 . 40326 750 4.2 34.92 27.72 . 96974 45 728. 76575 . 54626 820 ...do.... 44 02 48 35 3,126 0 10.8 34.01 26.06 . 97460 196 0 0 25 10.6 34.02 26.10 . 97445 192 24. 36313 .04848 50 3.6 33.89 26.95 . 97353 111 48. 71288 1 . 08638 125 6.4 34.75 27.32 . 97286 78 121. 70251 . 15739 250 5.3 34.88 27.56 . 97209 57 243. 26189 . 24190 450 14.6 34.92 27.68 .97110 48 437. 60089 . 36740 750 4.0 34.90 27.72 . 96980 51 728. 73589 . 50240 821 —do.... 44 02 48 50 1,993 0 5.5 33.11 26. 13 .97453 189 0 10 25 5.5 33.25 26. 25 . 97431 178 24.36050 ! .04585 50 3.9 33.76 26.83 . 97364 122 48.70988 ; .08338 125 2.6 34.40 27. 45 . 97273 65 121. 69876 ' . 15364 250 3.0 134.69 27.65 . 97198 46 243.24314 i .22315 450 3.3 34.78 27.69 .97107 45 437. 54814 . 31465 750 3.4 34.80 27.71 . 96973 44 728. 66814 . 43465 822 ...do 44 02 49 01 627 0 5.0 32.84 25.98 .97468 204 0 0 25 3.8 32.86 26.17 . 97439 186 24. 36378 .04913 50 -0.2 33.09 26.60 . 97386 144 48.69191 .06541 125 0.0 33.74 27.11 . 97305 97 121. 70104 . 15592 250 325 27.32 27.44 . 972.30 .97184 78 66 243. 28442 316. 18967 .26443 "V.~9,' "34."29" 625 2.8 34.64 27.63 . 97030 46 607.51067 I ...do.... 44 02 49 12 225 750 0 127.65 25.98 . 96978 .97468 49 204 728. 76566 . 53217 823 "4.'3T32.74' 0 0 25 0.2 32.66 26.23 . 97433 180 24.36263 ' .04798 50 1. ] 33.26 26.66 . 97380 138 48.71426 .08776 100 -0.8 33. 49 26.94 . 97331 112 97.34201 .10026 150 -0.9 '33.72 27.12 . 97292 95 145. 94775 i . 10201 225 -0.6 33.96 27.31 . 97238 75 218.89651 j ...do 43 49 48 56 813 250 0 127.45 26.11 .97217 . 97455 65 191 243. 20339 i . 18340 824 "I'l' "32.'97" 0 0 25 4.4 33.11 26.26 . 97430 177 24.36063 1 .04598 50 1.6 •33.47 26.80 . 97367 125 48.70726 1 .08076 125 1. 3 j 34. 17 27.38 . 97279 71 121. 70051 ' . 15539 250 2.6 : 34.61 27.62 . 97201 49 243.25051 1 .23052 450 3. 0 1 34. 72 27.68 .97108 46 437.55951 i .32602 750 3.4 134. 81 27.72 . 96972 43 728. 67951 . 44602 ■1 Interpolated. 118 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of 01 depth a = Meters Oj = Pressure in decibars station Tem- Sa- water pera- ture linity 0/00 h V V-Vi E E-Ei o / o / °C. 825- June 20.. 43 35 48 39 2,951 0 7.2 33.14 25.95 0.97471 207 0 0 25 3.0 33.73 26.89 . 97370 117 24. 35513 .04048 50 1.6 34.04 27.25 . 97324 82 48. 69188 . 06538 125 1.2 34.39 27.56 . 97262 54 121. 66163 . 11651 250 12.8 34.68 27. 66. . 97198 46 243. 19913 . 17914 450 3.3 134.78 27.70 . 97106 44 437. 50313 . 26964 750 3.6 34.88 27.75 . 96970 41 728. 61713 .39764 826 ...do 43 25 48 43 2,895 0 6.8 33.08 25.95 . 97471 207 0 0 25 4.4 33.26 26.38 . 97420 167 24. 35513 .04048 50 2.4 34.12 27.25 . 97324 82 48. 69813 . 07163 125 2.2 34.47 27.55 .97264 56 121. 66863 . 12351 250 2.8 34.69 27.67 . 97197 45 243. 20676 . 18677 450 13.2 34.76 27.70 . 97106 44 437. 50976 . 27627 750 13.3 34.87 27.75 . 96969 40 728. 62226 . 40277 827 June 21 43 14 48 46 2,090 0 6.0 33.06 26.04 . 97462 198 0 0 25 3.4 33.50 26.67 . 97391 138 24. 35663 .04198 50 2.4 34.07 27.21 .97328 86 48. 68401 . 05751 125 2.5 34.46 27.51 . 97268 60 121. 65751 . 11239 250 3.0 34.69 27.65 . 97198 46 243. 19876 . 17877 450 3.2 34.77 27.69 . 97107 45 437. 50376 . 27027 750 3.4 34.83 27.72 . 96972 43 728. 62226 . 40277 828 ...do 43 18 49 03 1,207 0 6.1 33.33 26.25 . 97442 178 0 0 25 5.2 33.66 26.61 . 97397 144 24. 35488 .04023 50 3.4 34.09 27.14 . 97335 93 48. 69626 ! . 06976 125 '2.4 34.47 27.54 . 97265 57 121. 67126 . 12614 250 2.8 134.68 27.66 . 97198 46 243. 21064 . 19065 450 3.0 34.75 27.70 .97106 44 437. 51464 .28115 750 3.2 34.83 27.75 . 96969 40 728. 62714 . 40765 829 ...do 43 20 49 20 343 0 4.4 33.01 26.22 . 97445 181 0 0 20 3.8 13.3. 05 26.27 . 97431 176 19. 48760 . 03565 70 -0.5 33.34 26.81 .97358 125 68. 18485 . 11090 120 -0.4 33.71 27.10 . 97308 98 116.85135 150 220 27.18 27.35 . 97286 . 97236 89 72 146. 03960 114. 12265 .19386 +i."i" '34.12" 250 340 27.40 27.47 . 97222 . 97173 70 65 243. 24022 330. 77010 .22023 "V.i' "34."33" 830 -.do 43 24 49 32 150 0 5.6 32.74 25.84 . 97481 217 0 6 25 3.0 32.94 26.26 . 97430 177 24. 36387 .04922 50 0.7 33.20 26.64 . 97382 140 48. 71537 .08887 100 -0.6 33.44 26.90 . 97335 116 97. 39462 . 15287 125 150 26.96 26.99 . 97319 .97306 111 109 121. 72637 146. 05449 . 18125 ""0.'9" "33."66' . 20875 831 ...do 43 08 49 46 100 0 5.7 32.94 25.98 . 97468 204 0 0 25 0.8 33.20 26.63 . 97395 142 24. 35787 .04322 50 -0.9 33. 39 26. 86 . 97361 119 48. 70237 . 07587 75 -1.0 33.52 26.97 . 97340 109 73. 03999 .10445 100 -1.0 33. M 26.98 .97328 109 97. 37349 . 13174 125 27.00 .97315 107 121. 70386 . 15874 832 ...do...- 43 02 49 35 1,150 0 "5.' 2" " 33.01 26.09 . 97457 193 0 0 25 3.9 33.03 26.25 . 97431 178 24. 36100 .04635 50 1.3 33.35 26.69 . 97377 135 48. 71200 .08550 125 -0.6 33.68 27.08 . 97308 100 121. 71887 . 17375 250 1.6 34.33 27.46 . 97216 64 243. 29637 . 27638 450 2.8 34.61 27.60 .97116 54 437. 62837 .39488 750 3.3 34.84 27.74 . 96971 42 728. 75887 . 53938 833 .-do...- 42 56 49 21 1,545 0 5.6 33.01 26.05 . 97461 197 0 0 25 3.1 33.13 26.40 . 97417 164 24. 35975 .04510 50 -0.5 33.38 26.84 . 97363 121 48. 70725 . 08075 125 +1.2 33.96 27.21 .97295 87 121. 70400 . 15888 250 2.6 34.60 27.61 . 97202 50 243. 26462 .24463 450 3.2 34.74 27.67 .97110 48 437. 57662 . 34313 750 3.4 34.83 27.73 . 96972 43 728. 69962 . 48013 834 ...do...- 42 42 49 05 2,286 0 6.8 32.98 25.87 . 97478 114 0 0 25 3.6 32.92 26.19 . 97437 184 24. 36437 .04972 50 -0.3 33.25 26.73 . 97373 131 48. 71562 .08912 125 -0.6 33.64 27.05 . 97310 102 121.72174 . 17662 250 1.7 34.16 27.34 .97228 76 243. 30799 .28800 450 3.1 34.75 27.69 . 97108 46 437. 64399 . 41050 750 4.0 34.92 27.74 . 96972 43 728. 76399 .54450 ' Interpolated. 119 Oceanographic station data and dynamic calculations, 1927 — Continued Date Lati- tude Longi- tude a depth of depth a = Meters 01 = Pressure in decibars station Tem- Sa- water pera- ture linity 0/00 «. V V-V, E E-E, o / o / °C. 835 June 21 42 43 49 39 1,832 0 5.8 32.90 25.94 0. 97471 207 0 0 25 4.2 32.87 26.10 . 97445 192 24. 36450 .04985 50 0.3 33.11 26,58 . 97388 146 48. 71862 .09212 125 -1.0 33.52 26. 97 . 97318 110 121. 73337 .18825 250 1. 0 34. 01 27.27 .97235 83 243. 32899 .30900 450 3. 0 34. 61 27.59 .97116 54 437. 67999 .44650 750 3.6 i 34.82 27.70 . 96975 46 728. 81649 .59700 836 June 25 43 10 50 11 78 0 8. 2 ! 32. 93 25.67 . 97497 233 0 0 15 7.8 1 32.98 25.74 . 97483 226 14. 62350 .03436 35 3.7 1 33.07 26.31 . 97420 171 34.11280 .07306 55 1.8 I' 33. 31 26.56 . 97387 147 53. 59350 .10496 75 1.7 33.85 26. 82 .97354 121 73. 06760 .13206 125 127.07 . 97309 101 121. 73335 .18823 837 ...do 42 55 50 09 225 0 "7.0' '32.87' 25.76 . 97488 224 0 0 25 3.8 1 33.09 26.31 .97425 172 24.36412 .04947 75 -0.3 1 33.57 26.98 . 97350 108 73. 05787 .12233 125 +0.8 33.81 27.11 . 97305 97 121. 72162 . 17650 225 2.4 1 34.26 27.36 .97237 218. 99262 250 1 1 27. 38 . 97224 72 243. 30024 .28025 838. — do.-.. 42 42 50 06 1,792 0 ""5'8T32"83' 25.89 . 97476 212 0 0 25 5. 4 ! 33. 15 1 26. 52 . 97405 152 24. 36012 .04547 50 3.8 ! 33.40 126.80 . 97367 125 48. 70662 . 08012 125 1.3 1 33.98 27.22 .97294 86 121. 70449 . 15937 250 2. 2 1 34. 44 27.53 . 97210 58 243. 26949 .24950 450 2.6 i 34.65 27.67 . 97109 47 437. 58849 .35500 750 3.3 134.82 27.72 . 96972 43 728. 70999 . 48050 839 ...do.-.. 42 24 50 06 2,286 0 7.0 ! 32.71 25.63 . 97501 237 0 0 25 1.8 33.11 26.49 . 97408 155 24. 36362 .04897 50 -0. 3 1 33. 25 26.73 . 97373 131 48.71124 .08474 125 -1.0 33.58 27.02 . 97313 95 121.71849 . 17337 250 2. 0 1 34. 15 27.31 .97231 79 243. 30849 .28850 450 3. 2 34. 68 27.63 .97112 50 437. 65149 .41800 750 4.0 134.90 27.73 . 96973 44 728. 77899 . 55950 I Interpolated. o TREASURY DEPARTMENT - UNITED STATES COAST GUARD BULLETIN No. 17 INTERNATIONAL ICE OBSERVATION AND ICE PATROL SERVICE IN THE NORTH ATLANTIC OCEAN - [ff °2''8'] TREASURY DEPARTMENT UNITED STATES COAST GUARD Bulletin No. 17 INTERNATIONAL ICE OBSERVATION AND ICE PATROL SERVICE IN THE NORTH ATLANTIC OCEAN Season of 1928 UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON: 1929 TABLE OF CONTENTS Page Introduction 1 Narrative of the seven cruises, March 20 to June 26 5 Radio communications 34 Summary report of the commander, ice patrol 36 Table of ice and other obstructions 39 Weather 50 Depth survey carried out by sonic methods 56 Ice observation 60 Charts of ice and ice drifts, 1928 Face 64 Oceanography 65 Oceanographic charts 75 Table of oceanographic station data 82 (III) THE INTERNATIONAL ICE PATROL 1928 The international ice patrol for the season of 1928 was carried out by the United States Coast Guard cutters Modoc and Mojave, with the Tampa acting as the stand-by vessel. Commander William H. Munter, in addition to being in command of the Modoc, was also in command of the patrol, as in 1927. Commander Cecil M. Gabbett was in command of the Mojave. Lieut. Noble G. Ricketts was detailed as scientific observer and remained at sea with two enlisted men as assistants throughout the patrol season, aiding the commanding officer of the vessel actually on patrol and keeping a continuous and uniform record of the patrol work for this annual report. Halifax, Nova Scotia, was the base for fuel and other supplies during the ice season. The Mojave and Modoc made alternate cruises of about 15 days each in the ice regions, the 15 days being exclusive of the 5 or 6 days occupied in going to and from base. The duties and scientific work carried on bj" the patrol were, in general, similar to the practice during previous ice-patrol seasons. The objects of the patrol were laid down in the instructions issued by Coast Guard headquarters on February 29, 1928, to the commanding officers of the patrol vessels. According to the orders the primary object was to locate by scouting and radio information the icebergs nearest to and menacing the North Atlantic lane routes, and to determine the southerly, easterly, and westerly limits of this ice by keeping in touch with it as it moved southward. Four radio broadcasts were to be sent out daily giving the whereabouts of all known ice in the vicinitj'' of the steamer lanes. In addition to giving the location, the probable drift of the known ice was indicated when possible. Special messages were drafted and sent to any ship that inquired for special information relative to ice conditions, routes, weather, or similar matters. The successive positions of the v/ater temperature and weather reports of the liners and other vessels were carefull}'- watched, and whenever a ship was observed to be following a course leading toward danger the master was so advised, and routes or suitable precautions were suggested. The secondary object of the patrol was to make scientific observa- tions of weather, ice, and oceanic conditions. This work was imposed upon the ice patrol at its beginning in order that a greater knowledge might be had of the area about the Grand Banks, with special regard to the movement of ice. It is obvious that when more facts are known about the ice and its behavior, and the causes that lie back of (ir •^p|F»N;iif7\ND ST JOHNS ST PIERRE^ ^ CAPE RACE -"^Z TRACKS • BANKS htt PATROL MSSELS STAY ^t%ST OF TIME /W'lTH BERGS /THAT ARE iN /iB'iS -^0.000 /Si^JARE MILE-' 15*M.- Figure 1.— Diagram of a portion of tiie principal Nortli Atlantic Laue Routes. (For detailed explanation see next page.) (2) its marked variations in position and quantity from year to j'ear, the more efficient a patrol it will be possible to maintain, and the greater will be the value of the service to shipping in general. The scientific and oceanographic work, being supportive and secondary in impor- tance to the practical scouting and advisory work, however, was so arranged as not to hamper ice scouting and trailing. The Mojave inaugurated the 1928 patrol on March 21, and from that date until the service was discontinued by a dispatch from Coast Guard headquarters on June 22, either that vessel or the Modoc was continually on guard in the ice regions. Most of the vessels that ply between Europe and the United States and Canada do not follow the shortest route. That would be the great circle track and it would lead them, when plying between most ports, close past Cape Race, Newfoundland. On account of the well recognized ice menace, vessels have for many years followed estab- lished tracks, or lanes, that are shifted from time to time as the limit of the ice advances and recedes. Figure 1 shows the approximate location of the different steamer lanes, and the explanation of the diagram shows when the different tracks are normally used. It is comparatively infrequent that the Explanation of Figure 1 A, B, and C, are routes to and from New York. D, E, F, and G, are routes to and from Canadian ports. Eastbound tracks are full lines. Westbound tracks are dashed lines. For fuller information relative to the North Atlantic lane routes see the special track charts published by the United States Hydrographic Office and by the British Admiralty. Inclosed area between tracks E and B about the Tail of the Grand Banks shows where the distribution of the ice usually keeps the ice patrol vessel. Normal periods different tracks are used: A, eastbound. March 25 to July 7. A, westbound. April 1 to June 30. B, eastbound. February 1 to March 24, and July 8 to August 31. B, westbound. February 1 to March 31, and July 1 to August 31. C, eastbound. September 1 to January 31. C. westbound. September 1 to January 31. D. February 15 to April 10. E. April 11 to May 15 or until Cape Race Route is clear of ice, and Dooember 1 to February 14. F. May 16 to opening of Strait of Belle Isle, and to November 30. when not using Belle Isle route. G. From opening of Strait of Belle Isle to November 14. Above so called normal periods were taken from United States Hydrographic Office chart of North Atlantic steamship routes. A tracks were not used at all during 1928. B tracks were used from April 14 to September 1. C tracks were used between United States and Europe throughout rest of year. southernmost lane, called track A, is crossed by dangerous ice. Dur- ing 1928 it is known to have been crossed b}^ bergs only twice. The tracks to the north of A are progressively more dangerous, being especially so in spring and early summer, when the Labrador current strengthens and brings large quantities of ice down from the Arctic. Those charged with the shifting of the tracks, and those concerned in any way with the navigation of ships along them, should realize to the full, in view of the many human lives concerned and on account of the enormous value of the floating property involved, their respon- sibilities in the matter, and act accordingly. The prevalence of fog and low visibility over the cold water areas Avhere the ice is usually found makes the exercise of caution necessary. During the 1928 ice patrol season the Canadian Pacific steamship Montrose struck a berg along one of the Canada-Europe tracks to the northeast of the area that is most closely guarded by the ice patrol. Although she stove in her bows with the reported loss of two lives, she was able to continue to her destination under her own power. While it is not desired to view the matter in a pessimistic light, it would appear that the increasing traffic along the northern tracks leading through areas where bergs are known to be normally present in considerable numbers, is liable to result from time to time in such collisions. The ice-patrol broadcasts, which list all the known ice, when they are coupled with good judgment on the part of masters and the exercise of caution at all times, will serve to reduce these collisions to the minimum, and should greatly mitigate their serious effects when thej" do occur. CRUISE REPORTS THE FIRST CRUISE, " MOJAVE," MARCH 20 TO APRIL 5 The Mojave left Boston, Mass., for the ice-patrol regions at 11.50 a. m. on March 20, 1928, in obedience to orders from Coast Guard headquarters. Westerly breezes and moderate seas were experi- enced until a position near the Tail of the Grand Banks was reached. While en route to the patrol grounds on the 21st, the Halifax wireless officer, who has charge of all the important Canadian sta- tions in the Maritime Provinces, was notified that the 1928 ice patrol was starting. His cooperation -during the coming season was re- quested. On the same day broadcasts to shipping were sent out to the effect that the patrol was inaugurated and that reports of water, temperatures, ice and obstructions to navigation sighted, courses speeds, and positions, were desired every four hours from all ships in the ice patrol area, which was defined as lying between latitudes 39° and 49° N. and longitudes 43° and 56° W. This broadcast was repeated every four hours until March 23, and occasionally after that in order that all vessels might be fully informed regarding the patrol. On the 22d, regular radio schedules with NAA, the naval radio station near Washington, D. C, were established in accordance with Coast Guard headquarters' instructions. On the 22d also the Cape Race radio stations and the French station at St. Pierre, Miquelon, were communicated with and requested to cooperate \^'ith the patrol vessel as in previous years. A cyclonic disturbance passing to the north of the Mojave caused lightning and warm rains on the evening of the 23d. During the day about a dozen water temperature reports were received from trans- Atlantic vessels and plotted in on the cruise chart. As time went on the number graduall}" increased until each four-hour watch nor- mall}^ produced 15 such messages. Morning of the 24th found the Mojave approaching the Tail of the Grand Banks from the westward. The whole day was spent in rectangular searching for ice that carried the vessel up to and slightly around the Tail. Strong westerly winds following the "low" of the night before raised a heavy sea. No ice was sighted and the night was spent drifting in the shallow water over the Tail. At daylight on the 25th the search for ice was resumed up the eastern edge, but fog shut in around 2.30 p. m., when a "low" ap- proaching from the northwest caused an indraft of air from the warm water to the southward to flow over the fold water in the vicinity of the Tail. The fog caused by these southerl}" \vinds lasted until (5) 6 the night of March 28 over all the cold water areas about the Banks, a very unusual condition to persist for so long so early in the season. The ice-patrol vessel took advantage of the time while balked from ice scouting by bad visibility to run two short lines of oceano- graphic stations off from the Tail toward the east. It was found that a considerable body of arctic water with temperatures as low as — 1.2° C. was situated off the Bank, but it was calculated from the formula in United States Coast Guard Bulletin 14, that this water was all practically stationary. This suggested that farther north there was some dynamic barrier to the free flow of the Labrador current down the eastern edge of the Bank, hindering the southward extension of cold water and ice. The t'me during this foggy weather that was not actuall}' consumed by station work was spent drifting over the Bank a little north of the Tail. This area was also north of the C tracks and so out of the way of the greater part of the trans-Atlantic traffic. The inac- tivity was useful in that it conserved fuel and insured that later on in the cruise there would be no enforced drifting during good weather due to lack of sufficient oil. Visibility of from three to four miles on the morning of the 29th enabled the scoutijig for ice to be resumed. Throughout this day the Mojave searched to the northward up the eastern edge of the Grand Banks. The visibility improved as the day advanced, being good from noon until dark, As might have been expected after the lifting of the fog blanket, several reports of ice came in during the day. The steamer M. Christensen approaching the Banks from the east- ward well to the north of the patrol vessel, reported four bergs, growlers, and field ice. It is believed that the only reason more reports of ice were not received was because there were no other ships crossing the Labrador current to the north of the Mojave. That there was a large volume of traffic on the C tracks to the south was evidenced by the water temperature reports pouring in from that area, at the rate now of about 70 a day. If any ice had been near the traffic lane it would have been reported along with the surface temperatures. The total absence of ice reports from vessels to the south led the patrol to conclude that the proper direction to search was northward. Late on the afternoon of March 29 the patrol ship sighted her first ice of the season, a growler in 44° 59' N., 48° 39' W. Shortly afterward a growler and a berg were sighted in 45° 15' N., 48° 21' W., and the Mojave was stopped to drift by the latter for the night. The 30th was a perfect day for ice scouting, clear and almost calm, with springlike temperatures and a gentle rolling swell. On such a day the white bergs show plainly against the dark blue water and the light blue sky to as great a distance as the curvature of the earth will allow them to be seen, usually from 15 to 20 miles for a masthead lookout. Speed had to be limited to 70 revolutions per minute, which gave between 9 and 10 knots, because of the continuing neces- sity for carefulh^ regulating fuel consumption. A rectangular area to the northeastward was covered during the da}'- and most of the ice reported by the M. Christensen w^as checked as to position and drift. The latter was found to be about 1 knot in a southwest direction. Two new bergs were found just south of 46° N. and just east of the forty-eighth meridian. The berg left early in the morning was reached again before dark and was watched during the night. It drifted first to the southeast and then to the east, evidently having been checked in its southwesterly course by some such shoulder of the Gulf Stream as often presses in close to the Bank a little north of the Tail, so cutting off the flow of the Labrador current. Reports of relatively high temperatures from passing vessels gave further evidence of the existence of such a shoulder of warm surface water at the time. Ice scouting was continued on the 31st, for the winds were as light and the visibility was about as good as on the preceding day. By noon it began clouding over, due to the approach of another *'low" from the west. By 3.30 p. m. the weather was thick and rainy so the searching was abandoned. During the good visibility a consider- able area to the westward to the 50-fathoni curve had been covered and one more unreported berg had been located. A check up was also had on the westernmost berg reported by the M. Christensen on the 29th, which proved to have drifted due south at about 0.5 knot. The night of the 31st the Mojave spent near the newest berg, which was believed to be the southernmost ice. During the night it was lost in the storm and fog, but the next morning was found by steaming about 10 miles to windward. The 1st of April was spent near this berg in order to follow its drift. It was the largest berg seen so far during the season, measuring about 200 feet square and averaging about 30 feet high above the water line. All the bergs sighted so far had been rounded and water glazed except where sharp cliffs were in evidence — in some places about the sides, w^iere overhanging projections of ice had calved off. At 4 a. m. on the 2d the patrol vessel stood to the southward to take a line of stations from a point in the warm current in toward the Bank. Seven stations were taken down to the 750 meter level during the day between the forty-eighth and forty-ninth meridians in latitude 44° 27' N. They showed a gradual cooling of the surface water from 7° to —1.1° C. as the Bank was approached. A calculation of these stations determined the comparatively narrow width of the south-flowing stream and its appro::imate speed at the time and place. 8 To menace the United States-Europe ti-acks it was necessary for the ice to pass down through the narrow straitlike formation of cold water lying just off the eastern edge of the Bank. It is obvious that the narrower the band of cold water remained the easier it would be to watch and the fewer bergs would flow along it, other things being equal. From her water temperature reports of April 1 and 2 it was noted that a steamer had passed only about 5 miles south of the southern- most berg. Steaming, as she apparently did from her successive positions, at a speed of 16.5 knots by it on a pitch dark night, it was deemed that her action was most foolhardy, especially so in view of the many factors of error that are possible in determining the position and drift of ice, and the possibility of the existence of ice not sighted or reported. April 3 was another day of perfect visibility and light breezes like the two preceeding days. A final station was taken early in the morning on the 100-fathom curve near where the vessel had been drifting for the night. Then a run was made to the northeastward to locate ice before starting west to meet the Modoc. Three bergs and five growlers were sighted during the day. No less than 10 bergs were reported to the east and northeast of the Bank. An abnormally high barometer prevailed, with gentle to moderate westerly breezes. On the morning of the 4th the wind had fresh- ened from the west but the search was resumed at 7 a. m., and during the day the Mojave worked first to the westward, and then to the southward down the eastern edge. Only one berg was sighted during the day. None were reported. At 7 p. m. the vessel's head was turned to the southwest across the Bank towards the Modoc, which vessel was now rapidly approaching the patrol area. During the first patrol cruise 38 ice reports were received from vessels and shore stations. Special ice information was sent on request to three steamers. There were plotted in all on the base map over 1,050 surface water temperature observations, 100 of which were made by the patrol vessel and the remainder received by radio from 130 different cooperating vessels. The remarkable feature of the first cruise was the comparativel}^ smooth seas and fine weather enjoyed most of the time. Except for the crisp air that almost invariably remained in the thirties and lower forties one might well have thought that the season was summer instead of early spring. One period of fog early in the cruise and two blustery but clear days were the only things that hampered the scouting and station work. On the evening of April 5 the Modoc was met at a rendezvous in approximately 43° N., 53° W. There the oceanographic party was transferred and the relief of the patrol was effected by 9.30 p. m. As 9 soon as relieved the 2Iojave stood to the westward for Boston in accordance with authority received from headciiiarters on March 28. Permission to proceed to Boston instead of Hahfax had been obtained because of the need of the fathometer for adjustment. The gyro- compass had broken down early in the cruise and was in need of over- haul also. The Modoc on taking the patrol duty over stood to the eastward toward the ice area. THE SECOND CRUISE, " MODOC," APRIL 6 TO 21, 1928 When the Modoc sent a boat over to the Mojave to receive the oceanographic party at 9 p. m. on April 5, 1928, the commanding officer of the latter vessel took advantage of the opportunity to call on the commander, international ice patrol, on the Modoc for a con- ference. There was a light southeast breeze with a moderate north- west swell. Searchlights lit up the white patrol ships and helped the moon to illuminate the transfer activities. Mail, baggage. Navy moving picture programs, and several enlisted men were transferred from one vessel to the other. The Modoc rounded the Tail about noon of April 6 and then started a search for bergs up the eastern edge. On the afternoon of the 6th and on the 7th and 8th perfect weather for scouting prevailed. The winds ranged from gentle breezes down to a flat calm, and the visibihty was excellent. The heavenh^ bodies were practically always available for sights to locate the ship's position. Coupled with the radio bearings received at 6 a. m. and 6 p. m. from Cape Race and with the depths from the fathometer the sights made the position of the ship as certain as it could well be in an area of conflicting currents. A large rectangle 50 miles wide and 80 miles long up the eastern edge was combed over for ice. That none was seen can be taken as conclusive evidence that there was none there. The southernmost bergs sighted by the Mojave had either been curved off to the north- east by the press of Gulf Stream water that w^as eddying in toward the bank around 44° 30' N., 48° 30' W., or forced inshore onto the Bank lower down by the same influence. Twihght and dawn fixes showed on the 6th and 7th the tendencies for night drifts to set to the westward when over the Banks and to the northeast when farther offshore. On the afternoon of the 8th, about an hour before sunset, three French fishing vessels were intercepted on their slow way to the fishing grounds north of the Tail. The easternmost of them proved to be the barkentine Bengali of St. Servan. This vessel was given its position. It was circled and photographed while it put oft' a dory with mail to be posted. The Bengali was already 30 days out from France. She was reported to the French radio station at St. Pierre^ 10 Miquelon. Shortly after this vessel was left a fog bank to the west- ward was entered. Immediately the Modoc stopped, to drift for the night, further searching being useless. The three days of high barometer and fine clear weather were followed by a falling barometer accompanied by southerly winds and dense fog. This was plainly due to the passage over Newfound- land of the cyclonic disturbance that had been noted on the weather map for several days, making its way across the Mississippi Valley, the Lakes, and the St. Lawrence regions. It was so far away that the strongest winds experienced by the patrol were only force six from the south. These occured on the night of the 8th a little after the lowest barometer reading of 29.83 was noted. Up at Belle Isle at this time the barometer read 29.24. The patrol vessel had escaped another storm almost untouched on account of being well to the south of the storm track. During the fog on the 9th four oceanographic stations were taken between the forty-eighth and forty-ninth meridians in latitude about 44° 30' N. The patrol vessel steamed at slow speed, about 50 revolu- tions per minute, to the westward between stations. It was thought that the westernmost station would be in the shallow waters over the Bank, but, due to the easterly drift during the night of the 8th while ofl'shore, it was found that the fourth station was located on the 1,000-fathom curve. After it had been taken the vessel was forced to drift by the approaching darkness. The stations served not only to indicate the dividing line between the cold and warm current, but also to familiarize the boatswains mates and the seamen of both watches with what was expected of them during station work. On the 7th and 8th, reports of ice were received from vessels on the westbound C tracks in the neighborhood of 44° 30' N., 46° 10' W. These tracks were considered dangerous in consequence, and a special broadcast so stating and giving the reported positions of the bergs was sent out several times. During the night of the 9th the fog cleared as the wind hauled more to the westward. An area of high pressure was noted on the weather map off the Middle Atlantic States, indicating a short spell of good weather for the ice-patrol area. At sunrise on the 10th the patrol vessel began standing due north up the heart of the Labrador current. At noon the course was changed to 44° true in order to run along about 10 miles outside of the 100- fathom curve of the eastern edge. In spite of vigilant lookout and good visibihty no ice was sighted until 3.30 p. m., when a large berg was observed nearly dead ahead and about 10 miles off. This berg was the first glacial ice that many on board the Modoc had seen. It was a stable looking berg with old water lines and much mass. There was one pyramidal pinnacle that was separated 11 by a wave washed trough from the main plateau of the berg. It was circled and photographed but a snow squall came up at this time and prevented the getting of good pictures. The northeasterly course was continued. After running about 12 miles another berg was reached and drifted by for the night in 45° 58' N., 47° 46' W. While running between these two bergs a whale was collided with. Being struck a glancing blow no percept- ible jar was felt on board, although the large creature was rolled over and seen to scrape along the ship's side. The 11th was spent running to the southeastward and eastward before a fair wind to investigate bergs that were being continually reported along the C tracks between the forty-fourth and forty-fifth meridians. One berg was sighted at about 11a. m. on the port beam. Its position was cut in but it was not approached because it was not the southeasternmost ice. On the morning of the 12th the search was resumed and the berg especially being looked for was found at 1 p. m. It was circled and used as a point of aim during general quarters. This berg was low like a monitor and much eroded. The water it was floating in was of a temperature of about 56° F. The swells were giving it such a good washing with this warm water that it was not expected to last long. The remainder of the 12th was spent searching for ice to the south- ward. One growler was found, probably the remains of what had been reported by steamers as a berg for several days past. The first berg, being larger and much more dangerous was returned to and drifted by until morning. Diu-ing the night no less than three steamers were seen approaching on the courses that would have carried them close to the berg. They were warned by blinker and searchlight of its presence and all of them altered their courses and passed clear. In the morning the berg was seen to have drifted to the southeast at about 0.7 knot. It was very small now and would not remain a menace to shipping many hours longer. Accordingly, at daylight it was left and a course was shaped to the westward through a different area than had been covered on the previous two days. No ice was sighted, but the berg left was reported twice during the afternoon by passing vessels on the C tracks. The last report placed it in 44° 11' N., 43° 21' W. It was never heard of afterwards, so must have melted entirely during the night of the 13th. The 14th was a day of increasing easterly winds that reached fresh gale force in the afternoon. The course toward the Banks was con- tinued before the wind. Three oceanographic stations were taken during the day in the warm water, but the wire slanted off to wind- ward too much for accurate results. 12 At 1.30 p. m. the vessel was stopped and Titanic memorial services were held in the gale. No berg was at hand this year, but the rough sea and howling wind made a fitting background for the ceremonies observed on this, the sixteenth anniversary of the great marine tragedy that created the ice patrol. An account of these exercises was radioed to the press as in previous j^ears. On the 13th the Modoc received inquiry from the press relative to news concerning the German trans-Atlantic fliers. A double lookout was kept from aloft for sight of them. When it was learned that they had landed in the Strait of Belle Isle it was realized that they were too far away and beset by too much ice to be assisted by the patrol vessel. On the 14th also the C tracks were ordered discontinued by the North Atlantic Track Conference. The B tracks were made effective, much to the relief of the patrol vessel. The unusual southeasterly drift of ice this year had menaced the more northerly C tracks for some days. Every broadcast for some time prior to and after the 14th contained warnings to vessels that the C tracks were crossed by bergs and that extreme caution should be used between the forty- second and forty-seventh meridians during darkness and other times of bad visibility. While the Modoc drifted on the night of the 14th the wind backed to the north and then gradually moderated as the "low" that had passed near by moved further out over the ocean. The whole of the 15th was spent scouting in the mixed water just east of the Banks trying to locate again the southernmost bergs in the central branch of the Labrador Stream. These waters w^ere noted to be of a brownish color like weak cypress water. The color was especially noticeable because of its contrast with the warm blue waters of the Gulf Stream drift that had surrounded the ship for the past three days. At 5.30 p. m. two large bergs were reached in 45° 03' N., 48° 22' W. These were circled and photographed in the light of the late after- noon sun. A station taken just clear of the bergs showed that the water at all levels was above the freezing point. Gulf Stream influ- ence, even here, was therefore apparent. On the morning of the 16th it was foggy at times, due to the winds having shifted to the southeast. The two bergs were still in sight to the northeast during clear intervals, distant about 6 miles. A station was taken at 9 a. m. that showed the Modoc to have been blown during the night into purer arctic water. The temperatures at the surface and down to 125 meters were between —0.6° and — 0.2° C. The day was gloomy and misty, altogether unsuitable for scouting, so 10 miles were run to the westward and there another station was taken in even colder water, probably near the axis of the 13 Labrador current. When this station was finished a berg about 5 miles to the northwest was approached and examined. This one proved to be a large picturesque berg. The blue tints and streaks in the ice were very striking. Peaks at two ends were seen to be cracked and apparently ready to fall, but w^histle blasts and the reports from several blank 6-pounder charges failed to dis- lodge any ice. This berg was seen to have a distinct line of brownish yellow dirt in it as noticeable and as even as the caramel icing be- tween the layers "of a white cake. It was surmised that this was due to dust deposited on the ice cap in Greenland at some time in the past, possibly after a great volcanic eruption. The berg was very stable and had an old deeply worn-out water line around it, with spray glazed ice just above. Three large birds, different from the regular species of sea birds about, were noted. These were perched on the high parts or on sheltered niches far up on the berg. "When the ship got close they were found to be snow}' owls that somehow had become passengers on this moving block of ice and been carried far from their arctic home. A little to the westward a station showed only 32 fathoms of water. All of it was cold arctic discharge from —0.6° to —1.0° C. During the remainder of the day and throughout the night the ship drifted on the Bank in the rain. A gradualh^ rising wind and a falling barom- eter were experienced. Since the 10th many reports of ice had been coming in from steamers. No less than 17 reports were received on the 15th and one of these was from a steamer just northeast of the Banks that reported nine bergs along her course for the day. Two other vessels on parallel courses, 40 and 65 miles south of her, reported altogether 11 bergs during the day. The ice had become much too voluminous to permit the listing of all the separate bergs in the broadcasts, so the practice of summariz- ing conditions in certain areas was resorted to. This expedient per- mitted the shortening of broadcast to practicable lengths. When- ever, as frequently occurred, ships would ask for special reports of ice along their courses their tracks would be laid down on the ice chart and messages would be immediately framed for their particular needs, giving the reported locations of all the bergs near their tracks. On the 12th the Montcalm began the Canadian ice patrol in the Gulf of St. Lawrence. A day or two later the first steamer bound for the gulf and river ports was noted approaching the Banks. By daylight on the 17th it was blowing fresh from the north, but the visibility was good. A search to the east and south off the Bank was made during the day. Three bergs were sighted in the deep water. On returning to the Bank for the night the two bergs 33382—29 2 14 first sighted on the 16th were relocated and approached, to be drifted by until morning. The southernmost of the pair was now in 44° 52' N., 49° 10' W. It had drifted due south at about 0.5 knot for the past two days and was believed to be the southernmost ice. Considerable calving and erosion had taken place during the past 24 hours. One of the three snowy owls seen on this berg the previous evening was missing. On the 18th the search for ice was resumed first to the east and then to the south down the Labrador current. No ice was sighted until toward evening, when two bergs reported earlier in the day by the Berlin as in 43° 43' N., 48° 45' W., were reached. Ice so far south was not expected. These bergs must have slipped down in the cold current during the Modoc's cruise to the eastward from the 12th to the 14th. During the night a rather severe storm of small propor- tions passed over, no doubt a secondary of the big "low" noted over Belle Isle. During the blow several dovekies were picked up from deck in a stunned and bewildered condition from having been dashed against the deck house. The two southernmost bergs were located again on the morning of the 19tli and then approached and examined. Both were rather small and were drifting south about 12 miles per day according to radio bearings, dead reckoning, and soundings. Clouds prevented the accurate determination of position. A run was made to the south but no more bergs were sighted. The visibility was excellent after the storm. At 10 a. m. a course to the northwest was laid which was changed to the southwest for the Tail at 1 p. m. After steaming about two hours on this last course, the masthead lookout sighted a berg three points forward of the port beam. It was headed for, proving to have been 15 miles distant when first seen. The berg was a solid low one that bore no resemblance to the dry-dock type whatever, being about 30 feet high and with cliff -like perpendicular sides. This berg was the southernmost ice sighted or reported so far this year, being in 43° 16' N., 49° 14' W. A south- westerly course was continued from the berg for 18 miles, when the course was changed to west for the Tail. The night of the 19th was spent drifting in the shoal water. On the 20th four oceanographic stations were occupied, three of them over and one to the south of the Tail. Pure arctic discharge was observed at the bottom in the shoal water and down to the 125-meter level in the deep water to the south. At 2 p. m. the vessel was hove to on a WSW course on account of a SW gale with heavy swell. The Mojave was met at 8 a. m. on April 21, 1928, in 43° N. 52° W., where the relief of the patrol was effected, As soon as the duty was turned over, the Modoc was headed for Halifax. 15 During the second cruise the weather was rather good on the average for the season until the storm of the 20th. Winds of gale force were experienced on seven different days, but lasted only about 40 hours in all, as the storms were of a very brief nature. The storm of the 20th was most inconvenient, for coming as it did toward the end of the cruise, the heavy swell remained to make the boating incident to relief of patrol quite nasty. Visibility was good about 75 per cent of the time. Bergs were noted unusually far to the southeast and east during this cruise period. Altogether 123 ice reports were received from ship and shore stations. Special ice reports were sent out on request to 18 vessels. The isotherms on the cruise chart were largety based on the 713 water temperature reports sent in by 113 vessels. No derelicts were reported during the second cruise, but a log was reported from on the Banks and two buoys and two alleged floating mines were reported from the waters south of the Banks area. THE THIRD CRUISE, " MOJAVE," APRIL 21 TO MAY 6, 1928 The Mojave at 8 a. m., on April 21, 1928, reached the Modoc's position in approximately 43° 00' N., 52° 00' W. There the ice observation party and the patrol records were received on board with some little difficulty, due to the heavy swell that was running. As soon as the patrol was relieved the Mojave set a course of 90° true to relocate the southernmost berg last seen by the Modoc in 43° 16' N., 49° 14' W. Visibility remained good on the 22d, so the search was continued on that date during the hours of daylight. The berg was not found south or southeast of the Tail, nor was any other ice sighted there. Reports of ice coming in from shipping slackened noticeably during the first part of the third cruise. On the 22cl one of the four ice reports received was that of a long low berg in 43° 09' N., 49° 17' W. This was suspected of being the Modoc's berg of the 19th. It was headed for on the morning of the 23d and reached at 9.30 a. m., being sighted by the lookout aloft when it was about 15 miles oft' and nearly dead ahead. It was recognized positively as the berg especially being searched for. It had changed but slightly in appearance in the four days since it was left by the Modoc. The berg was used as a point of aim during general quarters and then the remainder of the day was spent searching in the waters of the Labrador current to the northwest up to the Bank and back. No ice was found, though a strong southerly set was encountered with surface water temperatures well below 32°. The southernmost berg was drifted by during the night of the 23d. On the 24th an all- day search to the north and northeast and return revealed no ice. 16 Evidently the berg being watched was a large solitary one located well to the south of its fellow^s. Its drift was very interesting. It seemed first to slow dowTi and then to speed up again in a southerly course. It stopped in its career on the 25th and worked slowly to the northwest, then to the west at the rapid rate of 0.75 knot, only to slow up for a couple of days when it had reached a position just south of the Tail. On the 25th it was foggy part of the time. Three stations were taken at strategic points about the berg that at noon was in 42° 47' N., 49° 22' W. At one time during the daj" a start was made for the French fishing vessel Madiana reported by a passing freighter, the West Zeda, as 400 miles to the eastward with two seriously injured men on board, both with broken bones. The master of the West Zeda was advised by radio what to do until a doctor arrived. The Tuscania eastbound, was near the Madiana. When it was learned that she had turned about to the westward and would give medical aid very soon, the Mojave stopped and resumed station work. This was the second case, during the third ice patrol cruise, where medical advice was furnished by radio to ships 's\dthout doctors. On the 21st treatment had been prescribed for the chief officer of the Vogtland who was suffering from a leg badly hurt hj a boarding sea. The 26th was smooth and sunny but foggy. It cleared up around noon and a search was started for the southernmost berg, but no ice was found until noon on the 27th. Then the berg was relocated in 42° 49' N., 50° 10' W., 36 miles west of where it had been seen 48 hours earlier. The 28th was a beautiful, smooth, clear day because a high pressure area with shallow gradients was over the Banks region. The berg was drifted by all day. Boats were sent out for drill and recreation, as had been done on the preA'ious afternoon. Very little change in the size of the berg could be noticed in the nine days during which it had been under observation. The water it was in was well below the freezing point at all intermediate levels and just a little above freezing at the surface. At 8.30 a. m. on the 28th a liner was seen racing along to the west hull down to the southward. Her name could not be ascertained. This vessel crossed the patrol area without sending in an}'" water temperature or weather reports. Being far north of the prescribed tracks, she was evidently keeping her radio silent in order to avoid detection. At 3.30 p. m. another vessel, also westbound, passed about a mile and a half to the south of the patrol vessel and the berg. There was no danger to these passenger vessels on the bright smooth day they had, but if they had been beset by fog or darkness a very slight error in their reckoning or that of the patrol vessel standing 17 by the berg would have sufficed to have put them within striking distance of the southernmost known berg. On Sunday, April 29, the berg was left early in the morning in 42° 46' N., 50° 32' W., in order to take oceanographic stations down to the warm water. Fog shutting in at 2 p. m. forced the abandon- ment of this plan. The berg left was headed for after the fourth station had been completed, but it was not relocated on account of the bad visibility. The ice patrol vessel was forced to drift blindly four and one-half days, until 4.30 a. m. on May 4, when the clearing conditions permitted the search for the southernmost berg to be resumed. During these foggy days it was necessary to steam slowly at times to retain position near the most probable location of the berg. Sound- ings and radio bearings showed the drift was to leeward up over the edge of the Bank, sometimes to the northeast and sometimes to the northwest, depending on the tack on which the vessel was allowed to drift. During the period from the morning of April 29 until the after- noon of May 5, observations of the stars and sun were possible once onl}', for a few hours on the morning of May 1. The ship's position was fixed wholh^ by means of radio bearings and fathometer sound- ings at all other times. The latter instrument was invaluable as an aid to navigation. The uneven bottom enabled practicallj'^ as good a track of the ship's position to be kept as though sights were obtainable. Fifteen oceanographic stations were taken during the cruise. Con- siderable trouble was had with the salinity testing cabinet, but it was possible to keep it repaired sufficiently to work, and the stations were all calculated on board. The currents found by computation agreed well with what was to be expected from experience in the area. On account of the prevalence of fog and of the necessity" for keeping close watch on the southernmost berg, no comprehensive plan of oceanographic surveying could be carried out. The stations had to be taken here and there as opportunity^ offered. The only field ice reported during the third cruise was located along the south Newfoundland coast and in the Gulf of St. Lawrence by the Canadian ice patrol vessel Montcalm. Seventy reports of bergs and growlers were received from 43 different ships and shore stations. With the exception of the one berg which the patrol guarded the entire cruise near the Tail, and one berg reported on the 23d as in 47° 00' N., 40° 57' W., most of the glacial ice was concentrated close to the line from 47° 30' X., 46° 00' W. to 44° 30' N., 49° 00' W. It probably was disintegrating slowly on account of being in cold smooth water. The weather was remarkable for the slight seas and absence of gales. IS It was marred only by summer-time fog caused by southwest winds flowing from the ''high" over the ocean around to the north and northeast over the cold waters about the Banks. During the foggy times the sky was nearly always clear and blue overhead. Besides the routine broadcasts and reports to Washington special ice information was sent on request to 17 vessels. On the 2d of May her water temperature reports showed a large liner to be running in a fog at 223^ knots toward an area where the southernmost berg might be. She was warned and two extra broadcasts were sent out during the day that advised vessels westbound on B tracks to proceed with caution between the fiftieth and fifty-second meridians. These special warnings were sent out at noon and at 4 p. m. as long as the fog lasted. No derelicts were sighted or reported during the cruise. Three spars and five drifting buoys w^ere reported as in or near the patrol area. One hundred and eighty-four vessels cooperated with the patrol by sending in 1,077 reports of sea surface temperatures. On May 4 the weather was drizzling with visibility of about 4 miles. Search was resumed for the southernmost berg to the north- west along the 100 fathom curve of the Banks. Forty miles had been covered in this direction when a large berg was reported in approximately 43° 02' N., 50° 40' W. This point was headed for and reached but no berg was found, although a rectangular search was kept up until dark. The vessel that reported the berg (the Artigas) stated that she had not had observations for three days, and that her reckoning might be far out. On the morning of the 5th the search was resumed around the Tail. Visibility was but little better than on the preceding day with the added handicaps of strong breezes to gales and a rough sea from the west, so at a little after 8 a. m. it was decided to run on a westerly course for the Modoc, then 180 miles away in 43° 00' N., 54° 00' W. At 6.40 p. m. visual contact was effected and preparations were made to transfer the observing party and records. The relief of patrol was effected successfulh^ early in the morning on May 6 in approximately 42° 25' N., 52° 00' W., the conditions of wind and sea having been deemed too severe on the preceding evening to warrant the use of small boats except in an emergency. THE FOURTH CRUISE, " MODOC," MAY 6 TO MAY 21, 1928 As soon as the Modoc took up the ice patrol duty on May 6, the search for the southernmost ice was resumed. Visibility was good, but the day was blustery and on some of the courses the ship rolled deeph^ to the westerly sea and swell. The Bank just west of the Tail was reached shortly after noon. A rectangular search revealed no trace of the berg reported there on the 4th. At about 6 p. m. there 19 was received a report of a berg 40 miles to the southeastward in 42° 27' N., 50° 02' W. This ice was headed for and the distance was run up before the vessel was stopped for the night. At daylight on the morning of Ala}' 7 a low round water-washed berg was sighted near by. Three oceanographic stations were taken in the vicinity of the low berg and of another small one that was located about IS miles to the northeast. The bergs were both in water warmer than 42° F., so were eroding and diminishing fairly rapidly. They were drifting slowly southward toward the westbound B tracks, now about 40 miles away from them. On the 8th it was foggy most of the time due to a light southeast wind. During the intervals when the visibility was fair a few runs were made in search of the berg to the northeast of the small round one, but it was not to be found. The southernmost ice, now visibly smaller and looking like a big floating toadstool, was returned to for the night. May 9th commenced with clear skies and a rising barometer. It was the beginning of a two-day period of good visibility, during which a large area south and southeast of the Tail was searched. Both of the small bergs being stood by were relocated. The south- ernmost one was found to be in 42° 08' N., 50° 10' W. The other had closed up on it, being only eight miles off. These bergs were left early on the 9th. A course was laid for a berg reported in 42° 37' N., 48° 51 'W., which was seen by the patrol vessel when 22 miles away. It proved to be an immense piece of ice with pinnacles and ridges sticking up over 150 feet above the surface. With its large natural arch, and its patches of black dirt imbedded in some of the sheer walls it was a striking object in the bright sunlight. All hands gazed at it in fascination as it was circled, while the photog- raphers on board snapped shutters with all their might. TwentA'-four reports of ice were received during the 9th. One of these listed 12 bergs about 60 miles, 70° true from St-. Johns, New- foundland. Only three bergs were reported south of the forty- sixth parallel. A westerly course was run from the arched berg for 30 miles, but no more ice was located by the Modoc. On the 10th the visibility was still good. No less than 37 different messages reporting ice were received, the record for one day so far for the season. Courses were run first to the northeast, then to the northwest up to the 50-fat'hom curve of the Banks. This was followed to the southwest around the Tail, and then, late in the afternoon, 1;he two small southernmost bergs were headed for. While over the shoal water several trials were made to get bottom samples for Dr. P. D. Trask of La Jolla, Calif. His apparatus, being designed particularly for muds, failed to work on account of the sandy nature of the deposits. 20 Luckily both of the small bergs that were left on the 9th were found before darkness and fog closed in. They had diminished greatly during the past two days. The southernmost one was in 41° 55' N., 50° 00' W., and was small enough to be visibh^ rolling to the swell. It was believed that these bergs could not last over three days more under the existing conditions. The 11th, 12th, 13th, and 14th were days of dense fog. The ship lay drifting in the southerly airs and breezes, forced to await better visibility before attempting to relocate the southernmost ice, or to do any extensive station work. As soon as the fog blanket settled over the cold water the reports of bergs dropped to onl)^ one or two a day. These came from the ice-infested areas north of the forty- seventh parallel. The reporting ships on the northern tracks must have been close to disaster to have obtained them. Only extreme slow speed and cautious groping, such as is not practiced generally along the less thickly ice-strewn United States-Europe tracks, could have prevented accidents along these northern lanes. On the 12th six vessels requested special information. One of these, the Greek steamer Cape Corso, whose master was evidently a stranger to the fogs of the ice area, requested aid and advice no less than ten times during the day. On the 12th, also, hundreds of small whales, probably blackfish, played in thickly grouped schools about the ship. The largest were between 25 and 30 feet long. Tiny ones were seen svfimming close to the side of some of the larger ones, probably their mothers. The animals played about the ship aimlessly with slow and powerful motions for hours. There was much puffing and blowing to be heard from different directions as the groups came to the surface from time to time to breathe. Sometimes one or two would raise their heads straight up out of the water and keep them there for a moment, looking like slimy black creosoted pUings floating upright. By the 14th the vessel had been blown by the steady winds some 70 miles against the Labrador Current up to the Tail of the Bank. During the fog the wind seemed to blow with greater force through the rigging aloft than it did down near the water. On the 14th four oceanographic stations were taken in the shoal water about the Tail. Doctor Trask's bottom sampler was tried again but without success. In spite of the sensitive flapper valves at the top the deposit was too sandy to remain in the open-bottomed cylindrical pipe that projected downward from the central portion of the sinker. The loth was overcast, but good visibility prevailed once more. For nearly 15 hours the search was carried on to the southeast past where the large berg with the arch had been last reported. Thence a southerly course was run to a point where the limit of 21 visibility toward the south from aloft crossed the limit of visibility toward the north of the vessels westbound on the B tracks. Until dark the search was carried on to the westward roughly parallel to these tracks. Very few reports of ice were received during the day on account of the fog's presistence farther north. Advantage was taken of the fog, which lasted until 2 p. m. on the 16th, to take two oceanographic stations, one after the other at the same spot, to see how nearly identical the independent measurements of salinity and temperature would be at the different levels. As the results were very much alike, more confidence was felt for the accuracy of the station work done so far. A sudden shift of the wind from northeast to west occurred around noon. Within two hours this change had cleared up the fog suffi- ciently to enable a course of 0°, true, to be laid towards the Tail in search for the southernmost ice. No ice was sighted. Intermittent fog hampered the scouting. The morning of the 17th was ideal for searching, although con- ditions were favorable for thick weather — a light wind from the southeast with a low barometer. Thirty miles had been run up to the Tail, and thence a considerable distance to the east across the cold water had been covered by 10 a. m., before the fog shut in. The vessel stopped for an hour until it lifted. It shut in again verj^ soon, whereupon the vessel was again stopped. A station was taken be- tween 11.15 a. m. and noon. During the morning a report was received from south of both the eastbound and westbound B tracks of a piece of ice only 1 foot square in 40° 19' N., 47° 51' W. This was believed to be the remains of the great arched berg that on the 10th was 140 miles to the north- northwest. No other report 'was ever received of this berg or of the two small southernmost bergs of the 10th. All of them must have melted unwatched during the fog. It was decided not to search to the southward am^ more for this ice but to work up the eastern edge of the Banks, searching for new bergs. Before sunset two large bergs were found in 43° 34' N., 49° 06' W., and 43° 38' N., 48° 56' W. They were reported around noon by the YorcJc, which vessel claimed to have had them 20 and 24 miles off when abeam. This great visibility was doubted, but when the patrol vessel approached them from the south they proved easily visible at those distances. A short run to the Bank was made from the southwesternmost berg of the pair, but no more ice was sighted. A station was taken at dark, just inside the oO-fathom curve, where no water below 0° C. was found at any level. On the morning of the ISth the search up the eastern edge was renewed. A berg was located at 9 a. m. in 44° 05' N., 49° 13' W. 22 Courses were run a little farther north, then east, and finally south to return to the two tall bergs seen on the preceding day. When fog shut in early in the afternoon it was realized that these bergs could not be relocated, so stations were taken in toward the Bank until 11.30 p. m. On the morning of the 19th, it still being quite foggy, a row of six stations was run cautiously to the southeast from the shoal water in 43° 33' N., 49° 32' W. Arctic water was found extending east only 20 miles from the 100-fathom curve. From that point a mixed water was encountered at all levels. Forty miles southeast of the Banks the sea surface was 46° F. At about 4 p. m. a course of 270° true was set for the Tail. Visibil- ity was fair because the haze and fog were soon dissipated after the wind backed from Northeast to Northwest around 1 p. m. Neither of the two large bergs that were 30 miles to the north two days pre- viously were sighted. On the 20th the weather was still overcast and the moderate Northwest gale that commenced shortly after the wind backed on the 19th was still blowing. Search courses were run to the north and then to the west, but no ice was seen. The night was spent running slowly from the vicinity of the Tad toward the Mojare. That vessel was met and the relief of the patrol was effected at 9 a. m. on May 21 in 43° 00' N., 51° 00' W. During the fourth cruise, 27 oceanographic stations were taken. It was found that water below 0° C. was limited in amount, being confined about the Tail to the lower levels of a narrow band. This would seem to indicate a small supply from the north. The weather was moderate but foggy. The only time that the wind attained gale force was during the storm of the 19th and 20th. Visibility of less than 2 miles was experienced during 153 hours, nearly 43 per cent of the time. Altogether 137 ice reports were received from ship and shore sta- tions. Six logs and minor items of wreckage were reported bj^ steam- ers from south of the forty-third parallel. Three similar drifting objects were reported from farther north. One hmidred and sixty three vessels cooperated by sending in 1,153 water temperature reports. During the cruise 23 vessels were furnished special ice information on request. Only eight different bergs were sighted or reported during the cruise south of 45° 30' N. Those that reached the latitude of the Tail showed a tendency to drift south without curving either to the east or west. One of these, before entirely disentegrating. reached the low latitude of 40° 19' N., in the longitude of 47° 51' W. Prolonged periods of fog kept the patrol vessel from following closely the final drifts of the three bergs that were seen south of the 23 forty third parallel. Shipping should be made to realize continually the inability of the patrol to keep in close contact with bergs during fog. This greatly increases danger along the tracks during thick periods of weather over and near the Banks. Fully 75 bergs were reported east and northeast of St. Johns, New- foundland, during the cruise. Almost all of these were expected to ground or to disintregrate north of the forty seventh parallel. A few would get south in the narrow stream of cold water flowing down along the eastern edge of the Banks. Dynamic computations, which checked well with recorded berg drifts, showed that in the swiftest part this stream was setting south over 24 miles per day. Extreme southeasterly drift of bergs noted early in the season had stopped. This was accounted for by the marked extension north and northeast of the 60° and the 54° isotherms in the eastern half of the ice-patrol area. The effect of seasonal solar warming was noticeable in all the surface temperature reports that were received. THE FIFTH CRUISE, " MOJAVE," MAY 21 TO JUNE 5, 1928 The annual surfboat race between the two ice-patrol cutters was held on the morning of May 21 in 43° N., 51° W., as soon as the Mojave had received the ice observation party. When the race was over the Mojave hoisted her defeated boat and crew and headed east on the lookout for bergs. Visibility was better than for seversl days and the search revealed the southernmost known bergs to be in 42° 45' N., 49° 55' W., and 42° 42' N., 50° 25' W. They were last seen by the Modoc on the 17th and had traveled about 70 miles to the southwest in four days. At daylight on May 22 a search was begun up the eastern edge of the Banks from these bergs. Fog was soon run into, so the course w^as reversed. The fog was outdistanced and, although it remained in sight to the north all day, except for a few wisps it did not again trouble the patrol vessel. An unknown berg which was reported as in 42° 25' N., 49° 38' W., was run for, found, and examined. It was a small one of the dry- dock type with three distinct peaks separated bj" water. The sea was so smooth that this berg was examined closely from a boat. Photographs were taken of it with the Mojave in the background. It was not expected to last long because it was in 44° water and was crackling almost incessantly as if its ice was under great tension and stress. The 23d was a da}^ of glassy seas and calms. Unfortunately, it was foggy most of the time. When visibility permitted search courses were run for the solid berg seen the preceding day. It was found about 1.45 p. m. After circling it a search course was started to the west. Shortly afterwards the fog closed in thick. It was determined to /^%^^ teV RAR yhr v>«- 24 run to a point about 3 miles east of the berg before stopping to drift for the night. A course was set that it was thought would lead well clear of the ice, but soon a white radiance was seen in the fog ahead a little on the opposite bow to the one on which the berg was supposed to be. Collision with the ice was avoided by yards only by the giving of full left rudder. On the 24th the fog continued, so no ice was seen. Better visibility prevailed further north and numerous berg reports were received from vessels on the Canadian tracks east of St. Johns. Two stations were taken during the day to try out the oceanographic equipment. It was found that although the surface water in 42° 37' N., 51° 02' W., was warmed to 37° F. by the sun, the water at the 50 and the 125 meter levels was about 31° F. — pure berg-bearing arctic discharge. As there had been little mnd during the foggy weather a couple of hours' run to windward with, the fair visibility of the morning of the 25th sufficed to relocate the large, solid berg. Sights placed it in 42° 10' N., 50° 46' W., still moving southwest about 18 miles per day. A search to the west and south failed to reveal the berg that had been in that direction from the big berg a few days previously. Sixty- two-degree water was encountered, so it was considered likely that this berg had entered the warm water and entirely disintegrated. The solid, large berg was returned to for the night. On the 26th foggy conditions prevailed over all the cold water regions. Only two bergs were reported and none were sighted. Two oceanographic stations were taken. The next da}'^ a search was carried on for the near-by solid berg when visibility permitted. It was reported by a steamer as in 42°04' N.,49° 28' W., n the afternoon. This spot was run for at 110 turns, but fog came on that forced the patrol vessel to stop before the berg was found. While taking a station at 6 p. m. a Greene-Bigelow water bottle and two reversing thermometers were lost overboard due to their being clamped too loosely to the sounding wire. On the 28th a cold north-northeast wind reversed the recent weather conditions, giving good visibility over the cold water and fog and vapor over the Gulf Stream. A northerly course was accordingly run into clear weather where sights were obtained. These showed the vessel to be 40 miles south of her reckoning. The solid berg was found at 3.30 p. m. It had drifted in a general east-southeast direction at 1 knot for the past three days. The area of the top was smaller but the berg was still quite solid and high. There was water-hne evidence of its having tipped recently due to uneven melting below water. No other bergs were found during the day. The 29th was foggy and practically calm. A few minutes of fair visibility permitted the obtaining of sights that showed the rapid southerly drift was being continued. 25 On May 30th the visibility was good until 5 p. m. Just before that time, thanks to a report from a passing steamer, the berg of the 17th was found in 41° 10' N., 48° 17' W. It was drifting southeast 36 miles per day and was in a cold finger of arctic water that still had subf rigid temperatures 50 meters below the surface. Only a few miles away to the south was 72° Gulf Stream surface water. West-southwest winds and fog prevailed over the cold tongue of Labrador water on the morning of May 31. A station was taken at 8 a. m. that was most disastrous. Seven bottles were sent down on the line. They had all been tripped and were being hauled up. As the first bottle approached the working platform the chief electri- cian's mate operating the winch made a move to stop the motor, but his hand slipped from the operating lever, and, before he could grab hold again to move it to the stop position, the upper water bottle had risen to the fair-lead block on the span near the davit heads. When it struck this block the strain immediately became so great that the wire parted and 7 Greene-Bigelow bottles, 14 re- versing thermometers, 2,400 feet of ^32-inch wire rope, one 300-pound weight, and 7 "messengers" were lost. As all of the Mojave's best equipment was on the wire, station work was much hampered until the arrival of the Modoc on patrol. It was noted that vessels but 20 miles to the south were enjoying fine clear weather, so a course of 200° true was laid for the warm water of the Gulf Stream. After running slowly for a few minutes a large growler was sighted in the fog. A little farther to windward the main berg of the 17th was found. It was seen from aloft over the low fog when 3 miles off. From the bridge it could not be seen when only 1 mile distant. This berg was positively identified as the same one that had been trailed so long. It had rolled until its characteristically curved top now formed a perpendicular side. It looked while being approached lilve a great white submarine with a central cunning tower and sloping tapered ends. Clouds of vapor were being rolled from the ice by the warm wind. About 5 miles south of the berg there was no fog. There the patrol vessel drifted all afternoon, keeping watch on the berg that could be dimly seen until 6 p. m. through the mists that continued to hang low over the cold water. Good sights taken during this time showed that the berg had drifted no less than 54 miles on a course of 80° true during the past 24 hours. As was the custom during foggy weather recently, special broadcasts were sent out every hour that gave the changing positions of the southernmost known ice, and warned vessels on the B tracks to proceed cautiously on the lookout for unknown bergs that might be coming down from the north unseen in the fog. 26 For over a month the extreme southerly drift of ice had necessitated the presence of the patrol in the south and had precluded the proper searching of the eastern edge of the Banks for new bergs. The few- reporting vessels that had crossed the area between the Canadian tracks and the B tracks were much hampered by fog. The location and number of bergs now south of the forty-eighth parallel and between the fiftieth and the forty-seventh meridians was much in doubt. It was believed likely that many more than the eight reported and sighted since May 25 existed in this area. On the 1st of June the patrol vessel was still south of the edge of the fog area, but the berg could not be seen. Sights taken during the morning showed the phenomenal drift of 63 miles in 19 hours. The set was now 20° true. As soon as the heat of the sun burned off the fog over the cold water a bit a search was carried on to the westward. Numerous growlers were found in the vicinity of 42° 02' N., 46° 22' W. These were thought to be the remnants of the berg of the 17th. Search to the west and southwest for larger parts of the berg proved futile on account of the fog. The ice seen was in 60° water and would hardly last over night. Around 5 p. m. the growlers were returned to. They were much smaller already. A course of 225° true was run for 5 miles. Then the main berg from which the smaller pieces had been blown to leeward was found in the fog. It was low and very much cut into by the warm water, but it still possessed much mass. No resemblance to the berg being followed could be found, but it must have been that one on account of its location. On the morning of June 2 north winds were blowing and the clear weather following a shallow "low" was enjoyed. A 20-mile run towards the west sufficed to reach the berg again. It was drifted by all day. Once around 1 p. m. the berg suddenly listed 90° when a large piece of ice broke off. In the afternoon water temperatures were taken all around the berg, some of them close to it from a boat. Sixty-degree water was found at all times. Several persons went in swimming among the growlers surrounding the berg from one of the ship's boats. By dark the berg had become reduced to small proportions. Its highest pinnacle was about 40 feet above the water and it was about 90 feet long by 80 feet wide. Its position at 8 p. m. in 43° 00' N., 46° 17' W. showed that it had recurved and was now drifting away from the steamer lanes. It would certainly melt enough to cease to be a serious menace to navigation within 36 hours. Accordingly it was left. A course was run during the night to the northwest so as to arrive at a position in the cold current off the eastern edge of the Banks early on the morning of June 3. The berg left had been trailed with great difficulty through fogs and mists for 16 days along a curving track more than 480 sea miles 27 long. This track was very interesting for it showed clearly the dis- tribution of the Labrador water south of the Tail of the Banks. It is worthy to note that at the same time that the trailed berg was drifting north-northeast along a cold tongue of water, another berg was known from frequent reports to be drifting south-southwest at almost the same speed on the western edge of another cold tongue from the north. On June 2 the latter berg was reported in the very low position of 39° 39' N., 50° 00' W., apparently drifting south- southwest at 23^ knots. The next day it was last reported as at 38° 59' N., 48° 51' W., the southernmost ice reported or sighted during 1928. Good visibility prevailed on June 3 until 5 p. m. The cold stream was thoroughly searched between 45° 15' N. and 44° 00' N., but no ice was located. The warming influence of Gulf Stream mixing was noted inshore to the 100-fathom curve. Water less than 40° F. in temperature was found on the surface only in a very narrow band that was crowded over onto the Banks. On this account it was believed that very few more bergs would be able to drift below the fortj'-fifth parallel this season. June 4 was spent running slowly down the eastern edge of the Banks working toward a rendezvous with the Modoc. The fog was so dense at times that it was necessary to stop the ship. During the fifth cruise no gales whatever were encountered. There was fog 50 per cent of the time. When it is considered that several days were spent in warm water south of the fog area and that on at least two days a knowledge of surrounding conditions enabled the patrol to dodge the fog, an idea of the difficulty of keeping in touch with the bergs in cold water during May and June can be appreciated. The patrol felt keenly the probability of the existence of unreported bergs south of the fort3''-third parallel, and continually warned ship- ping in the regular broadcasts to beware of unknown bergs. It was made routine to send out such warnings with the location of the south- ernmost known dangers every hour during fog and darkness. Only six different bergs were sighted and reported south of 45° 30' N. during the period from May 21 to June 5. It seemed as though most of these few bergs that succeeded in passing down through the narrow neck of cold water along the eastern edge of the Banks made a grand circuit counterclockwise around the edges of the cold mixed waters southeast of the Tail of the Banks. Some of these bergs tended to follow the edges of the cold tongues of water that extended from the large cold body. A conclusion to be drawn from a study of the tracks and distribution of this ice is that while bergs may be met in warm water, a cold tongue often forms a broad avenue along the edge of which bergs can readily drift along at from 2 to 3 knots. 28 The finding of water of 60° F. in temperature about the berg on June 2 from 2 miles away right up to within from 100 to 50 feet of it in all directions shows what little dependence can be placed upon a fall of temperature to give warning of proximity to bergs. The smoothness of the sea during the fifth cruise prevented any very rapid disintegration of the ice seen. A steady slow dissolving was the rule. This was speeded up somewhat by calving and the consequent listing about in the warm water. No field ice was reported during the fifth cruise. Sixty different bergs were reported by vessels from the Cape Race tracks. Only one of these was located east of the forty-ninth meridian. A tend- ency for the ice to drift through the Gulley and to the west past Cape Race was noted. Only a very few of the easternmost of the northern bergs were located so they could possibly get south of the Tail. It was not believed that any of them would get so far south. The disintegration of the northern ice could not be observed as the patrol vessel was kept in the lower patrol latitudes by the few bergs south of 43° N. The continuance of solar warming in the north was noted from the reporting vessels' water temperature reports; 34° surface water had disappeared from the map. All the bergs south of 48° were undoubtedly being eaten into about the water line and calving and disintegrating at an increasing rate. Ten oceanographic stations were taken and computed. A little more would have been accomplished except for the loss of the equip- ment on May 31 described above. The salinometer on board was in need of a thorough overhaul. In addition to having to be heated by makeshift methods after the burning out of the heating coils its water bath sprang a leak during the cruise and had to be taken down and resoldered. In all 119 ice reports were received from ships and shore stations. Special ice information was furnished to 18 vessels. No derelicts were reported, but no less than 15 reports of minor items, such as logs and buoys, were received from passing ships. Good visibility attended the final run to the westward past the Tail on the night of June 4. On the following morning at 9 o'clock the Modoc was met in 43° N., 53° W., and there the oceanographic party was transferred and the relief of patrol was eft'ected. THE SIXTH CRUISE, " MODOC," JUNE 5 TO 20, 1928 Good visibility with moderate weather conditions prevailed when the Modoc took over the ice-patrol duties from the Mojave on June 5. The day was spent running to the eastward toward the Tail. Water warmed to over 45° F. was noted aU the way from 43° N., 53° W., to 43° N., 50° 15' W. To the east of that 40° surface water from the north was encountered. 29 Numerous bergs were reported from the Cape Kace tracks and three bergs from southeast of the Tail. The southernmost of these consisted of a pair of large bergs reported to be in 41° 25' N., 48° 31' W. This position was directly on the B tracks, so the Modoc steamed all night toward it. The 6th and 7th were overcast and mostly calm, but the excellent visibility continued. A thorough search in which vessels on the B tracks assisted was conducted, but the two bergs could not be found. As the water was comparatively warm (from 45° F. to 66° F.) it was concluded that they had entirely melted. Two small bergs seen on the horizon by the reporting vessel on June 5 had probably been mistaken for and reported as large bergs as is often done. The whole of daylight on June 8 was spent running back to the northeast to the Tail. It was hoped that the good visibility would continue and that the Labrador current along the eastern edge of the Banks could be searched for ice. From June 2 to 7 eight bergs had been reported along the northern end of this edge. They were no doubt moving south, some of them but how far they had moved it was impossible to tell on account of the scarcity of reporting vessels crossing the ocean between the Canada-Europe and the United States-Europe tracks. June 9, 10, and 11 were overcast foggy days. At times the visi- bility was good enough to permit search courses to be run, but not much progress was made. Just about enough distance was covered to enable the scouting to stem the cold current flowing southwest past the Tail between the forty-ninth and fiftieth meridians. This current was found by the stations taken and by the actual drifts experienced to be setting to the south and the southwest about 24 miles per day. Radio bearings from Cape Race and the fathometer depths enabled pretty close check to be kept on the ship's position, even though it was possible to obtain but two sights in three days. The Labrador current was about 40° on the surface, but tempera- tures below 32° F. were found around the 50-meter level at two of the stations taken east of the Tail during this time. On the 11th a 3-pinnacled berg with water separating the sections was sighted. Although the day was overcast and dull this berg was seen b}?- the lookout aloft when 20 miles distant. It was in 43° 04' N., 49° 00' W. at noon. Plans to scout up to the north from it had to be abandoned when rain and fog came on. Early in the afternoon the patrol vessel returned to the berg and took two stations in its vicinity. When these were worked out they showed that the berg was drifting south or southwest and not northeast as might have been thought from its rather far offshore location. At 2 p. m. a boat was lowered to allow the two newspaper men on board to examine a berg from close quarters. They had a great 33382—29 3 30 opportunity to observe action, for when they were near it one of the three pinnacles broke from the main berg where it had been eaten into about the water line. Hundreds of tons of ice fell off into the sea with loud reports and roars. The berg did not capsize but rose up and acquired a permanent tilt of about 30° when it was relieved of the weight of one end. A considerable amount of ice in small pieces was picked up by the boat and brought aboard. It was hard and brittle with a tendency to crack up into pieces with very irregular surfaces if struck hard or dropped. The ice itself was very clear but it contained many of the usual air bubbles, each about half the size of small common pinheads. At 8 a. m. on June 12 while the Modoc was drifting in a dense fog in the vicinity of the berg sighted the previous day a report was received from the Tampa, a freighter, stating that they had just passed a dory with two men in it apparently lost in the fog. They were endeavoring to relocate this boat. The patrol ship immediately started for the position, about 80 miles to the northwest, to assist in the search. Before half the distance had been run the Tampa radioed that the weather was now clear and that no dory was in sight but that a large sailing vessel was near by. As they assumed this to be the mother ship of the dory they had resumed their course to the east. The Modoc was stopped to drift again in the fog. Very soon the clear weather reached the Modoc. It was decided to run up the Labrador current until dark, searching for ice coming down. A strong current from the north with pronounced tide rips was observed over the uneven bottom east of the 100-fathom curve between the parallels of 43° 30' and 44° 00' N. The Tampa and the Gripsholm ran across the Labrador current to the north of the forty- fourth parallel. Neither they nor the patrol vessel sighted any ice on June 12. On the 13th the patrol vessel steamed to the southwestward and finished searching the lower end of the Labrador current. When no ice was found it was felt pretty certain that the only berg south of 44° 30' N. was the one found on the 11th near 43° N., 49° W. It was not seen near its previous location on the 13th because it had probably drifted to the southwest past the Tail by that time. On the 14th, loth, and 16th it was foggy or thick and stormy practically all of the time so no searching could be carried on. On the 17th the weather cleared. It was thought that the berg of the nth had melted by this time. At any rate it was futile to waste valuable time trying to find this single small isolated berg after such a long separation. It was deemed more advantageous to search up the Labrador current as long as the visibility held good. Such a course was followed but no bergs were sighted in the area east and 31 northeast of the Tail on the afternoon of the 17th although a double lookout was posted aloft and much area was covered. From the 13th to the 19th several weather reports by radio were sent each day to Cape Race for the benefit of the two planes wait- ing in Newfoundland for favorable conditions to cross the ocean. These reports gave not only the weather of the patrol vessel but also contained a compilation of late reports from a number of vessels strategically scattered over the ice-patrol area. Messages from the plane Friendship to Cape Race were intercepted on the afternoon of June 17 until about three hours after the plane had left Newfoundland for Europe. Advantage was taken of continued good visibility on June 18 to search about 4,000 square miles of the Labrador current between 43° 20' N. and 45° 30' N. No ice was seen. Unfortunately five hours of dense fog on the following day prevented the search from being contin- ued as far north as had been planned. B}^ running at 80 to 85 revolu- tions per minute an area of about 3,500 square miles was searched on the 19th, however. This area lay between 45° 10' N. and 46° 40' N. and just west of the fortj^-eighth meridian. Agaiji no ice was seen. The Modoc spent the night of June 19 steaming across the Banks toward a rendezvous with the Mojave. That vessel was met and given the patrol duty at 11 a. m. on June 20 in approximately 45° 08' N., 51° 39' W. No derelicts were seen, but one was twice reported during the sixth cruise. It was a schooner floating bottom up and was last reported on June 16 from 46° 31' N., 55° 25' W. Ten buoys, trees, and logs were reported to the patrol from in and near the ice-patrol area. During the sixth cruise 15 oceanographic stations were taken, bringing the total for the season up to 95. During 122 hours, or 34 per cent of the time, visibility was less than two miles. Very moder- ate weather was experienced. It was only during the blow of the 15th and 16th that winds as strong as force 7 were observed. The wind blew with greater force than 5 during but 34 hours. Continued surface warming of the sea was noted — 38° water retreated north of the forty-eighth parallel during the sixth cruise as completely as 34° water retreated north of the same latitude during the fifth cruise. This effect undoubtedly made the ice dis- integrate faster and faster in the higher latitudes. Only one berg was seen during the whole cruise and that one but for a short time on one day, so no great amount of first-hand information regarding disintegration could be accumulated. The isotherms on the cruise chart are based on 1,147 observations from 131 vessels; 87 reports of ice were received during the 15-day cruise from 36 ship and shore stations, but during the last week the falling off was so great that only 16 ice reports were received 32 from 10 stations; 31 ships were furnished with special advice on request. At the end of the cruise on June 20 it was estimated that about 27 bergs remained south of the forty-eighth parallel. Fully 22 of these were grounded on, or were very near to the Newfoundland coast and would never get anywhere near the United States-Europe tracks. The three bergs reported and the one sighted south of the Tail all undoubtedly melted before the cruise ended. On June 20 it could be stated fairly definitely that there was no ice nearer the B tracks than 250 miles. To reach these tracks it would have to follow the Labrador current down along the eastern edge of the Banks and past the TaU, a distance of over 350 miles. At this season the time that would be consumed in traveling this distance should suffice to melt any ordinary berg that might hereafter have a tendency to drift south because of its favorable location in the axis of the Labrador Stream. The ice menace to the B tracks was believed definitely over for the season of 1928. The above conclusion was arrived at in a conference held on board the Modoc as soon as the Mojave was met on the morning of June 20. THE SEVENTH CRUISE, " MOJAVE," JUNE 20 TO 23, 1928 The Mojave took over the oceanographic party and the ice-patrol duty at about 11 a. m. on June 20 in 45° 09' N., 51° 40' W. Nearly all the oceanographic gear on the Modoc was received at this time also, for further transfer to the Marion for use on a proposed cruise to Greenland waters. Just after the relief was efl'ected the commander, international ice patrol, sent a message to Coast Guard headquarters from the Modoc recommending the discontinuance of the 1928 patrol. Pending receipt of orders resulting from this message the Mojave undertook to search again along the eastern edge of the Grand Banks from 46° 45' N. to 43° N. By running at' 100 revolutions per minute during all times of good visibility the second search within a week of this area was finished before dark on June 22. The Hmiting longitudes were 47° 00' W. and 51° 30' W. Again no ice was seen, but a band of water about 30 miles wide with surface temperatures from 39° to 41° F. was encountered until the patrol vessel had passed to the westward of the fifty-first meridian. Moderate weather prevailed and the only thing that hampered searching was the usual fog that was occasionally experienced in banks and patches. At 6 p. m. on the 22d orders were received by radio from the Modoc at Halifax for the Mojave to discontinue the ice patrol and to return to Boston. Favored by easterly breezes at first, but hampered greatly 33 by fog later on, the Mojave finally arrived at the Boston Navy Yard on the afternoon of June 26, 1928. The isotherm chart for the short seventh cruise was based on but 366 temperature observations sent in by 29 cooperating vessels. Only one ice report was received from south of the forty-eighth parallel. This was for a small berg reported in 46° 15' N., 48° 17' W. on June 21. Vessels apparently commenced using the Belle Isle tracks on June 21, for 23 bergs and several growlers were reported to the patrol on that date from between Greenly Island and 52° 30' N., 53° 00' W. Special information on request was sent to three vessels. No dere- licts were heard of, and but one spar and one buoy were reported from within the patrol area. No oceanographic stations were taken. Upon the discontinuance of patrol messages of thanks for efficient assistance were sent to the radio stations at Cape Race, Halifax, and St. Pierre. The final ice broadcasts were sent out on the evening of the 22d and on the morning of the 23d. They contained thanks to all cooperating ships for their indispensable assistance in the form of ice, water temperature, weather, and other reports. Before leaving the patrol area, the following gratifying message was received from W. F. Berg, master of the Vacoil, "Realizing the hard- ships endured by the patrol, I wish to express my appreciation for your most valuable assistance to us during the past season. " Before reaching Boston similar messages of appreciation were received from the Majestic and Olympic. RADIO COMMUNICATIONS In addition to being sister ships structurally the Modoc and the Mojave were equipped with identical radio apparatus for the ice- patrol work. Each vessel had one T-2 2-kilowatt tube transmitter, using either CW, ICW, or phone transmission; one T-4 200-watt tube transmitter using either CW or ICW, which replaced the 2-kilowatt spark set used during 1927; and a 500-watt XA crystal control high- frequency transmitter. The latter was similar to the one used during 1927 with some improvements and redesigning of the circuits used. The alterations were made by the United States Naval Research Laboratory for the Coast Guard, and served to make the set more efficient and consistent than before. Direct communication with NAA, the United States naval radio station near Washington, D. C, was more successful than in any pre- vious year. This traffic was all handled on high frequencies and the average distance between the ship and the shore station was approxi- mately 1,350 sea miles. The receiving apparatus on each ship consisted of a CGR-5 low- frequency receiver used for ship traffic and for communication with shore stations on intermicdiate and low frequencies. An RG receiver was used for high-frequency work, covering from 1,000 to 20,000 kilocycles. No real trouble was experienced with any of the radio apparatus. Kolster radio com.passes were used to assist the vessels to find each other at relieving times. They would have been invalu- able, also, had any assistance work been necessary during the season. A splendid spirit of cooperation was noted on the part of the ship and shore stations in the vicinity of the patrol regions. There was an increase of over 17 per cent in the number of water-temperature and weather reports received from passing vessels over the 1927 season. A regular annual increase in all traffic seems to be the rule. An idea of the present volume can be gained by reading the tabulation on page 38 at the end of the summary report of the commander, international ice patrol. The following schedule shows the times when regular routine traffic was handled. The times given are all Greenwich mean civil times and show the conditions at the beginning of the season. A few minor changes were made in the schedules with NBD, Bar Harbor, Me., during the progress of the patrol: (34) 35 Time Remarks 0000 Radio broadcast to shipping on 175 kilocycles. 0030 Report to Government observer, Washington, giving meteorological information. 0030 To Hydrographic, Washington, giving latest ice news. 0100 Schedule with Bar Harbor, Me. 0300 Receive from NAA, Washington, D. C, traffic on hand for ice patrol and receipt for traffic received via Bar Harbor. 1100 Radio broadcast to shipping on 425 kilocycles. 1200 Radio broadcast to shipping on 175 kilocycles. 1230 Report to Government observer, Washington, giving meteorological information. 1300 Schedule with Bar Harbor, Me. 2300 Radio broadcast to shipping on 425 kilocycles. SUMMARY REPORT OF THE COMMANDER, INTERNATIONAL ICE PATROL Commander W. H. Munter The Mojave left Boston on March 20, 1928, to inaugurate inter- national ice patrol. When 43° N., 52° W. was reached on March 24, the first patrol cruise was started. The Modoc divided evenly with the Mojave six full 15-day cruises. The patrol was discontinued at word received from Coast Guard headquarters on June 22, when the Mojave was on the third day of the seventh cruise. Halifax, N. S., was used as a base for fuel and supplies as in previous seasons. During the season the two patrol vessels cruised a total of 18,083 miles, including the distance run in going to and from the base. Weather during the whole time was remarkably moderate on the average. A few moderate gales, but no really severe ones, were experienced. Somewhat more than the usual amount of fog prevailed. The season was a very early one. The effect of this, combined with the mild winter preceding, was seen in the practical absence of field ice south of the forty-seventh parallel, in the unusually small amount of field ice reported by the Canadian ice patrol in the Gulf of St. Lawrence, in the general use of the Belle Isle tracks by the early date of June 21, and finally in the early recall of the international ice patrol vessels. The patrol's discontinuance on June 22 was earlier than in any year since 1920, when it ended on June 20. While the total number of bergs that drifted south of 48° N. was greater than normal, less than half of the normal number of 51 bergs drifted south of the forty- third parallel. Early in the season many of the bergs came south well to the eastward of the Grand Banks and entered the Gulf Stream current south of Flemish Cap. They were then carried toward the northeast and melted clear of the B United States-Europe tracks but foul of the steamers on the C United States-Europe tracks between the forty-third and the forty-seventh meridians. There is grave danger under such conditions in adhering to the C tracks as late as was done this year. During May the average position of the bergs was farther west in the Labrador current with the result that many of them were caught in the branch that flows along the eastern edge of the Grand Banks; some of these avoided being set onto the Banks or being curved off to the northeast. They are the ones that drifted south past the Tail of the Banks. (36) 37 Towards the end of the season the bergs came down still farther west and most of them stopped in the slack water over the northern part of the Grand Banks or stranded along the Newfoundland coast between St. Johns and Cape Race. When the patrol was ended even these westerly bergs were thinning out rapidly, due in a large part, no doubt, to disintegration farther north. This would naturally be caused by summer solar warming of the air and sea surface water. It was noted that a large pool of arctic and mixed water remained south of the Grand Banks right up to June 22. This was fed by a narrow but swift stream running along the eastern edge of the Grand Banks. A large proportion of the bergs that reached the pool via this stream was swung in a counterclockwise direction around it at speeds varying from 15 to 60 nautical miles per day. During the latter part of May and the first part of June six bergs went south of the forty-second parallel in this circulation. One of these on June 3 attained the unusual latitude of 38° 59' N. in the longitude of 48° 51' W. It had traveled rapidly across both the eastbound and west- bound B United States-Europe tracks, then in effect, by running along one of the tongues of water radiating from the cold pool. Its most southerly position was due east of a point between Baltimore, Md., and Washington, D. C. Ninety-five oceanographic stations were taken during the season. These were all worked out in accordance with the methods described in Bulletin No. 14, United States Coast Guard. The calculated currents usuall}^ agreed closely with the sets and drifts encountered and with the actual observed berg drifts. Because of the necessity for scouting for bergs during intervals of good visibility and also for following menacing bergs for long periods in the vicinity of the steam- ship lanes, the stations taken were usually just about where and when opportunity allowed. Had the patrol vessel been more free, their distribution in the patrol area would have been much better arranged. One unusual feature of the bergs sighted this year was the amount of earth deposits in many of them. Some had layers of brownish gray matter streaked through them like icing between the layers of a cake. One was seen that had great irregular lines and patches of what looked like black soil embedded in one of its precipitous sides. It was impossible to obtain any dirt samples from the bergs. It is very difficult and dangerous to board a berg at sea. Only especially favorably shaped ones permit a footing to be obtained and then it is only during time of comparatively smooth sea that such bergs can be approached and landed on from small boats with any degree of safety. Another unusual matter may prove of interest to ornithologists. Besides all the usual forms of bird life about the bergs and the Banks, this season snowy owls were seen on several of the icebergs. The owls, 38 if they had been present in former years, were either not observed or not recorded. These birds are native to the arctic regions only and are never seen so far south unless there is a shortage in their usual food supply in their regular haunts. The owls found inhabiting the bergs this season were supplied bountifully with the sea birds com- mon to the regions comprising the Grand Banks. The most vital thing in making the ice patrol of real value to ship- ping is radiotelegraphy. Here, as in previous years, the most gratify- ing cooperation was had from ship and shore stations. The communi- cation personnel and apparatus of the ice patrol again proved equal to the task. Every effort should be continued to keep the radio material of the patrol vessels abreast with the progress of this most beneficial science. The magnitude and importance of the communication work of the patrol can be grasped in part by a study of the following figures: Number of routine broadcasts transmitted 380 (At the height of the ice season these messages averaged about 300 words each.) Number of official messages to Washington 348 Ice and other information given to vessels on request 113 Water temperature and weather reports sent in by vessels 6, 534 Total number of vessels cooperating with the patrol 489 Number of ice and obstruction reports received by radio 644 Number of times medical treatment was given by radio 4 Violations of steamship track agreements reported 2 Total number of words transmitted and received by radio 450, 460 TABLE OF ICE AND OTHER OBSTRUCTIONS, 1928 No. Reported by- Position Date Lati- Longi- Nature of ice or obstruction tude tude north west Feb. 9 1 Cape Race station. 48 35 (48 11 49 30 49 29 Field ice. 10 2 Frederick VIII. to 48 05 to 49 41 [small field ice. 48 12 49 9 11 3 Cape Race station \ to to [■Light field ice. 48 05 49 18 48 25 49 18 12 4 do - \ to 48 11 to 49 13 >Open drift ice. 45 10 59 45 12 5 Frederick VIII to 45 03 to 60 15 [Field ice. 48 25 49 19 Open drift ice, same as 4. 12 6 Estonia \ to to 48 11 49 42 47 45 51 27 12 7 do. \ to 46 36 45 01 to 53 01 60 42 ■Open drift ice. 13 8 do \ to 44 53 44 40 to 61 23 60 20 ■Patches of drift ice. 15 9 Cape Race station.. to 44 35 to 59 50 Open field ice. 18 10 11 do .. . 45 00 45 00 59 00 60 10 Heavy field ice. 19 do Do. 47 04 51 48 Ipatches of field ice. 21 12 ....do I to 47 22 to 51 10 j 22 13 Frederick VIII 47 05 49 00 Light field ice. • (47 04 51 48 22 14 do to 147 22 to 51 00 [Light field ice, same as 12. 47 46 50 23 25 15 Cape Race station to 148 24 to 48 57 [patches of field ice. (47 15 47 02 29 16 do. \ to to [Heavy field ice. 147 04 47 20 29 17 do 47 25 (47 03 47 05 47 53 Do. 29 18 do .- { to 4fi 45 to 47 20 [Broken field ice. 29 19 20 Korsholm 47 25 47 53 47 20 47 05 Field ice. Mar. 1 Cape Race station Do. (46 55 47 10 ( 1 21 do to 146 50 to [ Do. 47 35 1 44 38 60 00 !l 1 22 do \ to [44 38 to 60 20 >Broken field and slab ice. ) (45 56 47 34 1 3 23 do \ to (46 18 to 46 47 [Fields of broken ice. 3 . 24 25 do 49 15 56 57 |48 05 48 41 27 53 50 00 Field ice. 3 do. Large berg. 3 26 do to to [lleavy pan ice. (48 15 48 20 3 27 do 48 00 (49 15 48 30 46 30 Field ice. 1 3 28 Kolsnaren \ to (48 41 to 47 00 Wee field with bergs. 4 29 Cape Race station 48 26 47 30 Berg. 4 30 do.. 46 45 47 26 Field ice. 7 31 do .- 46 27 (47 55 47 13 50 35 Broken field ice. 1 ' 32 do... to ll46 26 to 50 00 [Field ice. 13 33 do ' 47 07 45 30 Small berg and growler. (39) 40 Table of ice and other obstrucHons, 1928 — Continued. Date Mar. 13 13 14 14 14 26 28 28 29 29 29 29 29 29 29 30 30 30 30 30 31 31 31 31 1 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 4 5 5 5 6 Reported by- 97 Cape Race station. -do. -do. -do_ -do. -do. Manatawny. ..._do ._-.do ....do .do. Pos'tion Lati- tude north Longi- tude west Manctiester Commerce Nova Scotia Quaker City M. Christensen ..-.do_ Ice patrol ....do M. Christensen .__.do : ....do. Ice patrol ....do .-_.do ....do. ._..do ...-do.. ....do do do do Kolsnaren do Broompark Estonia do do do do do Broompark Karlshruhe Broompark Ice patrol do do do do Commandante Le Maille. Hellig .\paf Bergensfjord Innarenua .do- Marguerite Finale-.. Innarenna do - do John M. Connelly.- Stockholm Manchester Citizen, .do. Montrose. Mexicano- 44 57 to 45 31 43 51 44 03 48 35 48 35 46 50 to 46 27 46 21 46 00 42 49 46 15 48 37 to 10 45 52 47 38 48 05 46 10 46 14 44 59 45 15 45 42 45 45 45 27 45 35 45 42 45 36 45 39 45 45 45 08 45 14 45 27 44 56 44 42 44 58 45 08 46 50 47 28 47 32 47 44 47 37 47 52 47 52 44 50 46 48 44 38 44 30 44 37 44 53 45 04 45 07 45 00 45 24 45 24 48 57 48 48 to 48 18 41 03 48 03 48 04 47 54 39 29 44 57 45 00 53 to 52 44 38 44 22 45 to 15 47 40 10 (44 (44 . 44 . 44 [47 60 55 to 58 07 45 48 54 35 48 50 48 50 47 36 to 47 02 47 34 48 00 51 25 47 45 49 11 to 50 20 46 54 46 51 48 05 46 00 46 55 48 39 48 21 47 37 47 55 48 25 48 08 47 49 47 49 47 38 47 35 48 21 48 22 48 27 48 40 48 23 48 25 47 49 44 30 46 58 46 37 46 21 46 04 46 11 46 07 48 08 44 32 48 40 48 39 48 41 48 07 47 44 47 16 46 45 47 09 47 09 49 16 49 03 to 47 50 46 17 46 51 46 32 46 31 53 31 46 17 46 24 46 17 to 46 27 46 02 46 05 48 35 to 48 50 48 40 Nature of ice or obstruction Heavy and light field ice. Lifeboat from S. S. Suevia. Spar 30 feet long. Berg. Small bergs, same as 37. Field ice. Berg. Field ice, small berg. Spar 15 feet long. Broken field ice. •2 small bergs, field ice, growlers. Low berg. Growler. Heavy field ice with small bergs. 2 large bergs. i Field ice. Growler. Berg and growler. Growlers. Large berg. Do. Berg, same as 53. Berg. Growler, same as 52. Growler. Berg. Berg, same as 54. 2 growlers. Growler. Berg. Berg and 2 growlers, same as 63. Berg, same as 53. Berg and growlers. Small berg. 2 bergs. Berg. Do. Do. Do. Do.. Do. Do. Do. Growler. Berg, same as 76. Berg and 4 growlers, same as 74. Berg. Do. Do. Do. Berg, same as 83. Field ice and growlers. ■Small growlers. Drifting mine. Large berg. Berg. Do. Small black can buoy. Large berg. Do. Growlers. 2 bergs. Large berg. |>Heavy field ice. I Large berg. 41 Table of ice and other obstructions, 1928 — Continued Date Reported by- Position Lati- tude north Longi- tude west Nature of ice or ol)struction Apr. 10 10 10 10 10 10 10 10 10 10 10 II 11 11 U II 11 11 11 II 11 11 11 11 11 11 11 99 100 101 102 103 104 105 lOfi 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 127 128 129 130 131 132 133 134 135 13f) 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 100 101 162 163 164 165 163 167 168 169 170 171 Lithuania ._..do Wytheville f'ranley New Amsterdam. Ice patrol_. _. Cranley ("airnvalona Ala._ Ice patrol Andania.-- Ciorm. -- Arlington, Va Oscar II Veendam Greennaek do do do. Andania Ice patrol Cedric Cranley do do... --- Topdalfjord do .do. do do _. Cameron ia. -.. Topdalsfjord do._ Scythia do._ Ice patrol do Scythia .-.-"-do do do Ice patrol Topdalsfjord- do Canadian Trapper. Braheholm Ocean Prince Canadian Trapper - Bellhaven Nortonian Kcllhavea Nortonian do Hada County Bellhaven do do -.do. -.do Nova Scotian. Nortonian do do.- Talisman do do.- - .-..do Ice patrol Nova Scotia.. do Aggcrsund Talisman Si.sto 47 08 47 15 44 68 47 48 44 21 45 42 47 49 47 40 43 46 46 00 41 55 47 00 41 54 46 26 44 21 47 25 47 28 47 51 47 53 44 21 44 43 44 20 46 46 46 39 46 37 47 27 47 18 18 to 47 22 47 35 47 17 44 30 let r [47 46 02 45 48 47 19 47 09 44 29 44 26 40 58 47 02 46 59 46 57 44 29 45 23 45 18 46 31 44 15 44 11 47 02 46 51 45 12 46 37 45 17 45 21 45 03 46 25 46 03 45 46 : 45 49 45 38 (46 37 \ 0 |46 22 46 19 46 06 46 20 45 14 45 28 45 18 45 20 45 06 47 00 47 04 47 00 45 10 48 58 47 52 47 48 46 35 43 37 45 12 48 02 43 50 43 45 50 03 47 46 50 24 45 10 50 36 42 40 44 49 44 45 44 30 43 30 43 20 44 20 45 58 44 25 46 40 46 40 46 54 44 51 45 04 45 09 tn 45 20 44 13 44 38 43 46 48 17 47 24 46 34 46 48 43 42 43 45 46 59 47 06 47 14 47 18 43 38 47 53 48 06 46 00 43 21 43 2! 44 49 42 33 48 25 43 38 47 50 47 41 44 05 44 34 46 16 47 20 47 27 48 09 46 44 to 47 54 44 06 46 06 43 24 47 27 47 22 47 53 48 02 48 22 45 09 45 10 49 00 49 04 50 00 Small berg. Do. Large. Medium. Large berg. Do. Do. Berg. Log 4 feet diameter, 30 feet long. Large berg. Large gas buoy painted red. Berg. Bell buoy. Small berg with calf. Berg, same as 1(13. Large berg. Small berg. Large berg. Small berg. Large berg. Do. Large berg, same as 118. Berg. Do. Do. Large berg. Berg. ■Several growlers. Berg. Do. Large berg, same as 118. Do. Do. Medium berg. Do. Berg and several growlers, same as 118. Growler. Large berg. Do. Do. Do. Growler. Berg. Large berg. Berg. Berg and several growlers, sime as 118. Berg, same as 118. Large berg. Berg and growler. Small berg. Berg. Do. Large berg and several trowlers. Berg. Large berg. Medium berg. Large berg. Do. Do. 9 bergs. Large berg. Small berg. Growler. Berg. Do. Do. Do. Two bergSi Berg. Growler. I,arge berg. I 2 bergs. I Big berg and growlers. 42 Table of ice and other obstructions, 1928 — Continued Date Apr. 16 16 17 17 17 17 17 17 17 17 17 17 17 18 18 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 21 21 21 22 22 23 23 23 23 23 23 23 23 23 24 24 24 24 24 24 24 24 25 26 27 27 27 27 No. 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 23(i 237 238 239 240 241 242 243 244 245 24fi 247 248 Reported by- Position Lati- tude north Ice patrol ._..do Emperor of Montreal. ..-_do _-..do Ice patroL ....do Canadian Ranger Sisto ....do ....do Ice patrol _.__do..- Carmia Berlin Ice patrol .._.do.._ Albert ic ....do ....do -...do do .\thenia __._do do do Montclare do Ice patrol-- .\lbertic.-- do Ice patroL _ Stavangerfjord do Perseus Beaverburn do Arabic Montroyal do Cape Race Station Waban. Lituania-.. Oracia... Concordia Cape Race Station Concordia Majestic Asta do Knockfierna do do Federal ' Kentucky Ice patrol Adour C airnvalon do do do Cairnglen do do do Winona County Cairndhu do Manchester Citizen.. Dresden do do. do do Ice patrol Beaverlake Montnairn Longi- tude west 49 02 48 51 48 19 45 22 47 05 48 46 48 49 48 02 49 56 49 47 49 47 48 31 49 10 47 52 48 45 48 45 48 44 46 40 48 28 48 21 48 11 48 06 48 00 48 00 48 07 48 07 48 37 47 48 48 52 46 32 46 31 49 14 47 45 47 33 47 44 47 38 53 18 48 00 46 16 49 17 46 52 48 56 48 29 63 29 49 30 50 00 46 28 47 17 47 22 42 22 46 42 49 10 40 57 48 09 48 00 48 04 47 46 46 01 46 26 46 37 46 39 45 25 46 20 47 10 47 07 46 01 46 01 46 16 46 38 46 39 50 10 47 11 47 21 Nature of ice or obstruction 2 bergs, I large and 1 small, same as 170. Berg. Large berg. Do. Do. Small berg, same as 157. Berg. Do. Field ice extending West. 2 bergs, several growlers. Patches field ice to southwest. Berg, same as 166. 2 bergs same as 172. Berg. 2 bergs and 2 growlers. Berg. Do. Do. Do. 2 small bergs. Berg. Do. Large berg. Do. 2 growlers. Large berg. Large growler. Large berg, same as 185. Berg. Small growler. Large growler. Berg. Do. Do. Floating mine. Berg. Large berg. Berg, same as 207. Large berg, same as 185. Large low berg, same as 205. Red cylindrical buoy. Spar 14 inches diameter, floating upright. Large berg. Long low berg, same as 203. Large berg. Berg and growler. Berg. Black spherical gas buoy, unlit. Large berg. 4 low larg,e bergs. Berg and growler. Berg. Do. Stump of mast projecting 8 feet out of water. Large berg. Low berg, same as 203. Berg. Large berg. "Do. Berg. Do. Large berg. Small berg. Large berg. Growler. Black and white bell buoy. Berg. Large low berg. Low berg. Do. Berg and growler. Berg. Do. Small berg. Berg, same as 203. Long low berg. Large berg; numerous growlers. 43 Table of ice and other obstructions, 1928 — Continued No. Reported by- Position Lati- tude north Longi- tude west Nature of ice or obstruction 249 I Hielmaren. 250 I Malmen... 251 Canadian Rancher. 252 I Cape Race station.. 253 I do 254 t do 255 I do _ 256 ! Laval County 257 do 258 I Metagama .do. .do. .do. .do. .do. do. number .\rm Manchester Civilian. do Torne Sergent Gouarre Trevose Beaverbrae America _ _ 259 260 261 262 263 264 I Montroyal. 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 Cape Race station. do Calgaric- Alaunia _-_ Alexander Alaunia Montcalm do - Andania Cairnross do .- Cameronia Melita Artigas Lord Downshire... do Aurania West Kedron Point Breeze Cape Race station. Paris Tynebridge Cape Race station.. do.. do.. Blairatholl .•...do do... Balsam Ice patrol do Blairatholl Newfoundland do Beaverdale Cape Race station. do do. do. do- do. Newfoundland - Regina Colytto do California do do 45 08 43 36 47 16 47 03 47 07 47 00 46 50 45 30 45-^2 47 15 47 04 46 53 46 53 46 49 46 48 46 10 46 22 48 12 48 00 47 52 44 14 44 54 34 42 47 22 40 44 48 48 47 20 47 16 47 15 47 22 47 10 47 20 47 35 47 47 47 19 46 43 48 25 46 42 43 02 47 15 47 16 46 26 39 29 44 55 (47 37 { to |47 34 42 39 42 27 47 59 48 12 48 07 47 34 47 37 48 12 42 37 42 22 42 13 47 10 47 59 48 10 46 12 47 48 47 35 47 34 47 29 47 21 43 28 48 22 47 10 46 13 46 08 46 42 46 41 46 40 47 58 56 46 46 05 46 49 46 52 46 57 47 05 48 17 48 34 45 27 45 51 46 35 46 40 46 51 47 00 46 52 46 02 47 30 45 53 46 23 48 20 48 52 45 45 44 47 49 10 50 35 46 21 46 08 44 30 45 42 45 35 46 38 46 07 45 57 44 23 46 42 43 59 46 08 50 40 46 39 46 55 45 25 64 23 47 15 60 00 to 59 40 44 58 50 02 52 17 51 40 51 44 48 46 48 50 47 36 48 51 49 53 50 13 49 35 50 37 50 20 44 55 48 34 49 42 49 46 49 27 49 50 50 00 49 48 46 47 46 3fi 46 55 48 49 48 40 48 20 Berg. Heavy round timber, sticking 3 .'eet out (,f water. Large berg. Small berg. Do. Growler. Low berg, same as 247. 3 growlers. Large berg. Long low berg.. Berg. Growler. Do. Do. Long low berg. Low lying berg. Berg. 3 large bergs. Berg. Berg and growlers. Large berg. Berg. Large buoy heavily barnacled. Small berg. Large white round top buoy marked "CABE." Large low berg. Small berg. Large berg. Small berg, same as 272. Berg and growlers. 2 bergs. Large berg. Large berg and several growlers. Large berg. Small berg. Low lying berg. Small berg and growlers. Small berg. Large berg, same as 203. Large berg and growlers. Lovv' berg and growlers. Growler. Gas and whistling buoy painted red. Berg. •Field ice to northward. Log about 50 feet long. Large berg. Do. Do. 2 growlers. Growler. Small berg. Small berg, several growlers. Large berg. Berg. Small berg, same as 295. Large berg. 5 growlers. Growler. Small berg. I.,arge growler. Small berg, many growlers. Very large berg. Berg. Do. Do. Large and small berg, scattered growlers. Large berg. Berg. Large berg. Do. Small berg. 2 growlers. 44 Table of ice and other obstructions, 1928 — Continued Date May 8 9 9 9 9 9 Nc. 322 323 324 325 326 327 328 329 330 331 332 333 331 335 336 337 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 Rerorted by- California Ice patrol do Bochuiii California Metagama do Cape Race station . do do do do Drakepool Bochum Bridgepool Cape Race station. do Africa. do. Doric. do. do. .QO. do do Bridgepool Canadian Aviator. do Beaverhill. Minnedosa Pennland Ansonia do do Cape Race station. ..do. ..do. ..do. .do. Doric do do-. do Concordia... Baunach do Ansonia do Pennland do Bolingbroke. Concordia... Lati- tude north .110- Bannock Albertic do do Concordia.. do Bergenfjord. do .... do do. Athenia... . do do do do do 46 43 42 08 42 10 46 17 47 02 46 02 46 11 47 37 47 56 48 00 48 13 48 02 45 56 46 K) 44 38 48 35 48 12 to 47 53 47 46 47 56 47 39 48 02 48 07 47 34 47 37 48 12 44 35 47 40 47 20 47 40 to 47 00 47 12 47 14 46 57 46 51 46 39 47 52 47 12 47 29 47 24 47 56 to 48 10 47 00 46 50 46 48 46 50 46 00 42 06 42 02 46 40 46 22 46 50 47 18 51 33 46 22 46 14 42 31 46 44 46 38 46 37 46 21 46 34 47 18 47 00 48 16 48 12 48 04 48 00 48 08 48 05 Longi- tude west 48 22 50 10 50 00 47 16 47 40 47 25 47 08 51 07 50 58 50 33 50 21 50 29 47 27 46 47 46 16 50 00 50 44 to 51 55 48 25 48 38 54 17 41 40 51 44 48 46 48 50 47 36 48 28 48 17 50 10 48 35 to 45 40 47 07 46 40 4d 48 47 22 47 28 51 56 50 05 50 08 50 05 52 00 to 51 40 48 12 48 15 48 35 48 37 47 35 50 08 50 08 48 10 48 38 47 le 48 00 47 23 46 40 48 56 47 54 48 03 48 00 46 08 45 48 47 59 48 26 48 35 48 36 48 53 49 51 50 03 50 07 50 07 50 07 Nature of ice or obstruction Growler. Small berg, same as 295. Small berg, same as 303. Do. Large berg. Large berg with growlers. Growler. Berg. Very large, low berg. Growler. Large berg. Small berg and growler. Berg. Do. Do. Small berg and growler. 12 bergs, several growlers. Berg. Small berg. Large berg. Do. 2 growlers. Growlers, same as 299. Small berg, same as 300. Small berg, several growlers, same as 301. Large, low berg. Very large berg, same as 339. 12 bergs. ■Medium berg. Low-lying berg. Large berg. Berg. Large low berg. Large berg, several growlers. Large bergs, several growlers in radius of 10 miles. Bergs. Do. Do. ►8 bergs, several growlers. Growler. Do. Berg. Large berg. Berg. Berg, same as 295. Berg, same as 303. Growler. Berg. Berg and growlers. • Growler. Heavy spar floating upright, wreckage attached. Small berg. 2 small bergs. Berg, same as 302. Large berg. Do. Small berg. Growler. Small berg. Growler, same as 371. 2 large bergs. Large growler. Berg. Do. Growler. Do. Do. Berg. 2 growlers. 45 Table of ice and other obstructions, 192S — Continued Reiiorted by— Lati- Longi tude I tude i north I west Nature of ice or obstruction 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 43! 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 Athenia nolingbroke Trocas Cape Race station. Nova Scotia Cape Race station. City of Florence... Cape Race station. No vara Alaunia.. Andauia.. Cameronia Limerick Somerstadt-- Yorck.. do. .- Terre Neuve .. Tricolor Cape Race Station. Vollrath Tham Coracero do _._ do do do-... do Ice patrol .. Cape Race station. .... do ... do_ Cora Sero Bristol City Baron Carnegie do do.. Ilagen Cape Race station. do do do do do do do do Bourdonnais 47 38 48 02 35 47 48 35 47 15 47 44 41 36 47 20 48 03 45 54 47 01 46 51 41 01 40 19 43 34 43 38 45 40 43 43 48 05 46 09 48 00 47 54 47 41 47 44 47 47 47 44 44 05 47 54 47 55 Kearney Minnedosa Ice natrol... do. do Cape Race station Montroyal Sarcoxie Beaverhill Montroval do do do do. Doric - - - - - - Cape Race station Demetrios M. Diacakis. Ampetco Lord Dounshire Swainby 47 52 47 33 42 01 46 49 46 51 46 05 47 53 47 23 48 46 48 45 47 S3 47 41 48 50 48 10 48 15 48 08 42 30 Cape Race station. do. - Aurania _ llybert Regina... do do 43 23 47 42 42 42 42 45 42 40 48 11 47 47 42 25 47 05 47 23 47 40 47 40 47 31 47 21 47 40 47 40 43 OS 39 29 47 35 41 54 47 40 47 23 47 14 38 03 47 13 47 18 47 09 55 10 26 37 38 41 14 48 38 30 43 22 02 51 06 56 02 43 41 41 57 44 43 46 50 ; 54 ! 13 i 37 ! 30 30 42 I 37 ! 36 34 50 : 50 38 ; l\ 48 30 1 32 20 43 I 55 I 46 I 21 I 32 t 50 1 39 I 37 56 Growler. Low lying berg. Conical whistle buoy. 2 bergs. Large berg. 3 small bergs. Flbating wreckage projecting 4 feet. Berg. Large bers, several growlers. Do. Do. Do. Large log, about 15 feet long. Small growler.. Large berg. Do. Berg. Spar 60 feet long. Large berg. Berg. Do. Large low berg. Large berg. Growler. Berg. Growler. Berg. Growler. Large berg. Growlers. Do. Heavy spar floating upright, 3 feet showing above water. Berg. Growler. Large betg. Large low berg. Low lying berg. Berg. Do. Large berg. Bergs. Do. Growler. Berg. Growler. Log 30 feet long, covered with marine growth. Log 30 feet long, 2 feet diameter. Berg. Berg, same as 405. Large berg, same as 406. Several growlers. Small burg. Large berg. Berg. Large berg. Berg. 4 small grov.iers. Large berg. Do. Do. 3 growlers, same as 447. One large; several small bergs. Berg. Gas and whistling buoy, painted red. Berg. Black can buoy, covered with marine growth. Berg. Growler. Small berg with growler. Large gas buoy, painted black. Berg. Growler. Do. 33382—29- 46 Table of ice and other obstructions, 1928 — Continued Date No. May 24 464 24 465 24 466 24 467 24 468 24 469 24 470 24 471 24 472 24 473 24 474 24 475 25 476 25 477 25 478 25 479 25 480 24 481 25 482 25 483 26 484 26 485 26 486 27 487 27 26 27 28 28 28 28 28 29 29 29 29 28 28 28 28 28 28 29 29 29 29 29 29 29 29 29 29 29 29 29 30 30 30 29 30 30 30 30 31 31 31 31 31 June 1 1 1 1 1 1 Reported by- 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 California Clara Camus Aurania dO-_ Letitia California Megantic do Letitia do_ do do Bolivian Arabic Bolivian Letitia do Cape Race station _ President Garfield. Ice patrol Pajala __- Norefjord Caledonian. __ The Lambs Cape Race station. Causasier Cape Race station. . Oswal Beaverford Fantoise France. Federal.. Ice patrol.. Calgaric ....do Elisebeth Maersk.. Cape Race station.. .-..do ....do ....do ....do ...-do ....do Montroyal Transylvania Val Fiorita Calgaric do do Transylvania do do do Yorkmoor do Transylvania Christian Ice patrol do Cape Race station.. do... do..-. do do. Duivendrecht Hallmoor Ice patrol do Suffren American Trader __ Ice patrol Montcalm ^Empress of France. ".^.ndania- Ice patrol ._ Emjiress of France. 42 04 46 24 42 03 46 41 41 10 41 18 40 00 41 50 46 30 46 38 40 20 47 30 46 52 47 00 47 04 47 11 46 32 46 34 47 00 46 25 45 36 46 50 46 51 47 06 46 43 46 51 46 52 47 21 45 48 45 47 47 06 41 10 41 08 41 12 46 13 46 16 46 46 46 57 46 47 40 56 40 47 41 13 41 18 40 39 40 26 42 02 46 42 46 59 46 42 46 47 10 59 52 01 51 02 50 55 51 59 51 19 51 43 48 32 49 34 51 50 51 52 52 01 52 03 48 41 50 44 50 18 50 35 51 03 50 05 55 39 50 46 52 14 52 02 49 00 44 20 52 38 49 28 53 05 49 17 51 54 45 56 48 23 52 56 49 18 52 47 51 59 62 42 52 30 52 40 51 23 51 26 50 56 52 42 52 56 50 01 52 56 48 31 51 36 51 33 50 58 52 05 51 43 51 40 49 54 48 43 48 26 51 02 48 17 47 58 47 57 53 33 53 05 51 46 51 05 51 40 48 51 48 54 46 53 46 53 48 52 49 14 40 22 52 43 51 44 52 35 46 28 51 34 Nature of ice or obstruction Berg and growler. Small berg. Berg. Growler. Berg. Do. Do. Do. Do. Growler. Berg. Growler. Berg. Small berg. Do. Berg. Do. Large berg. Red cage whistling buoy. Berg, same as 406. Large berg. Do. Berg. Log 2 feet diameter, 30 feet long. 5 growlers in vicinity between Motion Head and Bull Head, Z]/i miles oflshore. Large berg. Do. Do. Berg. Floating mine with several horns. Berg, l.=>0 feet long, 18 feet high. Large buoy with red superstructure. Berg, same as 406. Small berg. Do. Wreck of masthead 10 feet above water. Large low berg. Berg. Do. Do. Do. Small berg and growler. 3 growlers. Large berg. Berg and numerous growlers. Berg and several growlers. Small berg. Do. Berg and 2 growlers. Berg and growler. Small berg. Do. Large berg. Berg. Berg and growlers. Large berg. Berg and growler, same as 406. Berg and growlers, same as 406 Growler, same as 406. Do. Small berg. Do. Large berg. Small berg. Berg. Low berg. Berg, same as 406. Large growler, same as 406. Large berg, same as 529. Small berg, same as 529. Numerous growlers, same as 406. Large berg. Berg. Do. Berg and growlers, same as 406. Berg. 47 Table of ice and other obstructions, 1928 — Continued Date No. June 540 Ml M2 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557. 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 Reported by- Oak park Ice patrol Bea verwyk Ariano _.. do Cape Race station ....do_... Antonio Lopez. Simonburn Baunack Bochum Afrika Canadian Conqueror- Ice patrol Con vallari _ Bochum do ._ Megantic Cape Race station do do do do do do do.._. Vredenburg Yokohama . _ Goldmouth _ Hanover. _ Dresden Ivar Port Dowen Majestic Port Bowen. Letitia do Melita Jacques Cartier Melita Letitia. Cape Race station . do do.. do do... do do do .do. Tractor Regina Tiger Regina Esk Bridge Texas Vomeria Sydland.- do New York California do Narvik Schleswig California. Caledonia Cape Race station. do do do Athenia do do Doric Position Lati- tude north 40 18 40 30 47 10 47 15 47 16 40 13 47 47 47 35 46 .54 46 58 47 12 47 55 47 31 48 26 48 48 48 49 46 40 to 47 40 46 25 47 13 48 33 47 39 42 32 48 34 40 57 41 25 47 22 47 19 48 35 46 15 47 33 47 26 48 55 47 24 47 36 48 05 47 35 47 23 47 30 47 16 Longi- tude west Nature of ice or obstruction 49 52 46 20 49 41 51 .52 .')1 12 51 35 51 25 .50 00 43 55 48 45 50 51 48 44 50 05 46 17 51 08 52 31 52 38 49 50 51 52 51 12 52 52 52 50 52 37 50 05 51 04 51 40 52 30 48 54 48 57 48 .34 50 00 49 50 61 30 46 28 50 50 47 11 49 58 49 51 52 23 52 19 49 31 52 39 52 28 52 20 52 27 49 48 52 40 to 52 30 4S 21 50 52 50 26 49 47 48 50 49 18 52 07 49 48 49 48 48 31 51 00 50 46 49 56 52 14 49 38 50 56 .50 10 49 25 49 35 51 08 49 34 50 49 51 00 50 58 Berg, same as 529. Berg, same as 406. Small berg and growlers. Do. 2 growlers. Small berg. Growler. Berg, same as 529. Red bell buoy with black siiperstriK tnre Large berg. Do. 2 bergs— 1 large, 1 small. Large berg. Berg, same as 406. Large berg. Cone-shaped berg. Growler. Berg. Small berg, same as .543. 2 growlers, same as 544. Berg. Do. Low berg Berg. Low berg. Berg. Large berg. Small berg, same as 529. Small berg, same as 567. Do. Gas and whistling buoy paintedjred. 2 growlers. Log 30 feet long covered with marine growth. Do. Large red buoy or mine. Berg. Do. Small berg. Barnacled log 60 feet long. Large low berg. Berg. Do. Do. Do. Do. Large flat berg ?.i mile long, many growlers. Berg. Do. Large growler. Several bergs aground near coast. Berg and growlers. Berg. Small berg. Berg. Do. Small berg and growler. Gas and whistle buoy. Berg, same as 593. Low flat berg. 2 large bergs. Berg. Do. 2 large bergs. Berg and growlers. Berg. Do. Large berg. Berg. Berg, same as 60^1 Large berg and several grj Berg, same as 604 Do. Berg, same as 605 Berg. (uj I L I 8 R A ft V ^^;; ^Ta (.■"• n K 48 Table of ice and other obstructions, 1928 — Continued Date No. ei4 615 tUfi 017 61S 619 620 621 622 623 624 625 626 627 62S 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 640 647 64S 649 650 651 652 653 654 655 656 657 658 659 13 660 13 ! 661 13 i 662 683 664 665 666 667 66S 669 670 671 672 673 674 675 676 677 678 680 681 Reported by- Cape Race station. do. Fishpool ...-do Chifuku Maru do Beaverbrae .-..do_.._ do ;.. Doric Teiresias Cape Race station.. do _._. do._ do do do.... Albertic Cape Race station.. do ...-do ----do ....do --.-do Cortiino Rudby ---.do-. -.-- do Peursum Canadian Inventor - Montcalm ....do Ice Patrol Andania Peursum ...-do--- --.-do--.- Manstpool Cape Race station., ----do Cameronia .-.-do Beaver Dale Oleudam Cape Race station. ...do Cuba. Casper Lap'.and American Farmer . Caledonia Brant County Byron -- Cape Race station- .-.-do ....do -do. -do- do Albertic Cape Race station. Bochum. Cape Race station. do Position Lati- tude north ....do.... Wearpool. 46 45 46 48 40 38 40 38 42 28 48 33 47 28 47 27 47 24 48 09 47 26 48 26 47 26 47 05 47 29 47 13 47 16 47 51 47 06 47 06 46 54 45 30 47 21 47 12 47 12 43 04 47 18 47 06 47 08 48 20 47 16 44 32 46 22 47 14 47 22 47 29 39 23 47 22 47 42 Crefeld 47 11 Cape Race station 148 23 39 4: 48 20 47 36 44 31 42 17 47 58 40 41 47 20 47 33 47 00 46 25 46 31 48 07 47 16 47 22 48 05 41 27 41 57 47 35 to 46 45 47 20 Longi- tude west 49 28 49 38 47 57 47 45 48 14 48 17 50 39 49 28 49 38 52 12 46 20 44 24 51 OS 49 26 50 50 51 20 48 09 49 30 51 10 49 30 52 19 49 35 50 44 50 57 47 46 52 19 52 46 52 52 54 40 48 38 51 06 51 10 49 00 51 03 52 32 52 29 52 49 49 51 51 12 55 47 51 08 51 05 49 37 49 21 50 52 52 05 52 23 51 28 48 39 50 13 49 34 48 38 43 43 50 51 59 32 51 25 52 41 52 53 55 26 55 25 52 35 51 00 51 10 50 12 56 34 54 26 52 30 to 52 50 49 35 Nature of ice or obstruction Berg, same as 607. Berg, same as 604. 1 large and 2 small bergs. Small berg. Log 20 feet long 2-foot diameter. Small red buoy. Berg. Berg, same as 607. Berg, same as 604. Berg and growlers. Large round rusty buoy, marked "Danger- ous". Bell buoy. Large berg. Berg. Do. Berg, same as 605. Berg. Berg, same as 627. Berg, same as 626. Berg and growlers, same as 627. Large berg. Berg and 2 growlers, same as 604. Berg, same as 601 . Berg, same as 600. Small berg. Large berg, same as 634. 2 bergs, 1 large and flat. Large berg. Log projecting 4 feet above water. Large berg. Do. Small low berg. Berg and growler. Berg. Large berg. 22 growlers. Berg. Small berg. Oas and whistling buoy. Capsized schooner projecting 20 feet, bull painted black, rigging afloat. Small berg, same as 645. Berg. Do. Large gas and whistling buoy. Berg. Small berg. Berg. Do. Large gas and wiiistling buoy. Berg. Low-lying berg. Tree 40 feet long with branches attached. Bell buoy rusty and covered with marine growth. Small berg. Mast projecting 15 feet. Large berg. Berg in fresh water. 12 bergs grounded; growlers floaiing Joff from berg. Large dead whale. Capsized schooner rigging afloat hull paint- ed black projecting 20 feet. Growlers. Large berg. Do. Berg, same as 663. Red conical buoy. Buoy marked, cable painted white, small flags flying. [several bergs and growlers. 4 growlers. 49 Table of ice and other obstructions, 1.928 — Continued No. Reported by — Position Nature of ice or obstruction Date Lati- Longi- tude tude 1 north west j 1 June 20 f)82 Kolsnaren 47 22 50 ."9 i Berg. 20 683 Caledonia 47 13 50 41 i Small berg. 21 684 Regina 52 28 53 28 I Long low berg and growler. 21 685 do._ 52 22 53 44 1 Small berg. 21 686 Melita 52 32 53 09 2 growler.s. 21 687 do 52 15 53 22 2 bergs. 21 688 do 52 21 53 28 Large low berg. 21 689 do _ 52 10 53 45 3 bergs. 21 690 do_ 52 20 53 50 2 large bergs. 21 691 Aurania 52 03 54 44 Large berg. 21 692 do._ _ 51 57 54 51 Do. 21 693 do 51 56 54 57 Do. 21 694 Markland 38 12 44 47 Rusty gas and whistling buoy, working. whistle 21 695 Mmnequa_ 42 33 44 41 Floating spar 60 feet long. 21 696 Emma Maersk 40 11 46 37 Conical white and red buoy. 21 697 Stockholm _ 46 15 [51 53 48 17 56 00 Small berg. 1 21 698 California... i to [51 22 to 9 bergs along shore. 57 10 1 151 46 55 38 1 21 699 do \ to (51 15 5 06 U bergs, several small pieces. WEATHER This section gathers together certain meteorological facts observed on the ice-patrol vessels during the 1928 ice season. The conditions can be taken as those that prevailed at 43° N., 50° W., for all practical purposes, but too great stress should not be placed on this position, for the patrol ships cruised from 46° 50' N. to 40° 40' N. and from 53° 00' W. to 43° 20' W. There were areas of cold surface water and of warm surface water in the patrol area which had consequent marked effects on local weather, especially with respect to fog and surface air temperatures. It was noted that the air temperatures followed the values of the sea temperatures closely and quickly most of the time wherever the patrol vessels went. The weather diagrams for each month" give at a glance the wind directions and forces averaged for every 12 hours, the barometric curve, and the time and duration of fog and low visibility. This year maximum and minimum and average surface air temperatures are given for each month. The scientific value of these temperatures is mitigated by the above noted mobility of the observing stations and by the fact that ordinary poorly exposed ship's air thermometers were used in making the observations. It is believed that the values will be of interest, however, in showing about what temperatures should be expected and prepared for on ice patrol. The average air temperatures were obtained roughly by adding all the daily maxima to all the daily minima and dividing the sum by twice the number of davs. MARCH Maximum air temperature, 50° F. Minimum air temperature, 28° F. Average air temperature, 37.8° F. Visibility was less than 4 miles 57 per cent of time. Visibility was less than 2 miles 34 per cent of time. The ice patrol was in effect during onl}'^ the last 10 days of March. The percentage of bad visibility was extremel}^ high for early in the season. There were three days of dense fog from the 25th to the 28th caused by Southwest winds blowing, as in summer, over the cold water. They were apparently caused by the atmospheric circu- lation set up between a High over the ocean to the south and a Low situated over the northeastern part of North America. Only two cyclones affected the barometer on the patrol vessel to a marked degree. The one whose center passed just to the south on (50) 51 the night of March 23 gave a few hours of moderate gales from the Northwest on the 24th. These were the only gales of the month, for the storm of the 31st did not produce anything stronger than a fresh breeze In general the weather was very moderate for March. Figure 2.— March weather diagram. Inner figures show day of the montli; the next band out contains the record of the atmospheric pressure; the next outer one indicates the degree of visibility (black areas are for visibility of less than two miles and cro.ss-hatched areas for visibilities between two and four miles); the outer margin shows the average direction and force of wind per 12-hour periods, midnight to noon, and noon to midnight. APRIL Maximum air temperature, 52° F. Minimum air temperature, 30° F. Average air temperature, 38.7° F. Visibility was less than 4 miles 26 per cent of time. Visibility was less than 2 miles 18 per cent of time. Fog and poor visibility prevailed during April just about normally; that is, to the average extent that the ice patrol has experienced during the past eight years. There were a number of days of high barometer and fine weather. 52 The barograph curve records no less than 12 depressions for the month. None, except the one that ushered in the first, were par- ticularly deep where the patrol vessels were. Onl}^ three were able to give the ice patrol winds of gale force for as long as 12 hours, being for the most part very brief as well as shallow. The fully developed cyclones of large area passed to the northeast over Newfoundland and Labrador, well to the north of the Grand Figure 3.— April weather diagram. Banks. The depressions that went over the patrol vessel were, many of them, secondaries of the larger Lows. Some of these small storms were noted over the States traveling along more or less parallel to the larger ones. Others, it seemed to the patrol, were born between the Grand Banks and the New England coast, as they were either detected by means of ship reports or not detected at all until they unexpectedly broke. 53 MAY Maximum air temperature, 65° F. Minimum air temperature, 36° F. Average air temperature, 44.8° F. Visibility was less than 4 miles 55 per cent of time. Visibilit}" was less than 2 miles 48 per cent of time. Figure 4. — May weather diagram. About twice as much bad visibility as the patrol's 8-year average normal prevailed during May. On many of the foggy days the weather was really fine the fog being simply a conduction phenomenon limited to the layers of air chilled by contact with cold surface waters, with the sun shining in a perfectly clear sky overhead. The month was featured by long periods of steady barometer about 30.00 inches in height. Moderate conditions prevailed and there was a marked slowing down and several stagnations in the march of Lows and Highs across the eastern half of North America and out 54 towards the patrol area. A ridge of high pressure that extended at times unbroken from Greenland to Bermuda was noted during the last half of the month. The barometric gradients shallowed out markedly as compared with the preceding month. They became strongly suggestive of sum- mer weather conditions with shallow Lows over the land and Highs over the ocean. Only five noticeable depressions are visible in the barometric curve. Four of these are of trivial depth. The most marked Low occurred early in the month, and the passing of its center was followed by nearly 24 hours of northwesterly gales. A few more hours of gales were experienced on the 8th, 19th, and 20th, and no others were encountered during May. JUNE Maximum air temperature, 69° F. Minimum air temperature, 39° F. Average air temperature, 49.2° F. Visibility was less than 4 miles 47 per cent of time. Visibility was less than 2 miles 40 per cent of time. The ice patrol remained in effect during the first 22 days of June only. During this time poor visibility was experienced slightly in excess of normal. Winds of gale force were experienced only on the 15th. They were from the northwest as the majority of the patrol vessels' gales seem to be. Summer-time conditions of groups of weak Lows over the continent and a High over the ocean from Bermuda to the northeastward were observed. The persistence of a low pressure area to the northeast of Newfoundland, as in April and early May, was noted. There were about eight dips in the barometric curve but all were shallow where they passed the patrol vessel and were moving slowly. GENERAL REMARKS As in previous seasons a weather map was constructed twice daily on board ship for use in forecasting and in planning the operations of the patrol to the best advantage. The maps were obtained in large part from information in the general synoptic reports broadcast from NAA, Arlington, Va., at 0300 and 1,500 G. M. C. T., well supple- mented by means of ship reports from the ice patrol area. A special daily forecast for the patrol vessel was received from the United States Weather Bureau. The weather information on hand was always available to passing vessels on request. It was usually included, in part at least, in the routine ice broadcasts on account of the marked interest displayed by shipping early in the season in the weather being experienced by the patrol. -JO Twice daily a coded weather report was dispatched to the United States Weather Bureau, Washington, D. C, and at the end of each patrol cruise a more detailed report was forwarded by mail to the same office. Figure 5.— June v/eathcr diagram. Numerous special weather reports were sent to Cape Race for the benefit of trans-Atlantic fliers. During future patrol seasons the ice patrol should be of increasing importance as an observing and col- lecting station for up-to-the-minute weather reports of value to transoceanic aviation. DEPTH SURVEY CARRIED OUT BY THE SONIC METHOD Work was continued during 1928 with that part of the scientific program concerned with determining the bottom contours in the ice patrol regions. The echo or sonic method of depth finding was again used, the Modoc and the Mojai'e being both equipped with commercial instruments. Although one of the ice patrol vessels has been fitted with an experimental echo depth finder for several years, this year was the first one in which both patrol ships were equipped to obtain soundings rapidly and easily. The following brief description is given for the benefit of those who may be unfamiliar with modern sonic sounding methods. Ex- periments have dem.onstrated the speed with which sound travels through water under various conditions of temperature, pressure, and salinity. If the time between the outgoing and the return by echo from the bottom of a short sharp note is measured, the depth of water can easily be found out. The principles are simple but in practice many complications arise and the instruments have to be elaborate and ingenious devices. As might be expected the echoes are relatively much louder in shoal than in deep water. To get results in great depths the oscil- lators that produce the outgoing notes are strong and powerful. They are placed in the bottom of the ship near the keel. The echoes that com.e back are picked up by hydrophones in small tanks in- sulated from sound from all directions but downward. The echoes are carried electrically to the bridge where an instru- ment amplifies the intensity of the signals by vacuum tubes until they are audible in head telephones. There is an indicator by the phones which revolves at a constant speed. When the sound goes out the pointer passes a zero mark on the scale. When the sound comes back it is only necessary to notice the number on the scale to which the marker is pointing to get the depth in fathoms instantly. In shoal water, saj^ under about 60 fathoms, the incoming sound comes back so quickly that it merges with and becomes almost indis- tinguishable from the loud outgoing one. A different system is used to get the depth in this case, a svstem much more accurate than that based on the coordination between the ear and the eye of man. The energ}^ coming in from the strong echoes of shoal water is used to cause the flashing of a red neon tube electric light opposite the depth marks on the indicator. The light is carried alo'ig on the rotating (56) 57 disk. As it passes the stationary zero mark on the scale a red flash is seen like a blurred pointer of fire about an eighth of an inch wide. Then when the incoming echoes come in there is another similar red flash opposite the proper depth on the indicator, if all is working well. Very often there are confusing stray flashes caused by break- ing waves, outside noises, electric currents, etc. It is indeed fascinating, and often comforting to the navigator, to be able to steam along taking 150 soundings a minute and watching the depths var}^ automatically with the red light with such precision, as to delineate to the fathom every lump and hollow, every ridge and trough of the ocean floor. The white Ught or deep-water method is slower because of the time necessary to keep the incoming echoes properly compared with the right outgoing signals, and to allow time for the sounds to go down to the bottom and back at the rate of about 5,000 feet per second. When everything was working properly it was possible to take in depths of 1,000 fathoms or more, about as many soundings in every minute as would be possible with a wire and weight in a 12-hour day. Notwithstanding their limitations and shortcomings the echo depth fioders were invaluable navigational aids on ice patrol. They were especially useful in keeping track of the vessel's position during foggy and cloudy weather and at night, in telling exact points where certain contour lines were crossed, in locating the position of the ship on a line of position or radio bearing line, and in telling quickly the depth of water where an oceanographic station was about to be taken. The soundings that were taken when the geographical positions of the ships were very well and fairly well known were saved in a smooth record book. Each sounding so recorded meant not just one depth but the mean of several carefully taken over, say, a minute of time, depending more or less on the plainness with which the echoes were heard. If they were faint many would be listened for in order to be sure to have the depth just right. The accepted soundings were corrected by various amounts ranging up to about 5 per cent to allow for variations in the temperature, salinity, and compression of the water column. The corrections were deduced from the velocity chart published facing page 49 in ice-patrol Bulletin 15, season of 1926. Over 3,000 groups of sound- ings, taken when it was thought that either latitude or longitude could possibly be wrong by as much as 6 nautical miles, were dis- carded. Of course, soundings taken during fog, darkness, and in overcast weather were as accurate as those taken when it was clear; but when the position was in doubt, the values could not be used by hydrographers for amplifying the data on charts. Lists containing over 1 ,200 good soundings and positions have been forwarded to the United States Hydrographic Office and to the 58 United States Coast and Geodetic Survey, for their information, in connection with improving the soundings data on the North Atlantic Ocean charts concerned. As the instruments were a new type never before used on ice patrol, the following remarks are given regarding their action during the different partol cruises. These have been taken in substance from the cruise reports of the commanding officers on the several patrols. At the beginning of the first cruise only up to 200 fathoms could be sounded with the sonic depth finder on the Mojare. Even this was of value in conducting the search for ice, being sufficient to give instant notice when to change course at such times as when approaching or leaving the 100-fathom curve of the Banks. As the patrol went on the depth that could be sounded increased to a maximum of 1,300 fathoms. It was believed that this was due to smoother water which lessened the so-ealled water noises from whitecaps, and to increasing experience on the part of the operators, for the machine itself had practically no adjustments made to it. It was very encouraging when soundings could be taken in the deep water because of the com- parative scarcity of depth values on the chart in the area being searched. The greatest care was taken to keep track of the ship's position at all times in order that the locations of the soundings might be accurate. , The second cruise was started ^\^th a systematic gathering of fath- ometer depths on the Modoc. The officers of the deck, by taking soundings every 15 minutes, quickly gained experience in deep water depth sounding and obtained a number of particularly valuable records. Due to the small amount of wave motion and consequent quietness on April 8, audible echoes Avere obtained in depths up to 2,000 fathoms. On April 10 the apparatus broke down and could not be adjusted until engineers from the maker boarded the vessel at Halifax after the end of the cruise. It was routine during the third cruise for the officers of the deck on the Mojare to get the depth by the echo method every 15 minutes while cruising and every half hour while drifting. Only occasionally was there difficulty, as when the signals were weak in the phones. In all 1,700 successful echo soundings were recorded in the rough book on the bridge during the cruise. Of these 400 were preserved for use in checking the North Atlantic charts. The dift'erence was due to the fixed policy of rejecting for hydrographic use all soundings made when the position of the ship was in doubt due to lack of good sights. Tlie fourth cruise produced only 22 values of depth for the smooth record. The high percentage of bad visibility, coupled with inability to hear the fathometer echoes in the extremely deep water, where 59 most of the time was spent, prevented a more numerous result. The weak signals seemed to be caused by trouble in the sound-receiving and amplifying devices. The oscillators in the hull sent out good signals, but it was very difficult to pick up the echoes in the head telephones. The apparatus worked well during the fifth cruise. Soundings up to 2, GOO fathoms were obtained. Besides tabulating for reference 251 depths taken when the ship's position was well fixed, the instru- ment was an invaluable aid in locating the ship during thick and over- cast weather. The sixth patrol cruise produced 97 values for the depth records; 330 soundings were obtained but the majority were thrown out on account of doubtful positions due to the impossibility of getting enough sights. The short seventh cruise furnished 31 good sound- ings to be added to the season's total. It was noted that when the depth finders were in good v.oiking order, results in water up to 1,000 fathoms in depth could usually be counted on. The deepest soundings were all made under especially quiet wave and sea conditions. Very likely on ships using less electricity than the electric-drive ice-patrol vessels better results would be obtained. The Diesel-drive cutter Marion, on the Marion Expedition, shortly after the termination of ice patrol could sound with her instruments of the same make down to 2,000 fathoms consistentl,y, so long as the radio apparatus was not being used. Whenever the near-by transmitter was sending the fathometer was strongly affected with induced noises that entirely blotted out the incoming echoes. Such a condition did not exist on the ice-patrol cutters where the radio room was a long distance aft of the bridge, but no doubt some of the noises that interfered with the hearing of weak echoes were picked up from the numerous strong electric fields on board. ICE OBSERVATION The ice particularly watched and tabulated by the international ice patrol is that which, in passing south along the east coast of Newfoundland, gets south of the forty-eighth parallel of latitude. Every recent annual report of the International Ice Patrol Service has contained a section on ice observation. The reader is referred to the 1926 report for a statistical compilation of ice observed in the years to and including 1926, and to the 1927 report for the ice conditions prevailing that year. The figures are based during the actual ice-patrol season on the reports to and the observations of the ice patrol vessels themselves. During the remainder of the year the reports of ice contained in the weekly Hydrographic bulletins of the United States Hj^drographic Office and special reports from Cape Race radio-compass station are depended on. A number of ice charts and a discussion of ice conditions month by month during 1928 are given below: JANUARY There were no reports of ice during January, 1928 FEBRUARY No bergs were reported by trans- Atlantic vessels during the month from south of the forty-eighth parallel. Field ice from the Gulf of St. Lawrence was reported from between Cape Breton and Sable Islands. Field ice was reported from several other localities, most of which were north of 47° N., and all of which were north of 46° 30' N. The other reports were confined to areas off the Newfoundland coast between Cape Race and St. Johns, to the vicinity of 48° 00' N., 49° 30' W., and to the vicinity of 47° 00' N., 47° 30' W. MARCH During this month a number of bergs drifted south along the eastern edge of the Grand Banks, but only one got south of the forty-fifth parallel. Bergs were thickest along the eastern edge a little to the north of this latitude. They were on the whole distinctly below normal for the month in number, however. One berg was reported from a few miles west of Flemish Cap. A few bergs were located along the forty-eighth parallel to the westward of the forty-seventh meridian. Field ice reached its greatest southerly extension for the year during March. There were two reports of the Gulf of St. Lawrence (60) 61 pack from between Sable Island and Cape Breton Island. The most southerly report was one of this ice from the vicinity of 44° 30' N., 60° 00' W. The Canadian authorities in the Department of Marine and Fisheries, Ottawa, at the present writing have more detailed information regarding ice conditions in this western sector. In the vicinity of the ice patrol's activities field ice was reported as extending northward from 46° 20' N., 50° 00' W., and northward from 45° 50' N., 47° 30' W. The wording of the several reports indicated that the ice south of the forty-eighth parallel was neither close nor heavy. There were no reports of berg or field ice from along the east coast of Newfoundland, but not enough steamers were traversing the area off this coast to cover it at all well. APRIL A great increase in the total number of bergs was noted during April. The feature of their distribution was their scattered south- easterly drift past Flemish Cap and across the C United States- Europe steamship tracks. One berg was reported from an extreme easterly position in 47° 00' N., 40° 57' W. Two other bergs were reported from positions east of the forty- third meridian, between the forty-sixth and forty-seventh parallels. The southeasternmost berg of the month disintegrated in the vicinity of 44° 10' N., 43° 20'W. Further to the westward one berg was carried south of 43° N. in the vicinity of the forty-ninth meridian. All of the bergs that got south of 43° during the following months did so in the neighborhood of this same meridian. The bulk of the April bergs were situated along the eastern edge of the Grand Banks from 45° N., 49° W. to 48° N., 46° W. Agam, no bergs were reported from near the Newfoundland coast. Rather remarkably, none were reported from west of the fiftieth meridian. The continued absence of steamer traffic from this area makes this negative evidence weak, however. The probability is that there was a considerable quantity of unreported ice there, both berg and field. The last report of field ice in the Grand Banks area for 1928 was received on the 10th from the vicinity of 47° 30' N., 48° 40' W. The Canadian ice patrol service was inaugurated on April 12. On the 13th this service broadcast that there was field ice from the longitude of Cape Breton Island to Cape Race, the fields being heavy to the east and lighter to the west. MAY As is normally the case. May saw a greater number of bergs south of the forty-eighth parallel than any other month. Their extreme southeasterly drift was checked by the rapid extension northwest- ward toward Flemish Cap of Gulf Stream and solar warming. They 33382—29 5 62 were located further west on the average than during the previous month. This caused them to stop in the dead water or to strand along the north edge of the Grand Banks in the region from 46° 40' N., 52° 00' W., to 47° 50' N., 49° 30' W. A few were carried to the westward in the branch of the Labrador current that sets past Cape Race through the Gulley. The westernmost berg of this group just crossed the fifty-fourth meridian off St. Marys Bay, Newfoundland. Seven bergs from the large number concentrated along the northern half of the eastern edge of the Grand Banks during the preceding month escaped being stranded along the edge or being curved off to the northeast by the inshore edge of the warm Gulf Stream influence. These seven floated down the narrow band of cold water along the eastern edge oft" the Tail of the Banks and were swept across the forty-third parallel between the fiftieth and forty-eighth meridians. By the 31st one of them reached 40° 47' N., 48° 54' W. Three daj^s later this berg reached its extreme southerly position in 38° 59' N., 48° 57' W., which was 126 sea miles farther south than any of the 1927 ice drifted. No field ice was reported from the Grand Banks area in May. The only field ice report to be received by the ice patrol during the month was one of the St. Lawrence pack that by then had dwindled inshore to the vicinity of 47° 40' N., 60° 00' W. The ice season in the gulf was open and light and terminated unusually early. For authorita- tive information regarding field ice to the west of Cape Race, one should address the Department of Marine and Fisheries, Ottawa, Ontario, as that department is in charge of the ice-patrol service conducted by the Canadian Government for the benefit of shipping entering St. Lawrence Gulf and River ports. JUNE Only eight different bergs were sighted or reported from south of the forty-sixth parallel during June. Six of these were south of the forty-third parallel. These six were all disintegrated during the first week of the month by the relatively high surface tem- peratures resulting from continued solar warming and Gulf Stream mixing. Three reasons can be given for the fact that no bergs are known to have crossed the forty-third parallel after June 5: 1. Probable actual weakening of Labrador current. 2. Temper- atures of surface layers south of forty-eighth parallel well above freezing, even in the Labrador current, which, coupled with 1, would cause bergs to disintegrate before getting far south. 3. Failure of large supply of bergs to Labrador current where it rounds the north- east promontory of the Grand Banks. The ice was on the average even farther west in the ocean during June than it was during May. Many of the bergs were close to and stranding upon the coast of 63 the Avalon Peninsula of Newfoundland. Two groups of bergs were stopped or stranded on the northern part of the Grand Banks in the vicinity of 47° 20' N., 50° 50' W., and 47° 30' N., 49° 40' W. Neither of these groups was located far enough to the eastward to be favorably situated to serve as the origin of southerly berg drifts. Vessels apparently began using the Belle Isle steamship tracks on the relatively early date of June 21, for 23 bergs and several growlers were reported to the international ice patrol on that date from between Greenly Island and 52° 30' N., 53° 00' W. No field ice was sighted by or reported to the patrol vessels during June. JULY Fifty-five bergs were south of the forty-eighth parallel. All of them were within a 50-mile radius of Cape Race, Newfoundland. AUGUST Five bergs were south of the forty-eighth parallel. All were in the same area as the July bergs. SEPTEMBER No bergs were south of forty-eighth parallel in September. OCTOBER Four bergs drifted south of forty-eighth parallel during the month. Three of these were close to Cape Race and one was about 120 miles to the eastward. NOVEMBER Four bergs got south of the forty-eighth parallel. Ice w^as notice- ably farther east in the ocean than in four preceding months. DECEMBER No bergs south of forty-eighth parallel up to time of finishing this manuscript for printer, January 4, 1929. Very likely a few reports of ice sighted in December are yet to come in. The above monthly discussions and the charts following this section give a general idea of the ice distribution southeast of Newfoundland below the forty-eighth parallel throughout the year. For a narrative account of the ice seen, together with the attendant observations and conditions, see the 1928 cruise reports at the beginning of this pamphlet. As in former years the ice patrol kept track of and recorded the drift of as many bergs as possible during the season. The paths taken are shown on Figure 12. The longest track is over 480 sea miles in length and represents the results of 16 days of actual trailing and tracking by the ice patrol vessels. 64 Figure 12 also shows the known risks from bergs that the United States-Europe steamers experienced in April, May, and June, 1928. The ice-patrol broadcasts help to minimize these risks, but in times of fog and darkness real safety can lie only in radically reduced ship speeds and judicious caution. SUMMARY Month January February- - March April May -- June July August September- October November. December- Total Bergs south of 48° N. in 1928 0 0 14 156 190 87 55 5 0 4 4 0 Bergs south of 43° N. in 1928 Bergs south of 48° N. normally 3 10 36 83 130 68 25 13 9 4 3 2 Bergs south of 43° N. normally From the above figures it will be seen that the total number of bergs known to have been south of the forty-eighth parallel in 1928 was considerably above normal during the greater part of the heavy ice season. On the other hand, the number of bergs to drift south of the forty-third parallel was distinctly subnormal. Some of the latter bergs got into the circulation southeast of the Tail of the Grand Banks, however, and attained extremely low latitudes before melting. Field ice was distinctly below normal in amount about the Grand Banks as well as inshore to the westward. Its southerly extension was never great and it disappeared from the picture relatively early. &^ -a.- BERes. O -GROWLERS. it|*|lV- FIELD ICE. GENERAL CHART COVERIN» ICE PATROL GRAND BANKS ICE MAP FOR JULY, HZ8. Figure ll.— July ice map. R5 known icebergs were south of the 48th parallel during the month 33382—29. (Face p. 64.) Xo. 6 A4 A, \. J XI 7*^ --^3 . I i I I M I=F1= ''•'''' I , . I . , I I , , I , , l-l ll I I I iiiB ^ I I I I M I I I I 1 I I Jri^ «« ^ *< 56 55 -^- BEBes. O -GROWLERS. I^^l^- FIELD ICC. GENERAL. CHART CO V ELPING ICE PATROL GRAND BANKS ICE MAP FOR JUME, IIZS. Figure io,— June ice map. 87 kaown icebergs were south ol the 48th parallel during the month 33382—29. (Face p. 64.) No. 5 FiGVEE 9.— May ice map. 190 known icebergs were south o( the 4bth parallel during the month 33382—29. (Face p. 04.) Xo. 4 '^^^^'^■^■^{l^^J'X^ ■■ Mil' U^ M I i I I ' I I ^^^^1 1 1 I » 4t 47 7i 35 « ICE MAP FOR APRIL, l* <»I5 *?»7 m& STATI srw. 50°W. ONS. 4rw. Figure 13.— Distribution of oceanographic stations m HIS 48' W. 67 Throughout 1928 the saHnities were determined and the stations were computed at sea, as in 1926 and 1927, very quickly after the actual stations were occupied. In running the electric salinity cabi- nets the need was felt for standard water of dependably known salin- ity for calibrating and frequent check purposes. The carboys of tested water on hand from the previous year were of somewhat doubtful salinity. Graphical curves of temperature with depth should be made at every station before the ship is started ahead. Questionable — that is, seemingly erratic or unreasonable — values of temperature should mean the retaking of the whole station at once, or at least the retaking of the doubtful and adjacent levels. Irregular values of salinity should be watched for also in the same manner. When they are found the water from the level in question should be retested, this time in another electric cell from the one first used. As the salinities can not be de- termined for some little time after the stations are finished, the ship will always be too far from the station to permit the procuring of a new bottle of water. If reasonable results can not be obtained, inter- polation between adjacent levels must be resorted to. Where inter- polated values were used in 1928 the fact is noted in the table of station data. So delicate is the balance of the various water masses in the sea that the greatest methodical care in all work connected with the taking and computing of the stations is the only insurance against gross errors in the final results. The 1928 stations have been divided into seven groups or sets as shown in figures 14 to 20. Each set is made up of stations taken within a period of time short enough to permit the hydrodynamic values to be compared with reasonable safety for general current work. The arrows on the current charts were put in much like wind arrows could be put on a weather map if the barometric pressures at a number of observing stations were known. The four group iSgures by the dots that represent the various stations show in tenths of dynamic millimeters the height of the average sea surface above 728 dynamic meters that must have existed above the 750 decibar pressure level. (A decibar is a pressure equal to one-tenth of an atmosphere. A dynamic meter is approximately the same as an ordinary meter. It is a vertical unit of distance that varies from place to place in the same ratio as the force of gravity varies.) The four figure distances were computed from the known distribution of salinity and tempera- ture in the water of the various levels at each station. Seven hundred and fifty decibars was the deepest pressure level that was sampled during the 1928 ice patrol. If more time were available it would have been advantageous to go down to the 1,000 or even the 1,500-decibar levels at the deeper stations in order to be sure of determining all the current. It is beUeved, however, that not a 68 S^3 "852, g5l 850 841 812 847 84G ONE KNOT SET ONE I MAR. ^8 TO APRS. - 43*N. 48*w. FiGrRE 14. — Current tendency diagram §63 63X0 — ^—860 G8ANJD BANKS ^1 it' ) "7 ^^;w. '358 ^QtT'y n • • , ^5*N. '6631 85i> SET TWO AP -44*N.- i>S5X 864 ^IL ^ TO 18 48'W. Figure 15.— Current tendency diagram 69 great deal of accuracy is lost by neglecting the small variations in conditions that usually exist below the 750-decibar pressure level in the sea. Gi?AN D BANK3 -4336N^ SCT THPETE APJe/L l& TO -AZ^dO'N-. MAY 3 Figure 16.— Current map Where the four-group figures are larger it means that, because it is lighter, the water is puffed up so that the average height of the sea surface is heaped up more above the local mean sea level than where Figure 17.— Current tendency diagram the figures are smaller. Highs in the sea are thus formed, and these north of the equator, both by theory and by actual observations in many open seas, have clockwise currents circling about them. These 70 GRAND BANK5r ./o© ^^A 5\\\N. 43*30*N.- 67Z4 Gifts' 50'W 814 4^30 N.- ^'iiw. FiGUKE 18.— Current map A J^7 111 7 GRAND qj3,> . , ""■*■', 250 2.8 34.59 27.60 . 97203 51 243. 21287 . 19288 5is,jlv.r- 450 3.0 34.71 27.68 . 97108 46 437. 52387 . 2903S /" • W-C^:- »„ ."v 750 2.8 34.75 27.73 .96971 42 728. 64237 . 4228S .^j ': >^ vi^ >^' ,V 1 / ; u.^l 87 Oceanographic station data and dynamic calculations, 1928 — Continued Sta- tion Date Lati- tude, Longi- tude, Depth Deei- bar Tem- pera- Salin- ity 5: V V-Vi E E-Ei N. W. levels ture 0 / o / Meters "C. %o 899 May 17 42 55 49 05 2,012 0 7.0 33.83 26.53 0. 97415 151 0 0 25 6.8 34.26 26.89 . 97370 117 24. 34812 . 03347 50 5.2 34.29 27.11 . 97338 96 48. 68662 . 06012 125 4.8 34.53 27.35 . 97283 75 121. 66949 .12437 250 4.8 34.84 27.59 . 97206 54 243.22511 . 20512 450 4.8 34.86 27.61 .97116 54 437.54711 . 31362 750 2 5.8 34.92 27.54 . 96994 65 728.71211 . 49262 900 ._.do 43 23 49 21 75 0 2.0 33.17 26.53 . 97415 151 0 0 25 1.2 33.24 26.64 . 97394 141 24.35112 . 03647 50 l.S 33.32 26.66 . 97380 138 48. 69787 . 071.37 60 2.0 33.57 26.84 . 97359 122 58. 43482 . 08437 <)01 May IS ■13 33 49 00 2,012 0 2.0 33.12 26.48 . 97420 156 0 0 25 .4 33.73 27.08 . 97353 100 24. 34662 .03197 50 .7 34.03 27.31 . 97319 77 48. 68062 .05412 125 2.6 34.19 27.30 . 97288 80 121. 65824 .11312 250 2.8 34.68 27.67 . 97197 45 243.21136 . 19137 450 3.0 34.73 27.70 . 97106 44 437. 51436 . 28087 750 2.8 34.78 27.75 . 96969 40 728. 62686 . 40737 902 ...do— - 43 35 49 06 1,463 0 1.8 33.17 26.54 . 97414 150 0 0 25 2.0 33.30 26. G3 . 97395 142 24.35112 . 03647 50 1.6 33.55 26.86 . 97361 119 48. 69562 . 06912 125 1.4 34.11 27.32 . 97286 78 121. 68824 . 14312 250 1.8 34.33 27.47 .97216 64 243. 25199 .23200 450 1.4 34.59 27.71 . 97104 42 437. 57199 . 33850 750 12.8 34.73 27.71 . 96973 44 728. 68749 . 46800 903 ...do.... 43 37 49 11 1,097 0 1.5 33.05 26.46 . 97422 158 0 0 25 .7 33.15 26.60 . 97388 135 24. 35125 . 03660 50 -.8 33.31 26.80 . 97367 125 48. 69562 . 06912 125 -.8 33.54 26.98 . 97317 109 121. 70212 .15700 250 1.1 34.37 27.55 . 97208 56 243. 28024 . 26025 450 2.0 34.50 27.59 .97116 54 437. 60424 . 37075 750 2.8 34.59 27.68 . 96976 47 728. 74224 . 52275 904 ...do 43 39 49 16 412 0 1.8 33.04 26.44 . 97424 160 0 0 25 -.6 33.35 26.82 . 97377 124 24. 35012 . 03547 50 -.7 33.42 26.88 . 97359 117 48. 69212 . 06562 125 -.4 33.57 27.00 . 97315 107 121. 69487 . 14975 250 1.1 34.06 27.31 . 97231 79 243. 28612 . 26613 905 May 19 43 33 49 32 55 0 2.6 33.07 26.40 . 97428 164 0 0 25 1.4 33.16 26.56 . 97402 149 24. 35375 . 03910 40 1.6 33.24 26.61 . 97389 143 38. 96307 . 06097 50 3.0 33.38 26.62 . 97384 142 48. 70172 . 07522 906 ...do 43 23 49 14 686 0 1.2 33.06 26.49 . 97419 155 0 0 25 -.8 33.25 26.75 . 97383 130 24. 35025 . 03560 50 -1.0 33.51 26.97 . 97351 109 48. 69275 . 06625 125 -.8 33.56 27.00 . 97315 107 121. 69250 . 14738 250 .4 33.78 27.12 . 97248 96 243. 29438 . 27439 450 2.0 34.46 27.56 .97119 57 437. 66138 .42789 ...do.-.. 43 15 49 04 1,143 650 0 1.0 1.9 34.66 33.03 27.79 26.42 631.78638 0 907 "".'97426" "162" 0 25 1.5 33.15 26.54 . 97403 150 24. 35362 . 03897 50 2.0 33.32 26. 65 . 97381 139 48. 70162 . 07512 125 2.0 34.09 27.26 .97292 84 121. 70399 . 15887 250 2.2 34.33 27.44 . 97218 66 243. 27274 . 25275 450 2.7 34.41 27.46 . 97129 67 437. 61974 . 38625 750 3.2 34.52 27.51 . 96992 63 728. 80124 . 58175 908 ...do 43 10 48 52 2,195 0 2.4 32.89 26.28 . 97439 175 0 0 25 .6 33.38 26.79 . 97380 127 24. 35237 . 03772 50 .5 33.71 27.06 . 97343 101 48. 69274 .06624 125 2.0 34.16 27. 32 . 97290 82 121.68011 . 13499 250 3.1 34.47 27. 47 . 97216 64 243. 24636 . 22637 450 4.0 34.67 27.54 . 97122 60 437. 58436 . 35087 750 4.2 34.65 27.51 . 96994 65 728. 75836 . 53887 909 ...do.... 43 03 48 43 3,292 0 7.8 33.52 26.16 . 97451 187 0 0 25 7.2 33.84 26. 51 . 97406 153 24.35712 .04247 j £0 3.8 33.91 26. 96 . 97352 110 48. 70187 . 07537 125 3.8 34.33 27.29 .97289 81 121. 69224 . 14712 250 5.1 34.68 27.43 . 97221 69 243. 26099 .24100 450 4.2 34.72 27.56 . 97120 58 437. 60199 . 36850 750 4.6 34.77 27. 56 . 96990 61 728. 76699 .54750 910 ...do 42 58 48 32 3,292 0 5.8 33.37 26.31 . 97436 172 0 0 25 5.6 33.75 26.30 . 97426 173 24. 35775 .04310 50 8.7 33.86 26.30 . 97415 173 48. 71287 .08637 125 4.8 34.31 27.18 . 97299 91 121. 73062 .18550 250 4.6 34.59 27.42 . 97222 70 243. 30624 . 28625 450 4.5 34.75 27.55 . 97132 70 437.66QaL, ,1^2675 750 4.2 34.54 27.55 .97000 71 jsedS^ ir»*i5 ' Values by interpolation on account of loss of water sample, failure of thermome: 2 Values obviously in error, but included for completeness and to show what Oceanographic station data and dynamic calculations, 1928 — Continued sta- tion Lati- Longi- Deci- Tem- Salin- ity Date tude, tude, Depth bar pera- d. V V-Vi E E-E 1 N. W. levels ture o / o , Meters °C. %o 911 May 24 42 33 50 43 2,057 0 3.0 33.48 26.69 0. 97400 136 0 0 25 -.1 33.56 26.97 . 97363 110 24. 34537 . 02072 50 .1 33.70 27.07 . 97343 101 48. 68349 . 05699 125 2.8 33.96 27.10 . 97307 99 121. 67686 . 13174 250 1.5 34.09 27.30 . 97232 80 243. 26373 . 24374 450 2.8 34.58 27.59 .97116 54 437. 61173 . 37824 i 750 3.1 34. 69 27.66 . 96978 49 728. 75273 . 53324 912 ...do.--- 42 37 51 02 , 1,902 0 2.8 33.20 26.49 . 97419 155 0 0 1 25 -.1 33.41 26.85 . 97374 121 24. 34912 . 03447 50 -.6 33.38 26.85 . 97362 120 48.69112 .06462 1 125 -.6 33.64 27.05 . 97310 102 121.69312 .14800 250 2.1 34.22 27.36 . 97226 74 243. 27812 . 25813 450 2.6 34.56 27.59 . 97116 54 437. 62012 .38663 750 3.1 34.67 27.64 . 96979 50 728. 76262 .54313 913 May 26 42 13 50 29 2,972 0 4.1 33.29 26.44 . 97424 160 0 0 25 1.8 34.15 27.33 . 97329 76 24. 34413 . 02948 50 1.8 34.18 27.35 . 97315 73 48. 67463 . 04813 125 1.6 34.21 27.39 . 97279 71 121. 64738 . 10226 250 2.6 34.52 27.56 . 97207 55 243.20113 . 18114 450 3.2 34.66 27.62 . 97113 51 437. 52113 .28764 750 3.2 34.70 27.65 . 96978 49 723. 65763 . 43814 914 ...do 42 15 50 20 2,972 0 5.0 33.30 26.35 . 97432 168 0 0 25 3.9 33.24 26.42 . 97415 162 24. 35587 . 04122 50 1.4 33.53 26.86 . 97361 119 48. 70287 . 07637 125 1.7 34.38 27.51 . 97268 60 121.68874 . 14362 250 2.8 34.56 27.58 . 97205 53 243. 2343G . 214.37 450 3.0 34.67 27.65 . 97110 48 437. 54936 . 31587 750 3.2 34.75 27.69 . 96975 46 728. 67686 . 45737 915 May 27 41 45 49 40 3,200 0 18.6 36.00 25.90 . 97475 211 0 0 25 18.6 35.97 25.88 . 97467 214 24. 36775 . 05310 50 18.5 35.98 25.91 . 97452 210 48. 73262 . 10012 125 15.2 1 35. 68 1 26. 60 . 97356 148 121. 78562 . 24050 250 12.4 35.37 26.81 . 97283 131 243. 43499 . 41500 450 8.2 34.89 27.18 . 97160 98 437. 87799 .64450 750 5.0 34.84 27.57 . 96990 61 729. 10299 . 88350 916 May 28 41 57 49 04 3,338 0 5.0 33.54 26.54 . 97414 150 0 0 25 7.2 33.98 26.62 . 97396 143 24. 35125 . 03660 50 6.4 34.16 26.87 . 97361 119 48. 69587 . 06937 125 5.8 34.54 27.24 .97294 86 121. 69149 . 14637 250 6.1 34.61 27.25 . 97239 87 243. 27461 . 25462 450 4.4 34.74 27.56 . 97120 58 437. 63361 .40012 750 4.1 34.86 27.69 . 96977 48 728. 77911 . 55962 917 May 29 41 45 49 15 3,292 0 4.7 33.30 26.38 . 97430 166 0 0 25 4.1 33.37 26.51 . 97406 153 24. 35450 . 03985 50 3.8 33.50 26.64 . 97382 140 48. 70300 . 07650 125 2.2 34.08 27.24 . 97293 85 121.70612 . 16100 250 5.6 34.74 27.42 . 97222 70 243. 27799 .25800 450 4.5 34.77 27.57 .97119 57 437. 61899 . 38550 750 3.2 34.72 27.68 . 96976 47 728. 76149 . 54200 918 May 30 41 12 47 58 3,475 0 6.4 33.07 26.00 . 97466 202 0 0 25 6.4 32.97 25.92 . 97462 209 24. 36600 . 05135 50 —.6 33.66 27.08 . 97361 119 48. 71637 . 08987 125 2.6 33.91 27.08 . 97309 101 121.71012 . 16500 250 .0 34.03 27.35 . 97225 73 243. 29449 . 27450 450 3.0 34.59 27.58 .97117 55 437. 63749 .40400 750 3.9 34.84 27.69 . 96977 48 728. 77849 . 55900 919 May 31 41 10 46 48 4,207 0 12.2 34.18 25.93 . 97472 208 0 0 100 12.6 35.51 26.88 . 97339 120 97. 40550 . 16375 200 18.1 35. 26 2 25. 47 . 97432 258 194. 79100 . 35251 920 June 1 42 05 46 27 4,755 0 11.4 33.61 25.65 . 97499 235 0 0 25 14.8 35.19 26.19 . 97437 184 24. 36700 . 05235 50 11.2 35.32 27.01 . 97348 106 48. 71512 .08862 921 June 6 41 31 48 09 3,292 0 10.7 33.71 25.85 . 97480 216 0 0 25 8.5 .33. 51 26.05 . 97450 197 24. 36625 .05160 50 8.2 34.79 27.10 . 97340 98 48. 71500 . 08850 125 5.4 34.21 27.03 .97313 105 121. 70987 . 16475 250 4.9 34.53 27.34 . 97230 78 243. 29924 . 27925 450 5.0 34.87 27.60 .97117 55 437. 64624 . 41275 922 June 7 41 30 47 08 3,978 0 18.8 36.27 26.06 . 97460 196 0 0 25 18.7 36.31 26.12 . 97444 191 24. 36300 .04835 50 18.7 36.30 26.11 . 97433 191 48. 72262 . 09612 125 16.0 36.08 26.60 . 97356 148 121. 76849 . 22337 250 14.8 35.94 26.76 . 97289 137 243. 42161 . 40162 450 10.4 35.34 27.16 . 97164 102 437. 86461 .63112 750 5.4 2 35. 67 ' Values by interpolation on account of loss of water sample, failure of thermometers to work, etc. 2 Values obviously in error, but included for completeness and to show what was actually recorded. 89 Oceanographic station data and dynamic calculations, 1928 — Continued Sta- tion Lati- Loniji- Deci- Tem- Salin- ity Date tude, N. tude, W. Depth bar levels pera- ture «• V V-V: E E-E, o , o , Meters "C. %o 923 June 8 42 55 49 28 1,555 0 5.8 33.07 26.08 0. 97458 194 0 0 25 3.9 33.37 26. 52 . 97405 152 24. 35787 .04322 50 3.6 33.95 27.01 . 97347 105 48. 70187 . 07537 125 3.6 34.29 27.28 . 97290 82 121. 69076 . 14564 250 3.2 34.68 27.63 .97200 48 243. 24701 . 22702 450 3.0 34.70 27.67 .97109 47 437. 55601 . 32252 750 3.0 31.78 27.73 . 96971 42 728. 67601 . 45652 924 June 9 42 49 49 44 2,286 0 5.4 33.04 26.10 . 97456 192 0 0 25 4.4 33.12 26.28 . 97428 175 24. 36050 .04585 50 3.8 33.41 26.56 . 97391 149 48. 71287 . 08637 125 2.0 34.27 27.40 . 97278 70 121. 71374 . 16862 250 3.0 '34.50 27.51 . 97212 60 243. 26999 .25000 450 2.0 34. 73 27.73 . 97103 41 437. 58499 .35156 750 3.2 34.80 27.73 . 96971 42 728. 69599 . 47650 925 ...do.... 43 16 49 10 823 0 4.8 33.07 26.20 . 97447 183 0 0 25 3.6 33.17 26.39 . 97418 165 24. 35812 .04347 50 3.0 33.51 26.72 . 97374 132 48. 70712 . 08062 125 1.2 34.08 27.31 . 97296 88 121. 70837 .16325 250 2.0 34 32 27.45 . 97217 65 243. 27899 .25900 450 2.9 34.58 27.54 .97121 59 437. 61699 .38350 750 3.2 34.66 27.64 . 96979 50 728. 76699 .54750 926 June 10 43 10 49 34 274 0 4.8 32.97 26.10 . 97456 192 0 0 25 2.0 33.18 26.53 .97404 151 24. 35760 . 04285 50 -1.6 33. 32 26.83 . 97363 121 48. 70337 .07687 125 .6 33.81 27.14 . 97302 94 121. 70274 . 15762 200 .6 34.12 27.38 . 97246 72 194. 65824 . 21975 240 1.6 34.11 27.31 . 97233 233. 55404 927 ...do 42 59 49 27 1,463 0 5.2 32.99 26.09 . 97457 "193" 0 '0 25 4.8 33.02 26.16 . 97440 187 24. 36212 .04747 50 4.8 33.45 26.49 . 97396 154 48. 71662 . 09012 125 -.3 33.76 27.14 . 97302 94 121. 72837 . 18325 250 1.4 34.17 27.37 . 97225 73 243. 30774 . 28775 450 1.0 34.48 27.65 . 97108 46 437. 64074 . 40725 750 3.0 34.63 27.61 . 96982 53 728. 77574 . 55625 928 June 11 43 02 49 00 1,463 0 5.1 33.12 26.20 . 97447 183 0 0 25 5.2 33.41 26.42 .97415 162 24. 35775 .04310 50 3.4 33.56 26.74 . 97372 130 48. 70612 . 07962 125 2.0 34.44 27. 54 . 97265 57 121. 69499 . 14987 250 2.6 34.58 27.61 . 97202 50 243. 23686 .21687 450 3.0 34.70 27.67 . 97109 47 437. 54786 . 31437 750 3.0 34.79 27.76 . 96968 39 728. 66336 . 44387 929 ...do...- 42 57 48 55 1,646 0 6.6 33.51 26.32 . 97435 171 0 0 25 4.1 33.86 26.89 . 97370 117 24. 35062 . 03597 50 3.5 34.16 27.19 . 97330 98 48. 68812 . 06162 125 2.4 34.45 27.52 . 97267 59 121. 66199 . 11687 250 2.9 34.58 27.58 .97205 53 243. 20699 .18700 450 3.1 34.67 27.64 .97111 49 437. 52299 . 28950 750 3.1 34.73 27. 69 . 96975 46 728. 65199 . 43250 930 June 12 44 00 48 20 3,292 0 8.2 33.71 26.25 . 97442 178 0 0 25 5.4 33.89 26.77 . 97382 129 24. 35300 . 03835 50 3.2 34.15 27.21 . 97328 86 48. 69175 . 06525 125 3.0 34. 50 27.51 . 97268 60 121. 66525 . 12013 250 3.8 34.93 27.77 . 97188 36 243. 20025 . 18026 450 3.6 34.94 27.81 . 97096 34 437. 48425 . 25076 750 3.8 34.85 27.71 . 96974 45 728. 58925 . 36976 931 June 13 43 06 49 45 190 0 5.0 32.94 26.08 . 97458 194 0 0 85 25 -.4 33.24 26.72 . 97386 133 24. 35550 .040 50 -1.4 33.37 26.87 . 97359 117 48. 69862 . 07212 125 -.4 33.44 26.88 . 97326 118 121.70549 . 16037 June 14 42 00 50 08 3,475 175 0 -1.0 6.0 33.56 33.39 27.01 26.29 170. 35949 0 932 '.'97438" "174" .. 25 4.8 33.49 26.52 . 97405 152 24. 35537 . 04072 50 3.2 33.72 26.87 . 97360 118 48. 70099 . 07442 125 2.2 34.33 27.44 . 97274 66 121. 68874 . 14392 250 3.0 34.59 27.58 . 97205 53 243.23811 .21816 450 3.4 34.70 27.63 .97112 50 437.5.5511 . 32162 750 3.4 34.74 27.66 . 96979 50 728. 69161 .47212 933 June 16 42 52 49 43 1,317 0 4.4 33.03 26. 21 . 97446 182 0 0 i 25 3.8 33.10 26. 32 . 97424 171 24. 35875 . 04148 50 -.6 33. 34 26.81 . 97366 124 48. 70750 . 08101 125 1.0 34.01 27.27 .97290 82 121.70350 . 15201 250 2.4 34.42 27.49 .97214 62 243. 26850 . 24050 450 3.0 34.63 27.62 .97113 51 437. 59550 . 36038 750 3.2 34.68 27. 64 . 96979 50 728. 73350 . 51481 ' Values by interpolation on account of loss of water somple, failure of thermometers to work, etc 90 Oceanographic station data and dynamic calculations, 1928 — Continued Sta- tion Lati- Longi- Deci- Tem- Salin- ity Date tude, tude, Depth bar pera- 5t V V-Vi E E-Ei N. W. levels ture o / Meters °C. %o 934 June 18 43 33 48 58 2,012 0 6.6 33.25 26.12 0. 97454 190 0 0 25 5.4 33.22 26.24 . 97432 179 24. 36075 .04610 50 -.6 33.91 27.27 .97324 82 48. 70525 . 07875 125 1.0 34.16 27.39 . 97278 70 121. 68100 . 13588 250 2.1 34.44 27.53 . 97210 58 243. 23600 .21601 450 2.9 34.54 27.55 . 97120 58 437. 56600 . 33251 750 3.0 34.68 27.65 . 96978 49 728. 71300 .49351 935 ._.do.-.- 45 34 48 21 773 0 3.6 33.05 26.29 . 97438 174 0 0 25 .4 33.20 26. 65 . 97393 140 24. 35387 . 03922 50 -1.6 33.78 27.20 . 97330 88 48. 69424 . 06774 125 .0 1 34. 00 27.32 . 97285 77 121. 67486 . 12974 250 1.9 34.34 27.47 . 97216 64 243. 23798 . 21799 450 3.0 34.63 27.61 .97114 52 437. 56798 . 33449 750 3.2 34.59 27.57 . 96986 57 728. 71798 . 49849 ' Values by interpolation on account of loss of water sample, failure of thermometers to work, etc. o U.S. TREASURY DEPARTMENT- UNITED STATES COAST GUARD , BULLETIN No. 18 =ZIZ=ZIZ=z: INTERNATIONAL ICE OBSERVATION AND ICE PATROL SERVICE IN THE NORTH ATLANTIC OCEAN - [!''9'°2"9'1 U. S. TREASURY DEPARTMENT UNITED STATES COAST GUARD Bulletin No. 18 INTERNATIONAL ICE OBSERVATION AND ICE PATROL SERVICE IN THE NORTH ATLANTIC OCEAN Season of 1929 ^, I UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1930 TABLE OF CONTENTS Page Introduction 1 Narrative of the nine cruises, April 1 to August 6 6 Radio communications 25 Summary report of the commander, international ice patrol 27 Table of ice and other obstructions 81 Weather 67 Depth survey carried out by sonic methods 74 Ice observation 75 Charts of ice and ice drifts, 1929 82 Problems of the ice patrol and how it attacks them 83 Oceanography 93 Oceanographic charts 122 Table of oceanographic station data 135 (III) "A" TRACKS SS'-W 50»V/ 45'W Figure l.— The scene of the principal activities of the International Ice Patrol. Tracks A, B, and C are routes to and from United States ports. Tracks D, E, and F are routes to and from Canadian ports. Areas 1, 2, and 3 make up the "melting area" described in the chapter on oceanography. Fully 90 per cent of the icebergs that drift south of the 48th parallel each year disintegrate in this "melting area" covering in all some 74,000 square sea miles. The triangle "T" is a very critical area and must be frequently searched out for ice by the patrol vessels themselves INTRODUCTION In 1855 Matthew F. Maury, later to be known as "The Pathfinder of the Seas," was a heutenant in the United States Navy and in charge of the Naval Observatory at Washington, D. C. In January of the above year he began strenuously advocating in the interests of safety separate travel lanes for eastbound and westbound traffic between Europe and America. The cause of the great concern was a disastrous collision between eastbound and westbound vessels, in which 300 lives were lost. There was some opposition at first, but in the course of a few years a mounting list of disasters through collision forced such a system of tracks to be put into efi'ect. Al- though the danger of collision between vessels was thus greatly les- sened, there remained the problem of the ice menace that threatens in the vicinity of the Grand Banks off Newfoundland each spring. In 1890 Hugh Rodman, then an ensign in the United States Navy, was ordered to proceed to Newfoundland and Nova Scotia to make investigations relative to the ice. The information that he obtained was combined wdth that accumulated through reports for many years from shipping and w-as published by the Hydrographic Office as a pamphlet entitled "Report of Ice and Ice Movements in the North Atlantic Ocean." A partial list of disasters contained therein shows that from March 19, 1882, to April 16, 1890, there were no less than 14 vessels lost and about 40 vessels seriously damaged in the North Atlantic due to ice. Among these were many trans- Atlantic steamers that had collided with icebergs. The Hj'dro- graphic Oflfice admitted that if reports had been received of all the fishing and whaling vessels lost or damaged the list would have been much larger. A stud)' of the records up to 1890 clearly showed that the ice came down from the north in larger amounts and extended farther to the southeast of Newfoundland in some years than in others. The heavy ice years were the ones when the greatest toll of trans- Atlantic vessels was taken. Continual efforts were made to gather reports of ice conditions, and the United States Hydrographic Office gave out its information to the shipping interests as quickly and in as much detail as possible. Other than accumulating ice reports on shore from shipmasters, nothing new was done to combat the dan- ger until after the world had been horrified by the Titanic disaster of April 14, 1912, in which over 1,500 persons lost their lives. The Titanic sank on her maiden voyage shortly after collision with an iceberg in latitude 41° 46' N., longitude 50° 14' W. (1) Resolved to prevent the repetition of such a tragedy and to meet the almost universal demand for a patrol of the ice zone to warn passing vessels of the limits of danger from day to day during the ice season, the United States Navy scout cruisers Birmingham and Chester were ordered to inaugurate such a service that was to con- tinue until the end of the ice season of 1912. Very opportunely, radio had been developed and brought into use by this time, so that much more information could be gathered and disseminated by a ship on patrol in 1912 than would have been possible even a few years earlier. During the season of 1913 the patrol was undertaken by the Treasury Department and performed by the Coast Guard cutters Seneca and Miami. At the International Conference on the Safety of Life at Sea, signed at London on January 20, 1914, the high contracting parties provided for the inauguration of an international service of ice observation, ice patrol, and ocean derelict destruction in the North Atlantic. The Government of the United States was invited to undertake the man- agement of this triple service, the expense to be defrayed by the high contracting parties in a fixed proportion. The proposition was favorably considered by the President, and on February 7, 1914, he directed that the (then) Revenue Cutter Service begin as early as possible in that month the international ice-observation and ice-patrol service. Each year since then, with the exception of the years 1917 and 1918, a patrol has been maintained by the Coast Guard. Two of the largest and best equipped of the United States Coast Guard cutters have been ordered from their home stations and detailed to keep close watch on the ice so as to be able to warn shipping promptly and effectively of the position and movements of the menacing bergs and floes. The cutters inaugurate the patrol very early in the spring, as soon as the ice begins to push south along the eastern edge of the Grand Banks, and one of the two always remains on duty in the ice area until summer time conditions so melt back the limits of ice that it no longer constitutes a serious menace to the trans-Atlantic lane routes. The three southernmost pairs of tracks between North America and Europe (see fig. 1, United States Coast Guard Bulletin No. 17) carry the fastest as well as the largest amount of traffic and are the lanes that the ice patrol strives particularly to guard. They are laid down well to the south of the usual limits of field ice, so the patrol does not have to contend with that sort of ice itself or to warn the United States-Europe traffic of it to any great extent. The ice patrol's great problem is berg ice from the Greenland ice cap. The solid, massive bergs persist in the ocean much longer and extend to far lower latitudes before they melt than does the field ice. For instance, about 1,000 miles east of the American coast in 1928 one berg drifted to the latitude of Washington, D. C, just south of the thirty-ninth parallel, before it disappeared. During the same year the most southerly report of field ice, outside of that which was reported from the ap- proaches to the Gulf of St. Lawrence, was far to the north of the lati- tude of Portland, Me., or Halifax, Nova Scotia. The field ice of the Grand Banks region is broken off from the outer limits of the Arctic pack ice, or is formed locall}^ on the surface of the sea along the North American coast to the northward of Cape Race, Newfoundland. Bad as it is for shipping north of the forty-seventh parallel at times, it is, when compared with the bergs, a relatively short-lived ephemeral affair, even along the northern tracks that run across the Grand Banks. The patrol vessels do not attempt to destroy the bergs, as many people have been led to think through reading erroneous statements that sometimes get into newspapers and news reels after demolition experiments have been carried out on the ice. Except under very favorable conditions, bergs are dangerous to board in the open ocean because of the w^ash of the sea against their hard steep sides. The risks are augmented by the fact that the sea about them is usually icy and boisterous in early spring. Later on when conditions have ameliorated the bergs are much more frequently cracking up, drop- ping off large overhanging ice masses, and turning over. The ice patrol's experiments have shown that mining operations with high explosives, in the few cases when they are practicable are almost useless. The large bergs are so deep lying, massive, and hard that the explosion of a hundred pounds, more or less, of T. N. T. has very little effect other than to increase the size of the hole in which the charge is placed and to shake off a few pieces of ice already about to fall. Gunfire is even more futile than mining. Well placed shots will sometimes bring down a few tons of ice into the sea, but when it is considered that 500,000-ton bergs are not uncommon and that only about one-fourth to one-sixth of the mass of a berg projects above water to serve as a target, the futility of this method of attack becomes apparent. The series of experiments on the destruction of bergs undertaken by Prof. H. T. Barnes, of McGill University, have been followed by the ice-patrol authorities with interest. His thermite charges seem to give a little more promise of success than any other method evolved to date, but there are grave practical difficulties connected with placing the thermite in the heart of the bergs where it can act most effectively. Up to the present time, at least, it would seem that the only practicable thing that can be done is to watch, and to keep shipping advised of the changing positions of the various southernmost bergs and ice fields until in the natural course of events they melt. They disappear rather rapidly as they drift south into warmer waters during the advance of spring. As stated above, the field ice is disposed of very rapidly in the open ocean about the Grand Banks. Even the l)ergs have a comparatively short life there. Each one of the latter presents a special problem of melting, depending on its size, shape, and solidity, as well as on the sort of weather and water that it encounters. Along the northern edge of the Gulf Stream the accu- mulated observations of the ice patrol show that the largest and most resistant bergs can last only about two weeks. The thing that most hampers the patrol in its service of information is the prevalence of fog in the ice-infested regions. Experience shows that quick advantage must be taken of every spell of good weather if anything approaching an efficient information system is to be maintained. The critical areas just north of the southernmost steamer lanes must be searched again and again for ice during the course of the season. At night, and also when dense Grand Banks fog closes in, the patrol vessels usually stop and drift. This procedure not only insures that no bergs are passed unnoticed because of bad visibility, but also conserves fuel, which permits higher speed cruising when the weather is clear and bright. Much scientific work has been done in conjimction with the ice patrol and much statistical data regarding the ice has been gathered and published in the annual ice-patrol bulletins. A great deal more is now known about the Labrador Current and the Gulf Stream in the vicinity of the Grand Banks than was known when the Titanic went down. There is still much work to be done before the great variation in the severity of the ice seasons from year to year can be fully explained, however, and before the final drift tracks of bergs that are seen off the eastern edge of the Grand Banks can be predicted with confidence. The international ice patrol for the season of 1929 was carried on by the United States Coast Guard cutters Tampa and Modoc. The Mojave acted as the stand-by vessel, but she was not called upon for active duty on patrol. Commander Thomas M. MoUoy, in addition to being in command of the Tampa, was commander, international ice patrol. Commander Philip F. Roach was in command of the Modoc. Lieut. Commander Noble G. Ricketts was detailed as ice observation officer and remained at sea with two enlisted men as assistants throughout the patrol season in order to aid the command- ing officer of the vessel actually on duty in ice-patrol matters and to keep a continuous and uniform record of the year's work for this annual report. Halifax, Nova Scotia, was the base for fuel and supplies during the ice season,. The Tampa and Modoc made alternate cruises of about 15 days each-iil the ice regions, this time being exclusive of the five or six days occupied in going to and from the base. Eight times each day radio broadcasts giving locations or Umits of all known ice in the North Atlantic were transmitted for the benefit of shipping approaching the ice-patrol area. The different bergs, if not again sighted or reported, were kept from five to seven days in the broadcasts before they were dropped. The probable drift tracks of critical bergs were indicated when possible. The surface isotherms were very successfully used to esti- mate probable berg drift tracks and to determine limits of ice areas to be searched. The isotherm curves were drawn partly from infor- mation obtained by the ice-patrol vessels themselves, but mainly from careful plotting and analysis of the surface water temperature reports received by radio from cooperating vessels. The value of these reports can not be overestimated, and it is hoped that their number will increase annually. When every vessel crossing the ice- patrol area, particularly those off the most usually traveled routes, reports regularly to the patrol, then the latter will be able to render the most efficient and useful service possible. Special messages were drafted and sent to any ship that inquired for special information relative to ice, weather, routes, and similar matters. The successive positions of vessels as plotted from their water temperature reports were carefully watched. Whenever it was apparent that a ship was following a course leading toward danger the master was warned, safer courses or other suitable precautions being suggested. Once each day a compilation of all ice sighted or reported during the previous 24 hours was transmitted by radio direct to the United States Hydrographic Office at Washington, D. C. These reports were given wide dissemination among shipping circles by the hydrographer of the United States Navy. The scientific work carried on b}^ the patrol in 1929 was similar to that of previous years. Deep-sea soundings were obtained by the echo method at frequent intervals for the purpose of improving the bathymetrical charts of the ice-patrol area. Surface and subsurface temperatures and salinities were determined at numerous oceano- graphic stations. By the latter means it is possible to study the local currents generated where the Labrador Current meets the Gulf Stream, and to compare conditions prevailing in the different localities cruised over with those that prevailed there during former months and years. To facilitate reference and comparison the various sections of this bulletin are on the same subject matters and have been arranged in the same order as those in the 1928 Ice Patrol Bulletin, the 1928 publication itself being modeled on the form that has practically become standard during recent years. CRUISE REPORTS THE FIRST CRUISE, "TAMPA," APRIL 1-19 The Tampa left Boston, Mass., to inaugurate the 1929 mternational ice patrol at 12.30 p. m. on April 1. The 950-mile run to the Tail of the Grand Banks consumed four days. On April 6 a search to the northeastward for ice was started from a point about 50 miles south of the Tail, two bergs and several growlers being located in the vicinity of 42° 40' N. 49° 30' W. before night. Detailed reports of ice received from the Cape Race radio station and from steamers crossing the Banks showed that ice conditions were extremely bad north of the forty-fourth parallel. April 11 saw completed the search of the cold current lying off the eastern edge of the Grand Banks between the forty-fourth parallel and the "B" United States-Europe tracks, then in effect. Four additional bergs and several growlers were located and numerous sail of the French fishing fleet were sighted. The fishermen, all about 30 days out from France, were heading west toward the Banks. Upon request, four of these vessels with sick or injured men on board were visited by the Tampa's medical officer. Until the 14th the patrol remained near 42° 13' N. 49° 33' W., guarding the southernmost ice. During this time the first oceano- graphic stations of the year were occupied southeast of the Tail. On the 12th the scientific work was interrupted by a short search for the French fishing vessel Sylvanna, which, according to radio advices, had been abandoned on fire about 40 miles northeast of the Tampa. She must have sunk shortly after her entire crew of 32 had been rescued by the Swedish steamship Malmen, for the patrol never found other trace of her than a few charred timbers. On April 14 the Tampa cruised northward up the cold current to see what ice was coming down. No new bergs were located, but patches of slush ice were seen near 43° 10' N. 49° 45' W. From the latter point courses were run to search out the area southwest of the Tail, where a berg was located in 42° 16' N. 51° 04' W. on the 15th. The next two days showed that its drift was about 6 miles per day toward the southeast. Word was received on the 16th that the Canadian ice patrol in the Gulf of St. Lawrence had been inaugurated by the ice breaker Miquela. The 18th and 19th were spent drifting southwest of the Tail in the first prolonged dense fog of the season. The Modoc arrived at a rendezvous in this area at 12.55 a. m. on April 20 and received the ice-observation party and the patrol records. (6) Plate I.— Icebergs often keep their sides clifflike and perpendicular by repeated calving. When undercut tini; along the water line reaches a certain point the over- hanging ice masses fall down into the sea, leaving a rough surface like this. Taken from a ship's boat Julv 15. 1929, in latitude 41° .34' X., longitude 48° 58' W. Plate II. — The Modoc ;in2 bergs numerous growlers. Large berg, several growlers. Medium berg. Large berg and 3 growlers. Berg. 2 bergs, 2 growlers. Field ice stretching east and west 5 miles, 1 berg, and numerous growlers. 8 large bergs. 2 very large bergs. Large berg. Do. Low berg. 5 small growlers. Small berg. Do. Bergs and numerous growlers, same as 521. Large berg, may growlers, same as 520. Several small pieces of field ice. ^Numerous bergs. [7 bergs, many growlers, much field ice. 'Several large bergs and many growlers. Numerous pieces of ice. 1 growler, several pieces. 1 small berg. Large berg 300 feet high. Large berg, 4 growlers. Small berg, 6 growlers. Large, low berg. Growlers. Field ice, growlers, and heavy broken ' pieces. Large berg and several growlers. Berg 100 feet high. Small berg. S large bergs and some growlers. 41 Table of ice and other obstrudioiis, 1929 — Continued Date No. 549 550 551 552 553 554 556 557 558 559 560 562 563 564 565 566 569 570 571 572 573 575 576 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 595 596 597 598 599 600 Reported by— Beaverbrae Letitia do Empress of Scotland. Ice patrol Melita -do. Empress of Scotland. Sagauche Malmen Perseus Ice patrol Salacia. .do. Cape Race Station. Beaverford . do do Barom Elibank Cape Race Station. Wytheville Vallarparosa.. do Humber Arm. Vallarparosa.. Humber Arm. Nevisian Vallarparosa. Flensburg... Humber .\rm. do_ do do Nevisian do do do. Concordia. Nevisian.. do do do Ice patrol.. Concordia. .do. Nevisian. Bothwell. do.... do.... do.... do... do... Position Lati- I Longi- tude tude north west 46 23 47 20 47 03 46 18 43 14 47 28 [47 26 ■I to 147 20 46 35 43 00 45 50 43 34 42 59 [45 51 \ to 46 14 [46 20 •I to 46 42 [47 34 { to [47 11 46 51 46 54 46 47 [47 25 \ to 147 00 47 03 42 03 43 43 43 56 48 45 43 30 (48 45 \ to 148 29 48 29 44 06 [48 18 ■1 to 147 50 48 38 48 17 48 21 48 10 48 19 47 45 47 36 47 39 47 40 to 47 38 47 32 47 17 47 18 47 17 42 46 47 38 to 47 22 47 22 to 47 05 47 13 \ to 147 00 46 12 46 07 46 18 46 29 46 37 46 32 46 45 46 23 46 40 47 40 49 21 46 34 46 37 to 46 50 46 44 49 20 44 47 47 52 49 20 47 43 to 46 43 46 13 to 45 10 46 24 to 47 19 46 45 46 46 46 54 45 55 to 47 00 46 45 45 16 48 41 49 04 49 00 47 50 49 00 to 49 33 44 15 49 33 51 02 to 52 45 49 15 50 07 50 14 50 35 44 49 45 50 45 58 45 58 45 46 to 46 05 45 58 46 18 46 20 46 43 49 55 46 05 to 46 47 46 47 to 47 00 46 43 to 47 18 48 07 48 02 47 40 47 02 46 54 46 53 I Nature of ice or obstruction Berg. Do. Growler. Small growlers. Berg. Several growlers and small pieces. Open field ice and growlers. Large berg with numerous growlers. Berg, same as 560. Berg and 4 growlers. Large berg. Berg, same as 5.53. ■5 bergs and several growlers. ■Several growlers. ■Numerous bergs and many growlers. Large berg. Berg. 13 large bergs and several growlers. Growler. Large spar projecting 3 feet out of water apparently attached to submerged wreck- ■ age. Large berg. Small berg. Field ice running north and south, also 2 bergs. 2 bergs and growlers. 18 large bergs. Small berg and growler. Small berg. 10 bergs. Field ice. Berg. Do. Do. Growler. Growlers and field ice. Berg on southern end field ice. Do. Detached growlers and small pieces of ice. 3 bergs. 5 growlers. Berg. Do. Berg, same as 553. Small bergs and growlers on each side o track. Numerous bergs and growlers mostly north, of track. >8 large and 4 small bergs, also 4 growlers. Berg. Do. Do. Do. Do. Do. 42 Table of ice and other obstructions, 1929 — Continued Date No. May 12 601 12 602 12 603 12 604 12 605 12 606 12 607 13 608 13 609 13 610 13 611 13 612 13 613 13 614 13 615 13 616 13 617 13 618 13 619 13 620 14 621 14 622 14 623 14 624 14 625 14 626 14 627 14 628 14 629 14 630 14 631 14 632 14 633 14 634 14 635 14 636 14 637 14 638 14 639 14 640 14 641 14 642 15 643 15 644 15 645 15 646 15 647 15 648 15 649 15 650 15 651 15 652 15 653 Reported by- Kastalia Concordia Cape Race Station. Bothwell do do .-._do Mount Royal- Hardenberg_-. Laponia. ...-do Montroj'al . Laponia Montroyal- Federal Ice patrol Nova Scotia Andania __..do Nova Scotia Andania.- Nova Scotia ..-do ...-do .--.do ...-do ....do --.do Veendam .-.-do Cape Race Station. ...-do Nova Scotia - Veendam. Nicoline Maersk. Nova Scotia Laurentic. Veendam. Hardenberg. Laurentic... .do- -do- Position Lati- I Longi- tude tude north west f47 02 \ to [46 42 47 05 f46 57 ^ to 146 43 46 35 46 44 46 53 46 52 46 22 44 52 f49 00 •; to 148 50 48 45 \ to 148 36 47 09 48 46 47 23 32 57 42 48 48 52 46 49 46 58 48 36 47 22 48 23 48 20 48 20 48 15 48 13 48 09 Polonia i 46 ..--do Ice patrol — H ardenberg Polonia ....do do ....do do Kenmore. Polonia. 46 39 46 42 f47 44 \ to 47 40 46 35 \ to (46 50 41 28 47 42 (46 26 to 47 12 f46 10 { to (45 40 44 45 (47 12 \ to (47 45 48 00 47 56 07 46 19 42 21 44 48 46 34 46 31 46 33 46 35 46 41 47 32 to 47 20 46 40 to 47 05 46 10 to 47 11 47 22 46 17 to 47 07 46 27 46 26 45 52 45 49 48 03 45 00 49 50 to 50 10 50 28 to 50 50 46 35 50 30 46 05 47 15 50 47 44 42 46 59 46 36 45 24 45 43 46 05 46 07 46 15 46 19 46 31 46 34 46 52 45 12 45 22 45 43 45 42 47 23 to 46 41 46 53 to 46 53 45 00 47 45 47 44 to 46 24 46 53 to 48 08 47 53 46 24 to 45 34 44 55 44 37 47 51 47 53 50 50 48 31 47 30 47 08 47 04 46 56 47 00 46 46 to 47 40 47 10 to 46 05 Nature of ice or obstruction 8 bergs and 8 growlers and small pieces. Berg. '18 large, 6 small bergs, and 12 growlers, same [ as 567. Berg. Do. Do. Growlers. Berg. Do. 1 'Numerous growlers and heavy field ice. (•Several bergs and growlers. ) 1 large, 1 small berg with growlers, same as 567. Large berg. Berg and growler, same as 592. 3-masted derelict schooner Quaco Queen, bowsprit and about 40 feet of mizzen- mast standing. Berg, same as 553. Growler. Berg, same as .594. Small berg, same as 594. Several small growlers. Growlers. Berg. Growlers. Do. Large berg. Do. Small berg and growlers. Small ' erg. Growler. Small berg. Large berg, same as 634. Large berg and many small pieces. \s bergs and 2 growlers. [9 bergs and 4 growlers. Log 40 feet long 12 inches square. Berg. 1-24 bergs and growlers on both sides of track. 7 large bergs, same as 539-542. Growler. 4 bergs and numerous growlers. Growler. Small berg and growler. Berg. Berg .50 feet high. Berg, same as 616. Medium berg. Berg, same as 637. Do. Do. Do. Do. ►Numerous bergs, same as 637. 1 20 bergs and growlers. 43 Table of ice and other obstructions, 1929 — Continued Date No. lay 15 654 15 655 15 656 15 557 15 558 15 659 15 660 15 661 15 662 15 663 15 664 15 665 15 666 15 667 15 668 15 669 15 670 15 671 15 672 15 673 15 674 15 675 15 676 15 677 1* 678 15 679 15 680 15 681 15 682 16 683 16 684 16 685 Ifi 686 16 687 Reported by — Position Lati- tude north Longi- tude west Nature of ice or obstruction 6X9 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 Carmia do do Carmia ....do ....do Cameronia. Hangirland. Polonia Cameronia. ....do do ....do do do do do do do do do do do do do do. Cairnross. do.... Topsdalsfjord. California ....do ....do ...-do ...-do ....do ...-do ...-do ...-do ....do ....do Ausonia do Cameronia do do do do Cairnross Cape Race Station. Antonia. Beaver Hill. do do do do Metagama.. do do do do do do do do do do .'Vntonia Ausonia do do 45 02 48 06 48 14 48 14 48 17 48 37 46 28 47 48 47 40 46 57 46 36 47 00 47 03 47 19 47 05 47 12 47 10 46 40 46 47 46 59 47 00 47 08 47 05 47 00 47 10 47 18 48 20 47 45 to 48 40 48 45 to 48 10 48 17 48 03 47 55 47 50 47 46 47 38 47 29 47 29 47 10 47 30 47 12 49 18 49 15 48 57 48 48 48 44 47 56 47 15 52 54 45 02 47 25 46 48 47 00 46 48 46 50 46 25 46 27 46 20 46 58 46 40 46 58 46 48 46 30 46 22 46 18 46 12 46 05 49 15 50 30 to 48 50 48 15 to 50 15 45 13 44 48 45 40 45 56 45 55 46 30 46 42 46 48 47 09 46 37 47 07 48 42 44 30 48 45 44 31 47 30 45 38 47 37 45 15 47 43 45 08 47 44 45 28 47 48 44 55 48 20 49 15 47 40 52 40 48 36 48 18 to to 48 18 48 37 47 47 44 40 47 41 45 12 47 50 45 12 47 48 45 30 47 37 45 41 48 37 44 44 48 34 44 56 48 22 45 28 48 23 45 32 48 23 45 33 48 26 45 38 48 22 45 48 48 23 45 48 48 21 45 49 48 20 45 50 48 19 45 50 48 09 48 55 4S 35 45 OS 48 34 45 38 48 30 45 45 Berg. 2 bergs, numerous growlers. Berg. Do. Growlers. Berg. Small berg. Large berg and several growlers. 3 large and 3 small bergs and several growl- ers. Large berg, same as 637. Berg, same as 637. Large berg, same as 637. Do. Do. Small berg and growler, same as 637. Berg, same as 637. Do. Low berg, same as 637. Do. Berg, same as 637. Growler, same as 637. Do. Do. Berg, same as 637. 2 bergs, same as 637. 10 bergs and numerous growlers within 10 miles radius, same as 637. Small berg. 28 bergs and numerous growlers to south- ward. Field ice for about 10 miles and then ■ several large bergs and numerous growl ers. Small low berg. 2 bergs. Do. Berg. Berg, same as 652. Do. Large berg, same as 652. Large low berg, same as 652. 2 large bergs, same as 652. 7 bergs, same as 652. 4 bergs, same as 652. Several growlers. 2 bergs. Berg. Small berg. Do. Growlers. Large berg and growler. Small ice field. Berg aground. [3 small bergs and line of growlers and I small pieces of ice. Berg. Large berg and numerous pieces. Berg. Do. Growlers. Berg. Growler. Large berg. Do. Berg. Do. Large berg. 3 growlers. Growler. Berg and pieces. Berg. 2 small bergs. Berg. 2 growlers and 4 large pieces 3 growlers. 44 Table of ice and other obstructions, 1929 — Continued No. Reported by— Position Date Lati- tude north Longi- tude west Nature of ice or obstruction May 16 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 Ausonia 48 24 48 26 48 26 48 21 (48 21 \ to [46 57 47 06 •47 54 47 00 46 54 47 38 47 31 48 02 47 58 47 51 47 49 48 21 48 16 48 10 48 06 48 05 48 05 48 06 48 04 48 03 48 02 47 58 48 00 47 58 47 57 47 57 48 13 48 12 48 10 48 08 48 05 48 07 48 05 48 03 47 58 47 47 47 44 47 42 47 42 47 43 47 35 47 40 47 33 47 22 42 43 44 38 (48 42 { to [47 43 48 40 42 47 44 44 42 53 48 36 42 40 45 55 42 44 42 48 42 43 42 44 45 14 45 47 42 54 (48 03 \ to 147 40 47 39 46 56 48 02 (47 58 { to 148 17 45 49 45 53 46 00 46 03 45 29 to 47 45 45 26 46 07 45 47 46 07 45 50 46 47 47 10 47 30 47 45 47 55 45 49 46 07 46 20 46 34 46 41 46 48 46 55 46 55 47 01 47 07 47 20 49 12 49 14 49 22 49 27 46 10 47 26 46 40 46 50 47 00 47 08 47 13 47 20 47 34 48 21 48 27 48 35 48 36 48 39 48 40 48 50 48 50 48 31 51 16 45 44 44 30 to 48 39 49 31 50 49 45 33 49 53 49 34 43 59 45 34 50 54 50 22 51 13 51 13 48 07 47 44 50 08 46 13 to 48 06 47 24 46 19 45 38 46 39 to 45 00 2 small bergs. 1 berg. 16 do.-. 16 do 1 berg, 1 growler, and several pieces. 16 do 16 California 8 bergs, 19 growlers, and numerous pieces. Large berg, 3 growlers to eastward. Large berg. Do. 16 Penland 17 California 17 Penland . 17 do... Do. 17 Beaver Hill Do. 17 do -. Berg. 17 Metagama - .. 2 bergs. 17 do Large berg. 17 do . - Berg. 17 do.. Numerous growlers. 16 do Berg. 16 do Large berg and growler. 16 do Large berg. 16 do Large low berg. 16 do Large berg. 16 do Medium berg. 16 do Large berg. 16 do Do. 16 do 2 bergs. 16 do Berg. 16 do Very large low berg. 16 Antonia Growler. 16 do Large berg. 16 do Medium berg. 16 do Large berg. 16 Ausonia Growler. 16 -...do Small bergs, numerous pieces. 16 do.. 1 large, 2 small bergs, and pieces. 16 do Large berg. 16 do Do. 16 .... do .. Do. 16 do 2 large bergs. 16 do Large berg and several growlers. 16 do Large berg. 17 do Do. 17 do Do. 17 do Do. 17 17 '.V.\\^oV-"-'.V.'-".'."V"\'." Small berg. Large berg. 17 Metagama.. Do. 17 do 3 bergs. 17 do . Berg. 17 18 18 Beaver Hill Drottningholm Carlsholm .... Do. Large berg and several growlers. Large berg. 17 Cape Race Station [Numerous bergs and growlers and smal [ pieces of ice on both sides of track. 4 bergs and hundreds of growlers. 18 do 18 Ice patrol ... Berg and growlers. 18 Spilsby Berg. 18 Balsam Large berg. 18 Cape Race Station 6 bergs. 18 Grandon . . Log 3 feet diameter 20 feet long. 18 Firpark Small berg and growler. 18 Balsam . . . Large berg same as 776. 19 Quaker City Growler. 19 do Berg and several growlers, same as 772. 19 Berg, same as 772. 19 Henrik Ibsen Berg. 19 Firpark . One high and one low berg. 19 Ice patrol Berg. 19 Montrose •About 40 bergs on both sides of tracks 19 Magantic 1 Berg. 19 do.. Large berg. 10 do Small berg and 4 growlers. 19 Montrose 6 bergs, numerous growlers. 45 Table of ice and other obstructions, 1929 — Continued Date No. May 19 794 20 795 20 796 20 797 20 798 20 799 20 800 20 801 20 802 20 803 20 804 20 805 20 806 20 807 20 808 20 809 20 810 20 811 20 812 21 813 21 814 21 815 21 816 21 817 21 818 21 819 21 820 21 821 21 822 21 823 21 824 21 825 21 826 21 827 21 828 21 829 21 830 21 831 20 832 20 833 20 834 20 835 20 836 20 837 20 838 20 839 20 840 20 841 20 842 20 843 20 844 20 845 20 846 20 847 20 848 21 849 21 850 21 851 21 852 21 853 21 854 21 855 21 856 21 857 21 858 21 859 21 860 21 861 Reported by- Position Lati- Longi- tude tude north west o / o , 48 U 45 20 48 15 44 44 [47 53 49 59 ■i to to 148 11 49 17 47 43 48 24 45 23 45 40 47 47 48 09 47 53 47 56 47 47 47 55 47 24 47 49 47 53 47 48 47 31 47 48 47 47 47 49 47 44 47 42 47 49 46 43 47 46 46 40 47 49 46 35 47 54 46 33 47 59 46 32 47 54 46 30 47 09 45 16 47 17 44 57 47 27 44 19 46 45 46 26 46 50 46 25 46 52 46 21 46 52 46 10 47 07 45 49 46 25 47 37 46 37 47 30 46 27 47 00 46 32 47 10 46 40 47 00 f46 40 46 45 \ to to [47 00 46 30 48 03 45 44 48 06 45 38 (47 40 47 11 \ to to [47 53 46 08 45 16 46 41 42 38 50 40 45 27 47 56 47 44 52 10 47 51 52 13 48 10 52 17 47 58 52 16 47 58 52 21 47 49 47 10 47 47 47 07 47 44 47 05 47 44 46 58 47 53 46 53 47 50 46 43 47 36 46 41 47 49 46 35 47 54 46 33 47 59 46 32 47 54 46 30 47 55 49 50 47 58 49 43 47 59 49 41 48 00 49 32 42 45 51 15 (48 08 49 03 \ to to (48 24 48 28 48 24 48 28 48 10 46 45 47 58 46 45 47 54 47 00 47 48 47 14 47 59 47 20 48 08 47 23 Nature of ice or obstruction Montrose. Magantic. Molita Aurania Seattle Spirit. Aurania do do do do do do... do do do do do do do Letitia do. do do do do do do do do. do do. do. -do. Aurania. do... Pajola Seattle Spirit Ice patrol Cape Race Station. do. do.... do do do do. do do do do.. do do do do. do do. Doric do do do Coldilana Doric do Montcalm. do do do do do Berg. Do. 8 bergs and several small pieces. Very large berg. Small berg. Large berg and growlers. Do. Do. Do. Do. Do. Do. Do. Large berg and growlers, same as 789. Do. Do. Do. Large berg, same as 789. Small berg, same as 789. Berg! Do. Do. 2 bergs. Large berg. Berg. Do. Do. Large berg. Do. Do. Do. Do. 8 bergs. Small low berg. Growler. 31 bergs close to track, same as 789. Berg. Small berg. 2 bergs. Do. Berg. Do. Do. Do. Growlers. Do. Do. Do. Do. Large growlers. Do. Large growler. Do. Large berg. Small berg. Do. Long, low berg. Large berg and medium low berg. Large berg and 2 growlers. Large berg. Large and medium bergs, many growlers on both sides of track. Many bergs to northeastward. Small berg, several growlers. Large berg. Do. Do. Small berg. 2 small bergs. 1C0277— 30- 46 Table of ice and other obstructions, 1929 — Continued Date No. May 21 862 21 863 21 864 21 865 21 866 21 867 21 868 21 869 21 870 21 871 21 872 21 873 21 874 21 875 21 876 22 877 22 878 22 879 22 880 21 881 22 882 22 883 22 884 22 885 22 886 22 887 22 888 22 889 22 890 22 891 22 892 22 893 22 894 23 895 23 896 23 897 23 898 23 899 23 900 23 901 23 902 23 903 23 904 23 905 23 906 23 907 23 908 23 909 23 910 23 911 23 912 23 913 23 914 23 915 23 916 23 917 23 918 23 919 23 920 23 921 Reported by— Position Lati- Longi- tude tude north west o / 0 / 48 02 47 25 48 02 47 26 47 50 47 27 47 56 47 27 48 00 47 33 47 55 47 34 48 01 47 37 48 02 47 40 47 48 47 42 47 59 47 42 48 06 47 48 48 01 47 48 (47 58 47 48 \ to to 147 38 48 50 47 23 45 22 \ to to 147 05 46 17 45 04 45 46 47 33 49 49 48 08 48 38 48 06 48 45 48 05 48 45 46 50 40 31 47 29 48 23 47 40 47 38 48 16 48 14 (48 10 46 45 \ to to (47 38 48 50 (47 36 50 26 ■1 to to 148 35 48 06 47 27 43 51 47 08 44 41 47 11 45 00 47 09 45 11 47 05 45 30 47 04 45 44 46 55 45 53 46 55 46 00 48 34 48 02 48 25 48 14 49 00 48 16 48 57 48 18 (48 20 48 43 \ to to (47 45 50 10 48 06 47 55 48 04 48 00 (47 54 48 40 ( to to (47 40 49 35 48 07 48 50 48 43 48 19 48 36 48 33 48 23 48 29 (48 21 48 23 -1 to to (48 18 49 03 48 14 49 17 48 14 49 13 48 09 49 14 48 08 49 18 47 58 49 13 45 46 47 26 45 46 47 22 45 59 47 U 48 20 49 40 48 00 49 40 47 57 49 42 47 54 49 59 48 40 49 59 48 37 50 10 Nature of ice or obstruction Montcalm. do do do do do do do do do do do -do. Thuban. St. Amos Fafalios. Scythia do do do Frederick VIII. Beaverford do Scythia Cape Race Station. -do. do do do do do do do do Caledonia - do Koeln do Cape Race Station. Hada County. do do. Koeln. Regina. do.. Caledonia 48 do do do do do Koeln Heronspool do do- Caledonia do do do Cape Race Station, --..do Small berg. Do. Large berg. Medium berg. Large growler. Large berg. Do. Berg and growlers. Large low berg. Small berg. Berg. Growler. 20 large bergs north and south of liae. 5 bergs and several growlers. 2 bergs. Berg. Numerous bergs and growlers each side of track. Large berg. 2 long, low bergs. Large berg. Berg. Growler. Berg. ^36 bergs and many growlers both sides of track. 17 bergs and many growlers both sides of track. Berg. 3 growlers. Berg. Large berg and growlers. 2 bergs and 2 growlers. Berg. Do. 2 bergs. Growler. Berg and 5 growlers. Growler. Do. Numerous bergs and growlers on track. Growlers. Small berg. 8 bergs and many growlers. Field ice with uncountable growlers and large and small bergs. Growlers. Large berg also field ice and growlers on both side of track extending towards south-southwest. Large berg. Field ice extending north and south to horizon with growlers, small bergs, and two large bergs. Large berg. Very large berg. Small berg. Large berg. Do. Do. Large berg and growlers. Very large berg. Large berg. Do. Very large berg. Large berg. Small berg. Do. 47 Table of ice and other cbst ructions, 1929 — Continued Date May 23 23 23 23 23 25 25 25 25 25 25 25 25 25 25 25 No. 922 923 924 925 926 930 931 932 935 936 937 939 940 941 942 943 944 945 24 946 24 947 948 949 950 951 952 953 954 955 956 957 958 9fi0 961 962 963 964 965 966 967 968 969 970 971 972 973 Reported by- Cape Race Station. do do do do -do, -do. .do. Ascania. Athenia. do... Heronspool. Empress of Australia. Cape Race Station. .do. .do. _do. do do Ice patrol... HeronspooL Kentuckv.. do do _do. Ascania. Selvistan. Athenia.. do.... do.... do.... do.... do.._. do.-.. do.... do.... do.... Cape Race Station. Vallemare. Edouard Jeramec. do. do ....do. do. Cape Race Station. do do do do do do. do. Position Lati- tude north 48 36 48 27 48 28 48 23 f48 33 •I to !48 32 f48 32 \ to (47 57 48 02 f48 13 \ to 147 10 47 59 48 37 48 32 (46 12 I to 46 34 47 45 \ to 48 00 '48 20 \ to (47 45 48 21 48 02 (48 13 \ to 147 10 45 04 47 58 42 53 46 41 48 02 47 21 48 16 (48 20 < to 1 48 44 47 57 \ to 147 35 44 20 48 37 48 32 48 22 48 18 48 16 48 12 48 18 48 07 47 55 47 25 (47 38 to 48 00 145 27 \ to \45 54 45 08 45 11 45 11 45 05 44 59 47 30 47 14 47 26 47 07 47 07 46 47 Nature of ice or obstruction Small berg. Do. Do. Do. ^Field of broken hummocky ice. Scattered bergs and growlers north and I south of track. Very large berg. (Many bergs and growlers both sides of track. Small berg. 3 growlers and several pieces of ice. Growler. (l3 bergs. 1-7 bergs and some pieces. (Numerous bergs and growlers on "F" I track. Large berg. Do. iMany bergs and growlers both sides of I track. Large berg. Berg. Growler. 2 bergs. Berg. 3 bergs. Berg. >FieId ice with growlers and 1 berg. I35 scattered bergs and growlers north and I south of track. Large berg and 4 growlers. 3 growlers, numerous pieces. 1 growler and pieces. Berg. Berg and several growlers. Berg. Do. Do. 4 bergs. Berg. Do. >13 bergs, 4 growlers. I [-9 bergs and many growlers. Large berg. Do. Do. • Small berg. Very large berg and growler. Berg. Do. Do. Do. Do. 17 large bergs, 26 large growlers, and numer- ous pieces along track and north and south to horizon. >5 large bergs. 2 large bergs. 48 Table of ice and other obstructions, 1929 — Continued Date No. May 25 974 26 975 26 976 26 977 27 978 28 979 27 980 28 981 28 982 28 983 28 984 28 985 28 986 28 987 28 988 28 989 28 990 28 991 28 992 28 993 28 994 28 995 28 996 28 997 28 998 28 999 28 1000 28 1001 28 1002 28 1003 28 1004 28 1005 28 1006 28 1007 28 1008 28 1009 28 1010 28 1011 28 1012 28 1013 28 1014 28 1015 29 1016 29 1017 28 1018 28 1019 28 1020 28 1021 28 1022 28 1023 29 1024 29 1025 29' 1026 29 1027 29 1028 29 1029 29 1030 29 1031 29 1032 29 1033 30 1034 30 1035 Reported by- Position Lati- tude north Longi- tude west Nature of ice or obstruction Cape Race Station. Odensholm Cape Race Station. do Homeric Vlieland Cape Race Station. Antonia do do do do do do Metagama do do do Cape Race Station. do Beaverhill do Regnhildholm Ausonia Montclare do do do do do do do do Beaverhill. do.... do Cape Race Station. Montclare. do do ....do ....do Saguache. Tiger. Cape Race Station. do do. do do do California do Nova Scotia. Dalcairn California .do. Cape Race Station. do.. , do do-... Laurentic do 46 56 47 30 48 10 48 30 40 28 48 25 f48 35 \ to 148 10 47 16 47 55 48 07 48 07 48 09 48 01 48 16 48 13 48 11 48 15 48 14 48 07 48 16 47 38 47 41 43 30 48 09 48 22 48 28 48 36 48 32 48 27 48 33 48 40 48 25 48 25 [47 43 \ to [47 58 48 02 48 05 48 56 48 07 48 02 47 58 47 57 47 53 [46 20 ■i to [46 14 49 06 to [48 28 49 00 48 48 48 49 48 39 48 33 47 57 48 13 47 57 48 20 to [48 52 45 50 [48 13 to 48 21 48 21 to [48 35 47 15 47 22 47 00 46 55 48 26 48 18 47 10 51 38 49 20 49 50 50 01 45 50 49 48 to 60 30 51 18 49 58 49 34 49 15 49 14 48 52 48 22 48 50 48 50 48 42 48 39 48 52 48 22 48 17 48 17 51 30 45 49 46 07 46 20 46 23 46 35 46 36 45 53 45 55 46 47 46 48 47 30 . to 46 30 45 59 45 47 44 46 48 02 48 17 48 17 48 31 48 30 44 50 to 44 41 49 40 to 50 45 47 09 47 25 47 39 47 57 48 28 49 48 49 17 48 53 50 50 to 49 24 45 43 49 17 to 47 53 47 53 to 47 15 44 30 45 10 45 55 46 30 49 00 48 59 2 large bergs. 3 bergs. 2 large bergs. Do. Buoy about 10 feet high painted red with superstructure black, square cage on top. Berg and growlers. Several large bergs and numerous growlers extending north and south as far as could be seen. Small berg. Large berg. Ice island. Small berg. Large berg. Large berg and growler. Small berg. Large berg. Very large berg. Berg. Do. Small berg. Do. Large berg. Do. Small berg. Berg. Small berg. Large berg. Growler. Berg. 2 bergs and small pieces. Berg. Growler. Small berg. Large and small berg. Numerous bergs and growlers to north and south. Berg. Growler. Spar floating vertically apparently attached to submerged wreckage. Berg and numerous small pieces. Berg. Do. Do. 2 bergs. 1 large and 2 small bergs and several]growl- 4 large, 10 small growlers, 1 large, 2 small bergs. Berg. Do. Do. Do. Do. Do. Large berg. Large berg and several growlers. 100 bergs and unnumerable growlers. Large berg and growler. 9 large, 16 medium, and 9 small bergs.'also many growlers north and south of track. •5 bergs north and south of track. 1 large and 1 small berg. 2 small bergs. 2 large bergs, several growlers. 2 large and 1 small bergs. Small berg. Growler. 49 Table of ice and other obstructions, 1929 — Continued Date May 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1087 1088 1089 1090 1091 1092 1093 1094 1095 Reported by- California. do do do do Andania... Cameronia. Andania. do... do... do... do... do... do... do... do... do... do... do... do... do... ....do... do... do... Laurentic. .do. .do_ .do- Arabic. Minnedosa. do Andania do_ Cape Race Station. Andania Arabic. Hardenberg. Sonda Minnedosa. do do do do ....do ....do .do. do. Arabic. do. do. do. Villaperosa. .do. Minnedosa Cape Race Station. do. Ice patrol do.. do... do.... Position Lati- Longi- tude tude north west 48 11 48 37 48 46 48 43 48 58 48 20 [48 21 -I to 148 02 48 35 48 22 48 19 48 20 48 21 48 22 48 19 48 20 48 17 48 18 48 12 48 14 48 06 48 17 48 15 48 09 48 14 f48 26 \ to 148 09 48 05 47 31 47 13 f48 30 \ to (48 20 48 31 48 24 47 30 47 27 (46 28 \ to (46 13 47 16 (48 06 \ to (47 48 (45 05 \ to (45 03 47 00 48 09 48 04 48 00 48 00 47 58 47 54 47 55 147 52 \ to 147 49 47 41 47 46 47 43 47 45 47 40 (45 02 ■1 to 145 34 145 34 { to 145 40 47 04 48 31 48 24 43 04 43 20 43 17 42 53 47 29 47 31 47 08 46 45 46 31 48 57 48 49 to 49 09 48 59 49 16 49 16 49 17 49 20 49 21 49 20 49 36 t 49 35 49 43 49 39 49 43 48 36 49 44 49 46 49 45 49 56 49 00 to 49 33 49 07 51 20 51 44 46 04 to 46 50 46 29 46 50 51 19 51 25 47 05 to 47 53 51 37 47 46 to 48 48 49 13 to 48 25 46 34 47 44 47 56 48 08 48 19 48 27 48 27 48 31 48 42 to 48 52 49 20 48 50 49 00 49 04 , 49 16 ' 47 47 ! to ! 46 50 \ 46 50 I to 46 35 51 48 46 29 46 50 48 57 48 55 49 03 49 07 Nature of ice or obstruction 3 bergs. Berg. 2 bergs. Very large berg. Berg and many growlers. Growler, same as 1035. ■21 bergs and a number of growlers. Growler. Do. Do. Large berg. Growlers. Do. Berg. Large berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. 7 bergs and numerous growlers. Large berg. Do. Do. ►5 bergs and several growlers. 2 bergs and several growlers. Small berg. Large berg. Berg. 10 large, 3 small bergs. Berg. 10 bergs and 2 growlers. 5 bergs. Small berg. Growler. Small berg and piece. Growler. 4 growlers. Growler. 2 small bergs. Growler and 2 pieces. ■2 large and 3 medium bergs and 1 growler. Berg. Large low berg. Berg. Berg and growler. Growler. 13 large bergs. ^3 small bergs. Berg. 2 bergs, 4 growlers, and several pieces. Small berg. Large berg. Do. Do. Do. 50 Table of ice and other obstructions, 1929 — Continued Date May 31 No. 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 Reported by- Ice patrol. Trevaljan. do... do.-. do.. America. Carmia.. do... America. Fluorspar. . Beaverbrae. Ice patrol.. - do do Montcalm.. do. do do. do. do do .do. do.... Ice patroL Beaverbrae. Ice patrol. American Shipper. Cape Race Station. Beaverbrae. do do do Esonia do Valfiorota.. ...-do ....do. Korsholm. Concordia. ....do ....do ...-do Korsholm. Lati- tude north Longi- tude west Beaverbrae Cape Race Station. ....do do do do Bird City. Athenia Concordia. do do do Ascania do do Ranja 43 05 f46 03 \ to 146 17 46 12 46 12 46 18 40 34 48 25 47 47 40 55 41 22 48 17 42 55 42 52 42 48 47 12 47 14 47 18 47 20 47 21 47 22 47 23 [47 22 •I to (47 40 47 26 43 06 f47 46 { to 147 38 42 40 40 43 (47 15 \ to (46 54 47 30 47 28 47 25 47 28 47 43 47 46 43 46 43 42 43 41 (47 55 \ to [47 45 46 45 46 47 46 52 46 55 47 14 (47 01 \ to (47 06 46 45 (47 01 •I to (47 06 46 43 46 41 46 44 49 34 47 24 47 20 47 25 47 42 47 39 47 20 47 16 47 27 40 37 49 29 47 50 to 46 25 46 47 46 23 45 08 55 47 49 30 50 55 50 37 48 23 46 30 49 26 49 11 49 17 49 20 49 15 49 00 48 52 48 42 48 40 48 28 48 39 to 47 16 48 30 49 08 48 16 to 48 46 49 25 56 48 51 15 to 51 40 48 57 49 00 49 17 49 20 51 05 50 59 48 10 48 12 48 17 50 20 to 50 50 52 13 52 07 52 03 51 35 51 45 50 10 to 49 52 52 15 50 10 to 49 52 52 27 52 33 52 38 48 08 51 00 51 17 50 55 50 02 50 15 50 00 49 50 49 50 56 05 Nature of ice or obstruction Large low berg. i'19 bergs and several growlers. Berg and many growlers. 2 bergs. Berg. Large tree covered with marine growth. Berg. Do. Tall white cage lattice top buoy sur mounted by black square top; lettered A, B, E, L, on side; lower part of buoy covered with marine growth. Log about 20 feet long and 2 feet diameter. Large berg and several growlers. Large berg, same as 1096. Large berg, same as 1092. Large berg, same as 1095. Low-lying berg. Small-piece ice. Growler. Berg. Growler. Small-piece ice. ' Berg. I j-4 bergs, 2 growlers, and numerous pieces. Extremely low-lying berg and low-lying ice. Large berg, same as 1094. 9 bergs and numerous pieces, and soft pack. Large berg. Spar projecting 5 feet apparently attached to submerged wreckage. 2 large and 2 small bergs and several growlers. Low flat berg and small pieces. 3 growlers. Berg. Do. Small growlers. Do. Large berg. Berg. Berg, 2 small bergs, and several pieces. 4 bergs and several growlers. Small berg. Do. Do. Do. Berg. 5 bergs. Berg, same as 1134. 5 bergs, same as 1139. Berg. Growler. Berg. Large berg. Growler. Berg. Small berg. Large berg. Berg. Large berg. Berg and growlers. Large berg. Spar floating upright apparently attached to submerged wreckage. 51 Table of ice and other obstructions, 1929 — Continued Date No. Reported by — Position Lati- tude north Longi- tude west Nature of ice or obstruction Jime 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 Pennsylvania. Teucer Bird City. Athenia... do do do do do do do do do Parklaan.. Bird City- Ascania do Etna do do Blair Gourie Cape Race Station. do do do do do Caledonia do- Ice patrol do do United States do Caledonia do do do do do. do Naples Maru Regina Koeln Caledonia do. Koeln Naples Maru do Cape Race Station. do do--.- do.... do.... do.... do.-.. do..-- do.... do.... do.... do.... do.... do.... do.... do.... Koeln Ice patrol. do._.. do.... do.... Regina... do..-. 40 15 40 28 48 15 47 24 47 33 47 41 47 36 47 37 47 42 47 44 47 43 47 47 47 52 42 54 47 50 47 40 47 38 44 43 44 40 44 30 42 47 46 08 46 09 47 40 47 38 47 32 47 25 46 42 47 04 42 50 42 43 42 33 42 26 42 28 47 14 43 05 47 17 47 48 47 47 47 44 47 44 43 10 43 07 47 46 (47 17 { to 147 44 48 16 47 54 47 50 47 49 48 32 42 29 42 36 42 42 42 26 48 19 48 40 43 37 50 15 51 00 50 41 50 29 50 29 50 14 50 14 50 08 50 05 49 53 49 48 51 10 51 06 48 37 48 12 47 31 47 53 48 44 49 00 48 00 47 55 50 18 50 24 50 32 50 30 51 49 51 33 49 04 49 00 49 48 49 45 50 02 51 20 50 57 50 43 50 40 50 29 50 20 50 08 49 10 50 44 50 48 49 50 49 42 50 41 52 08 52 17 49 42 50 44 to 49 40 49 31 50 17 50 25 50 27 50 32 50 39 51 50 51 01 51 09 51 36 51 58 45 44 45 48 46 35 49 09 50 19 50 07 50 23 49 53 48 03 47 42 Spar 10 feet long 3 feet diameter dangerotis to navigation. Red iron cylinder about 40 feet long and 6 feet high. 1 large and 1 small berg. Growler, same as 1146. 2 bergs. Growler. Berg. Do. 2 growlers. 1 berg. Berg. 3 bergs. Berg. Large berg. 2 large bergs, 1 growler. Large berg. 24 bergs and growlers scattered north and south of track. Berg and growler. Do. Berg and growler. Berg. Do. Large low-lying berg. Berg and growlers. Do. Do. Do. Small berg and growler. Berg and numerous small pieces. Large berg. Do. Large berg and growlers. Large berg, same as 1186. Large berg. Do. Growler. 2 bergs. Very large berg. Do. 2 large bergs. Berg and growlers. 3 large bergs. Several bergs. Several small bergs. Large berg. Do. Several bergs. Numerous growlers. Large berg and growlers. Two large bergs. A number of bergs on each side of track. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Growlers. Large berg. Do. 2 small bergs. Berg and growlers, same as 1188. Berg. Do. Large berg and growlers, same^as 1186. Large berg. Small berg. 52 Table of ice and other obstructions, 1929 — Continued Date No. June 5 1227 5 1228 5 1229 6 1230 6 1231 6 1232 6 1233 6 1234 6 1235 6 1236 6 1237 6 1238 6 1239 6 1240 6 1241 6 1242 6 1243 6 1244 6 1245 6 1246 6 1247 6 1248 6 1249 6 1250 6 1251 6 1252 6 1253 6 1254 6 1255 6 1256 6 1257 6 1258 6 1259 6 1260 6 1261 6 1262 6 1263 6 1264 6 1265 6 1266 6 1267 6 1268 6 1269 6 1270 6 1271 6 1272 6 1273 6 1274 6 1275 6 1276 6 1277 6 1278 6 1279 6 1280 6 1281 6 1282 6 1283 7 1284 Reported by— Position Lati- Longi- tude tude north west o / 0 / f48 24 48 45 •1 to to (48 02 49 40 48 14 49 10 48 05 49 32 47 49 49 43 47 46 49 51 47 34 50 06 47 29 50 12 47 40 50 20 47 30 49 25 47 09 50 42 46 55 51 32 46 51 51 49 46 53 52 18 46 44 52 27 48 07 49 04 48 07 49 00 [47 28 49 07 \ to to 147 11 50 37 47 25 51 07 45 57 43 25 44 55 46 57 42 59 51 16 43 00 51 00 49 08 47 10 47 07 50 38 48 00 50 22 48 02 50 33 47 51 50 51 [47 49 50 55 ■1 to to 147 19 51 50 48 26 48 44 \ to to (47 25 51 07 46 39 52 48 47 32 50 26 47 29 50 24 47 16 51 02 47 39 49 14 47 42 49 26 47 47 49 34 47 29 49 24 47 35 49 40 47 29 49 39 47 32 49 45 44 53 47 35 44 48 47 46 42 58 52 30 [47 02 50 56 { to to [47 29 49 55 40 05 44 16 42 26 49 43 46 04 44 00 48 24 48 46 48 14 48 59 46 57 51 46 46 59 52 08 46 48 52 08 46 44 52 15 47 00 52 32 [48 14 48 59 \ to to [47 56 50 30 40 29 48 17 42 42 51 15 47 40 50 40 \ to to 47 30 50 45 Nature of ice or obstruction Doric. do do.... Melita do do... do do Empress of Australia. Montrose do do do do Melita do Montrose. Doric Polonia do Koranton. do Letitia Empress of Australia. Cairnross. do.... do_..- Cape Race Station. .do. do.. Melita... do... do... Alaunia. do.. do... do... do... do... do_. Polonia.. do... Mincio.. .\launia-. Einarjarl- Ice patrol Bergensfjord. Letitia -...do Melita ....do .-..do ...-do ....do.. Letitia President Wilson. St. Amos Fafalios. Letitia ►Several growlers. Berg. Low-lying berg. Berg. Growlers. Berg. Do. Do. 18 bergs, 5 growlers, numerous pieces north and south of track. Growler. Do. 2 bergs. Berg. Do. Do. Growlers. 7 bergs, 1 growler on or near track. Very large low berg. Berg. Do. Do. Hogshead painted black with white band carrying mast surmounted with lantern. Berg. 7 bergs, 4 growlers, and numerous pieces, one low-lying dangerous berg. Berg. Do. Berg and growlers. 16 bergs and several growlers on both sides of track. 14 bergs and many growlers on both sides of track. Large berg. Berg. Do. Do. Growlers. Berg. Bergs and growlers. Do. Do. Do. Do. Berg. 3 growlers. Large berg. !20 bergs and many growlers north and I south of track. Cylindrical iron tank 18 feet long SH feet diameter apparently long time in water, no visible marks, no color. Berg and growlers, same as 1186. Berg. Large berg. Do. Berg. Do. Do. Do. Do. 12 bergs with growlers and small pieces; ' westernmost berg 250 feet high. Large, round smooth spar 25 feet long 1 foot diameter. Berg. 9 bergs, several growlers, and several pieces. 53 Table of ice and other obstructions, 1929 — Continued Date Reported by— Position iRi- Lati- Loi tude tude north west o / o , 48 35 46 52 42 11 43 26 41 38 48 56 47 03 51 05 (46 35 52 15 \ to to 1 |48 00 48 40 44 54 47 02 44 45 47 40 47 12 51 06 47 04 51 11 42 24 49 40 46 58 51 34 47 33 47 31 47 24 51 16 47 21 50 22 47 26 50 32 [47 37 49 43 { to to 1 147 24 50 16 44 35 48 47 42 29 50 27 46 27 40 55 46 56 50 39 47 02 51 14 46 49 51 30 46 37 51 58 46 40 52 22 46 40 52 10 46 03 40 55 48 57 50 05 45 42 48 15 45 52 48 09 46 54 51 36 46 40 52 36 47 28 50 12 47 36 51 59 48 03 51 00 47 54 50 33 48 00 50 35 48 08 50 44 47 09 50 38 47 18 50 11 47 22 50 02 47 25 50 03 47 17 49 59 47 16 49 56 47 18 49 53 f46 54 51 33 \ to to 1 47 37 48 53 47 10 51 48 to to 1 48 04 50 36 42 52 48 41 42 46 48 52 42 30 49 43 46 35 45 29 46 12 45 43 46 18 46 03 46 16 46 11 48 18 50 23 48 24 50 30 (48 24 50 20 to 1,0 1 [48 22 49 46 48 28 49 50 48 40 49 00 48 22 49 01 48 08 47 14 42 32 49 48 45 45 47 28 45 39 45 25 42 43 50 05 46 39 52 46 Nature of ice or obstruction June 7 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 Scythia Eupatoria. St. Amos Fafalios- Beaverbrae Cape Race Station. Oxelosund- .-..do Megantic ....do Bergensfjord. Megantic Scythia ....do do ....do .do. Oxelosund... Bergensfjord. Pipiriki Cynthia do do do do Scythia Hatteras Cape Race Station. Lord Kelvin do Montclare... Cape Race Station. do. do. do. do. do. do. Montclare. do. do. do. do. do. do. TjTifjord do do.... Cape Race Station. do do do do do -do. do do do Montclare Ice patrol Highcliffe do Ice patrol Cape Race Station- Small berg. Piece of wreck 25 meters long, 1 to 2 meters high. Very large berg. 3 growlers. 40 bergs and many growlers north and south of track. Berg. 3 bergs. Low-lying berg. Large berg. Large berg same as 1186. 1 large berg, 1 low berg, and 4 growlers. Growlers. Small bergs. Do. Large berg. Several small pieces. Several bergs. Berg. Small berg. Small flat berg. Large berg. Small berg. Flat berg. Large berg. Small berg. Berg 200 feet long, 50 feet high, same as 1298. Berg. 2 bergs. Berg. Small flat berg. Berg drifting southwest. Berg. 4 bergs. 4 bergs and 1 large berg. Large berg. Do. Do. Berg. Do. Growler. Berg. Do. Do. Do. 28 bergs and numerous growlers north and south of track. 50 bergs and numerous growlers along track. 8 bergs. Berg. Large berg, same as 1186. Large berg and growler. Large berg. Do, Do. Berg. Large berg. Growlers. Large berg. Do. 4 small bergs and 2 small growlers. Large berg. Berg ami growler?, same as 1186. Large berg. Growlers and several pieces. Berg. Large flat low berg. 54 Table of ice and other obstructions, 1929 — Continued No. Reported by- Position Date Lati- tude north Longi- tude we.st Nature of ice or obstruction June 10 10 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 Cape Race Station ... do O 1 [46 37 to [48 16 48 24 48 17 47 47 47 45 47 42 47 39 47 18 47 03 43 02 43 04 52 33 to 48 39 49 00 49 13 50 12 50 26 60 32 50 38 51 25 47 51 50 22 50 on >8 bergs. Small berg. 10 do Do. 10 do Berg. 10 do Four bergs. 10 do Berg and 2 growlers. 10 do . . Berg and several growlers. 10 . . do.... 2 bergs. 10 do . - 3 small bergs and 5 growlers. 10 Ice patrol . . . 2 bergs. 10 . do Berg. 11 Nieu Amsterdam . . 48 15 46 12 1 Growler. 11 do 48 03 47 47 42 19 47 24 47 20 47 07 47 37 46 37 46 49 46 49 46 57 47 14 47 33 47 30 47 35 47 40 47 57 48 00 48 18 48 13 48 33 46 38 46 54 42 27 42 42 42 37 43 05 to 42 50 42 39 147 43 \ to 47 52 48 01 47 57 47 51 47 55 47 58 48 02 48 16 48 06 48 11 46 38 46 54 48 19 48 14 46 49 46 54 46 39 47 40 47 53 47 51 42 48 42 42 1 42 48 48 10 48 01 48 24 48 20 48 10 39 18 42 11 46 45 47 10 49 40 43 51 49 11 49 46 51 02 52 33 52 15 52 11 52 04 51 03 50 33 50 09 50 10 49 50 49 34 49 10 48 30 48 28 48 25 52 29 51 26 49 52 50 03 50 22 50 40 to 49 45 49 53 50 58 to 50 41 50 41 50 35 50 18 50 17 50 20 50 21 50 15 50 15 49 53 52 29 51 26 48 27 48 17 52 25 51 12 52 22 52 31 52 32 52 31 49 24 49 40 48 51 52 35 52 47 52 40 52 35 52 50 50 29 43 26 Do. 11 ... do Do. 11 Kungsholm . .. Small berg. 11 Nieu Amsterdam. Do. 11 .. . do.... Growler. 11 ..__ do Berg. 11 Do. 11 Large berg. 11 do Growler. 11 do 3 growlers. 11 .... do Berg. 11 do Do. 11 do 3 bergs. 11 do Berg. 11 do 2 bergs. 11 do 2 bergs and growlers. 11 .... do Berg. 11 do Growler. 11 do 2 growlers. 11 do Do. 11 do Large berg. 11 Laurentic Large flat berg. 11 do -. Small berg. 11 Ice patrol Berg, same as 1186. 11 .do Large berg. 11 do Berg, same as 1343. 11 .. .do [7 bergs. 11 do Several growlers. 11 U bergs and 4 growlers. 11 do 1 11 large bergs. 11 do . Growler. 11 do.. Berg. 11 .do - . Do. 11 do Growler. 11 do Large berg. 11 .do Do. 11 do Do 11 do Do. 11 Laurentic Do. 11 do Small berg. 11 do Growlers. 11 do . Growler and small berg. 11 Cape Race Station Growlers. 11 Nieu Amsterdam Growler. 11 do Large flat berg. 11 C F Liljevalch Berg. 11 do Do. 11 11 11 11 11 do Ice patrol do do C F Liljevalch Growler. Large berg. Growler. Berg. Small berg. 11 do 2 bergs. 11 do Small berg. 11 .. .do Large berg. 11 do Several bergs and growlers along shore. 11 Dalblair Heavy spar floatmg vertically, projecting 6 11 West Kyska feet. Floating oil drum on end, partly sub- merged. 55 Table of ice and other obstructions, 1929 — Continued Date June 12 12 12 12 12 12 12 12 12 12 12 No. 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 13 1446 13 1447 13 1448 13 1449 13 1450 12 1451 13 1452 13 1453 13 1454 13 1455 13 1456 13 1457 13 1458 1459 1460 1461 1462 1463 1464 1465 1466 14ei7 1468 14(.9 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 Reported by- Villedvs do do Transylvania. ....do Oripsholm Transvlvania. .-._do Montroyal do Position Lati- I Longi- tude I tude north west Cape Race Station. -do- -do. Mount Royal do Transvlvania. do" do Mount Roval do.. -_:__. do Montroyal do Cameronia... 46 45 46 50 46 44 48 00 47 54 45 43 47 33 47 14 48 07 47 55 f47 58 { to (48 03 f47 57 \ to 148 02 48 27 |47 45 { to 148 10 47 43 47 35 46 .59 46 59 46 45 47 28 47 31 47 22 47 27 47 31 48 05 49 03 Crefeld __ \ to 148 33 Zonnewvk 42 52 ....do 43 01 do 43 06 ....do 1 43 15 Oripsholm I 42 31 Cape Race Station.. | 48 40 Urania i 47 do.-.. ....do...- Pennland. Ice patrol. ....do-_-_ Crefeld ... .do. Ice patrol.. do ....do Aurania ....do do. -...do Metagama Pennland Montroyal Beaverbrae do do.. do do do do_ do Metagama do do... Empress of Australia. Frode Deerlodge Cape Race Station do... do do. 48 32 42 57 42 54 47 38 |'48 30 \ to [47 38 42 55 42 53 42 58 47 .52 47 44 47 43 47 .38 48 26 48 08 47 27 47 26 48 06 48 02 47 55 46 46 47 38 40 53 47 18 48 36 48 10 48 05 47 10 47 20 47 20 49 49 50 01 42 20 .50 45 51 59 47 32 48 04 50 .53 to 50 44 50 35 to 50 21 48 58 52 45 to 51 01 48 41 49 17 52 00 52 14 52 40 49 33 49 34 50 16 48 38 49 41 49 45 50 48 to 51 16 51 32 51 56 51 56 52 12 49 33 45 30 48 12 i^ 12 48 08 45 28 49 16 49 16 51 48 51 16 to 51 48 49 40 49 50 49 41 48 42 48 58 49 00 49 19 48 17 47 17 51 04 49 12 48 54 48 42 48 42 48 42 48 32 48 30 48 29 49 04 49 11 49 35 52 27 44 22 47 10 48 54 49 43 50 18 50 30 Nature of ice or obstruction Large and 3 small bergs. Large berg. Do. Growler. Several growlers. Partly submerged wreckage. Berg. 3 small bergs. Growler. Berg. ■11 bergs. 3 large bergs and 2 growlers. Small berg, 40 bergs, Berg. Large berg and 2 growlers. Small berg and growler. Do. Large berg and 7 growlers. Growler. Large berg. Berg and several growlers. Berg. 2 bergs. Several pieces of ice. Great number of large and small bergs; many bergs still ahead. Small berg. Berg. Large berg. 2 bergs. Berg. Long, low dangerous berg 4 feet high. Low berg. Growler. Do. Low-lying berg. Berg and growlers. Small berg. 3 large bergs. Many bergs. Large berg and growlers. Do. Berg. Berg and growler. Growler. Small growler. Large berg. Low berg. Growler and several pieces. Large berg. Berg. Do. Do. Do. Do. Do. Do. Do. Large berg. Do. Small berg. Large low berg. Several heavy growlers. White cage top buoy. Berg. Do. Large berg. Several bergs in vicinity. 56 Table of ice and other obstructions, 1929 — Continued No. Reported by- Position Nature of ice or obstruction Date Lati- tude north Longi- tude west June 13 13 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1.521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1.538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 Cape Race Station do 47 53 47 30 47 29 48 45 48 49 48 30 48 39 47 56 47 53 47 44 47 38 47 56 47 30 47 29 48 45 48 22 48 20 48 13 48 04 48 01 48 38 48 24 48 16 48 10 48 03 48 40 48 29 48 20 48 17 48 09 48 02 47 56 47 54 48 08 47 55 47 42 47 36 47 33 46 56 46 55 46 55 46 51 (46 46 Us 00 48 38 48 00 47 54 48 00 47 47 48 26 48 06 48 02 47 55 47 56 47 56 47 53 47 44 47 38 46 16 47 33 47 55 45 00 47 20 47 47 46 52 47 58 47 49 47 36 47 31 47 27 47 25 47 25 47 15 47 11 40 09 40 09 50 45 49 39 49 44 50 55 50 31 50 21 50 38 49 40 49 42 50 28 50 47 49 40 49 39 49 44 50 58 51 36 51 45 51 51 51 48 51 58 51 41 51 45 51 40 51 59 51 48 51 21 51 42 51 45 51 58 51 56 51 48 52 11 52 18 47 17 48 13 48 40 48 31 48 43 51 54 51 56 51 57 52 13 48 50 to 52 27 48 00 48 12 48 52 49 16 49 31 48 17 49 04 49 11 49 35 49 40 49 42 49 42 50 28 50 47 47 50 48 S6 46 55 48 35 49 37 47 32 51 07 46 56 47 42 48 35 48 53 49 10 49 08 49 37 49 52 49 56 51 34 51 08 Small berg. ^%o. Do. Do. Do. Do. Do. Do. Do. Large low -lying berg. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Growler and small berg. Small berg. Small flat berg. Berg. Do. Large berg. Do.' Large long berg. >35 bergs and growlers. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Large and 2 small bergs. Berg. Do. 2 large and 2 small bergs. Berg. Do. Do. Small berg, same as 1547. Small berg. Berg. Small berg. Do. Do. . Berg. Large berg and 1 growler. Large berg. Spar 40 feet long covered with growth. Spar 50 feet long 2 feet diameter with marine growth. 13 do 13 ..do 13 do 13 do. 13 . do 13 Metagama 13 do 13 do 13 .do 13 ..do 13 Aurania 13 do 13 .\ntonia.. 13 do 13 do.. _ 13 do . . 13 do 13 do 13 do 13 do 13 ..do -. 13 do 13 do . - 13 do -. 13 do 13 do 13 .... do 13 do 13 do 13 do 13 do.-_ 13 Pennland 13 do 13 do 13 .. do 13 do 14 Metagama . .. 14 ...do 14 do 14 do 13 14 Cape Race Station do... 14 do 14 do 14 do 14 do 14 .... do 14 do 14 do . . 14 do -.-- 14 do . 14 do 14 do . 14 do 14 14 Frode 14 14 Empress of Australia do 14 14 14 Cape Race Station do 14 .. do 14 14 Beaverford . . do 14 do 14 . do 14 do li ... do 14 do 14 . . do 14 do 14 Toruguero manna 14 do -. covered Oi Table of ice and other obstructions, 1929 — Continued Date No. June' 14 14 14 14 14 Reported by- 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 15 ; 1579 1580 1581 i582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1590 1597 1598 1599 1000 1601 1002 100" 1004 1005 1006 1607 1008 lOOfJ IGIO 1611 1012 1613 1614 1615 1616 1617 1618 1619 1020 1621 1622 1623 1624 1625 1626 Pennland. do Nevisian.. Mansepool Cape Race Station. do 47 02 46 50 37 28 42 48 f47 27 \ to 147 50 147 25 \ to [47 00 48 10 48 07 48 00 47 54 47 51 .do i 47 39 47 40 43 45 43 17 48 09 f47 56 \ to (47 37 47 55 41 22 .do. .do. .do. -do. .do. Position Lati- tude north .do. do. Hesperos Melmore Head. do.. do Toruguero. City of Fairbury 45 05 do 44 55 do 44 4; do 44 41 Valleluce , 43 5.3 Ice patrol l 42 17 Hesperos I 43 06 do --- I 43 06 Manchester Hero [48 10 [47 14 Montrose \{ to [47 30 Tortuguero 41 40 Manchester Hero '47 50 f43 50 Valleluce \ to 44 00 47 34 45 29 45 27 45 20 47 46 47 18 47 11 48 00 47 45 47 44 47 56 47 49 47 42 48 06 48 12 48 11 47 14 47 18 46 58 47 10 47 15 47 27 46 34 48 02 48 18 47 00 47 18 47 52 to 48 02 Ice patrol 42 55 .do i 42 46 .do ..1 42 46 .do I 42 38 Melmore Head Amersham _ do do Ovre Melmore Head do City of Canberra... Montrose do do do City of Canberra.. Cape Race Station. do do Megantic do Cape Race Station. do do do do do.... do Melita do Nova Scotia. Longi- tude west 52 07 52 27 67 26 50 05 49 25 to 48 20 49 25 to 51 13 47 12 47 25 48 0. 48 53 49 04 48 58 49 06 51 20 48 10 48 39 48 50 to 48 47 49 09 45 02 47 16 47 44 48 25 48 36 48 14 49 23 49 04 49 15 49 03 49 38 to 48 22 44 16 49 50 48 12 to 48 35 49 57 49 20 47 22 45 17 41 17 50 55 50 51 47 18 48 08 48 05 47 19 47 02 48 27 49 09 49 52 .'■.0 20 49 02 48 41 51 10 50 20 49 40 49 40 52 39 51 56 51 29 51 20 50 43 51 35 to 51 00 49 40 51 35 52 19 52 02 Nature of ice or obstruction Small berg. Large berg. Schooner Cutty Sark abandoned on fire rudder gone, salt cargo, leaking badly. Berg and growler. •18 bergs and numerous growlers. ■6 bergs. Growlers. Small berg. Berg. Large berg and growlers. Berg. Do. Do. Do. Do. Large growler. 4 large and 1 small berg and 1 growler. 2 large bergs, 2 large growlers. Large rusty iron barrel, shape resembling buoy. Berg. Large berg. Several small bergs and growlers. Small berg. 2 large bergs. Berg. Do. Large berg and several growlers. Berg. J-12 bergs and numerous growlers. Large rusty iron barrel resembling a buoy. 2 large bergs and several growlers. 1 ^8 large bergs. 2 bergs and 1 growler. Small berg. Large berg. Growler. Berg. Growler. Large herg. Berg 100 feet high 600 feet long. Very large berg. Large berg. Berg. Growler. Large berg. Do. Do. Berg. Small growler. Small growler and several pieces. Large berg. Do. 2 bergs. Very large berg and several growlers. Several growlers. Large berg. Do. Berg. Large herg. 6 bergs and 1 growler. Growler. 2 large bergs. Small berg. Berg. 58 Table of ice and other obstructions, 1929 — Continued Date No. Reported by- Position Lati- tude north Longi- tude west Nature of ice or obstruction June 18 18 17 17 18 18 18 18 18 18 18 19 18 18 18 18 18 18 18 18 18 18 18 18 18 18 19 19 19 19 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 1627 1628 1629 1630 1631 1632 1633 1634 163.5 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 Dutchess of Bedford - ....do Cape Race Station... ....do.. ....do_ Iserhol.n Dutchess of Bedford. ....do .-..do Izarco Calgaric Ice patrol Cape Race Station... do do do. do do.. do do do.. do do do do-. Concordia Letitia... Ice patrol do do Cape Race Station... do '. Collamer. Levenbridge Ice patrol Cape Race Station... do do do-... do do do.... do do do do do do.... do do do do do do do do do. do do do .do- .do... .do... .do... -do... .do... .do... .do..- .do... .do... .do... .do... .do... .do.-. -do.-. -do-.. 47 16 47 20 47 17 47 14 48 00 42 10 47 20 47 29 47 32 57 10 47 14 42 37 47 31 47 27 47 43 47438 47 40 47 10 47 46 47 36 47 24 48 15 47 25 47 43 47 13 43 16 48 14 42 50 42 53 43 00 47 28 47 38 42 13 45 25 42 23 47 18 47 24 47 20 46 34 47 00 47 32 47 38 47 41 47 34 47 44 47 54 47 40 47 58 47 49 47 44 47 38 47 49 47 45 47 43 47 40 47 35 47 12 47 00 46 33 48 14 (47 52 \ to (47 49 47 44 47 42 47 39 47 31 47 02 47 14 47 26 47 24 47 25 47 31 47 02 46 32 47 55 48 08 48 25 49 38 48 55 52 12 50 44 51 12 48 12 48 34 48 25 48 12 44 28 50 44 50 56 49 45 48 34 50 44 48 20 48 09 52 03 50 37 50 53 51 45 52 10 49 35 49 45 49 54 51 10 48 11 51 30 52 13 52 40 51 25 48 22 48 23 49 27 48 33 51 52 51 55 51 32 52 35 49 29 49 25 49 06 48 55 48 55 48 45 48 52 48 40 48 38 48 34 48 38 48 47 48 55 49 01 49 03 49 27 49 29 50 02 51 00 52 29 47 41 48 49 to 49 08 49 14 49 27 49 42 52 46 52 46 52 44 52 39 52 41 52 32 52 35 50 40 52 25 50 45 50 29 49 58 Berg. Do. Berg and 2 growlers. Berg. 2 bergs. Large berg. Berg. Berg and 2 growlers. Berg. Red conical buoy carrying nunihei 2. Large berg. Berg. Do. 2 bergs. Berg. Do. Do. Large berg. Berg. |Do. Do. Growlers. Berg and growlers. Large berg. Do. Berg. Large berg. 2 bergs. Berg. Berg and growler. 2 bergs. Berg. Do. Growler. Berg, same asll659. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. 2 bergs. Berg. Do. Do. Do. Growlers. Do. Do. Many beres and growlers. 3 bergs. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Large berg. Very large flat berg. Berg. Do. Do. 59 Table of ice and other obstructions, 1929 — Continued Date No. June 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 18 18 18 20 20 20 20 20 20 20 20 20 20 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 Reported by — 1737 1738 ! 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 Cape Race Station. ...-do Ausonia ....do. ....do.. Doric Cape Race Station.. do do do do do do do do do.... -do- -do. -do. Doric Cairnross.. do do Cragpool . . do Caledonia. .do. .do. .do. Bothwell. do.-. 1736 Montcalm. Cape Race Station. do-.- do.... do.... do do-... do-... do-..- do-.. Valflorita. do..... Lake Gorin do do Cape Race Station. Carinthia Ice patrol Athenia do do — do do do -.. do do do do 47 45 47 26 47 53 47 42 47 56 47 10 48 10 48 10 48 20 47 67 47 51 47 31 47 49 47 44 47 25 46 40 (47 23 \ to [47 58 47 53 47 49 to 48 20 48 31 47 20 47 28 48 15 45 24 45 19 47 35 47 13 46 34 46 41 .do I 46 34 [47 48 Montcalm \ to 47 28 47 48 47 59 47 28 to 47 12 47 56 to 47 17 47 37 47 53 Position Lati- tude north 1764 I Brighton - 1765 1766 New York.. Lake Gorin. 47 56 47 42 47 30 47 15 46 30 46 34 43 08 42 55 43 14 43 09 43 03 46 32 41 13 42 42 48 12 48 05 48 15 47 45 47 59 48 07 47 34 46 53 46 45 46 43 (46 00 \ to (46 00 41 22 43 08 Longi- tude west 51 05 52 37 47 36 48 46 47 51 51 10 49 24 49 27 49 30 50 23 50 18 50 39 50 44 50 51 51 35 52 40 52 35 to 52 43 49 11 52 47 to 50 45 48 04 51 45 51 35 50 10 49 23 48 58 49 22 50 35 52 21 52 47 52 43 48 25 to 49 20 48 05 47 31 49 20 to 51 00 50 23 to 51 52 50 42 47 25 47 51 48 46 49 28 50 38 52 20 52 33 52 47 51 45 48 36 48 42 49 06 52 48 49 69 48 06 48 51 49 04 49 10 49 10 49 26 49 38 50 34 52 42 52 42 52 43 47 44 to 48 00 49 67 50 27 Nature of ice or obstruction 7 bergs in vicinity. Several bergs. Berg. Do. Small berg. Large berg. Do. Large growler. Large berg. Berg. Do. Do. Do. Do. Do. Do. 14 bergs. Large berg. 14 bergs, many growlers. Large growler. Berg. 2 bergs. Growlers. Small berg and growler. Berg and growler. Large berg and several growlers extending 5 miles north. Large berg. Large fiat top berg, 2 large bergs. Small berg. 14 bergs and many growlers. Berg. Do. \b bergs. ■14 bergs north and south of track. Very large berg. Large berg. Small berg. Berg. Large berg. Small berg. Large berg. Small berg. Large berg. 1 small and 2 large bergs to north, 1 berg to south. Berg. Do. Berg and several growlers. Large berg. Large red conical buoy unlit. Berg, same as 1659. Growler. Berg. Do. Do. Do. Do. Do. Do. Do. Do. 3 low bergs. Red conical buoy marked "2AFP." Berg. 60 Table of ice and other obstructions, 1929 — Continued Date No. Reported by — Position Lati- Longi- tude tude north west 0 , o / 43 02 50 31 43 08 50 42 42 42 49 00 42 45 49 11 42 41 49 56 42 49 49 44 43 16 51 12 43 21 51 20 44 33 48 55 41 30 50 25 43 04 51 25 43 17 51 36 43 05 51 48 42 33 49 08 4fi 37 52 41 46 39 52 38 46 45 52 39 46 35 52 19 47 06 51 45 47 29 50 13 45 22 48 31 45 16 47 55 42 42 49 18 42 40 49 54 42 35 50 02 42 35 50 10 42 38 49 08 48 01 49 24 47 57 49 03 47 50 48 58 47 57 48 32 42 20 49 23 43 15 49 20 45 26 47 56 4fi 48 44 01 4fi 55 44 07 48 16 51 30 48 40 50 29 (48 00 47 50 \ to to |47 30 50 00 46 35 52 24 46 41 52 42 42 37 50 12 42 46 50 39 42 51 50 38 43 06 50 21 43 05 50 28 43 03 50 25 43 11 50 36 46 32 52 45 43 31 51 39 42 25 50 20 43 24 51 09 43 25 51 18 43 25 51 22 43 29 51 31 43 29 51 42 42 37 50 51 43 05 50 35 43 13 51 14 44 10 48 48 42 20 49 20 42 24 49 05 42 59 51 46 42 53 51 57 43 03 52 10 42 44 52 09 42 27 51 42 42 53 51 36 42 33 52 11 42 55 51 24 42 48 48 00 43 19 51 38 Nature of ice or obstruction June 21 21 21 21 21 21 21 21 21 21 21 21 21 21 21 21 21 21 21 22 22 22 22 22 22 22 22 22 22 22 22 23 23 23 22 22 22 22 22 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 Lake Gorin. do Ice patrol do Valfiorita... do Lake Gorin. do Valnegra Schenectady Lake Gorin ....do .-..do Valfiorita Montroyal do .-..do ....do ....do ....do Lituania ....do Ice patrol ....do ....do ....do .-..do Montroyal ....do .-..do .-.-do Cold Harbor Coelleda Villedys Wright .-..do Cape Race Station -do. .do. do do Ice patrol do do do do do do Cape Race Station. Quaker City Cold Harbor Ice patrol do do do do Cold Harbor. do Coelleda Quaker City. Waukegan do Ice patrol do do do Cold Harbor. Ice patrol Cold Harbor- Ice patrol McKeesport.. Coelleda 2 bergs. Berg 60 feet high. Berg. Large tabular berg. Large and 2 small bergs. Berg. Do. Do. 2 large bergs and several growlers. Red nun buoy marked "2AFP." Large berg. 3 large bergs, same as 1747. Large berg, same as 1747. Small berg, same as 1779. Large berg and several pieces. Large berg. Small berg. Large berg. Berg. Berg and pieces. Berg. Do. Berg, same as 1780. Small berg, same as 1782. Growler, same as 1781. Berg, same as 1781. Berg, same as 1779. Large berg and pieces. Do. Large berg. Do. Large berg, small berg 4 miles to eastward. Large growler. Big berg. Berg. Small berg. Large berg 150 feet high, with 1 fairly large berg, 2 small bergs, and numerous growlers in vicinity. Large flat Berg 60 feet high. Numerous bergs. Large berg and numerous growlers. Large berg. Berg. Do. Large berg. Do. Berg. Growlers. Large berg. Do. Small berg. Berg with small berg 3 miles north, same as 1818. Large berg. Large high berg. Small berg. Berg. Large flat-topped berg. Berg. Do. Large low growler. Berg. Berg, same as 1808. Do. Large berg. Do. Large low berg. Berg. 3 bergs to northwest 10 to 15 miles, same as 1839-41. Berg. Small berg. Berg. Large berg. Berg. 61 Table of ice and other obstructions, 1929 — Continued No. 850 851 852 853 854 855 856 857 858 859 8fiO 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 884 885 891 897 Reported by— Coelleda do__. do do do do do do do.. do Cape Race Station. do Leviathan Bird City Aurania Beaverford Bird City do Cape Race Station. California do do do do do do do do.... do do..._ do do do do do do ....do..._ Ice patrol do do ....do ....do Ausonia ....do ....do ....do ....do .-..do Bird City Svendal Beaverford ....do .do. Ice patrol.. do California. Aurania... do Beaverford. Cape Corso. do do do Svendal 903 Cape Race Station. ] do.. I do.. i do.. I do.. I do_. 100277—30- Positlon Lati- tude north 43 21 43 18 43 24 43 24 43 06 43 06 43 15 43 05 43 08 43 07 47 00 47 05 41 21 42 38 46 56 47 12 42 00 42 20 47 20 48 18 47 44 47 37 46 36 47 34 47 44 47 24 47 21 47 37 47 30 47 37 47 37 47 27 47 36 47 21 47 22 47 16 47 03 43 02 42 48 42 55 43 04 43 00 47 07 47 17 47 13 47 08 47 06 47 30 42 51 43 30 47 20 47 25 47 26 to 47 35 42 24 42 18 46 55 47 22 47 23 f47 45 \ to (47 38 43 03 43 00 42 57 42 55 43 30 1 47 07 ■. to (47 26 46 44 46 49 47 00 47 10 Longi- tude west 51 44 51 47 51 54 51 50 51 57 52 00 52 02 52 05 52 24 52 40 47 38 48 14 50 20 48 38 51 38 50 32 50 00 49 18 49 37 49 09 50 02 50 07 50 25 50 27 50 37 50 45 50 51 50 52 51 03 51 06 51 08 50 41 50 25 51 30 51 31 51 25 51 53 52 18 52 13 52 03 50 52 50 33 51 15 50 56 50 34 50 21 50 20 50 00 48 25 49 16 49 37 49 03 48 56 to 48 15 50 00 49 50 52 05 49 38 49 35 47 35 to 47 58 52 55 53 03 53 00 52 35 49 16 50 41 to 51 38 51 10 52 14 51 39 51 22 Nature of ice or obstruction Berg. Growler. Berg. Do. Do. Do. Growler and small pieces. Berg. Small berg. Do. 8 bergs within radius of 5 miles. Berg. Buoy marked "2AFP." Berg. Do. Do. Large berg. Large berg and small berg. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Growler. Many growlers. Berg. Do. Do. Berg and growlers. Berg. Do. Do. Do. Do. Do. Very large berg. Small berg. Berg. Growler. Berg. Large berg. 7 large bergs. Small berg. 3 small growlers. fl3 large scattered bergs. Large growler. Small berg. Do. Berg. Growler. 4 scattered bergs. Large berg. Berg. Do. Do. Large berg, same as 1898. '7 bergs and some growlers. 2 small bergs. Growler. Berg. Do. Do. 62 Table of ice and other obstructions, 1929 — Continued Date No. Reported by- Position Lati- tude north Longi- tude west Nature of ice or obstruction June 24 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 27 27 28 27 27 27 27 27 27 27 28 28 28 28 28 28 28 28 28 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 Cape Race Station. Veendam Ausonia do Maria Mediaca Cape Corso Montclare Veendam do do. Transylvania.. do do. Bellhaven Metagama do Cape Race Station.. .do. Transylvania do do. Montclare do do.- Metagama Transylvania Carlsholm. do.-.. -. Cape Race Station. ....do Minnedosa do do do do do Cape Race Station do do.-.. do do do do do do M alaren Cape Race Station Laurentic Empress of Australia. do do do do do Munchen Laurentic do do do do... do do do.. --- - Arabic do.... Svithiod Cape Race Station Arabic Cape Race Station Arabic do do .-..do .-..do .- do Alf 47 33 47 44 47 38 47 35 45 21 42 05 47 53 46 55 46 57 46 33 46 13 46 22 46 34 46 25 46 56 46 58 46 32 [48 04 { to 147 15 46 32 46 53 46 55 47 29 47 25 47 22 47 37 47 22 47 19 47 54 46 43 46 35 47 25 47 25 47 27 47 16 47 21 47 07 48 03 47 54 47 38 47 42 46 46 47 50 47 04 47 00 47 13 44 43 46 43 47 47 47 13 46 52 46 51 46 49 46 34 46 33 41 30 47 52 47 30 47 32 47 31 47 17 47 28 47 19 47 13 48 02 47 44 42 27 46 30 47 32 46 43 47 34 47 25 47 31 47 33 47 31 47 31 46 05 50 26 48 25 48 37 48 27 48 10 49 48 48 42 51 32 51 39 52 11 52 45 52 32 52 27 47 20 51 38 51 32 52 53 49 50 to 51 28 52 16 51 43 51 46 50 05 50 21 50 33 50 00 50 30 51 34 50 37 52 48 52 11 50 21 50 40 50 49 50 53 51 06 51 32 50 34 50 44 50 32 50 42 52 03 51 44 51 35 51 23 50 45 44 18 52 49 49 52 50 40 51 39 51 43 51 50 52 52 52 56 50 25 50 09 50 41 50 47 50 52 50 44 51 04 51 06 51 03 46 50 49 20 49 06 53 00 49 45 52 49 49 47 50 08 50 24 50 26 50 30 50 40 52 47 2 large bergs. Berg. Do. Do. 7 bergs. Large berg. Large berg and many bergy bits. Berg. Do. Do. Do. Do. Do. Large berg. Do. Do. Large flat berg. 8 bergs and some growlers on both sides of track. Large berg. Berg and growlers. Do. Berg Do. Several small pieces. Large berg. Numerous growlers. 1 large berg and 1 small berg. 2 bergs. Berg. Very large berg. Large berg. Do. Do. Berg. Large berg. Small berg. Large berg. 2 bergs. Berg. 2 bergs. Large berg. Berg. Do. Do. I>arge berg. Berg. Do. Do. Do. Growler. Berg. Do. Growler. Berg. Red conical buoy marked "2AFP."' Small berg. Do. Do. Medium berg. I>arge berg. 1 large berg, 1 small berg. Small berg. Large berg. Small berg. Large berg. Small berg. Berg aground. Large berg. 2 bergs drifting south. Growler. Berg. Do. Do. Small berg. Berg. Large berg. 63 Table of ice and other obstructions, 1929 — Continued No. 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 199fi 1907 1998 1S99 2000 2001 2002 2003 20(M 200r, 200r, 2007 2008 2009 2010 2011 2012 2013 2014 2015 201 n 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 202S 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 Reported by ■ Arabic do do... -.- do do.... W. D. Anderson. Santa Aurora Ice patrol-.- Cape Race Station, Nortonian. Ellen .--.do Nortonian --.-do Cape Ra^e Station- Nortonian ....do ..--do ----do Cape Race Station- --..do Montcalm .--.do - ....do do ----do Rdderheim Montcalm Tieupa ViileDys Montcalm.. .- Winnebago- -- --.-do- Cape Race Station. ----do- -..-do- .---do.-. --. .---do - ...-do.- .---do.- --.-do .---do ---.do ...-do Lancastria. Cape Race Station. --.-do- Maroc .--do Cape Race Station, .---do Calgaric- --.-do-- -.-. Cape Race Station- Reliance.. Ice patrol Port Darwin Cape Race Station . ---do -.--do ----do -.- Port Darwin ----do Cape Race Station - ----do ---.do ----do ----do...- Position Lati- tude north .do. Ice patrol, -.-do.... 47 47 47 10 46 53 46 55 46 38 42 32 42 18 42 26 46 44 to 46 34 45 44 46 16 46 18 46 12 46 10 16 49 45 47 45 56 45 57 46 12 46 42 46 34 46 31 46 49 46 32 46 44 46 48 42 08 47 26 44 20 44 20 48 12 45 30 45 30 46 38 47 03 47 04 47 13 47 30 47 21 47 26 47 31 47 50 47 54 47 43 40 26 47 52 48 00 43 50 43 50 46 35 46 36 47 23 47 23 47 45 41 03 43 03 43 09 46 25 46 22 46 39 46 42 43 08 43 04 47 54 47 45 47 38 47 35 47 33 46 30 to 46 43 42 26 42 31 Longi- tude west 51 08 51 38 51 46 51 52 52 30 48 36 50 21 50 12 52 44 to 52 53 48 28 47 06 47 29 47 02 46 56 51 30 48 OS 47 55 47 50 47 24 51 42 52 07 52 50 52 50 52 14 51 44 51 28 52 28 48 54 48 30 40 30 45 30 52 51 51 40 51 39 51 14 50 53 50 39 50 32 50 27 50 08 49 52 49 47 58 55 51 42 51 46 51 40 51 47 52 44 52 43 51 47 51 43 51 20 46 20 53 07 49 22 52 49 52 42 52 51 52 43 48 49 48 49 50 55 50 00 50 15 50 20 50 24 52 51 to 52 49 50 00 50 DO Nature of ice or obstruction Berg. Berg and growler. Berg. Do. Large berg. Small berg. Do. Berg. 5 bergs. Large berg. Scattered small bergs. Berg 660 feet long 170 feet high. Bergs and growlers, same as 1996. I^arge berg. Berg. 2 large growlers. Large berg and several growlers. Small berg. T>arge berg, same as 1996. Berg. Do. Large berg. 2 large bergs. Large here. Berg. Large berg. Berg and growlers. Berg. Do. Mast of a sailing vessel. Berg. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Buoy about 12 feet higb, wilh frame struc- ture and light. 2 bergs. Do. Berg. Do. Do. Growler. Berg. Large growler and several small ones. Large berg. Wreckage of wooden ship not visible above surface. Berg and growlers. 2 bergs and 1 growler. Large berg. Berg. Do. Do. Berg 15 foet high 150 feet long and several gro%vlers. Berg. Large berg and 6 growlers. Berg. Crrowler. Berg and growlers. Do. 4 bergs. Large berg. Small berg. 64 Table of ice and other obstructions, 1929 — Continued Date e No. 4 2056 4 2057 4 2058 4 2059 5 2060 4 2061 4 2062 4 2063 4 2064 4 2065 4 2066 4 2067 4 2068 4 2069 4 2070 4 2071 4 2072 4 2073 5 2074 n 2075 .5 2076 5 2077 5 2078 5 2079 .5 2080 fi 2081 6 2082 8 2083 8 2084 8 2085 7 2086 7 2087 7 2088 7 2089 8 2090 9 2091 9 2092 9 2093 9 2094 9 2095 10 2096 10 2097 10 2098 10 2099 10 2100 10 2101 10 2102 10 2103 10 2104 10 2105 10 2106 10 2107 10 2108 10 2109 10 2110 10 2111 10 2112 10 2113 10 2114 10 2115 11 2116 11 2117 11 2118 11 2119 11 2120 10 2121 10 2122 10 2123 10 2124 10 2125 11 2126 11 2127 11 2128 11 2129 Reported by- Position Lati- Longi- tude tude north west o , o , 48 12 49 40 47 48 50 03 42 04 49 34 41 51 49 33 42 06 49 33 47 28 51 42 47 38 51 23 47 50 51 08 47 52 50 34 47 58 50 34 48 13 50 12 48 30 49 57 46 23 52 10 46 41 52 20 46 42 52 32 48 19 49 45 48 25 50 14 (48 26 50 02 to to l47 33 52 32 40 13 49 37 43 07 48 53 43 00 48 59 47 48 51 10 48 04 50 24 48 12 50 08 46 29 52 57 42 24 49 51 42 42 53 33 48 06 48 13 47 57 49 10 47 40 50 00 48 45 50 20 48 25 50 54 48 18 51 27 48 14 51 31 46 30 52 45 45 09 49 08 42 57 52 30 43 12 49 15 43 11 49 25 42 06 49 43 48 30 50 04 48 11 51 10 48 02 51 06 42 57 49 38 43 03 49 42 42 35 49 52 42 15 49 30 46 19 53 01 46 18 52 47 42 32 49 54 47 01 52 30 41 55 49 30 41 50 49 02 41 48 49 01 46 42 52 08 41 55 49 25 42 37 50 20 41 44 49 04 41 44 49 00 45 03 49 02 44 15 49 11 48 39 45 14 46 47 52 12 48 04 47 17 41 21 48 43 48 53 50 17 48 34 50 11 47 45 51 09 47 46 51 24 47 38 51 40 41 30 48 40 46 00 47 17 45 55 47 16 45 52 47 16 Nature of ice or obstruction July Letitia do Ice patrol Malmen lee patrol Cape Race Station. do -_.do __..do .-._do .._-do do do .._-do --..do .-..do ....do -do. San Ugon. Lehigh do Cape Race Station- do do do Ice patrol Lehigh Cameronia do do Cape Race Station. ....do do do do Villarparosa Vittero Veneto Ice patrol do Saguache Gripsholm do do Ice patrol do do Koranna Hofuku Maru Cape Race Station. Koranna Gripsholm Vittorio Veneto do do Brazil Ice patrol Koranna Dordrecht Ice patrol Consul Olson Ragnhildsholm Pennland Transylvania Pennland Stuttgart Cape Race Station. do do do do Manchester Hero.. Hofuku Maru do do Berg. Berg, same as 2049. Berg. Small borg. same as 2058. Do. Berg. Do. Do. Do. Several small pieces. Large berg. Do. Do. 2 large bergs. Large berg several grovlers. Small berg. Large berg. 17 large bergs and numerous growlers north and south of track. Buoy marked "FID US Survey" with white superstructure and white flag height above water about 15 feet. Large berg. Small berg. Do. Large berg. Do. Do. Berg. Small berg in 67° water. Large berg. Do. Do. Do. Do. Berg. Do. 2 growlers. Large berg. Do. Berg. Do. 2 large bergs and 1 growler. 2 bergs and 1 growler. Berg. Do. Small berg, same as 2093. Berg, same as 2094. Small berg. Berg. Large berg 200 feet high. Large berg. Large berg, same as 2101. Berg 135 feet high. 2 large bergs. Berg. Berg and growler. 2 growlers. 2 bergs, same as 2107. Berg. 2 large bergs, same as 2108-09. 2 bergs, same as 2113. Berg. Do. Large berg. Low-lying berg. Large berg. 2 large bergs and several growlers. Berg. Do. Do. Do. Do. 2 bergs, same as 2107. Large berg. Do. Do 65 Table of ice and other obstructions, 1929 — Continued No. Reported by- Lati- tude north Longi- tude west Nature of ice or obstruction 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 Hofuku Maru Capricorne United States Kearney Ice patrol do Piako Cape Race Station. Rochambeau Ice patrol Bergensfjord- .do- .do- .do. -do. .do. Invergoil- Lackawanna Artigas do_-.- Ice patrol do do__.- Sergeant Oouarme. Lake Benbow Cape Race Station. do.__ do do do do._ Tuscania Ice patrol do Lake Benbow Ilagno Scythia do do do do Saco Ice patrol do Cape Race Station- Westphalia Schenectady Cape Race Station. do..._ do do do do do Scythia do Ice patrol do.-__ __. Ellin._ Koenig Alexandre Andre... do Ice patrol do. do.... West Arrow Cape Race Station. Ilallaren Drachenfels Henri Jaspar Doric do do do 45 50 44 55 42 00 42 31 41 39 41 36 41 23 46 17 41 44 41 30 48 16 47 46 47 43 47 44 47 35 47 27 49 55 41 57 45 58 45 26 42 13 41 41 41 45 43 30 41 36 42 52 45 32 45 15 48 20 48 36 46 33 40 15 41 33 41 44 41 24 43 33 46 33 46 57 47 47 47 58 48 12 41 28 41 34 41 34 47 51 41 44 42 13 47 24 46 57 48 39 48 33 48 29 48 14 46 33 48 07 48 12 41 43 41 46 43 51 42 07 41 39 41 31 41 45 41 43 42 08 46 10 46 28 48 27 43 35 42 24 51 20 51 23 51 26 51 46 47 12 54 10 50 10 50 04 48 38 48 32 <48 36 52 00 49 50 48 15 49 49 50 42 50 56 50 48 51 48 52 05 45 17 49 43 47 08 48 55 48 35 48 30 48 32 49 10 48 11 50 00 48 56 54 55 49 42 50 09 53 05 46 03 48 05 48 44 49 38 48 09 52 56 52 08 49 13 48 59 49 00 49 28 48 58 48 53 51 00 49 34 50 34 52 24 52 20 50 20 50 31 50 52 50 48 53 00 48 32 48 16 48 50 48 40 49 15 50 11 48 24 48 38 48 40 48 27 49 42 46 00 53 05 50 01 49 14 49 09 57 15 57 03 56 54 55 49 Berg. 2 bergs. Small berg, several growlers. Small berg and 2 growlers. Large berg same as 2113. Do. Large berg with 2 peaks, same as 2113. Large berg 80 feet high. Large berg. Large berg, small berg, and several growlers, same as 2113. Berg. . Do. Do. Do. Do. Do. Wooden skeleton 15 feet high marked "FID US Survey" with 2 flags. Small berg. 2 bergs. Berg and 2 growlers. Berg, same as 2113. Small berg. 2 growlers. Large berg. Large berg and several growlers. Berg. 4 bergs and growlers. Berg. Do. Do. Do. White buoy marked "FID US Survey" with tripod superstructure black cage and blue and white flags. Berg. Growler. 3 large bergs. Small berg. Large berg. Berg. Do. Large growler. Large berg. 2 bergs, same as 2164. Large berg and growlers, same as 2164. Berg, same as 2164. Berg. Growler. Large berg, 3 growlers. Large berg. Do. Do. Do. Small berg. Large berg. Berg aground. Berg. Large berg. Berg, same as 2164. Do. Berg. Large berg and 4 growlers. Large berg, same as 2164. Do. Berg, same as 2164. Small berg, same as 2164. Large berg. Growler. Berg drifting south. Berg. Large berg 40 to 45 feet high. Growler. Large berg. Berg. Do. Large berg. 66 Table of ice and other obstructions, 1929 — Continued Date No. Reported by- Position Lati- tude north Longi- tude west Nature of ice or obstruction July 16 16 16 16 16 16 16 16 18 18 18 18 18 18 IS 17 17 17 17 18 18 18 18 11 19 19 19 19 19 19 20 20 20 20 21 21 21 21 21 21 21 22 22 22 22 22 22 22 23 23 23 23 23 23 23 23 23 23 24 24 24 24 24 25 25 25 26 26 27 27 28 28 29 29 Aug. 1 3 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 Doric do do do.... do do do do do do Caledonia . do do Ice patrol Griesheim Cape Race Station. do do do do Ice patrol HelligOlaf Clara Cape Race Station. Phyrcania Ice patrol do Cape Race Station. do Tiger Ice patrol. Byron Gripsholm Baron Dalmeny Vimeira Transylvania Cambridge Mercer Seattle Spirit Dakarian Seattle Spirit Szeldedyk do Paul Albert-. Ice patrol do Scandia do Olna Ice patrol do Scandia Jenny do United States do Scandia Cape Race Station. Olna Aquitania Ice patrol.. do Cape Race Station. Dresden Ice patrol Arabic Albertic Ice patrol City of Hankow Cape Race Station . do Westphalia Cape Race Station. do Frederic VIII Cape Race Station. 51 43 51 50 51 52 51 51 51 52 52 00 52 05 51 58 52 57 52 46 48 17 48 06 48 19 42 28 48 50 47 00 47 11 47 11 47 18 46 2fi 42 03 41 49 39 58 47 00 39 46 42 06 41 57 47 15 48 23 46 30 42 10 41 09 46 23 41 49 42 40 46 25 46 21 41 45 48 23 41 42 48 02 41 55 41 44 43 20 42 00 42 34 45 45 45 44 42 36 41 49 42 10 42 57 41 51 41 56 42 10 41 55 42 31 48 18 42 43 41 47 41 54 42 11 48 40 41 34 42 14 48 06 48 28 42 20 44 58 48 02 47 10 40 31 49 04 48 46 48 28 47 52 55 44 55 39 55 32 55 25 55 17 55 30 54 49 54 33 50 54 50 54 48 30 49 04 49 17 50 05 48 38 52 51 52 50 52 40 52 45 52 56 49 31 48 16 53 08 30 34 53 30 49 28 48 22 47 20 51 01 52 50 48 23 48 42 52 41 49 53 49 44 52 42 52 43 49 43 45 52 49 42 46 41 49 32 49 35 50 40 49 32 49 47 45 14 45 47 49 48 49 18 49 28 49 20 49 19 49 18 49 30 49 20 49 46 50 38 49 37 49 15 49 16 49 29 49 45 54 40 49 30 47 06 48 47 49 45 48 34 46 47 46 40 54 13 49 45 50 42 49 40 52 39 Berg. Small berg. Berg. Large berg. Do. 4 large bergs. 2 large bergs. 1 large berg. Do. 2 growlers. Berg. Do. Large berg. Berg. Growler. Large berg. 2 bergs. 2 small bergs and growlers. Berg. I^arge berg. Large berg, same as 2194. Berg, same as 2192. Black buoy with a structure 15 feet high. Wreckage of schooner hull 40 feet long 20 feet wide. Red buoy. Large berg, same as 2194. Small berg, same as 2192. Large berg. I^arge berg and 2 growlers. Berg. Growler. Small berg. Berg. Large berg. Do. Berg, same as 2236. Do. Berg 75 feet high with growlers extending 2 miles to south. Large berg. Large berg and several growlers. Large berg and growlers. Large berg. Do. Berg. Large berg, same as 2245. Berg. Large berg. Small berg. Large berg, same as 2249. Small berg. Berg. Berg and growler. Large berg. Do. Do. Small berg. Berg. 2 large bergs. Berg. Growler, same as 2253. Do. Berg, same as 2254. Large berg. Big mast with yard. Berg, same as 2254. Large berg. Very large berg. Growler, same as 2254. Large berg. Very large berg 100 feet high. Large berg. Open fishing boat marked "Nr. 2." Berg. Large berg. Berg. Do. iferi 67 WEATHER Throughout the 1929 ice-patrol season the vessels actually on patrol remained within 120 nautical miles of 42° 30' N., 49° 30' W. That position, therefore, can be taken for all practical purposes as the place where the observations, which are described below, month by month, were made. But too much stress should not be placed on this position, for the weather experienced by the ice-patrol vessels depends to a very great extent on their location in the ice-patrol area. The northern part of the area cruised in is often cold and foggy because of Labrador Current water, while, at the same time, the near-by southern part of the ice-patrol area is warm and sunny be- cause of Gulf Stream influence. In comparing figures like average air temperatures and fog percentages of any one month with those of the corresponding month in previous years, or of other months of the same year, the fact should not be lost sight of that warmer and clearer conditions recorded may be due not so much to actually dif- ferent conditions in the region as a whole as to whether or not the patrol vessels remained in the colder or warmer parts of the ice area during the greater part of the time under consideration. The weather diagrams for each month of the active patrol season show graphically the wind directions and forces averaged for each 12 hours, the barometric curve, and the time and duration of fog and low visibility. In addition, the maximum, minimum, and average AIT temperatures, as well as percentages of the time that bad and poor visibility prevailed, have been given for each patrol month. As these figures were obtained in exactly the same manner as the corresponding ones for last year, the remarks made regarding them on page 50 of the 1928 Ice Patrol Bulletin apply with equal force to this season's values. APRIL Maximum air temperature, 57° F. Minimum air temperature, 30° F. Average air temperature, 40° F. Visibility was less than 4 miles 35 per cent of the time. Visibility was less than 2 miles 26 per cent of the time. The first ship to go out on the- 1929 ice patrol left Boston, Mass., for the eastward on April 1 during the early stages of one of the four deep barometric depressions of the month. Winds of gale force were experienced on the second day out, but, fortunately for progress and fuel consumption, they came from a following direction. The temperature and fog figures given above are those from noon of the 3d to the end of the month. The values for the first two and a half days of April were disregarded because the patrol vessel did not get out into the real ice-patrol area conditions of weather until after that time. 68 The monthly weather diagram plainly shows that fog* was almost entirely absent until the morning of the 18th. From then on to the last of the month there was so much fog and bad visibility, however,, that the figures for the whole month are slightly above what has; here been called normal for the time and region. There were two prolonged periods of fog, the first with a low barometer on the 18th, 19th, and 20th, and the second with comparatively high barometer on the 27th, 28th, 29th, and 30th. The latter period of thick weather was terminated on the 30th by a shift of wind to the westward which followed upon the passage, far to the north through the Strait of Belle Isle, of the center of a large cyclonic storm. Throughout nine half-day periods the wind force averaged Beaufort 7 or greater. This shows more boisterous conditions than obtained during April, 1928, for then only five such periods were recorded. During two of the cyclonic disturbances very heavy swells were noted with waves at least 30 feet high. This height was estimated by noting when the ship was on an even keel in the trough between swells the height above the water line at which the line of sight ran off tangent to the tops of the seas. When over the cold water, even during the periods of good visi- bility, morning and evening star sights could very seldom be obtained because of a typical stratus cloud formation, resembling a high fog, that was very frec^uently noted at certain hours. It was dark and heavy early in the morning, but gradually thinned out during the course of the forenoon. Around 10 a. m. a pale sun could be seen through the thinner parts, and at this time the first observations of the day could be taken, usually without the use of any shade glasses in the sextants. From about 11a. m. to 3 p. m. sun sights could usually be taken at will, but as the afternoon progressed the rolling, fairly low, cloud layer would form again, blot out the blue sky, and gradually thicken until the sun's disk could be seen no more. This sort of cloudiness did not hamper the search for ice greatly, for the visibility usually remained excellent just over the sea, the lower limits^ of the fog or cloud keeping at a uniform moderate level at all times. The delay in fixing position was the most serious thing involved, preventing as it did prompt and accurate determination of ship's- position, berg drifts, currents, and exact limits of areas fully searched. MAY Maximum air temperature, 56° F. Minimum air temperature, 34° F. Average air temperature, 42.9° F. Visibility was less than 4 miles 34 per cent of the time. Visibility was less than 2 miles 27 per cent of the time. May, 1928, had about twice as much fog and bad visibility, as usual, but in 1929 the figures for the month were back to normal again. "VIS. 7, 8 4 9 VIS. 5 4- <> -VIS. 0,I,2,S 44 APRIL VCATWER DIAGRAM V/HlTE CROSS HATCHED ei.ACK 1929 Figure 2.— Inner figures show day of the month; the next band out contains the record of the atmos- pheric pressure; the next outer one indicates the degree of visibility (black areas for visibility of less than two sea miles and cross-hatched areas for visibilities of between two and four miles) ; the outer margin shows the average direction and force of wind per 12-hour periods, midnight to noon and noon to midnight. Wind directions are toward the small circle in each case. Arrow indicates true ■north MAY WEATWER DIAGRAM 1929 VIS. 7.8.4.9 •\JU\TC VIS. 5 4 4' .CROSS HATCHED Vl5 0.1,7.3 44 * BLACK Figure 3.— For explanation of symbols, see Figure 2 69 The month was quite a pleasant one, taken as a whole. Air tempera- tures were quite low due to the unusual coldness of the ice-bearing waters, but there was much bright sunshine, and the air and sea temperatures slowly rose as the month advanced. A few large cyclones passed northeastward across Newfoundland and Labrador, but the patrol vessels escaped all but the southern edges of these, and so had only two 12-hour periods of gales and no baro- metric pressure lower than 29.62, which figure was reached on the last day of the month. One feature noted on the weather maps made on board from synoptic data was a succession of large high-pressure areas that moved southeastward across the United States Atlantic Coast States and out to sea to join the Azorean High. Barometric pressures in the ice-patrol area became very high at times, exceeding 30.50 on five different days, which were invariably fine and sunny, though on two of these five days there was a slight haze that made bergs appear yellowish in the distance and disappear from sight when from 8 to 10 miles distant. Phenomenal visibilit}^ prevailed on the 2d, however, when the barometer was at 30.22 and light variable airs were blowing. At this time a berg about 50 feet high was seen from a height of eye of 30 feet when it was 38 sea miles distant. The short period of fog experienced on the 11th with a high and rising barometer and north-northwest breezes was most unexpected. It occurred just before sunset over cold water near the junction of the Labrador Current and the Gulf Stream. The line of demarcation between the two waters was very ragged, for a little earlier in the day the patrol had cruised though alternate areas of cold and warm water each about 2 miles wide. The fog can best be explained by assuming that the surface air had just passed over a warm band of water and become moist and warm. A cold band of water happened to be to leeward of the warm band and, the critical conditions being just right, the moisture in the north-northwest breeze was condensed as fog as soon as the lowest layers of tbe warmed moistened air were chilled by contact with the small cold area in the sea. This unusual local fog occurred again on the 21st under almost identical conditions, except that in the second case the barometer was even higher, about 30.50 throughout the time. With northerly breezes fog is sometimes formed over the warm water, but its presence over cold water was very hard to explain. Many other interesting meteorological phenomena were observed. For instance, the weather diagram shows that fog was finalh' caused on the 19th after southeasterly airs had been blowing for some time. As a general thing it takes a considerable time for southerly bieezes to bring on a period of fog, and the further advanced the season is and the warmer the surface water is the harder it seems to be for the thick weather to get started. 70 When fog is formed over the cold water it is often very thin ver- tically with a clear blue sky showing overhead, as was the case on the 22d. Veiy often the rays of sunlight that reach the deck through the fog around midday have considerable warmth left in them, but not enough to remove the fog from the cold water as long as the wind continues to blow from warmer water toward colder. When con- ditions are rather finely balanced there is sometimes a tapering clear lane over the sea for a quarter of a mile or more directly to leeward of the drifting patrol ship, caused by the warmth escaping from the stack and hull. The weather cleared slowly on the 23d after a shift of wind to the northwest. By evening the atmosphere was remarkably clear to the westward and sunset was followed by a very distinct green flash at the spot on the horizon where the sun had just disappeared. The next day, with its high barometer and gentle breezes, was about the brightest, clearest, and finest day of the whole season. JUNE Maximum air temperature, 70° F. Minimum air temperature, 38° F. Average air temperature, 51.2° F. Visibility was less than 4 miles 42 per cent of the time. Visibility was less than 2 miles 34 per cent of the time. June, as is quite normal, had a higher percentage of hours with fog than either of the two preceding months. There was a marked change to general summer weather conditions. The procession of "Lows" along the American coast and up the St. Lawrence Valley slowed down, and a great high-pressure area in the ocean east of the United States and southern Canada stood opposed to a fairly constant condition of low pressure over North America. This distribution of pressures always gives the Grand Banks region a large proportion of gentle but steady southerly breezes, which are over the colder water areas, accompanied by foggy weather. An even greater number of times than during May there was low-lying fog with clear or partly cloudy sky plainly visible overhead. The bright sunshine on some of the days made fogbows and allied phenomena of common occurrence. When cruising along the temperature wall many areas of fog patches were encountered. The search courses at such times fre- quently changed the surface water temperatures 11° F. in 11 minutes, say, from 48° F. to 59° F., and the air temperatures fluctuated almost as much and as rapidly. It would be raw and foggy over the cold water and damp and muggy over the warmer mixed water close by. During the fir%t half of the month cold water pushed 150 miles to the southeastward to '4(y° N., 46° 40' W., in a band about 20 miles wide. This stream was very difficult to search for ice because winds from JUNE WEATHER DIAGRAM VIS. 7. 8 O * WHITE VIS. 54.6, • CROSS HATCHCO. V15. 0,1.2.3,4. - BLACK. 1929 Figure 4.— For e.xplanation of symbols, see Figure 2 ^ n JULY WEATMER DIAGRAM J929. FIGURE 5.-For explanati ci. of sjnbols, see Figure 2 71 any direction except northwest came from warmer water areas and usually gave fog. The lowest barometric pressure for the month, 29.50, was reached on the 2d, but this depression was unaccompanied by gales, there being only a few hours of fresh breezes while the wind was hauling through south to southwest. The whole month saw no full 12-hour periods of gales, but there was a near approach to one on the 29th, when the wind averaged force 6 between noon and midnight. During a period of good visibility on the 4th, which was a drizzly, overcast day, a berg was sighted about 10 miles off. While it was being approached the cloud blanket shut down closer and closer to the sea. When the berg was finally reached it was seen that its upper parts were completelj^ hidden in a fog. It was then noted that the patrol ship's topmast and crow's nest were also in fog, though visibility still remained good at sea level. In a short time the fog shut down completely. The wind was light from the north-northeast and the air temperature was 42° F. This case is mentioned because it is quite the opposite condition to that much more often experienced where the upper layers of the air remain clear and only the lower layers are foggy. On the 9th the ship was in warm mixed water near the long south- east push of cold water mentioned above. It had been foggy, and after the wind hauled to the north of west it remained so, instead of quickly clearing as usual. In order that the good visibility which, it was thought, must exist near by might not be lost for searching purposes, the patrol stood to windward and in a short time entered cold water, over which there was no fog whatever. Over the region of warmer water to the southeastward the pall of fog could be seen hanging throughout the remainder of the day. There was noticeably bad refraction on four days. On one a 40-foot berg was sighted 26 miles away, and a few hours later the sun went down not like a round ball of fire but greatly flattened, like a vertical section through a watch being lowered face uppermost into the sea. On another day double horizon lines were noted for some hours until continuing southerly breezes finally brought on fog and rain. During several foggy days which were spent along the temperature wall, copious showers were experienced. Some of these were regular tropical downpours. From ship reports received, it is believed that at the same time bright weather was prevailing over the Gulf Stream drift, and the usual Grand Banks fog with clear sky overhead was prevailing farther north well inside the area of cold water. At other times, when cruising near the temperature wall, squalls from varying directions were experienced, all of which indicates that at times along the line of junction of Labrador Current and Gulf Stream there is 72 an unstable area, where uprushes of air, indrafts, and such activities take place. JULY Maximum air temperature, 73° F. Minimum air temperature, 43° F. Average air temperature, 59.8° F. Visibility was less than 4 miles 38 per cent of the time. Visibility was less than 2 miles 32 per cent of the time. Previous to the 1929 season the ice patrol has always been dis- continued by the middle of July, but the 1929 ice conditions neces- sitated its continuance until August 3. The July meteorological information given here and on the July weather diagram is, therefore, for the first time that for the full month. The patrol was discontinued so early in August that no separate discussion or weather diagram has been prepared for the time after July 31. July was marked by very weak barometric gradients with accom- panying fine moderate weather. The weather maps showed a tend- ency for a low-pressure area to remain over the central portions of North America and for high pressures to prevail over great areas of the North Atlantic Ocean and over the United States Middle Atlantic States. There was a marked increase in sea and air temperatures in the ice-patrol area because of continued solar warming, and a falling off in fog percentages as compared with the previous month. The last three days of the month were days of dense fog because of per- sistent southerly breezes and airs, and this fogginess was continued, over the colder waters along the eastern edge of the Grand Banks at least, without a break until after the patrol was discontinued on August 3. This shows that an advanced summer season, while it lessens the hours of fog over the warm and the warmed mixed waters, has but little beneficial effect over the southern reaches of the Lab- rador Current proper. It was often possible to pick clear-weather areas and to remain in them by working toward cold-water areas during northerly breezes and running toward warmer water when southerly breezes began to cause fog. GENERAL REMARKS Because much interest is shown b}'' shipping in the patrol vessel's weather, the conditions prevailing were always incorporated in the routine ice broadcasts. Placing the data in these messages not only assured as wide a dissemination of it as possible but saved time and effort for all concerned through the cutting off of many inquiries regarding weather conditions that experience has shown would otherwise have come in from single vessels. Twice daily a coded weather report was dispatched to the United States Weather Bureau, Washington, D. C, and at the end of each 73 cruise the regular Weather Bureau forms were filled in for the patrol period and mailed upon arrival in port. The coded dispatches to Washington always included, when available, the weather at one or more ship stations well separated from the patrol. These composite messages were transmitted direct to Washington at scheduled times which were sufficiently early to insure that the data would be available for use in making up the Weather Bureau's ocean forecasts. The same weather information sent to Washington was transmitted via Canadian coastal radio stations to the Canadian meterological officials at Ottawa, Ontario, for their use. This was a new departure,, beginning with the 1929 patrol season. An average of 60 water-temperature reports were received each day from vessels within the ice-patrol area, which may be defined as the area bounded by latitudes 39° and 48° N. and longitudes 43° and 56° W. Shipping was frequently reminded of the need of the patrol for reports by broadcasts worded about as follows: "AU vessels while within the ice-patrol area are requested to transmit to the ice-patrol vessel, call NIDK, the following every four hours: Ship's name, G. M. C. T., latitude, longitude, course, speed, temperature of water, weather conditions, and any ice or other obstructions sighted." In response many of the ships included in their water-temperature reports all the necessary meterological elements, for the most part^ no doubt, very carefully and regularly observed. When a number of the best-cooperating ships were well scattered along the tracks, there was a w^ealth of material to choose from, and most of the remain- ing time there were at least a few vessel reports to consider when making up the Weather Bureau dispatches. Only the latest, most reliable, and best situated reports were marked for coding and transmission to shore. On the patrol vessels, especially during foggy periods, the weather obtaining at the positions of reporting vessels would be frequently plotted on suitable ocean charts. The limits of fog sheets, rain areas, good weather, gales, and other conditions could then be seen with considerable accuracy and ease. Detailed weather information obtained from reports so plotted was several times furnished the United States Weather Bureau officials on request during the anxious times just prior to projected trans-Atlantic airplane flights. Following the customs of previous years, two weather maps were made up each day from data contained in the general synoptic broadcasts transmitted by NAA, at Arlington, Va, Supplemented by the weather reports received from shipping, these maps were used for forecasting the local weather. They proved most useful for use in connection with planning the patrol's cruising as well as interesting. With their aid it was always possible to know what weather conditions were prevailing in a large area to the westward. These conditions, it 100277—30 6 74 is very soon clear to observers on the patrol ships, control to a great extent the immediate future course of weather in the ice-patrol area. DEPTH SURVEY CARRIED OUT BY THE SONIC METHOD Throughout the 1929 ice-patrol season both the Tampa and Modoc were equipped with commercial instruments for determining the depth of the water by sonic means. It was usually possible to use these instruments successfully so long as the ships remained inside the 1,400-fathom curve. On smooth days when the sets were work- ing especially well they could be used in water up to about 2,000 fathoms deep. Whenever echoes could be obtained from the sea bot- tom frequent soundings were taken and recorded. One hundred and ninety-one values that were obtained when the vessels' positions were well fixed by sights have been corrected for certain errors due to actual conditions of salinity, temperature, and pressure in the water column and forwarded to the United States Hydrographic Office and to the United States Coast and Geodetic Survey for use on charts of the North Atlantic Ocean. Altogether many times 191 values were recorded, but the great majority of sound- ings, though useful for immediate navigational purposes, were taken when the exact geographical position was in some doubt due to such things as abnormal refraction, cloudiness, darkness, and fog. The depths obtained when the position was uncertain were without ex- ception discarded so far as giving them consideration for hydro- graphic use was concerned. The area where the patrol vessels cruised in 1929 has been rather well sounded out, and for this reason noth- ing but the best work of the season was considered worth keeping. Two navigators worked out the different positions of the ships independently for check purposes, so the locations listed with the sounding values saved are based on double work and are believed to be as nearly correct as such values can be on board a ship on ice- patrol duty in the Grand Banks region. Of course some of the posi- tions are closer to being right than others. The radius of error prob- ably varies from next to nothing at all up to a maximum of about 10,000 yards. ICE OBSERVATION The varying ice conditions that existed during the first nine months of 1929 in the North Atlantic south of the forty-eighth parallel are dis- cussed here. The monthly ice charts (figs. 6-1 1 inclusive) show plainly where the ice at different times was located with respect to the coast lines, principal steamship tracks, and other features of the Grand Banks region. They furnish a far better means than written re- marks for comparing the change of ice conditions from month to month and those of certain months of one year with corresponding months of another. United States Hydrographic Office Miscellane- ous Chart 2,511 was used as the base map for plotting all ice data. Iceberg totals and ice conditions are based during the actual active patrol season on first-hand information, supplemented by that re- ceived by radio from ship and coast stations. Reports of ice published weekly in the United States Hydrographic Bulletin and those received from Canadian Government authorities are depended upon during the inactive season when there is no patrol ship in the vicinity of the Grand Banks. The large number of ships on the various tracks that cooperate by reporting regularly makes much care necessary to keep duplications from unduly swelling the berg totals. Suppose, for instance, that 10 ships all pass along the same general line and each one reports four bergs to the patrol from about the same locations on the same day. Only one of these reports of ice can be considered for broadcast and statistical purposes, for it is obvious that all the ships have seen and reported the same ice. Probable drift tracks of ice are rather well known from experience, and the general principles of these drifts are explained in conjunction with the charts on pages 68 and 69 of the Ice Patrol's Bulletin for 1927. In addition, particular detailed drifts and variations from the general .rules can often be forecast after a study of the cruise isotherm and ice charts that are always kept up to date on the patrol vessels. Bergs reported from one position on one day, therefore, are frequently .assumed to be identical with bergs reported from two or three and sometimes even five or six days earlier from different locations, and are eliminated from the statistical totals. But no reported berg is omitted from the broadcasts unless it is pretty definitely known to be identical with some other reported berg. It is certainly wiser to broadcast the presence of slightly more ice than exists rather than .to eliminate from the reports mention of any ice that may still remain. (75) 76 In accordance with the practice of all previous years, it was considered that the start of a new month cleared off the statistical slate, all bergs reported anew on or after the first of a month being considered once more for determination of monthly totals, whether or not they had already been reported. Nine months instead of twelve are discussed here because complete ice information for the last three months of the year is not at hand as this section is being written. The 1930 Ice Observation and Ice Patrol Service pamphlet will contain the discussion for October, November, and December, 1929. As these three months share with January the distinction of being the very lightest ice months of the year, their omission from this publication is really of no moment. Frequent reference is made throughout this and other sections to the "ice-patrol area." This never refers exclusively to the rather limited area south and east of the Tail of the Banks that can be physi- cally covered by the efforts of the ice-patrol vessels themselves. It always includes all that area between the thirty-ninth and forty- eighth parallels and the forty-third and fifty-sixth meridians, which is constantly being crossed and recrossed by reporting vessels. In general, during clear weather all parts within these limits that are at all near the several steamship tracks are well covered either by the patrol or for it. During good weather conditions the situation may be said to be well in hand, and, therefore, advice can be given about ice conditions with confidence to vessels that maj^ be crossing the ocean hundreds of miles to the north or the south of the actual limits of vision of the ice patrol. During the long periods of fog, however, when the eyes of reporting vessels as well as those of the patrol are blindfolded, the exact status of affairs with respect to the location of the ice is not so well known, and then extra precautions are regu- larly advised both in the broadcasts and in the special ice-information messages. The patrol's experience is that bergs can be detected only when they can be seen. It is only rarely that bergs are sighted or reported during thick weather or darkness, though undoubtedly the the brightest lookout is kept for them during just those times. The ice-patrol area as defined above does not by any means set a bound to the patrol's interest, information, or service. Reports of ice and obstructions that come in from far to the eastward of the forty-third meridian and from far to the northward of the forty-eighth and even forty-ninth parallels are gladly received and when on hand are invariably included in the broadcasts. Far to the westward, also, the changing field-ice conditions in the approach to the Gulf of St. Lawrence are followed and reported as closely as the radio advices ^ received make possible. Water-temperature reports from the area surrounding the so-called ice-patrol area are also frequently received. They ar& always care- Plate X. — Medical officer of the Tampa on board a French fishing vessel off the eastern edge of the Grand Banks. There are between 20 and 30 men on each of these sailing vessels, and usually at least 1 member of the crew is in need of medical treatment. Complaints range from injuries and sores to abscessed teeth and tuberculosis Pl.vte XI.— Dory pulling from a French fishing vessel to the Tampa with letters to be posted. The fishermen are frequently at sea for seven months at a stretch, and are always eager to send letters home and to exchange fish for articles of food which will add variety to their diet I'LATK XII. — For approximately nne-third of the time the ic? iiatrol cutters are bhndfolded by dense fog like this. The fog is usually brought on by long continuing light southerly breezes". Often it is so thin vertically tliat the sun is able to shine down dimly to the water, as here '^' -i Plate XIII. — There are a number of storms each season. These, as well as the fog, interfere w-ith the scouting and scientific iirograms. This wave was photographed from the stern of an ice patrol cutter while not far from the tail of the flrand Banks 77 fully plotted and studied to see what bearing they may have upon ice, current, and weather conditions now obtaining or that may soon obtain wathin the area that is most intimately under the cogni- zance of the patrol. JANUARY There were no reports of ice from the region of the Grand Banks. Some field ice, however, was carried seaward from the Gulf of St. Lawrence by the Cape Breton Current and was reported during the latter part of the month from 60 miles southeast of Cape Breton. FEBRUARY Considerable field ice from the Gulf of St. Lawrence was reported from areas about midway between Sable Island and Cape Breton, Further east the first field ice of the season began to drift south into the international ice-patrol area proper, where it was reported fre- quently from the region just north of the Grand Banks. By the end of the month the southernmost limits of this latter ice had pushed south of the forty-seventh parallel along the line between Cape Race and the northeastern shoulder of the Grand Banks, and on the 28th there was a report of field ice and growlers extending south in the main branch of the Labrador Current along the eastern edge of the Grand Banks to 46° 25' N., 47° 40' W. So far as is known during this month no bergs drifted south of the forty-eighth parallel in company wdth the field ice from the north. The ice map for February, 1929, is almost identical with that for February, 1928. MARCH The ice map for this month also bears a remarkable resemblance to that for the corresponding period of the preceding year. The ice of March, 1929, being apparently somewhat heavier and of greater extent, however, gave the first hint that an unusually heavy ice season was about to develop. Vessels passing north of Sable Island reported large patches of loose field ice from the Gulf of St. Lawrence to be extending to about 120 miles southeast of Cape Breton. Some of these patches over the northeastern limits of Banquerau Bank were described as heavy. Ten degrees to the eastward, along the eastern edge of the Grand Banks, the first bergs of the season began to be reported wherever the trans-Atlantic traffic sighted the southward moving field ice. Indeed, throughout most of the area northwest of the line from Cape Race to Flemish Cap and on both sides of the line from Flemish Cap to 44° 30' N., 49° 00' W., field ice and bergs were frequently reported together. 78 APRIL No reports were received of the Gulf of St. Lawrence field ice but in the Labrador Current along the eastern edge of the Grand Banks- there appeared a far greater amount of all kinds of ice than usual for- the season. In the first place a great amount of field ice seriously obstructed navigation within the area partially bounded by lines running from Cape Race to 44° 20' N., 48° 30' W., thence to 47° 30' N., 46° 30' W., and thence northwestward past the forty-ninth parallel, and so out of the field of observation. Everywhere this field ice was more or less thickly studded with bergs. Toward the end of the month ship reports indicated that the limits of the field ice had retreated rapidly to north of the forty-seventh parallel. After the flat ice w^as melted by sun, wave, and warmer water the large bergs, being much more resistant, remained to con- tinue their southward drift toward the Gulf Stream waters. The great majority of the April bergs were situated between the 50-fathom curve of the eastern edge of the Grand Banks and a line located 60 miles to the eastward of it. The most southerly bergs of the month were located along the direct southerly extension of this ice stream, where they almost reached to the forty-second degree of north latitude in longitude 49° 30' W. There was also a very distinct curving of ice and cold water to the westward around the Tail of the Banks. If this outlet had not existed it is very probable that the southward push of icy waters would have been greater and woidd have sufficed to carry bergs across the westbound B tracks to the south and southeast of the Tail. About the middle of the month reports showed that scattered bergs were rapidly advancing southeastward into and across the area of warm surface water to the east and west of 42° 50' N., 44° 30' W. One of these bergs actually crossed the westbound B track from Fastnet, in longitude 43° 50' W. This push of bergs was quite alarm- ing, and was one of the factors that made the patrol recommend a shift of tracks south to the extra southern or "A" lanes on April 19, though, as matters turned out, after that date there were very few further reports of threatening bergs in the eastern part of the ice- patrol area. The warm waters rapidly melted the southeasternmost of the invading bergs and their ranks were not filled by new levies from the continuous procession moving south along the eastern edge. During April, 1928, there was a southeasterly push of bergs very similar to the one of 1929. The feature this j^ear, however, in common with all ice conditions about the Grand Banks from April on, was far heavier and more serious. This j^ear the patrol ships were prevented by the ice just below the Tail from investigating the southeastern sector themselves; therefore a careful study of the subsurface condi- tions in the latter area could not be carried out. The bergs, as shown 79 by numerous reports, were apparently drifting southeast across warm water at right angles to the surface isotherms and to the usually conceived direction of the Gulf Stream drift. The 120-mile berg-free separation of the southeasternmost bergs from the ice just below the Tail precludes, when combined with a study of the successive reported positions of the ice, the belief that the former group was made up of bergs that had earlier drifted south past the Tail and got into a north- east-flowdng current. MAY Early in the month the two latest reports for the year were received of the Gidf of St. Lawrence field ice, both from the northern end of St. Pierre Bank. In the Grand Banks region farther to the eastward great changes took place in the ice situation. Throughout the month the surface waters north of the forty-second parallel remained on the average considerably colder than in 1928. Nevertheless, the effects of the advancing sim caused field ice that drifted south of New- foundland to melt with considerable rapidity and the southern limits of the pack ice to retreat apace. Before the end of the month field ice was reported for the last time in 1929 from anywhere in the ice-patrol area. Bergs were present in almost unheard-of numbers northeast of the Grand Banks, especially in the area extending 150 miles northeast from the line between 48° 15' N., 51° 10' W., and 45° 50' N., 47° 10' W. The patrol vessels, as usual, watched the southernmost ice and in the cases of a few critical bergs were able to determine their drift tracks. These are located in the general vicinity of the Tail and are shown by dotted lines on the ice chart. During May there was an unexpected falling off in bergs south of the forty-third parallel and a lull in the menace to the United States, Europe tracks. Almost all bergs that reached the latitude of the Tail curved closely around it and passed to the westward. Instead of continuing northwestward along the southwest edge of the Banks, some of this ice, as it had done during April, turned offshore and pushed southward along the fifty-first meridian from the forty-third parallel. However, the southernmost ice of the month, which was along this line, failed to reach even the westbound "B" track to Boston by over 30 miles. The ice chart for May shows an apparent lack of bergs along the eastern edge of the Banks between 44° 00' N. and 45° 30' N. This is probably due to the fact that the area concerned was crossed so little by reporting steamers that many bergs undoubtedly escaped observa- tion there. The shifting north of the Canadian tracks as soon as the ice conditions permit in the spring leaves a wide comparatively^ un- searched gap between the usual seat of operations of the ice patrol 80 in the latitude of the Tail and the next set of traffic lanes to the north. JUNE The severity of June, 1929, from an ice standpoint, can best be seen when one compares the month's ice map with that for June, 1928. (See United States Coast Guard Bulletin No. 17, fig. 10.) Though the chart for the latter month shows a total number of bergs south of the forty-eighth parallel somewhat in excess of normal, and one berg with an extreme southerly drift, the total number of bergs in the ice-patrol area during June, 1929, was several times as great and the situation was considerably more dangerous. The surface waters north of the Banks, along the eastern edge, and to the westward of the Tail continued to be abnormally cold. A feature of the month was the recurrence of a great number of bergs south of the Tail. These bergs extended from 43° 10' N., 53° 00' W., to 42° 40' N., 48° 00' W., and along a 190-nautical-mile front the foremost of them pushed farther south than did any bergs during May. North of this group, except along the tracks of the few cooperating vessels that crossed the eastern edge, there is a relative scarcity of bergs plotted, but, as stated above in the discussion for May, the lack of bergs plotted in certain areas can often be credited to lack of report- ing vessels rather than to actual lack of bergs. In June the Canada- Europe traffic was on the Cape Race tracks, still farther north than it had been during the preceding month. Had the waters along the eastern edge been well covered by the patrol ships or by reporting vessels, doubtless a considerable number of bergs that remained unreported would have been found. From along the Cape Race, or F tracks, great numbers of bergs were reported. Even there, however, they noticeably thinned out in numbers as the month progressed. During June shore stations located along the Newfoundland coast between Cape Race and St. Johns began to sight bergs for the first time in 1929. This was the result of the bergs in the northern part of the ice-patrol area being located on the average much farther westward in the ocean than earlier in the year. The disappearance of the field ice with the ad- vance of the season is regularly followed by a westward movement of the average of the drift tracks of bergs north of the forty-seventh parallel. A continuation of such a tendency finally results in a failure of supply of bergs to the narrow cold stream that runs south along the eastern edge. It is just as though the supply of grain to the hopper of a mill were cut off by the slow deflection of the grain chute that keeps it filled. Even though the bergs should keep coming down in undiminished numbers across the forty-eighth parallel (which they never do), the farther west they come down in the ocean the less is 81 their chance of getting south past the islands and rocks of the Labra- dor and Newfoundland shores and past the shoals and slack waters that exist along the northern edges of the Grand Banks. JULY Though stiJl abnormally heavy from an ice standpoint, July, 1929, when compared with the preceding month, shows a great decrease of bergs along the Cape Race tracks. The ice extended a little farther to the westward around Cape Race than in June, but it did not drift through the guUey off this point beyond longitude 53° 10' W. Many ships went east and west past Cape Race, and if any bergs had been located farther to the westward they would certainly have been reported. The few bergs reported from unusual positions near 45° 00' N., 54° 30' W., and 43° 00' N., 53° 00' W., were doubtless straggling remnants of the ice that had made its way so freely to the westward around the Tail during the previous month. The westward tendency in the southern part of the ice-patrol area was definitely stopped early in July by the pushing northeast to the Tail of an undulation in the northern limits of the Gulf Stream. This invasion of warm surface water almost entirely obliterated the extension of cold current that had previously passed westward around the Tail. At the same time it caused the southern branch of the Labrador Current to increase in power and extension until it was carrying bergs southeast almost to 41° N. 48° W. The United States-Europe ships had been recalled from the extra southern A tracks, and such an unlooked-for final push of ice and cold water caused the patrol deep concern. From the 11th to the 24th it sent a number of large bergs drifting eastward right along the path of the liners on the westbound B tracks. During the last few days of the month the southernmost bergs melted under the eyes of the patrol. Their final disintegration was quite rapid because of midsvmimer air and water temperatures and apparent mixture of the surrounding northern waters with the Gulf Stream drift. As the southern limit of the ice gradually retreated northward the patrol followed it along from berg to berg, for the push of the cold waters had weakened and no new ice was coming down to take the place of that melting below the Tail. The exact status of affairs a little to the northward along the eastern edge could not be determined during the closing days of the month because persistent fog remained over the narrow stream of pure, Labrador Current water that according to surface temperatures, still extended to just south of the forty-third parallel. AUGUST The long, heavy ice season finally ended during this month. August saw but one report of ice from the ice-patrol area proper, that of a berg on the 3d near the Newfoundland coast just north of St. John's. 82 There were reports of five bergs early in the month from north of the Banks, but none of these were ever reported from south of the forty- eighth parallel. Constant fog prevailed over the narrow cold stream of cold water along the eastern edge of the Banks until after the ice- patrol service for 1929 was discontinued on the 3d, so it is just possible that an unreported berg or two may have disintegrated there unseen. SEPTEMBER A berg was reported on the 19th from 44° 05' N., 44° 30' W. GENERAL REMARKS AND SUMMARY The above monthly discussions and the charts following this section show in general how ice was distributed southeast of Newfoundland throughout the 1929 ice season. A narrative account of the ice seen from the patrol vessels, together with remarks on circumstances attending its disintegretion in some instances, can be found, respec- tively, in the sections devoted to the cruise reports and oceanography. The following tabular summary shows how the 1929 monthly berg totals compare with those of the average year, the latter being based on a study of iceberg reports from south of the forty-eighth parallel for the period 1900-1926: Month Bergs south of 48° N. in 1929 Bergs south of43°N. in 1929 Bergs south of 48° N. normally Bergs south of43°N. normally January February.. March April May June July August September. Total 0 0 45 332 460 376 107 1 1 1,322 3 10 36 83 130 68 25 13 9 It '-1 o ,jv fc.VJ':.''A'''fi M^ ...( 60 50 56 57 56 A- BEBCS, O -GROWLERS. p^H- FIELD rcc. GENERAL CHART COVERING ICE PATROL GRAND BANKS ICE MAP FOR FEBRUARY, m^. Ki'.rp.E I!.— February ice map. No known in-lrrjs were soutli oflhe 4Sth parallel liurinc the nionlh 100277—30. (Face p. S2.) No. I I it I* \. ..i 60 sa ^- 8ERSS © -GROWLERS. «M- FIELD ICE. 57 56 55 52 ICE PATROL GRAND BANKS A9 *» 47 46 45 ICE AUP FOR MARCH, I'i^^. Figure 7.— March ice map. Forty-flve known iceberp> I'lesouth ol (he 4i-lli i iinilltl iluriiig the monih 100277—30. (Face p. 82.) No. 2 1- ii.i p.E ^.- April n-e ii-.iii'. ■] hrt'f Imnilred und thirty-two kiKiwii icvbergs were south ii( tht -IMh iianiliel diirini; tlie ninntli 100277—30. (Face p. 82.) Xo. 3 i ^5""^;'./ ^yy^^i^y^^, 100^77—30. {Face p. 82.) No. i +7M(>'«. •a-b sue t" ' ' !,.!.- I I ' I I I I I Ji^ii I I I I I 1 I l"'-^' ' ■ ' ' ' ' ^- BERCS- O -GROWLERS. IVH-FIELD ICE. ICE PATROL GRAND BANKS ICE MAP FOR JUNE, 1^?^^. FiGiKE 10.— June ice map. TliR-e hun'ircd ;ind seventy-sn kn "n Icebergs were south of the 4slh p.irallel iluriug the month 100277—30. (Face p. 82.) N"o. 5 I FiGUKK 11.— July ite iiKip. Alxmt 100 known icebergs wcrjlouth of the -IMh i/ars!Iel during the month 1002::— 30. (Face p. 82.) No. 6 I SOME OF THE ICE PATROL'S PROBLEMS, AND HOW IT ATTACKS THEM The primary duty of the ice patrol is locating and broadcasting the position of all ice near the steamship tracks which cross the North Atlantic south of Newfoundland. The patrol service is maintained to assure, if possible, that vessels using these tracks will not run unwarned into ice-infested waters. The patrol's responsibility is certainly not the safe passage of }?er- sons, vessels, and freight across the ice-patrol regions. That is, indeed, the final aim of the ice patrol's work, but the safety of each individual ship is something not under the control of the ice-patrol officials. Safety from dangers incident to collision with ice is de- pendent upon the judgment of the individual shipmasters in estimat- ing the situation ahead of them. The patrol's broadcasts give these men a certain amount of late information, which is undoubtedly useful as a guide for shaping their course and speed policies past the Grand Banks. One patrol vessel is out on duty at all times during the heavy ice ^season. The fuel capacity and other limitations of the vessels that. have been used to date are such that they can cruise at about 10 knots 'during daylight hours of good visibility during their 15-day duty periods in the ice regions, and ordinarily no more. Greater work than :that they can not do because of the need for fuel to carry the ships to and from the ice area, to evaporate sea water for domestic and boiler purposes, to supply demands for steam during long stand-by periods •of fog, darkness, and storm, to retain position in currents, and for .emergency reserves. Bad visibility and bad weather together are so prevalent that on the ■average the patrol can count on no more than 150 hours of efficient ■searching weather per 15-day period of patrol duty. During these 150 hours the patrol ship averaging 10 knots can run 1,500 sea miles and can sight bergs at an average distance of not over 15 miles on either hand. In other words, the patrol vessel herself can examine not over 45,000 square sea miles of water area per average patrol •cruise, even when every available hour of good visibility is utilized to .the full for search purposes. Some ground is lost because of doubly searched areas that unavoid- ably exist about the corners of the search patterns. Other reasons, such as necessary overlapping of searches made on different days due (83) 84 to indeterminate differential surface drifts of neighboring sea areas, and large ship drifts during periods of darkness and low visibility, cause additional losses. As a matter of fact, a good figure to take for the maximum actual area that can be well covered for ice by one patrol ship per 15-day patrol cruise is 30,000 square sea miles. The area about the Grand Banks that most frequently contains bergs and to which it is desirable to confine most of the patrol's activity lies between longitudes 43° and 54° W. and latitudes 40° 30' and 48° N. Deducting the area of the Avalon Peninsula of New- foundland and that of a warm iceless portion in the southeastern corner of this region, it will be found that the total area south of the forty-eighth parallel which is most likely to contain ice contains about 168,000 square geographical miles. Some of the areas over the Grand Banks themselves are not frequented by trans-atlantic traffic. There is, besides, very little sustained current in the shoal water. Therefore, the total area which must be most closely watched can be reduced to about 150,000 square geographical miles. North of this great southern ice area and extending eastward for several degrees of longitude from the North American coasts, the waters are particularly liable to be congested with ice. It is normal for unnavigable field ice to exist over broad areas immediately north of the forty-eighth parallel during several winter and spring months. The same waters are liable to be more or less thickly strewn with bergs throughout the whole year. Though ice conditions vary in -dif- ferent localities for various reasons, it is true, generally speaking, that the farther north of the forty-eighth parallel one goes along the North American coast the worse will be the ice conditions met. This holds true all the way up into the Arctic regions that are choked all year round with impenetrable field ice. The serious ice conditions likely to be met at any time to the north of the Grand Banks and the forty-eighth parallel are doubtless well realized by the masters of all vessels crossing in the higher latitudes, so for all practical purposes this area can be considered as beyond the ice patrol's particular sphere of action, though not at all beyond its sphere of experience, interest, or knowledge. Ice information received in the form of reports from the northern sections is always placed in the broadcasts and retained for about five days before being dropped. Any vessel requesting special information from the patrol ship regarding ice in the area north of the forty-eighth parallel will usually be able to get valuable information. There have been occasional reports of bergs to the west, south, and east of the usual ice area between 43° W. to 54° W. and 40° 30' N. to 48° N. Ice in such locations, however, may be considered as due to extraordinary berg or current conditions. The ice-patrol ships themselves can not attempt to locate ice in waters where it is 85 -only phenomenally present any more than they can keep track of all the ice in the tremendous ice regions of the north. As a matter of fact, if the patrol limits its cruising activities to the important ice area of 150,000 square sea miles about the Grand Banks, it is con- fronted with a very sizable problem, for it has been shown that in a full 15-day cruise period the patrol's own searching can be made to cover but about one-fifth of such an area. The result is that the patrol is compelled to concentrate on the most critical parts of the 150,000 square sea mile ice area south of the forty-eighth parallel. It relies upon reports from passing ships for its knowledge of ice in many parts of this area, as well as in the surrounding northern and southern regions, that on the one hand always, and on the other only exceptionally, contain ice. It may be of interest to state here what takes place on the patrol vessel when ice or water temperature reports are received. Copies of all these incoming messages are promptly taken to the chart room and delivered to the ice-observation force. They first scrutinize the reports for errors. The tracks and approximate positions of all regularly reporting steamers while in the ice-patrol area are kept plotted on special charts. If a new report is from an obviously im- probable location, some distance from where the reporting ship should have been at the time of origin of the message, the value is thrown out if an ordinary temperature report. If it is an ice report, or a water temperature value from an area that few vessels have been through recently, an inquiry for verification of the questionable location or other particular is promptly sent out. At this point it should be noted that the size of bergs seen at sea at a distance of 2 or more miles is very deceptive. There is usually nothing of known size near them with which they can be compared. The patrol itself has frequently seen bergs that appeared to all on the bridge to be very large pinnacled ice masses when they were near the horizon, but which, when closely approached, proved to be rather insignificant, rising less than 30 feet above the sea and being less than 100 feet in diameter. So it is that bergs in the frequently bright smooth waters of the southern ice sectors, though reported as "large" and "very large," are often found when reached to be in fact quite small. They were probably sighted on the horizon line when nearly abeam of the reporting vessel, which had never closely approached and examined them because of the loss of valuable time that this would have involved. The unusually large refraction values often found near the junction of the warm and cold waters makes the identification of bergs diffi- cult and adds to the uncertainty when determining berg sizes from a distance. Sometimes bergs not over 30 feet high can be seen for 20 to 30 sea miles from a height of eye of 20 feet. Once during the 1929 86 ice season on a day when refraction was making objects loom iip' higher than usual the white ice-patrol vessel was reported to herself as a berg by a steamer that was observed to be passing by at a distance of approximately 10 miles. However, if after a careful inspection no flaw in an incoming iceberg or temperature report is apparent, it must be accepted as correct and plotted on the cruise chart. The plotted bergs always have the date of the report written near by so that their successive positions from day to day can be followed. The water temperature values are plotted in different colored inks, the colors being changed every few days to enable the special portion of the cruise period during which they were received to be readily seen. The water-temperature values and the ice, but especially the latter, are never looked upon as something fixed and unmoving. They are constantly regarded as though in motion, and from the moment they are plotted they are looked at with a continually questioning attitude. Where will they be and how much will they be changed in one, two, or more days? If the patrol is to be of high value to shipping this attitude is necessary. Bergs often have to be found several days after they have been reported, as at the end of a period of fog, or after the patrol has been released by the complete melting of a par- ticularly dangerous berg that was being watched. Constant esti- mates must be made of berg positions at the expiration of different time intervals. The patrol has time to search out only the most probable locations of reported bergs. In most cases, due to the normal prevalence of strong currents, it can afford to go directly toward the spot where a berg w^as last sighted or reported only when the information is extremely recent, say, less than one day old. The task of keeping track of the southern ice limits would be fairly simple if good visibility were as prevalent over the Labrador Current as it is over the Gulf Stream 180 miles south of the Tail of the Banks. As it is, the patrol has to keep up a constant matching of its wits against fog-shrouded currents. Its errors and successes are strongly brought home as its searches during daylight periods of good visibility are suc- cessful or fruitless. There is a constant stimulus to find new ways of predicting berg movements and to perfect the old, not so much for the information of shipping, but for the guidance of the ice searches of the patrol vessels themselves. As the bergs are little affected by the wind, their movements are mostly controlled by ocean currents. Therefore, any method of predicting ice movements entails finding out the drift of water at the time. The present state of knowledge regarding ocean physics about the Grand Banks makes it appear that hydrodynamic surveys are the best means for determining the oceanic circulation there. The ice patrol has studied and worked with dynamic oceanographic 87 methods for some years. It has been found that the makmg- of satis- factory surveys of this sort entails steaming over lai^e areas fre- quently, for the precise surface and subsurface information that must be obtained can only be gathered by the patrol vessels themselves. With only one ice patrol vessel out on duty at one time this interferes greatly with the normal conduct of the practical part of the service. The second-best method of determining currents and berg drifts about the Grand Banks is the interpreting of surface isotherm curves in the light of past experience. The cooperation from shipping that has been worked up enables the patrol vessel to plot the surface iso- therms over a large area. The requirements of the hydrodynamic method and the dependence which can be placed on the surface iso- therms are both discussed in the next chapter. Conditions under which the patrol vessels work vary from month to month and from year to year. Weather conditions and informa- tion about ice coming in by radio often make it wise for the patrol to alter its course of action several times during even a single day. No hard-and-fast rules can ever be laid down, but existing circumstances^ as viewed in the light of the patrol's past experience, must always determine the cruising and other activities of the patrol vessels on each cruise. As a general principle, however, it can be said that the patrol must leave for other vessels to find and report all ice east of the forty-seventh meridian and north of the forty-fourth parallel. To narrow down and simplify the problem still further, it can be stated that the patrol vessels should almost exclusively confine their own activities to the area of an equilateral triangle with sides about 175 sea miles long and corners near 41° 30' N., 47° 00' W., 41° 30' N., 51° 00' W., and 44° 48' N., 48° 00' W. The above triangle contains about 13,200 square sea miles, and so is of the order of size that theoretically can be searched for ice two times during each patrol cruise. The areas along the western and southern edges of this triangle are most critical and should never be left unguarded for more than a very few days at a time, even during light ice periods. The reason for this is because the general drift of ice is southward down the western part of the triangle, then eastward along the westbound B steamship tracks near the southern part of it, and, finally, northward and northeastward away from the southern tracks and across the eastern side of the triangle. A berg entering the circulation at the northern apex of the critical triangle, if it is not melted, shunted off by local currents, or held up by some means such as grounding or coming into an eddy, can easily be discharged into a very dangerous position right along the westbound B tracks within a period of from 10 to 15 days. Fog and strong cur- rents and the necessity for standing by the most dangerous bergs, whether they are inside or outside of the critical triangle, make the 88 actual proper patroling of even the critical western and southern parts of its 13,200 square sea miles a continual problem. During heavy ice periods about the only times when the area inside of this triangle should be left are w^hen bergs that must be followed drift west or south of its southern portion. Of course during very light-ice times, which occur near the ends of some seasons, it some- times happens that there is no ice in the critical triangle. Then occasional runs to the north can be made in order to locate the south- ernmost ice limits. Generally speaking, however, throughout the active ice-patrol season, if a high degree of safety from danger of collision with ice is to be maintained during times of low visibility along the B tracks, the western and southern portions of the critical triangle must be constantly and repeatedly searched. The ice found there must be most carefully watched and followed until it either melts or recurves and drifts so far to the north that it no longer menaces the B tracks. During most of the ice-patrol season the B tracks just south of the critical triangle are in constant use. That means the route of west- bound traffic to the United States lies right along the southern edge of the critical triangle. These westbound ships are of great assistance in reporting water temperatures and in notifying the patrol of chance bergs that may be crossing the southern part of the triangle for points farther south, with some drift of cold water. The eastbound B tracks are 60 geographical miles south of the westbound ones, and so are considerably safer than the latter, on the general proposition that the farther south of the Tail of the Banks one is in the ocean, in the long run, the fewer bergs will be encountered. The eastbound traffic is doubly protected from liability of meeting unreported ice by the active operations of the westbound ships in cooperating with the patrol. Nevertheless, the 60 miles separating the eastbound and westbound traffic streams of the B tracks can be traversed by a berg during cer- tain times of accelerated circulation in a period of about 30 hours. Therefore, especially toward the ends of periods of fog of two or more days' duration, even along the eastbound B tracks, vessels while between 52° W. and 45° W. are subject to a real, though very slight, chance of unexpectedly meeting an unreported iceberg. Because of the much greater danger along the westbound B tracks, however, the ice patrol must at all times exert its utmost efforts to locate all bergs that are approaching the latter lanes from the north. Freighters, tankere, and other vessels not carrying passengers are not included in any track agreement and are not expected to adhere to any definite lane. A large number of the bolder vessels of the non- passenger class cross the ocean about where they see fit. The reports from such sources are the main dependence of the patrol for its knowl- 89 edge of by far the largest part of the great area lying between the United States and the Canadian tracks. This area is large when the patrol season starts, but it becomes very much larger as the advance of the spring melts back the field ice and permits the Canadian tracks to be shifted farther and farther north. It goes without saying that the value to the patrol of temperature and ice reports from vessels crossing between the usual tracks is inestimable. A large gain would be effected by the ice-patrol service if all such vessels would report their positions and water temperatures regularly instead of remaining silent unless they see ice, as it appears a number of them still do. Those passenger vessels which cut to the north of the tracks that are in effect (and the patrol noted, in 1929, 100 different cases where vessels carrying passengers were 20 miles or more north of their pre- scribed lanes), if they do not take rigid extra precautions, decrease their chances of coming through the ice regions safely. Their masters should bear in mind the fact that the ice-patrol broadcasts do not necessarily list all the icebergs in any area, but only the icebergs of which the patrol and the reporting vessels have knowledge. The positions of ice in the broadcasts are always subject to a certain amount of observational en or in the first place, and they become less and less reliable as time goes on, due to the impossibility of accurately fore- €asting berg drifts. Hope to make absolute determinations of future berg drifts can be expected neither from construction of dynamic cur- rent maps nor isotherm and ice charts. The best that can ever be hoped for is some reasonable approximation of the most probable courses and rates of movement that given bergs will take. South of the Tail of the Banks reported positions of bergs, even if correct within a mile to begin with, are normally subject to a 24- sea-mile radius of error with every day that passes from the time of the last report of them. Occasionally swift currents cause the radius of error to reach 48 sea miles daily, and very exceptionally to approach 72 sea miles per day. The dates given with the positions of the south- ernmost bergs enable the recipients of the broadcasts to determine within 24 hours the time the different bergs were last reported or sighted. This permits their making a very rough approximation of probable berg locations when knowledge of the usual drifts of ice is at hand. Some passenger liners, both eastbound and westbound, maintain notoriously high rates of speed, such as 20 knots, more or less, ac- cording to ability, even during periods of fog and darkness. The ice patrol has noted that a few of them actually maintain such speeds during bad visibility conditions when they are 100 miles and more north of their proper tracks. Such action is extremely foolhardy and is bound to result sooner or later in disaster. 100277—30 7 90 Vessels maintaining high speeds southeast of the Grand Banks, as- well as in more northern parts of the ice-patrol area, are at times dependent for safety on their chances of having an ice-free track ahead of them. It is entirely idle to think that micro thermographs,, subsurface echo or listening devices, or any other instruments that have as yet been developed by science, can protect ships from colli- sion with ice if they are traveling at from 10 to 24 knots during dense' fog, pitch darkness, and the like. If any device for detecting the presence ahead of bergs or heavy field ice were practical the fine- steamers on the Canadian tracks would adopt it and proceed at reasonable speeds during bad conditions of visibility instead of stop- ping or groping along at about 3 knots, as many of them do at such times, while between the longitudes where icebergs are situated. The danger of collision with ice is a real and not a fancied one at many times and places south of the Cape Race tracks and even south of the Tail. The Titanic is far from being the only vessel to have- struck a berg. To mention two recent cases, the reader is reminded of the Montrose, which in 1928 and the Vimeita, which in 1929, struck bergs head on off the eastern edge of the Grand Banks. Neither vessel was lost, but heavy damage was sustained in both cases. No one should deceive himself in this matter. To depend blindly on the broadcasts of the ice patrol is not enough. The only way to be sure of not hitting ice in regions where bergs are liable to exist is to keep a bright lookout and to travel at speeds low enough to insure ability to stop or turn aside before striking a berg just visible ahead under the prevailing atmospheric conditions. The Western North Atlantic can be likened to a great dance hall and the bergs to dancers. The southern part of the room is warm and unoccupied. The cold northern part of it is where the orchestra of the wind holds sway. There the floor is crowded by jostling dancers through whom one must pick one's way with great care. The central part of the room is occupied at times by a few of the hardiest and swiftest performers. Their maneuvers are watched, but the floor is vast and the light is so bad that fully half the time they can not be seen. Sending vessels past the Tail at high speeds during low visi- bility is like rolling thin glass balls across the central part of such a dance floor and hoping that they will not strike the flying feet of the dancers that occasionally execute intricate figures in the middle of the hall. For postulated berg sizes and frequencies the mathematical chances of collision with ice under the worst conditions of high speed and low visibility can easily be calculated. Let us suppose that bergs 300 feet in diameter are ahead of a fast liner and that there is only one such berg along each 60 mile front at right angles to the course line. It very frequently happens that the southernmost bergs have not been 91 sighted for 24 hours because of fog. A berg may move north, though the flow of the main body of the Labrador Current more often makes it move south. If it goes south very rapidly under the above con- ditions of berg distribution the chances are good that the next berg to the north will take its place in the 60 mile section immediately ahead of the ship. In 24 hours the position of each berg south of the Tail may be assumed to be indeterminate by about 30 sea miles. What is the chance that ice will be hit? The breadth of the liner can be neglected, for her maneuvering powers may be such that she can avoid a berg sighted ahead by half the amount of her beam, though if not properly made use of these same maneuvering powers are capable of causing a long raking colli- sion when otherwise the vessel would have just passed clear. The chance that a berg \vil\ be hit works out at 1 chance in 1,200, the ratio between the 300-foot diameter of the bergs and the 60-mile front at right angles to the course line along which each berg was assumed to lie. Such chances are not desperate ones, and the}^ would doubtless be welcomed by trans-Atlantic fliers; but the aspect becomes different when it is considered that there are exceedingly many steamship crossings past the Tail during fog and darkness each season and that when bergs are far south they are likely to be spaced much closer than one to every 60 sea miles at right angles to the track. Frequent long periods of fog make it impossible to guarantee that occasionally unannounced bergs will not get upon the B tracks. Whether or not there will be disastrous collisions with ice in the North Atlantic depends largely on the speed at which vessels run during thick weather and darkness while they are east, south, and southwest of the Tail. Ships crossing north of the Tail are, as has already been said, liable to meet more and more icebergs in proportion as they cross the Labrador Current in higher and higher latitudes; but their masters realize this and generally run very slowly during low visibility, thereby minimizing the ch-ances of serious damage in the cases where they find collision with ice is unavoidable. The above all serves to place some of the problems of the patrol before the reader and shows the inherent danger that lies in neglecting the scouting program for any purpose at all, even that of attempting to make current maps by the hydrodynamic method. So long as there is only one vessel out on patrol at a time, oceanographic stations can be taken here and there without any appreciable interference with the practical program, and this should certainly be done to keep up the annual continuity of the records of salinity and temperature offshore about the Grand Banks. Much useful information and much training in physical oceanography that may be valuable in the future, is given by the occasional scattered stations; but such station 92 arrangement only gives fragmentary dynamic information, and most assuredly does not permit the making of current maps of a sort that can be used as the basis for confident prediction of berg drifts. The Convention for the Safety of Life at Sea that was held in London in 1929 took up the matter of the ice patrol and recommended that a maximum of three instead of two ships be made available for the work. It is hoped that in the future it will be possible to employ a third vessel whose complement will include a professional ocean- ographer. The ice-scouting and information-broadcasting vessels could then be relieved of the burden of the larger part, at least, of the scientific oceanographic work. The addition of a vessel primarily for the scientific program would mean a great step forward and would be justified even if the dynamic current maps which it could make should finally prore to be of small practical value. In addition to the large funds of knowledge that such a ship should be able to obtain for pure science in such fields as oceanic circulation and submarine bottom configuration, her pres- ence about the Grand Banks under the direction of the commander, International Ice Patrol, would at critical times be of great practical value. She could send in surface temperature and weather conditions reports to the scouting ship from areas from wliich no ships were reporting and could be called upon when necessity arose to search key areas or to trail and observe the final disintegration of especially dangerous bergs. The main patrol vessels, on the other hand, when relieved of the oceanographic station work could better take on board the necessary additional personnel and gear to permit a start to be made in the matter of ice scouting by aircraft from the patrol vessels. The cautious and well-thought-out use of aircraft to assist during periods of fine weather in searching out the region in and near the critical triangular area just north of the B tracks would seem to be one of the most promising of the fields of development that are open to the ice patrol at the present time. OCEANOGRAPHY 1. Scientific work during the 1929 patrol season. 2. Prediction of iceberg drifts. A. Surface isotherms as basis for prediction. B. Dynamic current maps as basis for prediction. 3. Estimate of total annual amount of glacial ice south of forty-eighth parallel and its total chilling eftect on the water. 4. Observations on iceberg disintegration south of the forty-fourth parallel. 5. Possibility of breaking up icebergs artificially. 6. Local convectional circulation about icebergs. 7. Miscellaneous. 1. SCIENTIFIC WORK DURING THE 1929 PATROL SEASON Following" immediately after this chapter the reader will find figures showing a number of current diagrams and oceanographic sections constructed from data obtained at some of the 69 oceano- graphic stations occupied during the season. That portion of the year's stations too isolated either in time or place to be utilized for the construction of current diagrams or sections are of scientific interest as records of 1929 surface and subsurface temperatures and salinities in the vicinity of the Tail of the Grand Banks. There- fore, all station data are given in full at the end of this pamphlet. Station procedure in general and the normal levels to be sampled were the same in 1929 as since 1925. The main advantage in ad- hering to the same levels year after year is that the values found are then strictly and easily comparable over long periods of time. Uncorrected Richter and Wiese reversing thermometers without attached auxiliary thermometers were used in Greene-Bigelow water bottles at all stations. The variable-speed electric hoists used at the stations were ec(uipped with spooling devices that laid up the ^^2-inch steel ^\•ire on the drums satisfactorily. The hoists gave good service without any interruptions and there was no loss of gear. One of the ice patrol's two electrical salinity determining cabinets having worn out, the use of a titrating outfit for the Modoc was obtained through the courtesy of Harvard University. This method of determining salinities, new for the ice patrol, was purposely set up and tried out during rough weather early in the season. It was found perfectly workable when due precautions were taken to handle the delicate glass instruments with care and to protect them by the use of suitable racks and string ties. The electrical salinity measuring method as used on the ice-patrol vessels is about twice as fast as the titration method and is much easier and simpler; hence it should be used when a very large number (93) 94 of water samples are to be handled. The comparative cheapness, light weight, and availability of the titrating outfits, however, make them preferable to the electric-salinity cabinets, unless over 1,000 samples of water are to be analyzed per ship per season. The former are from twenty-five to fifty times cheaper and lighter than the electrical outfits. For worth-while residts both methods require well-trained and conscientious operators. Under comparable condi- tions the accuracies obtainable by the two methods are probably about equal. The large number of bergs south of the forty-eighth parallel during the 1929 ice season claimed the patrol's almost undivided attention. If the ice had been less, either in extent or amount, more oceano- graphic work woidd have been done. In a general way, and as in previous years, the currents that the dynamic oceanographic compu- tations showed theoretically should exist, actually did exist in fact, as shown hj occasional iceberg and patrol-ship drifts. 2. POSSIBILITY OF PREDICTING ICEBERG DRIFTS A. SURFACE ISOTHERMS AS BASIS FOR PREDICTION Berg-drift predictions are highly necessary for the information and guidance of the patrol itself, even though the conclusions should not be accurate enough to send out in the broadcasts. Therefore, any method simpler than the dynamic one that the patrol ships could employ without interfering too much with their primary scout- ing and trailing duties is much to be desired. Having explained at some length in the preceding chapter the features of some of the problems confronting the ice patrol, the matter of predicting berg drifts can now be taken up with clearer understanding. The only other method besides dynamic mapping that has been suggested for picturing the varying circulation in the ice-patrol area has been that based on a study of surface isotherm charts. The surface isotherms have always been assinned to give a broad general idea of the prevailing water and ice movements m and about the Labrador Current throughout the season. The main reason why the patrol vessel carefully plots both her own surface-temperature observations and those coming in from other ships is because the ice in general is expected to be found and to remain where the water is coldest. The cruise isotherm charts have been considered valuable enough to reproduce each year in the ice patrol's bulletins, but they have not been given important consideration when attempting to fore- cast movements of bergs that have not been sighted or reported for some time. The reason for this lack of confidence lies in the numerous discrepancies that have been noted when bergs did not move parallel to the isotherms or even close to the dii-ection which the surface isotherms seemed to indicate thev should take. 95 It IS obvious that if it were possible to deduce from a study of the surface temperatures alone the circulation existing at the time, and that is likely to continue to exist for some time to come, the making of estimations of future berg drifts would be rather simple. Exper- ience shows that with the cooperation of passing vessels isotherm charts can be constructed every 15 days which show in excellent detail the picture of surface temperatures over almost the whole of the region between the thirty-ninth and forty-ninth parallels and the forty-third and fifth-sixth meridians. This embraces all of the usual ice regions south of Newfoundland and a goodly area of their surrounding waters as well. It covers an area between ten and twenty times as large as that which two ships of the character of the present ice-patrol vessels could keep properly mapped dynami- cally in the eddjdng waters about the Grand Banks, even if they devoted alternating at-sea periods entirely to oceanography. The making of the isotherm charts from the ship's log and from the received radiograms is a routine process that requires but one or two hours of work per day from two men. It does not consume any of the ship's scouting time or interfere with any other of her ice-patrol duties, and so is entirely within the capabilities of the present ice patrol. On the other hand, the full projection of dynamic current maps is not, as will be shown in the next section. The vital question is whether the best surface isotherm charts procurable can be interpreted in any way to be relied upon to prop- erly picture the circulation of the layers of water which control the movements of the bergs. Hardly less important is another query: If the true circulation at the instant is mirrored properly, how much can the surface isotherms be depended upon to tell the story of what currents will prevail from two to seven days later? The first thing that must be done when approaching the problem is to determine what paths icebergs have taken in the past. The main courses that they are likely to follow in the southern part of the Labrador Current are very clearly shown in Figure 30 on page 69 of Coast Guard Bulletin 16. This chart, which sums up the berg-drift information gathered b}^ the ice patrol up to and through the 1927 season, is one of the fundamental sources of practical ice- drift information. It is constantly referred to when bergs are reported or sighted because it gives some information of the direction in which the ice may drift while not under surveillance. This chart and its companion chart, Figure 29 on the page facing it, when compared with the composite picture obtained from a study of all the isotherm charts explain why it has been assumed that the bergs tend to remain in the colder waters and to follow in general the usual paths taken by the varying pushes of the same. 96 Even when the case is narrowed down from full seasons and cruise periods to that of individual drifts it is still found that a good agree- ment is actually observable between many berg, wreckage, and ship drifts, on the one hand, and the particular distribution of current that the surface isotherms at the time suggest, on the other. This raises grounds for hope that an intelligent interpretation of the isotherm curves alone can be used to forecast future berg drifts, at least in some regions and cases. Let us examine the isotherm and ice charts of the 1928 and 1929 ice-patrol seasons and see how much the isotherm charts in their present state of development can be depended upon to indicate berg drifts. The charts should be considered with the usual drifts of bergs about the Grand Banks in mind and with a knowledge of the general subsurface conditions of the region that the oceanographic station work to date has furnished. To depend upon the different isotherm charts alone would be to invite confusion and misinter- pretation. Some of the rapid berg drifts indicated by dotted lines south of the forty-third parallel on the ice charts for the months of May and June, 1928, show a general agreement with the isotherm chart for the period during which they occurred, May 21 to June 5, 1928. Com- parison of three drifts shown on Figures 9 and 10 with the isotherms on Figure 28 in Coast Guard Bulletin No. 17 suffices to show this. The berg drifts during the period of the seventh and eighth patrol cruises of 1929, from July 3 to August 2, again illustrate the good correlation between the surface isotherms and the regional oceanic circulation in the area of special danger to shipping south and south- east of the Tail. To facilitiate comparison the drift tracks of all of the 1929 bergs whose drifts the patrol was able to determine have been placed on the respective isotherm charts appearing in this Coast Guard Bulletin. From the comparatively pure Gulf Stream waters just to the south of the limits of bergs many temperature reports are received by the patrol. These waters are found to be often characterized by deep embayment of the isotherms, similar to those that occur in the colder mixed waters just offshore of the Tail. Coming in with the temperature reports from the waters of tropical character there are frequent reports of spars, buoys, and other floating objects. Atten- tion is called to the particular drift of a buoy shown on the isotherm chart for the period June 18-July 2, 1929. This buoy's drift was plotted from a series of reports each so complete and specific as to positively identify it. There were no strong breezes or gales to interfere with the local currents. It can be seen that its successive positions indicate that the local drift among the isotherm cmbay- ments in the warm water was at the time to the northwestward, 97 very much at variance with the ordinary conception of the flow of the Gulf Stream drift but in direct agreement with the direction of drift which would. have been predicted from an inspection of the local surface isotherms on the chart. But watching the drift of bergs and other passively floating bodies is not the only available means of ascertaining local currents. The moderate wind conditions that usually prevail in the ice-patrol area during the last half of the patrol season enable that portion of the patrol ship's own drift which is due to current alone to be rather accurately determined during times of good visibility. The value of current determinations of this sort varies with the accuracy with which the vessel's observations of the heavenly bodies are made. Methods of position fixing by means of soundings and radio bearings, though at all times useful for check purposes, and necessariljT^ relied upon during foggy and overcast w^eather, are not exact enough to be of much use for accurately determining ocean currents oft" the Tail of the Grand Banks. On the other hand, the positions obtainable through celo-navigational methods during favorable periods are at times dependable within a radius of not over 3 miles, and so quite valuable for this purpose. Position fixing is of prime importance to the ice patrol for a num- ber of reasons and great attention is paid to it. The most modern methods of handling the observational and chart work are followed. Positions are checked by independent work of at least two experienced navigators. Spending most of its time searching relatively small areas near the temperature wall between the Gulf Stream and the Labrador Current, drifting at night, and keeping track of its position as it does, it is believed that the ice patrol is at man}^ times particularly capable of observing the rates and directions of the local currents. Many of these currents are so restricted in size and vary so much in direction over the course of one or two hundred miles that they are frequently averaged out and lost during the long runs made daily by ships bound east and west across the ocean at speeds exceeding 8 or 10 knots. In three cases when the ship's location was well determined strong currents were observed during the 1929 ice-patrol season, as follows: On April 25 and 26, a sustained 2.6-knot current setting east and northeast along the forty-second parallel between 49° W. and 51° W. On June 7, a current setting southeast over 2 knots near 41° 38' N., 48° 56' W. On June 24 and 25, a 2-knot easterly current near 42° N., 50° W. In every case the existence of these strong currents is fully indicated by the position of the curves on the isotherm charts. When a well-developed cold wall exists between the Gulf vStream and Labrador Current a rapid flow parallel to the isotherms seems to be characteristic. 98 One of the striking features shown by the surface isotherms south- east of the Banks is that of the tremendous embayments in the boundary between the cold and warm currents. That the warm and cold tongues are especially well developed in the middle part of the ice season is shown by the isotherm chart for the period May 21- June 5, 1928 (fig. 28 in Coast Guard Bulletin 17), and the one for the period June 3-18, 1929 (fig. 29 in this pamphlet). Very often where an extra cold tongue from the Labrador Current extends southward on the surface an extra warm tongue will pro- trude north close to it and just to the westw^ard, it would seem almost as a compensation. This sharp contrast of waters at times appears to accelerate the local oceanic circulation along the adjacent intensi- fied temperature walls. The 5-day drift of 160 miles across the forty- fifth parallel of the southeasternmost berg of April, 1928, is not in close agreement with the surface isotherm indications in the area, but it is quite characteristic, and may be typical of the local area and the particular contemporary distribution of surface temperature. The writer believes it to be referrable to the close approximation of tongues of 42° and 54° surface water near 44° 20' N., 45° 50' W., which are plotted on the isotherm chart for the period April 6-21, 1928 (fig. 25, Coast Guard Bulletin 17). Examples of berg drifts much at variance with the surface isotherm indications are easily found. Off Cape Race, along the eastern edge of the Grand Banks and close to and west of the Tail, such apparently anomalous berg drifts are freci[uent. Possible explanation of this condition can be found in the persistent streaming along of the layers of cold water controlling the bergs. It appears as though the cold water is at times forced under warmer and lighter surface layers, and in these cases the surface isotherms should not be taken as guides for berg drifts. To be able to detect these cases experience in the ice- patrol region or close study of the old ice-patrol records is necessary. Before any definite statement can be made it will be necessary to determine more fully under what conditions and how regularly surface isotherm curves can be assumed to mirror the underlying circulation. Present indications are that this is the case and that valuable infor- mation can be. obtained from them in the cases where and when a cold wall is strongly developed. By a cold w^all is meant a region in which the surface isotherms are noticeably packed. It is a narrow belt across which the surface temperature gradient is much greater than it is farther on in either direction along the line drawn at right angles to the different isotherm curves. The dynamic investigations have shown that the density wall, which usually controls the circulation, normally lies a variable dis- tance ipshore of the cold wall in the Grand Banks area. When depending on the surface temperatures alone the exact location of 99 the densit}' wall is, of course, unknown. Nevertheless, in cases where a cold wall is strongly developed, it appears that the following rule holds good. An observer stationed along the junction line between markedly warmer and colder water, will, if he faces directly toward the cold water and puts the warm water at his back, have the local ocean current in his immediate vicinity, both behind and before him, flowing from his left-hand side toward his right-hand side. This is not advanced as any general rule for the Northern Hemis- phere-or even as an infallible one for use in the whole of the 150,000 square sea mile most probable ice area about the Grand Banks. At some times and in some places the varying relations between different water masses are affected by earth rotation, wdnds, shoals, and other factors too much for that. There are complications caused by shifting of surface and subsurface layers from their original posi- tions, and masking effects due in place to late season surface warming over true cold water. Nevertheless, the rule is a good working one for the ice patrol when it is used with due regard for the special dynamic and other circulation conditions that are liable to be encountered. When the horizontal surface temperature gradient is small, and in the localities liable to subsurface pushes of cold water the case is not clear. Nevertheless, the surface isotherm charts are already of such great value to the patrol for the estimation of berg drifts that every effort should be made to improve their character, regardless of whether or not the dynamic oceanographic maps are continued. It is certain that the isothermal method is susceptible of greatly increased development, mainly through increasing the number of incoming water-temperature reports. Such an increase in number would be very desirable even if the values were not useful for con- structing surface isotherm charts. These reports serve to keep a close check on the positions and courses of the different passing vessels, inform the patrol what areas are being searched for ice, and tell what weather conditions are prevailing in different localities. An average of 60 water temperature reports per day were received during the 1929 ice season. If this could be increased to 100 reports per day the value of the isotherms for estimating currents and berg drifts would be more than doubled. The value of the isotherm charts would be greatly increased by a few more reports per day if these could be obtained from vessels crossing the ocean between the United States and the Canadian tracks. Requests for water temperatures from this area are often inserted in the broadcasts in order to obtain more values from the little-frequented parts of it. An increase" in the total number of temperature reports and a little better distribution of them would permit the making of a valuable isotherm chart weekly instead of every 15 days and would also permit a slight 100 reduction in the temperature interval between some of the isothermal lines. Any final general statement at this time of the value of the isothermal method of determining ocean currents in the Grand Banks region would be premature, however. The whole matter of correlating berg drifts and surface isotherms is now under critical study. The drifts of bergs during the 1930 ice season will be closeh^ watched for instances of their adherence or nonadherence to the isothermal indica- tions. They should furnish considerable additional data upon which to judge the merits of the case. B. DYNAMIC CURRENT MAPS AS BASIS FOR PREDICTION Another method, distinct from the examination of surface isotherm curves by experienced observers, has been suggested for prediction of iceberg movements. It involves the construction of dynamic current maps, and is undoubtedly accurate when certain conditions are fulfilled. To make good current maps of this kind, however, a more detailed d^'namic mapping of the area is necessary than the ice patrol can usually undertake. Therefore, under the present condi- tions it is impossible to get the maximum obtainable amount of benefit from this method. How an exact knowlege of the temperatures and salinities prevailing at the different levels throughtout an area permits the construction of a current map showing the local oceanic circulation has been fully explained in the Coast Guard bulletins describing the ice patrols of 1926, 1927, and 1928. Coast Guard Bulletin 14, December, 1925, gives detailed information telling how such maps can be made and interpreted. Some idea of the effort which the ice patrol must put forth to do satisfactory dynamic oceanographic work will be obtained from the discussion which follows. Because of rapid mixture of warm Gulf Stream and cold Labrador Current water, the ocean currents off the Tail and the eastern slope of the Grand Banks are in a particularly active state of turmoil and fluctuation. Therefore, to be sufficiently comparable, dynamically, to give satisfactory current maps, the different oceanographic stations within an area about 100 geographical miles square must be occupied during a period of not over 10 days. The results would be more reliable and lasting if the stations were taken within a period of seven days. To confine the station work to an area smaller than 100 sea miles square, or to an equivalent rectangle of less than 10,000 square geographical miles, would be to limit so seriously the scope over which the berg-drift predictions could be made as to make the current map of very small practical value. The time during which the taking of a series of stations can be safely spread out will vary much with the rate of change of location of the different water masses in the area under observation. The 101 7 to 10 day periods mentioned above represent the estimated time lapse which the writer considers permissible for a set of observations taken under the usual conditions that prevail in the various 10,000 square geographical mile areas located over the deep water just east and southeast of the Grand Banks. A case of shift of position of water masses due to time lapse can be seen when stations 1078 and 1091 are compared. These were occupied within 10 miles of each other, but the interval of 21 days between them prevents a reasonable dynamic comparison of the two water columns. In the period between the taking of the first and second of these stations a lighter water column appears to have pushed inshore toward the eastern edge of the Banks. The warming of the surface layer can be attributed to seasonal effects, but this cause can not explain the large temperature rise of the 125 and 50 meter levels. The salinities at all levels above 750 meters are much alike at the two stations. The considerable difference in temperature values at some levels can best be explained by postulating an inshore invasion of warm water. Fifty stations, taken within the stipulated 7 to 10 day period, are about the minimum number that can give a current map of a 10,000 square sea-mile area of sufficient accuracy to be of much real practical value to the ice patrol. From the experience of the past four years it is known that 50 stations, arranged in five rows 20 miles apart, with 10 stations in each row spaced at intervals averaging 10 miles, would suffice to give a dynamic current map showing in some detail the complicated local currents of a 100 sea-mile square area. When completed, the dynamic current maps are interpreted much like weather maps, but the stations must be placed much closer together than the Weather Bureau's observing stations if the compli- cated detail of the water circulation is to be caught. They must be spaced much closer about the Grand Banks region than similar ocean- ographic stations taken for like purposes in parts of the ocean where erratic currents due to mixture of radically different water masses are absent. The hydrographic station values need not be regathered so fre- quently as meteorological observations at weather stations. It is well that this is so because it is much more tedious and difficult to get the required dynamic data properly at an oceanographic station than it is to observe the meteorological elements at an ordinary Weather Bureau station. The great mobility of the atmosphere requires the weather map to be remade from the synoptic data every 12 hours and in the sea off the Grand Banks where the currents are especially complicated and interlocking, the stations must be taken, as stated previously, within a 7 to 10 day period and com- paratively close together to get the full story of the sea-water inter- 102 actions. Because the current speed and the mobiUtv of the ocean swirls are of the order of twenty to forty times less than that of those in the atmosphere, the current maps when once made are probably good for about one week, though it is doubtful if the detailed current map of the hypothetical 10,000 square sea-mile area made during the course of 7 to 10 days, can be depended on very closeh^ after three or four days from its completion, due to the length of time required to develop it. Taking the most favorable arrangement of courses possible, to make a good useful current map of the 100 sea-mile square area with 50 stations as outlined above, it is necessary to steam about 600 sea-miles. At 8 knots, a high average speed for a scientific ship to maintain under the conditions prevailing about the Grand Banks, this would take 75 hours. Add 50 hours to this for the time required for work at the 50 stations, and a period of 125 hours, or just over five and one-sixth days, of intensive undivided work by a ship in midocean is seen to be necessary to gather the data required for the making of a dynamic current map of what is really a very small portion of the usual ice area south of the forty-eighth parallel. During a large part of the station taking period good visibility should prevail, for it is very necessary to insure accurate geographical location of at least a number of the stations to keep the whole map from being hazy and indefinite. In places near the edge of the Banks radio bearings and sonic soundings serve to locate position rather accurately at times, but in most places many and good celo-naviga- tional observations are absolutely essential to satisfactory position fixing. Observations can only be obtained during weather excellent for ice searching. If the Yerj exacting oceanographic work inseparable from the con- struction of detailed dynamic current maps is seriously prosecuted, the primary object of the patrol, the location by scouting and radio infor- mation of ice for the protection of shipping, must be neglected to an appreciable extent. Each time, before commencing upon the cruising necessary to the construction of a current map, the commanding officer of the patrol ship must weigh the possible advantages to be obtained from a dynamic current map against all features inimical to the prac- tical program that such construction will entail. A current map made at the expense of a vessel's disastrous collision mth ice which might have been averted, but for the oceanographic work, would involve a cost entirely too high to pay. A single patrol ship can either make cm-rent maps or stay with the ice. It can not do both at the same time with any degree of justice to either. Apart from their practical value to the ice patrol, dynamic current maps have a permanent scientific vailue which is not interfered with by delay in plotting them. A number of current maps in the Grand 103 Banks region have already been made, however, and it would seem to be established that they can be made, and that they can be made again whenever necessity arises. A close study of maps already on hand would now seem to be in order, rather than a multiplication of maps of very transient value to the patrol. During very light ice years, and at times when all the bergs are 200 miles or so to the north of the steamship tracks being used between Europe and the United States, an ice patrol with one vessel only out on duty might be justified in devoting itself to the tasks of dynamic oceanography to the extent of attempting to make detailed current maps of 10,000 square sea mile areas. Even during such times, how- ever, such a procedure is open to question. When the Europe-United :States tracks are not endangered by ice it would seem to be but logical to devote attention to actual patrolling along the southern- most routes between Canada and Europe. The ice patrol, besides being international in name, is entirely so in fact, receiving its support from international contributions, and therefore bound to protect impartially to the limit of its ability all the ice-endangered tracks across the North Atlantic. Putting aside this possible exception during light ice years and periods, it would certainly seem that the ice-patrol service as now conducted, that is with two ships alternately out on duty, should most emphatically not devote its activities to oceanography to the extent required for the construction of good dynamic current maps. Depending upon poor current maps is worse than not having any at all. The real solution of the dynamic mapping problem lies in the employment for the ice-patrol duty of an additional vessel, charged primarily with the scientific work. 3. ESTIMATE OF TOTAL ANNUAL AMOUNT OF GLACIAL ICE SOUTH OF FORTY-EIGHTH PARALLEL, AND ITS TOTAL CHILLING EFFECT ON THE WATER It has been argued by a certain school of scientific thought, influenced by the oceanographer, O. Petterson, that the bergs about the Grand Banks in melting furnish the energy which keeps the southern reaches of the Labrador Current moving along as they do. On the other hand, others, and especially F. Nansen, contend that melting icebergs have little effect in producing great ocean currents. Attempts to estimate the total amount of glacial ice that comes south of the forty-eighth parallel in any one year and to consider its possible chilling effect on the water masses there may throw some light on this problem. If it is a fact that a negligible amount of cold water is produced by the melting of the bergs that get south of the forty- eighth parallel in the Labrador Current, it will be reasonable to sup- pose that their melting will be unable to have much effect on the hori- 104 zontal ocean currents that exist to the east and south of the Grand Banks plateau. In 1929, the heaviest ice year that the international ice patrol has experienced to date, approximately 1,300 bergs drifted south of the forty-eighth parallel in the Western North Atlantic. When it crosses the forty-eighth parallel the cubical contents of the average berg, above water, is not greater than that of a block of ice 100 feet high, 400 feet long, and 100 feet wide. That means that the average berg has, above water, not more than 4,000,000 cubic feet of glacier ice. Lieut. Commander Edward H. Smith, a former ice-observation officer of the patrol, estimates the average above-water volume of bergs about the Grand Banks to be one-third of this amount. However, a certain amount of glacial ice in the form of growlers crosses the forty-eighth parallel each year. To allow for this ice, and to insure that the total quantity of fresh-water ice will not be underestmiated, a rather larger average size has been allowed for the bergs than would otherwise be the case. It is quite likely that a fair estimate of the correct annual total amount of above-water glacial ice that enters the region about the Grand Banks will be obtained by multiplying the total number of bergs given by the ice patrol as south of the forty-eighth parallel each year by 4,000,000 cubic feet. This figure is advanced as a maximum one, the real amount being probably somewhat smaller,, due mainly to duplication of berg reports. The total amount of ice to come south of the forty-eighth parallel is^ of course, the sum of that which is above and below the sea surface. The underwater body of a berg being quite irregular and largely hidden, its total volume is extremely hard to determine by actual observation or measurement. In the past it has undoubtedly been overestimated. The fresh-water glacial ice of the North Atlantic iceberg is, according to experiments made by the physicist, H. T. Barnes, about 10 per cent lighter than the solid ice which is formed on the surfaces of lakes and streams in winter. The reason for its lightness is found in the much larger proportion of air in the form of tiny bubbles that it contains. All the pictures of ice in this bulletin show how white and clouded with innumerable tiny air bubbles the glacial ice of icebergs really is. According to Barnes' estimate its specific gravity averages close to 0.830 as compared with about 0.916 for clear ice and 1.000 for pure water at the point of maximum density. Since nearly all of the bergs to the south of latitude 48° N. float in sea water of density varying between 1.02 and 1.03, they must float on the average about one-fifth out of water instead of one-eighth. Until recently the latter figure has commonly been accepted a& approximately correct, but if Barnes is right, it is entirely too small. 105 The actual range of density of glacial ice in the Grand Banks region should be checked by more observations. The size of the average berg has been taken great enough to insure that no large underestimation can be introduced into the final figures by the slight uncertainty that still exists relative to the average specific gravity of the ice. Therefore, multiplying the average berg's 4 million cubic feet of above water ice by five, we find that on entering the waters about the Grand Banks it contains not over 20 million cubic feet of ice in all, or, in other words, has a total mass slightly in excess of 500,000 short tons. The total amount of berg ice, both above and below water, south of the forty-eighth parallel in 1929, may, therefore, be estimated as thirteen hundred times 20 million or 26 billion cubic feet, which is roughly about 676 million short tons. Such an amount of ice would require well over 100 trillion British thermal units to reduce it to water at 32° F. This is a formidable amount of heat, for each British thermal unit is equal to 252 gram calories. It is with this draft of heat that icebergs melting south of the forty- eighth parallel directly affect the temperature of the waters in which they are distributed. As soon as the area in which the 26 billion cubic feet of ice melts is estimated, the possible eft'ects on water layers in the area can be computed. The isotherm and ice maps show that the cold waters that would be directly aft'ected by this melting ice extend over about 20,000 square sea miles south of the Tail, 30,000 square sea miles along the eastern e6.-7,e of the Banks, and 24,000 square sea miles between the forty- seventh and forty-eighth parallels. (See figure 1.) This is a total area of 74,000 square sea miles or 2,644 billion square feet. Hereafter this area will be referred to as the "melting area." The section of it to the south of the Tail, and the southern half of the sec- tion of it along the eastern edge of the Banks, include the whole of the 13,200 square sea-mile critical triangle of the patrol described in the chapter on procedure and remarks. They include the waters that surround the critical triangle as well. The northern parts of the "melting area" include all waters through which the bergs pass to reach the critical triangle. It was also stated in the discssion of the practical problems of the patrol that berg ice is normally found each year inside a 150,000 square sea-mile area south of the forty-eighth parallel. The "melting- area" is the very heart of this usual ice area, and inside of it fully 90 per cent of the ice that comes south of the forty-eighth parallel can be expected to melt. To draw comparisons so that the size of the "melting area" can be more readily visuahzed, its 74,000 square sea-mile extent is a little larger than the six States that comprise 100277—30 8 106 New England, and a little smaller than the combined area of England and Scotland. Without attempting to discuss the vertical circulation that takes place within the radius of a mile or so from a berg melting under the varying weather and water conditions that it encounters during its life span in the Grand Banks region, it is certain that the bergs do chill sea water there in melting. It makes no difference in a discussion of their total chilling effect whether they affect surface or subsurface layers. From whatever stratum the heat is chiefly drawn, the total amount consumed will be the same. Let us assume that the bergs directly affect a layer of water averag- ing over the 74,000 square sea-mile "melting area" 50 feet thick. This is a minimum thickness to expect them to affect and a convenient one for calculations. It gives 133,200 billion cubic feet of water in the "melting area" to be affected by the disintegration of the total of 26 billion cubic feet of glacial ice. Simplifying the problem, it is found that for each 5,123 cubic feet of water there is 1 cubic foot of ice. The latter is very close to 32° F. in temperature when it crosses the forty-eighth parallel. Neglecting the lightness of the glacial ice, and the salinity of the sea water, and generously allowing that 80 cubic feet of the latter can be chilled 1° F. by the melting of 1 cubic foot of the ice, it follows that the melting of the total amount of glacial ice present throughout the whole ice season in the region under discussion would only counteract the normal seasonal warming of a 50-foot layer of w^ater in the melting area south of the forty-eighth parallel by 0.0156° F., an insignificant amount. It should be borne in mind that the 1929 ice year, on which the 26 billion cubic-foot berg ice total used above is based, was an ice year about three times as heavy as the normal one. It is safe to say that during the normal year, when less than 400 bergs come south of the forty-eighth parallel, supplying the heat requirements of the glacial ice disintegrating in the "melting area" does not chill any 50-foot stratum of water in the cold current there by more than 0.01° F. It has been assumed in arriving at the above estimate that no chill- ing effect from the bergs is lost directly to the air. This loss exists, but it is doubtless extremely small. It has been further assumed that no locally ice-chilled water is lost from the "melting area" to the westward past Cape Race, to the westward to form bottom water over the Grand Banks, or to the southeastward past Flemish Cap. Analy- sis of berg drifts shows that, during the ice season at least, there is but little push of cold water to the westward past Cape Race or onto the Banks. Some losses in these directions occur, however, and even more ice and cold water are lost to the southeastward past Flemish Cap. The sum total of losses in all three directions probably amounts 107 to well over 5 per cent of the effect of the melting bergs. The larger this percentage loss is, the less will be the chilling effect on the local waters of the bergs that melt in the "melting area." The 0.01° F. figure is a maximum for still another reason not pre- viously brought out. During a 100-day ice-patrol season, the cold current is entirely renewed at least once throughout the "melting area" if the average southerly drift of the current is only 4 sea miles per day. But the southerly drift of the ice bearing waters averages much more rapid than this. Therefore, the chilling effect of the sea- son's bergs should not be figured upon the simple extent of the 74,000 sc^uare sea miles. It should be spread out over a water volume cover- ing a surface more than twice as large, over the total area of cold water that passes through the "melting area" during the ice season. These conditions need not be emphasized because the approximate figure of 0.01° F. which was arrived at is already sufficiently small to indicate the relative unimportance of the bergs as chilling agents in the southern reaches of the Labrador Current. Even if ver}^ large miscalculations have crept in, and the total amount of berg ice to get south of the forty-eighth parallel should by any chance be twice as large as has been estimated, still its effects will be so small as to make them extremely unimportant. An oceanic effect diametrically opposite to the chilling influence of melting bergs is to be found in the vernal w^arming at and near the surface about the Grand Banks. The next paragraphs will discuss that part of the tremendous seasonal warming which the ice patrol is able to observe, and will compare its magnitude with the 0.01° F. chilling value just deduced. The normal ice-patrol season can be taken as 100 da3^s long, from March 25 to July 3. A slight amount of exterpolation is necessary to arrive at the March 25 and Juh^ 3 surface temperature values in 3'ears when the active patrol season begins late or ends unusually early. On the whole such allowances are easy to make and the ice- patrol period can be used as a convenient measuring stick. Since the normal ice-patrol season extends from just past the vernal ec^uinox to well past the time of the sun's most northerly declination, the sun has a high position in the heavens at noon, and the surface waters warm up rapidly over the whole Grand Banks regions through- out the time. Although there are large local variations, and also annual variations of less amount but larger significance, comparison of the patrol's surface isotherm charts show that the rates and amounts of warming in the same areas in different years agree closely. At the beginning of the season, just before April 1, the temperature of the Grand Banks surface water is about 33° F. At the close of the season, a little after July 1, it is about 55° F., a rise of 22° F. Over the varying extent of cold Arctic stream water south of the Tail, the 108 temperature is about 33° F. at the start of the season and 50° F. at its close, a rise of 17° F. Along the eastern edge of the Banks the true cold water rises from about 32° F. to about 47° F., a rise of 15° F. Between the forty-seventh and forty-eighth parallels the Labrador Current surface water during the same time warms from about 32° F. to about 44° F., a rise of 12° F. South of the Banks along the fortieth parallel in the Gulf Stream the rise during a 100-day ice-patrol season amounts to 10° F., from about 60° to 70° F. The varying rates of warming in different areas about the Grand Banks are in the main easilj" accounted for. The Grand Banks water, for instance, is shoal and it is somewhat less subject to fog blankets than the Labrador Current. Moreover it is relatively stationary in so far as the effects of true ocean currents, as distinct from tidal ones, are concerned. It is, therefore, favorably situated to show a high degree of vernal surface warming. On the other hand, the surface water of the southern parts of the Labrador Current is constantly being replenished by cold water from the north. It is underlaid by extremely cold water and overlaid by much fog throughout the season. The effects of solar warming show up slowly and it is easy to see w^hy it only warms up 14%° F. on the average during the time in which the Grand Banks surface waters are warming up 22° F. The Gulf Stream's small surface warming despite much clear weather can be attributed principally to the fact that its waters are already warm. It is flowing with a large northerly component into cooler regions of decreased sun strength where radiation and other losses can with less and less facility be counterbalanced. The area of mixed surface water between the Gulf Stream and the Labrador Current changes position and size rapidly, varying so much from month to month and 3^ear to year that it is hard to say just what its exact increase in temperature is. A fair figure would be one some- where between that of the pure Labrador Current and Gulf Stream surface water, say 13° F. Coming back to the 74,000 square sea mile "melting area" it can be seen that, though principally over the Labrador Current, it slightly overlaps the Banks, and extensively overlaps the mixed water oft"- shore. Fourteen degrees Fahrenheit can be taken as a good figure for the total rise of its surface water temperatures during the 100- day ice-patrol season. The warmed waters tend, of course, to remain near the surface of the sea, hence the warming effect decreases rapidly with depth throughout the Grand Banks region. Let us assume that the rise of temperature at the 50-foot level in the "melting area" during the ice-patrol season is 10° F., as compared with 14° F. at the surface during the same time. The stations which the ice patrol has taken in the area usually sample the surface, the 25- 109 meter, and lower levels, and tell nothing directly about the tempera- ture of the 50-foot level. Nevertheless, a study of temperature curves made from the station figures shows that 10° F. is a conservative estimate to make for the average increase in temperature at the 50- foot level between March 25 and Juh^ 3. Let us neglect the tremendous sum total warming that takes place in decreasing increments in the 50-foot la^'ers of water below the 50- foot layer that has its upper boundary at the surface of the sea. We can for the purpose of this discussion simply assume that the total effect of solar warming from March 25 to July 4 is not less than enough to warm all the water from the surface down to the 50-foot level in the "melting area" an average amount of 12° F. Now a rise of 12° F. in 100 days means that the average rise is 0.12° F. per day. It has been shown that 0.01° F. is a very generous amount to allow for the chilling effect of a full season's bergs south of the forty-eighth parallel on a 50-foot layer of the "melting area." One one-hundredths degree Fahrenheit is only one-twelfth as much as the average daily rise of 0.12° F. In other words the total chilling effect of bergs in the "melting area" is not sufficient to nullify more than two hours of the average vernal warming effect that is active throughout the ice-patrol season. This seems hard to believe at first when one looks at the ice charts of the ice patrol. It must be kept in mind that the bergs marked on these charts must be large enough to be plainh' seen. As drawn they are far too big in proportion to their proper scale size. The real amount of glacial ice south of the forty-eighth parallel each year is comparativel}' small when considered in relation to water volumes of 50-foot layers of the "melting area." One way to get a conception of the relative smallness of the 26 billion cubic feet of glacial ice that came south of 48° N. during the hea^*A' 1929 ice season is to assume it to be spread out evenly over the surface of the "melting area," of 74,000 square miles, or 2,664 billion square feet. The whole season's bergs spread out at once would make a uniform layer of glacial ice only about 0.01 foot, or one-eighth inch thick. A skim of ice only one-eighth inch thick would not be expected to last long or to interfere much with vernal warming of a fresh-water lake. It should be expected to last far less time and to interfere with warming no more over the "melting area." On second thought the comparatively negligible effect of the bergs south of the forty-eighth parallel on the water masses there is seen to be quite plausible. It is recognized that none of the variables that have been considered in arriving at the conclusions reached in this section are accurately known. Therefore, the results can be only approximate and can only serve to give an idea of the orders of magnitude involved. In cases no of doubt large values have been taken to arrive at the chilling effects of the bergs, and extremely small values to arrive at the total effect of vernal warming. For this reason the estimate that the melting of bergs south of the fortv-eighth parallel offsets the solar warming effect in the ''melting area " by but two hours is likely to be much too large. The true time figure is probably less than one hour. But even if gross errors have crept in and the two hours should be 100 per cent' too small instead of too large, the negligible effects of the melting bergs in the southern parts of the Labrador Current would still be apparent. If the bergs melting south of the forty-eighth parallel do not make and keep the southern reaches of the Labrador Current cold and active, then what does? The answer to this question leads very far afield and can not be more than hinted at here. Barnes ' sees the source of the cold water la3'ers in the Gulf of St. Lawrence and southeast of Newfoundland in the melting of icebergs. Lieut. Commander Edward H. Smith, United States Coast Guard, has stated in the course of conversation with the writer that, because of their large size and immense numbers, the melting of bergs north of the fortj-eighth parallel has a much more powerful effect than that of bergs melting in the "melting area." The sum total of the berg effects, in his opinion, amounts to almost nothing, however. It is many times exceeded by that of melting northern field ice. He further stated that the combined eft'ects of both bergs and field ice were entirely inadequate to account for the enormous volume of cold water that is discharged annually past Labrador by the Labrador Current. He contends that its true source must be looked for in direct winter chilling of the sea in northern regions by the air. He bases his opinion on a critical study of all the important oceano- graphic and explorational work that has been undertaken in the North Atlantic and polar basins, as well as on the results of his own work while with the ice patrol and the Marion Expedition. The latter scientific expedition into the waters between Greenland and Labrador, it will be remembered, was sponsored by the United States Coast Guard for the benefit of the scientific program of the ice patrol in 1928. The results of its work have not yet been fully pub- lished, but will be issued from time to time as special numbers in the series of Coast Guard bulletins. Lieutenant Commander Smith has just finished his discussion of ice and currents, and these sections, embodying his views, a few of which are briefly outlined above, should appear at an early date. It is believed that the calculations of chilling and warming eft'ects made in this section will help in a small way to support the Nansen idea of oceanic circulation as interpreted by Lieut. Commander Edward H. Smith. • p. 75, Transactions Royal Society of Canada, 1914, Sec. Ill, third series, vol. 8. Ill 4. OBSERVATIONS ON ICEBERG DISINTEGRATION SOUTH OF THE FORTY-FOURTH PARALLEL One might assume that the ice patrol as now conducted has more frequent and better opportunities actuall}^ to observe the disinte- gration of icebergs and field ice than is the fact. There are some opportunities for first-hand observation, of course, but these are often not so good as might be \\dshed. For instance, during the writer's four years' experience with the ice patrol he has never seen a single square foot of the field ice that is so abundant during the earlv season in the northern parts of the Grand Banks region. The reason for this is that the patrol must almost always remain close by the southern- most ice limits. About these limits the field ice is not usually found, and even the bergs themselves are rather few and far between. Frecjuently after a day of searching a berg reported earlier by a passing vessel is found late in the afternoon after the completion of a predetermined search pattern. It is usually given a berth of from one-half to one-fourth mile, though sometimes it is passed closer, depending upon weather and other conditions. The ship will then be stopped 1 or 2 miles to leeward of the berg, where it is ''secured" for the night — that is, steam is turned off the propelling machinery and the larger generators and auxiliaries, to save fuel for future searches for ice. When daylight returns next morning the berg is usually only a small white mass on the horizon. It may even be 8 or 10 miles to windward, on account of the relatively greater effect of breezes on the ship and surface water than on the deep-lying berg. It may be approached again before the new day's search is started, but in many cases it is onh^ relocated from a distance by a series of bearings taken with the aid of the gyrocompass repeaters on the wings of the bridge. Such bearings can locate the geographical position of the berg as well as steaming up to it, and the}^ can be taken while the ship is running along on a set of courses planned to make the new day's search for ice most effective. Possibly the patrol will return to the old berg for the night, and if this is done, a comparison can be made with the way the ice looked 24 hours earlier. But new bergs that require watching may be found in more threatening positions than the old one, and if this is the case, the former may never be seen again. Each season a few of the most southern bergs are watched during a period of days. Then the usual procedure is to drift well clear of the ice and to run up toward it once or twice a day, in the evening, or both morning and evening, depending on the rate at which the patrol ship is drifted or blown away. During about one-third of the ice-patrol season fog makes all con- tinued observations of ice impossible. Bergs under surveillance when 112 a long period of fog shuts down are invariably lost. After a protracted foggy spell the patrol does its most intensive cruising, trying to relocate the new positions of the dangerous bergs. Each year a certain amount of time is lost in futile searching for bergs reported from extra southerly locations. These bergs frequently can not be found because of the strong currents and rapid ice dis- integration, which obtain in the warm surface waters along the northern edge of the Gulf Stream. Besides the rather limited opportunities for close first-hand observa- tion, the varying shapes of the bergs themselves, and the varying conditions of wave motion and water temperature about them, all go to make the subject of berg disintegration a complicated and con- jectural one. The determination of the life of a berg that is sighted south of the Tail of the Banks is certainly not obtainable through the application of any hard and fast rules. Obviously 130,000 tons of ice in the form of growlers and small pieces will melt much faster than the same amount of ice in the form of a single solid berg. Not only will the smaller pieces have a greater total area exposed to water action, but they will be entirely in the upper layers of water that are warmer and more affected by wave motion than the layers that are 50 feet and more below the surface. The pieces of ice that calve from a berg nearly always stream off to leeward, under the influence of winds, waves, and surface currents. They rapidly melt and disappear and the life of the parent berg is undoubtedly materially shortened by continued prolific calving. Some of the bergs, because of their peculiar shape and particular internal structure, or the unusual conditions of water and weather that they experience, calve more than others. The fresh ice exposed when a piece falls from a berg south of the forty -fourth parallel is dry and frosty at first. The spot, even though far above the reach of sea and spray, soon becomes wet, however, and so it generally remains. After long exposure the upper parts of bergs sometimes become rough and granular and apparently dry, while between the granules they may be wet in fact. Barnes ^ states that bergs calve most near sunrise and that they dry up and freeze on account of radiation from their surfaces at night. This may be true of bergs north of the Grand Banks, but that it is true of bergs melting in the warmer southern portions of the "melting area" south of the forty-fourth parallel should not be assumed with- out more direct evidence. On the contrary, the late afternoons, nights, and early mornings are foggy or cloudy more than 50 per cent of the time during the ice season in the southern parts of the "melting area." Such conditions are not conducive to eft'ective nocturnal chilling of berg surfaces by radiation and keep as well the early rays * H. T. Barnes, " Thermit and Icebergs." Journal of the Franklin Institute, May, 1927. 113 of the sun from striking the ice. During 1929 one herg southeast of the Tail approached on a cloudy night was seen when the beams of a searchlight were pla3"ed on it to be pouring off water from all visible surfaces, just as so usually happens during the day. Notwithstanding the need for further observation and study, the observations which the ice patrol has been able to make to date permit some conclusions to be drawn about the life of bergs south of the forty-fourth parallel. Two late instances will be given. A berg of not less than 500,000 short tons mass was seen by the patrol for the first time on July 17, 1929, about 55 miles south- southeast of the Tail. It was in water close to 60° F. at the surface at this time and remained in such water throughout the remainder of its life. It disappeared entirely late on July 26, nine days after it had been first sighted. The berg was a rather sohd one and this disintegration was considered quite rapid. A berg of about the same size in 1928 lasted south of the Tail from May 21 to June 4, a period of 14 days. The time was earlier in the season and the water was con- siderably colder during most of this time. In fact, it was in surface water colder than 38° F. from May 21 to May 25. Both of the above bergs were larger than the average berg that gets below the forty- fourth parallel, being of the approximate size of the generously large berg taken in section 3 of this chapter as the average size which crosses the forty-eighth parallel. The experience of the ice patrol all goes to show that in the 50° to 60° surface water south and east of the Grand Banks the average berg can be counted on under all ordinary circumstances to be entirely melted in from 7 to 10 days. Only extremely large and resistant bergs are able to survive longer in water warmer than 50° F. It was computed in the section of this chapter dealing with glacial ice totals that the abnormally heavy 1929 ice season provided only enough ice south of the forty-eighth parallel to cover the "melting area" of 74,000 sc{uare sea miles with a film of ice one-eighth inch thick. The only reason why the glacial ice reaches so much lower latitudes and persists south of the forty-eighth parallel each season two to three months longer than the field ice does is because of its con- centration in the large masses known as icebergs. If it were not so concentrated it would vanish overnight and never reach the 50° and 60° water east and south of the Banks. The field ice so prevalent during the first third of the ice patrol season in the northern half of the "melting area" and in the regions to the north of that, has an enormous preservative influence on the bergs. If there were no field ice oft' the Labrador and Newfoundland coasts in the winter and spring there would be far less of a berg problem along the trans-Atlantic tracks than there now is. The field ice has been credited with acting as a fender which keeps the 114 bergs during certain months from grounding along the North Ameri- can coast north of Cape Race, and so ehminating themselves from southern waters. Whether this be true or not, it is an undeniable fact that the field ice tends to keep the surface water about it ice cold. A berg surrounded by field ice in the Labrador Current until it is south of the forty-fifth parallel is conserved much as a cargo of meat is conserved in a refrigerating vessel that is steaming through the Tropics. But the field ice prolongs the life of the bergs in another way than through its great cooling effect. In addition it effectually prevents the development of wave motion, and in this way protects most efficiently the vulnerable waterlines of bergs from the washing and melting attacks of moving surface water. Calving most frequently takes place by the dropping down of ice masses that overhang an. undercut water line, and so is closely related to surface water attacks. Calving upwards from the smoothly rounded underwater portions of a berg is exceptional in the ice patrol regions. Sometimes a projecting spur that is mostly submerged is broken off by stresses arising from the rise and fall of the swell. These stresses are very large at times, and so are the blows of the sea against a berg's sides. Bergs are usually very dead in the water and take the full force of the seas like rocks. They do not normally roll or ride over the seas like well-designed ships do when drifting. Calving generally involves but a very small portion of the mass of a berg at any one time. Of course bergs sometimes break up into two nearly equal parts, but in fully 90 per cent of the cases the amount of ice involved in a calving is so small in comparison with the mass of the berg that equilibrium is only slightly afi^ected. This is the case, even when the meaning of calving is restricted to production of ice volumes of more than 1 ton. The breaking off of small pieces is very frequent under some conditions, and this production of small amounts of ice in the form of chips and tiny blocks is not considered real calving, such as is contemplated here. It is reasonable to suppose that the chances of calving and rolling will be much greater in warm water than in cold, but it must be remembered that the conditions will vary much with each individual berg. To venture an opinion for the benefit of those who in the future may be called upon to work upon bergs for any purpose, it is esti- mated that the average berg south of the forty-fourth parallel can be expected to have natural calvings involving the falling off of over 1 ton of ice about three times a day, and to experience changes of position involving the turning about an axis more than 60° in less than one minute of time about twice a week. The above is only a rough estimate, based on comparatively few observations. Some bergs wiJjoo;|~.ealve for days at a time and will never turn over until < ■■ A, ^.-*j -^ 115 they have been reduced to the size of a ship's boat. Other bergs will both calve and roll about much more than the average. The varying water temperatures in which a berg may be floating have a great effect on its speed of disintegration, but it is doubtful if the percentage of the total wastage due to calving, compared with that due to direct melting from the berg, varies much under any conditions met south of the forty-fourth or even the forty-eighth parallel. The effects of calving are more noticeable in some cases than others, however. For instance several bergs seen near the Tail in 1929 had water lines showing that the upper parts of the berg were rising higher and higher out of the water. They were very few in number, and they may be explained by excessive calving, or by floadng in very cold sub surface water during periods of warm bright weather that were especialh^ destructive to large portions of their above-water bodies. Nevertheless, despite low temperatures of surface water at all places during the early season, and in many places until close to the end of the ice period, and despite permanent low temperatures at the lower levels reached by bergs in the "melting area," the constant effect of the sea water moving about in intimate contact with the water line and the great underwater surfaces of bergs must be the most important factor working toward their destruction. Subaerial melting from the bergs is a minor factor, but still it adds its quota to the melting process of berg disintegration, as distinct from the loss of mass through calving. Over the whole ice-patrol area the sum total calving effect is probably much less than the total surface melting effect in getting rid of the bergs. From a small boat that pulled about a berg which pitched heavily while calving on July 15, many air bubbles were seen to be rising through the smooth water and breaking at the surface within a dozen feet or so of the vertical ice walls of one side. Some of these bubbles appeared to be nearly 1 inch in diameter and these made a consider- able disturbance at the surface like the large bubbles of marsh gas that rise through shallow waters under certain conditions. Each of the larger bubbles of gas in the case of the berg were undoubtedly made up from the combined contents of many of the formerly im- prisoned tiny air bubbles of the glacier ice. The separate air bubbles in the bergs are generally less than one-thirty-second of an inch in diameter, much smaller in size than the head of an ordinary common pin. The particular berg of this instance was floating in surface water of ten]perature 57° F. The continuous coming up of air around it is good evidence of the rapid underwater wastage which occurs whenever the water is that warm. When movement of the slight swell exposed portions of ice below the average water line of the above berg it was seejiiHrtSPiBt'fee under- 116 water surfaces were not smooth, but dimpled. This condition was undoubtedly due to differential melting about the individual glacier grains. This dimpled effect is almost always noticeable when the water lines of bergs are closely inspected. Perhaps the underwater bodies of bergs while melting about the Grand Banks, though smoothed and rounded in general outline, may all be composed W'hen the detail is considered of these roughened surfaces. They can be compared to nothing so well as to magnified "goose-flesh" w^ith the intervals between the individual projections or the individual hollow^s of the order of about half an inch. To mention a few^ more examples of berg disintegration observed during the 1929 season it can be stated that on the afternoon of July 24 the ice patrol was standing by a berg in 61° water 55 miles south- southeast of the Tail. The berg was seen to calve heavily. In a few minutes a boat put out from the patrol ship with a swimming party and a number of the growlers in the vicinity of the berg were boarded. This could be easily be done, either from the boat or the w^ater, without much discomfort, for the chilling eft'ects of the ice on the surface water could be noted on ordinary ship's hold water ther- mometers only when within a few yards from some of the berg's ice walls, and when the boat was in the midst of a group of growders spaced on the average 50 feet or less apart. In a few such places tem- peratures 58° F., but 3° low^er than the general sea surface of the neighborhood, w^ere recorded. About the berg that pitched wdien calving on July 15 slightly greater local depression of surface temperature was noted. This berg, as already stated, w^as surrounded by sea water of 57° F. temperature at the surface. In one direction only from this berg w^as any chilling noted, but a depression of over 1° F. extended on this side to about one-fourth mile from the ice. Close to the berg the sea was 54° to 52° F. at the surface on this chilled side, and here, inside an ice- bottomed, w^ell-washed bay cut into the berg behind an outljdng ice pinnacle the temperature was 50° F. Among some near-by growlers a minimum surface temperature of only 48° F. was found. On the other hand, unchilled 57° F. surface water was found close to the vertical walls of the berg on the side opposite to the chilled water and growlers. The w'eather w-as calm, warm, and clear, and there was onl}^ a slight swell. 5. POSSIBILITY OF BREAKING UP ICEBERGS ARTIFICIALLY It has often been stated that noise or small blows can break up bergs. The firing of 6-pounder blanks and the sounding of the steam whistle and siren within 100 yards of unstable looking bergs has always failed to bring dow^n any pieces of ice at all during the dozen or more instances-^ in w^hich the writer has seen it persistently tried. Even Plate XI\'.— Filing explosive 6-pounder shells into the high thin wall formin? one side of a dry-doc'.c t vpe of berg. In this instance a number of tons of cracked ice were brought down into the sea. .lulv 11, 1929. latitude 41° 34' N., longitude 49° 00' W. Plate XV.— Two olRcers from the Modoc on a large growler that an hour earlier formed a projecting ledge just below the water line of a near-hy berg. This ice was entirely melted within 24 hours, 61- degree water, July 24, 1929, latitude 42° 10' X., longitude 49° 30' \V. Plate XVI.— Fragments of iceberg hoisted aboard. This ice is hard and homogene- ous. Its opacity is due solely to great numbers of tiny spherical air bubbles Plate XVII.— Swimming close to an iceberg in 58° surface water. This ice is not in the Gulf Stream, but is in a great pool of Labrador current water that has been highly warmed at the surface by continued vernal warming. At 10(1 feet below the surface the temperature was less than 40 F. The striping on the sunlit berg wall directly behind the swimmers may be due to differential melting between annual layers accumulated on the ice cap of ( ireenland. Taken from ship's boat Julv 18, 1929, latitude 42° 28' N., longitude 50° 05' \V. 117 overhanging and towering ice walls and cracked pinnacles seem un- affected by such noises. Six-pounder shells will bring down from a few pounds to a few tons of ice. They are most likely to produce damage if fired into weak portions of vertical or overhanging walls. Sometimes a lucky shot placed in a crack near a pinnacle or a corner about ready to fall will serve to produce a sizeable growler. That a berg about the Grand Banks can be noticeably shattered or affected by any such thing as the making of noises near it, or by weak blows like those from an axe should be considered as conceivable, but verging upon the extreme height of improbability. The above state- ment is made in spite of the following experience with a seemingly fragile berg. One day in August, 1928, the United States Guard Cutter Marion was run alongside a small grounded berg oft" the Labrador coast for the purpose of obtaining ice. While the berg was being attacked with an axe it calved and pieces of large size thundered into the sea, pushing the vessel well clear. The action of this berg was alarming and impressive to those witnessing it, but it should not be taken as showing the great liabihty of bergs to disintegrate because of small blows. As a matter of fact the ice that calved off amounted to very little when compared to the total mass of the berg. The parts that fell off were located along an almost vertical, slightly undercut wall. The ice was probably just about to come down of its own accord from the internally strained, grounded berg. It did so when the ship was gently bumped against it by the slight swell, and when the men on deck struck at the ice surface opposite them with an axe. Because of the rapidity with which bergs break up themselves, and because of the known physical properties of ice, it has been suggested that the southernmost bergs be removed from the paths of navigation by boarding and mining them. Some experiments along these lines have been carried out in past years by the ice j^atrol, but without much success. There are on the average 51 bergs south of the forty- thu'd parallel each year, and to attempt to mine any large proportion of them, even if feasible, would consume much valuable time that might be devoted to ice scouting. It has already been shown that bergs in the warm waters south and east of the Grand Banks have a life span of only 7 to 10 days. The rapidity with which they break up from natural causes throws no little element of risk into mining operations on them. The condi- tions are brought out somewhat in the preceding section on ice dis- integration, but to evaluate further the risks the next few paragraphs have been written for the benefit of future ice patrol officers who may be called upon to experiment again with the mining of bergs. Some bergs are very delicately balanced. Two turned over during 1929 while being passed by the ice patrol vessel. It is hard to see 118 why a great piece of ice riding on the swell of the open ocean should turn over when struck by the almost imperceptible waves of a vessel passing 100 yards or more away at a speed of 10 knots, but that is what seemed to take place. Many bergs, even among the number of those that project like rounded cones and hills from the sea, are so finely balanced that they require but little to make them roll over. One small rounded berg that was boarded in 1927 from a small boat ofl the eastern edge of the Banks turned over half an hour after the boarding party had departed. One smoothly rounded 1929 berg that was watched for about a week southeast of the Tail was seen to roll over at least once a day without any noticeable calving or breaking up. Assuming, however, that the situation appears to be favorable, and that it is decided to attempt to mine a berg, the first problem is to get upon it. Bergs too steep to be boarded without the aid of ropes can doubtless in some cases be solved by shooting lines over them, hauling stronger lines over their summits, and fastening floating weights such as log fenders to the end of the line opposite to the boarding party. Spiked shoes are needed to keep from slipping, and axes for cutting footholds in the hard ice are essential if any steep slopes are to be ascended. The officer in charge of the boarding party must bear in mind that, to the ordinary small boat risks attendant on landing upon and getting picked up from a large uninhabited object in the open sea must be added the danger of immersion in cold water. The actual cold water and boarding risks approach the vanish- ing point about bergs in smooth water over 50° F. at the surface. But whether a berg will calve or turn over while being approached or worked upon is hard to predict. The observations of the patrol show that calving south of the forty-fourth parallel is not generall}^ con- fined to any particular time of the day but is liable to occur at am^ time. Turning over of a berg usually occupies a number of seconds, but it is liable to occur without warning, or only after the sudden warning of a heavy crackling and calving. Probably in most cases where a berg turns rapidly through 60° or more the boats attending the working party will have the duty of pulling their charges out of the water. Even if all parts of the berg that have towering pinnacles are avoided, there is danger that a subsequent rolling movement will cause ice to slide down upon persons on a berg. A movement in the other direction would elevate the working party and put them in danger of dropping down over cliffs to ice shelves or down into the sea upon or among closely spaced growlers. The most stable bergs on the whole are the tabular ones. A squad of infantry could be placed upon the tops of the largest of these bergs and drilled at both close and extended order with comparative safety. In 1929 the tabular bergs south of the forty-fourth parallel were 119 about as numerous as the thin-walled diy-dock type or the rounded water-worn type. The undulating top surface of the tabular bergs often appears to be but a very slightly modified form of the surface of the original glacier from which the ice was set free. From a short distance it appears to be composed of rough grains about the size of marbles and it is often muddied and soiled by the abundant bird life. Many of the tabular bergs have walls that are kept vertical through- out almost all of their life history in the Grand Banks area by calving off of overhanging pieces as the waves eat into the berg about the water line On May 31 a tabular berg approximately 115 feet high and 400 feet square was seen near the Tail, and on July 15 another large berg, seen around noon 90 miles south-southeast of the Tail, was of a form bordering upon this type. At about 2 p. m. attention was called to the latter berg by a cry from the bridge. It was calving heavily and pitching as it did so. Whenever its sheer end walls became over- hanging ones they gave way, and then the suddenly lightened end of the berg would lurch upwards. This caused the process to be re- peated from the other end. The berg calved three or four times in this manner duiing the space of about a minute. It was not over 2 miles away and could be clearly seen at the time by those on the bridge and about the decks. Soon it became quiescent very close to its former position of trim. 6. LOCAL CONVECTIONAL CIRCULATION ABOUT ICEBERGS Barnes ^ slates that melting bergs draw in the surface waters toward them and that they have warmer surface water immediately about them than is the case farther away. It is quite possible that bergs do draw in, chill, and sink certain amounts of surface water under some conditions of melting. This might easily be concluded in view of the rather small surface temperature effects described in the section of this chapter on ice disintegration. Nevertheless it is difficult to see from theoretical consideration how bergs can do much along the line of sinking chilled water in the "melting area" south of the forty-eighth parallel. During the ice- patrol season the surface water of the region is in general much warmer and somewhat fresher than the layers 25 and 50 meters down. Such conditions indicate a marked stability of the water column, and are directly opposed to the production of vertical convection currents. In the early season many of the bergs keep in water that is below 32° F. at all levels about them until they are well south of the TaU. Of course, in the case of such conditions they can not cause much local circulation through chilling and sinking water that they draw in ' Annual Report of the Smithsonian Institution for 1912, p .737. 120 toward themselves because of the physical impossibility of anything chilling the already frigid water by more than 1° or 2°. Throughout the year, just below the upper 25 or 50 meters of water throughout almost all the 74,000 square sea mile "melting area," the next layers of water remain, in general, very cold. At many stations 38° and 37° F. water is found just below the 25-meter level, even though the time may be June or July, and 50° to 55° F. water may be encountered at the surface. Let us consider the conditions that prevailed in the upper portions of the water column at station 1085. That station was taken at 42° 01' N., 49° 29' W., about 3 miles east of a large berg, on July 18, 1929. The conditions there are listed below and are a bit more extreme than the average, but still they are rather typical of the melting conditions that surround nearly all the bergs that melt south of the forty-fourth parallel during the last half of the ice-patrol season. Levels Temper- atures Salinities Surface ' °F. 57.2 39.7 3.'5. 4 37.0 Per mille 32.89 25 meters . . . . . - - . - - 33.31 SOmeters 33.91 125 meters - - - 34.42 It is evident from an inspection of the above figures that the berg because of the increasing salinity wdth depth, woidd be forced to chill the surface waters very much more than 21.8° F. in order to sink them down to the 50-meter level. The inevitable freshening of the waters while they are being chilled by the glacial ice w^ould make it still harder for them to be sunk. Let us neglect the great differences of salinities and the freshening effects and assume that the berg will chill the surface waters in immediate contact with it 20° F. and sink them to some depth located between the surface and 50 meters where they will find their new hydrostatic level. It is easy to calculate the approximate amount of water that can be chilled 20° F. by an individual berg of 130,000 short tons mass. Lieut. Commander Edward H. Smith estimates this to be the size of the average berg about the Grand Banks, so it can safely be taken as the average size of bergs in the southern half of this area south of the forty-fourth parallel. If each pound of the ice can chill 80 pounds of water 1° F., a 260-million pound berg can chill approximately 1,040 million pounds of water 20° F. At 62}^ pounds per cubic foot, the amount of water chilled 20° F. would be 16,640,000 cubic feet. Suppose the berg lasts out a full life-expectancy for surface water over 50° F. and continues to melt for 10 days. It will then sink daily, on the average, 1,664,000 cubic feet of water chilled 20° F. 121 Assuming that the sinking action attracts in toward the berg the surrounding surface waters down to the 10-foot level, what wiU be the rate of inflow of these surface layers? At the circumference of a circle of 1,000-foot radius from the center of the waterline plane of the berg the area of a 10-foot vertical section of the surface layers of water will be 62,832 square feet. A horizontal inflow of but 27 feet per day, which is only about 0.0002 knot, will more than suffice to> supply 1,664,000 cubic feet of water daily through an opening of this size. By proportion it can be assumed that the inflow will amount to about 270 feet per day, or 0.002 knot, at a point close to the ice walls, but 100 feet from the center of the waterline plane of the berg. The above figures are believed to give a very fair theoretical value for the order of magnitude of surface inflow that is possible about a berg melting in the Grand Banks region. The inflow is undoubtedly so small in value that differential drift of surface and subsurface layers, wind and wave effects, and other confusing elements, are easily capable of distorting and entirely masking most of the notice- able effects of such an inflow, if and when it exists. Even should the above approximations be in error by a factor of 10, still the inflow toward the most rapidly melting bergs would be extremely small. It is now" plain why growlers calved while breezes of any appre- ciable strength are blowing generally float away rapidly to leeward from a berg. Even those produced during periods of light airs and calms almost invariably move away, though on the average at much lower rates of speed. The maximum flow that the sinking of chilled water can cause apparently produces an inflow of surface water so small that it is nearly always masked by the other forces operating. If the inflow were at all large it would often be able to hold calved growlers and small pieces in positions alongside the parent berg. Final conclusions regarding the local circulation, both vertical and horizontal, about bergs south of latitude 44° or 48° N. should not be drawn from theoretical considerations, however. Neither should they be formed from the results of a study of tank experiments or of the few actual observations about bergs that have been made to date. It is hoped that when opportunity offers the ice patrol will take numerous special oceanographic stations and make studies with variously colored stains placed in the water close to bergs during aU sorts of weather and water conditions. What is now needed is a larger body of exact observational data upon which to base sound opinions. Microthermographs have been suggested as instruments for warn- ing ships of the proximity of ice during times of low visibility, but whether they will ever be of much practical value is stiU an open question and subject to grave doubt. The scientific observer of the international ice patrol should never be satisfied until after the detailed 100277—30 9 122 circulation about bergs under all conditions has been thoroughly investigated and is well understood. 7. MISCELLANEOUS Detailed sounding and bottom sampling work about the Grand Banks region would be very useful, practically as well as scientifically. For the past five centuries the fishermen of France have been fre- quenting this area, yet even to-day the French scientists admit that they know almost nothing about the composition or detailed bottom configuration of the top or slopes of the Grand Banks plateau. Steam trawlers are annually increasing in numbers there. These vessels can not proceed haphazardly with their fishing like the old fashioned sailing vessels. Their costs prohibit hit or miss methods. They must know promptly where the greatest numbers of fish are located and where the bottom characteristics are not destructive to their expensive gear. Well coordinated scientific investigations are caUed for by the fisheries problems alone. In 1927 one of the French Government ships attending the fishing fleet reported that three new shoals were situated less than 30 miles to the westward of the main track of bergs along the 1,000-fathom curve of the eastern slope of the Grand Banks. These shoals, though small, were said to have only 8 to 11 fathoms of water over them. Do they presage the birth of another low sandy island like that grave- yard of the Atlantic, Sable Island, or will the water over them eventu- ally be deepened by the waves of the open sea? Only continued soundings in their vicinity can tell. On November 18, 1929, there occurred an earthquake centered in the sea south of Newfoundland. The shock was severe enough to be distinctly felt in the New England States, over 800 miles to the west- ward. Twelve cables crossing the area of greatest disturbance were broken in 23 places and the Burin Peninsula of Southern Newfound- land was visited by an earthquake wave. This wave was so large that much property and a number of lives were destroyed. Some geologists believe that the section of the ocean floor where the cable breaks occurred foundered during this earthquake. The ice-patrol ships will have a good opportunity to sound out the supposedly sunken area south-southeast of Cabot Strait with sonic depth finders, for they must cross it every time they proceed between the ice regions and their Nova Scotian base of supplies. If any great increase in depth over the form values exists, it should be detected when the new sound- ings are compared with the old ones that are already on the charts. 123 NO STA" IONS WERE THE LIMITS OF TH GRAND BANKSX •^o. I03(> OT^: "AKEN OUTS ID S CHART.,;.^'- /• \ •=r> 15*N 44'N / \4io4i« "\m /''•mi 1045 ,; • ,'01050 ,04^^' 1030* .._..L\ooo fM^^ • I03q .1035 • 10^0 1053 1038 '1055 1071 <' 1047 •105^ • 1042 1045 1064 ^3'N 105^ 1040 '048,^^^ 1074 1 03 1 1037 1051 032: 1034 1075 THE '1033 IQ83 H^^ STATIONS. •I0 N ^^"Kl / / -4 J IM. / y ,^'' y^ .^^ 610 • y / / /'""ilZy^^^ ^^-^^ / '"'/a^ ^^.^^^A^*^^ ^3 //h'^'^y^^^^^^ .* /// / *^^^ 595/// / / SLACK - CURREr •660 / A '^"M ^ Ac N. ^/^ 684 • TEN STATIONS JUNE 1-19. 1 / '819 4C °w. 48"W Figure 16.— Current map made from a group of stations occupied during June, 1929. The S-figure numbers near stations show in dynamic millimeters the distance in excess of 728 dynamic meters from sea surface to 750-decibar pressure level. It appears from this map that two bands of cur- rent setting northeastward existed southeast of the Banks with an almost currentless area between them. Such slack waters do exist in fact off the Banks at times and bergs getting into them may remain almost stationary for several days (126) Figure 17. — Current map constructed from small groups of late season stations. Dashed lines show areas that are t o be considered separately because of time-lapse factor. Three-figure numbers near stations show in dynamic millimeters distance in excess of 728 dynamic- meters from sea surface ta TSCSdecibar pressure level. A few known berg drifts are plotted to show relation between actual and dynamicaBy determined currents (127) ^I'^^-K MAP OF SECTION ONE. METERS Figure 18.— Oceanographic section one was drawn from data obtained at stations taken April 11-12, 1929. The vertical scale is exaggerated about sixty times. Note very steep slope of isotherms and isohalines, characteristic of temperature wall (128) FiGUEE 19.— Oceanographic section two was drawn from data obtained at stations taken April 23-26, 1929. The vertical scale is exaggerated about one hundred and twenty times. The salinity Increases marlcedly with depth. This is characteristic of the cold and mixed waters About the Tail, where the Labrador Current overrides warmer Atlantic water of higher salinity (129) FiGUEE 20.— Oceanographic section three was drawn from data obtained at stations taken May 6-11, 1929. The vertical scale is exaggerated about one hundred and twenty times. The salinity increases rapidly with depth. A cold-water layer between warmer surface and bottom waters can be seen. This is characteristic of the Labrador Current after the sun warms up the surface layers in the spring (130) FiGTJEE 21.— Oceanographic section four was drawn from data obtained at stations taken May 20-31, 1929. Vertical scale exaggerated about two hundred and forty times. Temperature and salinity distribution similar to that of section three (131) . MAP or SECTION nv£ -^ IO*/9 StA AA/US' O A lO ■A2'iZ'H • 49'04W. \016 1077 I07S MCTCPS- -=f50- -^^ -4:0^^ tcmpepatui^e: -4ra -2-3- MElTEf?^ FiQtJKE 22— Oceanographic section five was drawn from data obtained at stations taken July 5-8, 1929. Vertical scale exaggerated about two hundred and forty times. Temperature and salinity distribution similar[to that of section sis (132) Figure 23. — Oceanographic section six was drawn from data obtained at stations taken July 15-26, 1929. Vertical scale exaggerated about two hundred and forty times. Surface layers much warmed. Salinity increases rapidly from surface to 200-meter level due to push of Labrador Current over North Atlantic mid-depth and bottom waters (133) Figure 24. — Oceanographic scctToif seven was drawn from data obtained at stations taken July 28 to August 2, 1929. Vertical scale exaggerated about sixty times. Temperature and salinity dis- tribution similar to that of section six (134) ^- BERCS O -CROWUERS. l^^-FIELO ice. APRIL I- n, 1^2^. ICE PATROL GRAND BANKS ISOTHERMS BASED ON lOgg TEMPERATURE REPORTS. i luUKE .;.-iarfLce teuii.tralurei A|,i.l l-;«. i92S. l-orlious of steamship tracks in use and souii-ernmost K-e are sliown. Uoucd lines conDecting berg pos-t.ons indic-ate probable drift tracii. 100277—30. (Face p. 134.) No, 1 ^-FmiutcE, APRIL ^0 TO MAY 3, \^ZH. GENERAL CHART CO V E.RING ICE PATROL GRAND BAMKS isotheraas based on 1137 temperah;re reports. FiGUKE 2C.— Surface temperatures April 20 to M^y :, 1929. Sec remarks under Figure 25 lt0277— 30. (Face p. 134.) No. 2 !Uh^^^^ I I I I I L^^ri^d^±±±± ^- BERCS e -GROWLERS _ ^ ^-FIELDICC. AAAY 4- 18, 1^2,^. GENERAU CHART COV E.R1NG ICE PATROL GRAND BANKS ISOTHERMS BASED ON 1182. TEMPERATURE REPORTS. Figure 27.— Surface temperatures May 4-15, isl See remarks under Figure 25 100277—30. (Face p. 134.) No. 3 ^- BERSS. O -GROWLERS. ^- FIELD lO^. MAY 1^ TO JUNE 3, \^Z^. GENERAL CHART cov cniNC ICE PATROL GRAND BANKS ISOTHERMS BASED ON 12.00 TEMPERATURE REPORTS. FIGCRE 28.— Surface temperatures May 19 to June 3,M29. See remarks under Figure 25 100277—30. (Face p. 131.) No. 4 I to ss A- BCROS. O -GROWLERS. 1^- FIELD lOE. JUNE 3-18, 1*?^^. GENERAL CHART COVERING . iCE PATROL GRAND BANKS ISOTHERMS BASED ON 1150 TEMPERATURE REPORTS. fioUKi: 2y.— ::;urfai;e temijeraiures June ^-l'^. j''.'i See reiii;ir*.:s CLdt-r 1 jgurc Jo lWJ27:-30. (Fuco p. 134 J Xu. Z I iy-^^^^'^Y'j^^^^j^' 60 sa -A.- BERSS. O -CROWLEPS. .^-F,Ea>,cE. jy^E 18 TO JULY l,\C{ZC\. GENERAL CHART ICE°PAfROL GRAND BANKS ISOTHERMS BASED ON 180 TEMPERATURE REPORTS. FiocBE 30.— Surfiiof temperatures June ;« lo }'•:.;: .. OS. See remarks under Kisure 2S I 100277—30. (Fate p. 13J.) \0. ■ti.- BEBSS e -CROWI.EMS. JULY 3-18, W^9. GENERAL CHART COVERING ICE PATROL GRAND BANKS ISOTHERMS BASED ON 850 TEMPERATURE REPORTS. Figure 31.— Surface temperatures July 3-l.S, r*-"' Bee r :(027:— 30. (Face p. 134.) N'o. 7 ^-REUiice. JULY 18 TO AUGUST Z, H^q. GENERAL CHART CO V EPINQ ICE PATROL GRAND BANKS ISOTHERMS BASED ON 830 TEMPERATURE REP0RT5. Fi'jIke 32.— Surface lemiieruturos July Is u Xuir. i i, l'j.".i. .-f- ri.i;.;,rk: uiiiler f ifurt -.' 1002;:— 30. (Fuco p. 134.) No ' ' ' ■ ■ ' ' I I ■ I ) 38 57 S6 SS ^- BERCS. O -GROWLERS. ffpl'FlliD ICE. AUGUST 2-4, l'?2.In terpolated 136 Oceanographic station data and dynamic calculations, 1929 — Continued a = meters 01 = = pressure in decibars Date Lati- tude N. Longi- tude W. a Depth -of water Depth Sta- tion Tem- pera- ture Salin- ity Si V V-V, E E-Ei o , 0 , " C. 0100 1037 Apr. 26 42 11 50 45 3,109 0 3.2 33.70 26.85 0. 97385 121 0 0 25 2.8 34.17 27.26 . 97336 83 24. 34012 .02547 50 2.2 34.25 27.37 .97313 71 48. 67124 .04474 125 3.0 34.45 27.47 . 97272 64 121. 64062 .09650 250 6.2 35.01 27.68 . 97198 46 243. 18437 .16438 450 4.1 34.97 27.77 .97100 38 437. 48237 .24888 750 3.9 34.99 27.81 . 96965 36 728. 57987 .36038 1038 —do 42 13 51 32 3,475 0 4.2 33.68 26.60 .97409 145 0 0 25 3.8 33.72 26.86 .97373 120 24.34775 . 03310 50 3.7 33.86 26.98 .97350 108 48. 68812 .06162 125 6.2 34.88 27.45 .97275 67 121. 67250 . 12738 250 5.2 34.97 27.68 . 97198 46 243. 21812 . 19813 450 4.6 34.97 27. 73 . 97105 43 437. 52112 .28763 750 4.1 35.00 27.80 . 96966 37 728. 62762 . 40813 1039 —do 42 31 51 31 2,880 0 3.8 33.77 26.85 .97385 121 0 0 25 1.6 33.75 27.02 . 97358 105 24.34287 .02822 50 1.7 33.94 27.17 . 97332 90 48. 67912 . 06262 125 3.8 34.61 27.52 . 97267 59 121. 65374 . 10862 250 3.0 34.63 27.61 .97203 51 243. 19749 . 17750 450 3.0 34.89 27.82 .97094 32 437. 49449 .26100 750 3.6 34.91 27.78 . 96967 38 728. 58599 .36650 1040 Apr. 27 42 25 51 19 2,743 0 1.0 33.56 26.91 . 97379 115 0 0 25 .2 33.94 27.26 . 97336 83 24. 33937 .02472 50 .4 34.05 27.34 . 97316 74 48. 67087 .04437 125 1.8 34.43 27.55 . 97264 56 121. 63837 .09325 250 2.8 34.78 27.75 . 97189 37 243. 17149 . 16150 450 3.2 34.87 27.79 . 97097 35 437. 45749 .22400 750 3.2 34.88 27.80 . 96964 35 728. 64899 . 32960 1041 May 5 43 38 49 14 136 0 2.0 32.97 26.37 . 97430 166 0 0 10 .9 32.90 26.38 .97424 164 9. 74270 .01650 25 -.1 32.99 26.51 .97406 153 24. 35495 .04030 50 -1.0 33.04 26.58 . 97387 145 48. 70407 .07757 75 -1.1 33.22 26.73 . 97362 131 73. 04769 .11215 100 -1.1 33.28 26.78 . 97347 128 97. 38631 . 14456 125 -.8 33.46 26.92 . 97322 114 121. 71993 .17481 1042 May 6 42 36 49 18 2,560 0 7.6 33.64 26.29 . 97438 174 0 0 25 -.8 33.31 26.80 . 97379 126 24. 36225 .03760 50 1.2 33.68 26.99 . 97349 107 48. 69326 . 06675 125 3.4 34.44 27.42 . 97276 68 121. 67762 . 13250 250 3.0 34.61 27.60 . 97203 51 243. 22699 .20700 450 3.4 34.75 27.67 . 97109 47 437. 53899 . 30550 750 3.3 34.95 27.84 .96960 31 728. 64249 .42300 1043 May 8 43 00 49 48 248 0 2.5 33.03 26.37 . 97431 167 0 0 25 -.2 33.09 26.59 . 97399 146 24. 35376 . 03910 50 -1.0 33. 18 26.70 . 97376 134 48. 70062 . 07412 75 -1.0 33.30 26.79 . 97357 126 72. 04224 . 10670 125 -1.0 33.48 26.94 .97320 112 121.71149 .16637 200 .2 33.79 27.14 . 97267 93 194.68161 . 24312 225 1.2 34.08 27.32 .97239 76 218. 99486 1044 —do 43 03 49 45 184 0 1.8 33.02 26.42 . 97426 162 0 '0 25 -.6 33.08 26.60 . 97398 145 24.35.300 .03835 75 -1.0 33.22 26.73 . 97362 131 73. 04300 . 10746 150 -.8 33.50 26.95 . 97308 111 146. 71050 175 1.0 33. 58 26.92 . 97299 113 171.03637 1045 May 9 43 14 49 50 70 0 1.8 32.99 26.39 . 97429 165 0 "0 15 .6 33.01 26.49 . 97412 155 14. 61307 . 02393 25 -.5 33.10 26.61 . 97397 144 24. 36362 .03887 50 -.7 33.11 26.63 . 97383 141 48. 70102 . 07452 1046 May 10 42 56 49 21 1,600 0 1.5 32.90 26.36 . 97432 168 0 0 25 .0 32.97 26.49 .97408 155 24. 36500 .04033 50 -.8 33.31 26.79 . 97368 126 48. 70200 . 07550 125 -1.5 34.33 27.64 . 97253 46 121.68487 . 1397c 250 2.8 34.61 27.62 .97201 49 243. 21862 . 1986K 450 3.2 34.76 27.70 . 97106 44 437. 52562 . 29213 760 3.2 34.79 27.72 .96962 43 728. 64262 .42313 1047 May 11 42 40 49 25 1,920 0 2.0 32.80 26.24 .97443 179 0 0 25 2.0 33.02 26.40 . 97417 164 24. 35750 .04285 50 -.3 33.17 26.67 . 97379 137 48. 70700 . 08050 125 1.1 33.93 27.20 . 97296 88 121. 71012 .16500 250 -.1 34.51 27.74 .97188 36 243. 26262 .24263 450 3.3 34.76 27.69 .97107 45 437. 56762 . 32413 750 4.0 34.93 27.75 . 96971 42 728. 67462 . 45513 137 Oceanographic station data and dynamic calculations, 1929 — Continued a = meters 01 = = pressure in decibars Date Lati- tude N. Longi- tude a Depth of ai Depth sta- tion Tem- Salin- ity water pera- ture St V V-Vi E E-Ei o / o , ° a 0/00 1048 : May 12 42 44 49 53 1.460 0 2.5 32.81 26.20 0. 97447 183 0 0 25 1.0 32.89 26.37 . 97420 167 24. 35837 . 04372 50 -.8 33.30 26.78 . 97369 127 48. 70699 . 08049 125 2.2 34.18 27.32 . 97286 78 121.70261 . 15749 250 2.2 34.55 27.61 . 97202 50 243. 25761 . 23762 450 2.1 34.74 27.78 . 97098 36 437. 55761 .32412 I 750 3.2 34.87 27.79 . 96965 36 728. 65211 . 43262 1049 May 20 42 43 50 27 1,645 0 1.6 33.06 26.46 . 97422 158 0 0 25 -.9 33.26 26.76 . 97383 130 24. 35062 . 03597 50 -1.1 33.39 26.88 . 97359 117 48. 69337 . 06687 125 _. 7 33.41 26.88 . 97326 118 121.70024 . 15512 250 L2 33.70 27.01 . 97259 107 243. 31586 . 29587 450 2.9 34.62 27.62 .97113 51 437. 68786 . 45437 750 3.1 34.94 27.85 . 96960 31 728. 79736 . 56387 1050 May 21 42 45 51 04 1,645 0 3.1 33.05 26.34 . 97433 169 0 0 25 2.1 33.11 26.47 . 97410 157 24. 35537 .04072 50 .0 33.05 26.56 .97390 148 48. 70537 .07887 125 -1.1 33.48 26.95 .97319 111 121.72124 . 17612 250 2.4 33.43 26.71 .97287 135 243. 34999 .33000 450 3.3 34.86 27.77 . 97099 37 437. 73599 .50250 750 3.3 34.96 27.85 . 96960 31 728. 82449 .60500 1051 May 23 42 07 51 39 3,509 0 2.9 33.02 26.34 . 97433 169 0 0 25 2.7 33.10 26.42 . 97415 162 24. 35600 . 04135 50 2.8 33.55 26.77 . 97370 128 48. 70412 . 07762 125 3.3 133.75 26.88 . 97327 119 121.71549 . 17037 250 4.5 34.60 27.44 . 97219 67 243. 30674 . 28675 450 3.6 34.74 27.64 .97112 50 437. 63774 . 40425 750 3.5 34.84 27.73 . 96971 42 728. 76224 .44275 1052 May 24 42 40 49 53 2,110 0 1.0 32.96 26.42 . 97426 162 0 0 25 .0 33.04 26.54 . 97403 150 24. 35362 . 03897 50 1.9 33.83 27.06 . 97343 101 48. 69687 . 07037 125 1.9 134. 00 27.20 . 97297 89 121. 68687 . 14175 250 1.9 34.45 27.56 . 97207 55 243. 25187 . 23188 450 3.0 34.81 27.76 . 97100 38 437. 55887 . 32538 750 3.2 34.87 27.79 . 96965 36 728. 65637 . 43688 1053 May 25 42 18 51 13 2,744 0 5.8 33.38 26.32 . 97435 171 0 0 25 5.9 33.46 26.37 . 97420 167 24. 35687 .04222 50 2.2 33.47 26.75 . 97371 129 48. 70574 . 07924 125 4.0 34.35 27.29 .97289 81 121. 70324 .15812 250 4.0 34.83 27.67 . 97198 46 243. 25761 . 23762 450 3.5 34. 89 27.77 . 97099 37 437. 55461 .32112 750 4.2 35. 00 27.78 . 96968 39 728.65511 . 43562 1054 May 27 42 52 50 13 510 0 4.9 32.88 26.03 . 97463 199 0 0 25 .2 33.06 26.55 . 97402 149 24. 35812 .04347 50 -.2 33.30 26.76 . 97371 129 48. 70474 . 07824 125 -.2 33.67 27.07 . 97309 101 121. 70974 .16462 250 1.3 34.41 27.57 . 97206 54 243. 28161 .26162 450 2.5 34.82 27.81 . 97095 44 437. 58261 . 34912 1055 May 28 42 32 50 27 2,010 0 3.0 32.88 26.22 . 97445 181 0 0 25 3.0 33.40 26.63 . 97395 142 24. 35500 . 04035 50 1.2 34.09 27.32 . 97318 76 48. 69412 . 06762 125 2.9 34.64 27.64 . 97255 47 121. 65899 . 11387 250 2.9 34.74 27.71 .97193 41 243. 18899 . 16900 450 3.2 34.95 27.86 . 97091 29 437. 47299 . 23959 750 3.2 34.97 27.87 . 96958 29 728. 54649 . 32700 1056 May 29 42 57 49 50 183 0 4.6 33.16 26.28 . 97439 175 0 0 25 2.2 33.20 26.53 .97404 151 24. 35537 .04072 50 1.0 33.25 26.66 . 97380 138 48. 70337 . 07687 75 -.2 33.35 26.81 . 97355 124 73. 04524 . 10970 100 -.8 33.37 26.85 . 97340 121 97.38211 . 14036 1 125 -.3 33. 56 26.98 .97317 109 121. 71423 . 16911 1057 May 31 42 56 50 00 140 0 3.0 33.11 26.39 . 97429 165 0 0 25 .0 33.20 26.68 . 97390 137 24. 35237 . 03772 50 -1.0 33.50 26.96 . 97352 110 48.69512 . 06862 75 -1.1 33.61 27.05 . 97332 101 73. 03062 .09508 100 -.8 33.64 27.06 . 97320 101 97.36212 . 12037 125 -.5 33.74 27.13 . 97303 95 121.68999 .14487 1058 June 1 42 51 ' 49 23 1,462 0 3.2 32.93 26.20 . 97447 183 0 0 25 1.6 33.45 26. 77 . 973S2 129 24. 35362 . 03897 50 1.1 34. 06 27.31 .97319 77 48. 69124 . 06474 125 2.7 34.58 27.60 . 97259 51 121. 65799 .11287 250 3.0 34 75 27.71 .97193 41 243. 19049 . 17050 450 3.1 34.85 27.78 .97098 36 437. 48149 .24800 750 3.2 34.90 27.81 . 96963 34 728.57299 . 353J;0 Interpolated. 100277—30 10 13S Oceanographic station data and dynamic calculations, 1929 — Continued Sta- tion Date Lati- tude N. June 4 June 7 1061 June 8 1032 1053 1064 1065 42 26 Longi- tude W. 49 48 49 46 Depth of water Depth 2,744 41 20 June 9 42 2' June 10 June 11 June 12 1066 1067 1068 June 13 48 12 3, 382 49 19 50 23 48 30 43 00 42 07 49 40 48 50 49 30 2,927 2,812 3,209 0 25 50 125 250 450 750 0 25 50 125 250 450 750 0 25 50 125 250 450 750 0 25 50 125 250 450 750 0 25 50 125 250 0 25 50 125 250 450 750 0 25 50 125 250 450 750 1000 1500 1700 0 25 50 125 250 450 700 0 25 50 125 250 450 750 0 25 50 125 250 450 750 Tem- pera- ture C. .0 3.1 3.1 3.4 3.1 4.0 1.1 1.0 2.1 3.0 3.2 3.2 9.1 7.5 5.2 4.9 3.0 4.9 4.0 4.9 1.8 1.1 2. 1 3.0 4.1 4.9 2.2 .1 .0 .2 1.4 6.0 5.2 1.8 3.0 2.9 4.0 24.3 7.2 5.2 1.4 4.1 4.2 4.0 4.6 4.5 4.1 3.0 2.8 .2 -1.0 .0 2.0 3.2 3.2 7.0 3.9 1.0 2.4 3.2 4.1 4.0 5.8 2.6 3.9 3.8 4.1 3.5 4.6 Salin- ity 0100 32.81 33. 15 33 70 34.58 34.75 34.87 34.90 32.85 33. 31 33.78 34.48 34.74 34.86 34.88 33.19 33.22 33.27 33.77 34.45 34 89 34.92 32.78 33.04 33.85 34.40 34. 62 34.91 34 92 33.08 33. 13 33.28 33.81 34.24 32.93 33.21 33.73 34.45 34.66 34.92 34.97 33.22 33.52 34.49 34.68 34.88 34. 88 34.89 34.88 34.86 34.86 32.80 32.92 33.34 33.69 34.42 34.81 34.85 33.04 33.29 33. 76 34.42 34.73 134.86 34.85 33.18 33.71 34.29 34.56 34.82 34.84 34.92 25. 16 2.-. 62 27.08 27. 56 27.70 37.77 27.82 21 10 23.70 27.09 ' 27. 56 27.70 27.78 27.80 2.-. 70 2£(!.97 26. 31 26.74 27.47 27. t2 27.74 25.95 2X44 27.14 27.50 27. n 27.72 27.65 26.44 26.61 2). 74 27.16 27.43 25.94 26.26 26.99 27.47 27.65 27.75 27.75 26.01 26.50 27.63 27.54 27.74 27.71 27.71 27.66 27.69 27.80 26.17 26.44 26.83 27.07 27.53 27.74 27.78 25.91 26.46 27.07 27.49 27.68 27.68 27.69 26.16 26.99 27.25 27.48 27.65 27.73 27.68 i 01 = pressure in decibars 0.97451 . 97396 . 97341 . 97263 .97194 . 97099 .9;,9(.2 . 97456 . 97388 . 97340 . 972ij3 .97194 . 97098 . 969r4 . 97494 .97458 . 97413 . 97340 . 97216 .97115 . 96972 . 97471 . 97413 . 97335 . 972< 9 . 97202 .97105 . 96982 . 97424 . 97397 . 97372 . 97300 . 97219 . 97471 . 97430 . 97349 . 97272 . 97198 . 97102 . 96971 . 97465 . 97407 .97288 . 97265 .97191 . 97106 . 96977 . 96873 . 96657 . 96559 . 97450 .97413 . 97364 . 97309 . 97210 . 97102 . 96989 . 97474 .97411 . 97342 . 97270 . 97196 . 97109 . 96977 . 97451 . 97361 . 97324 . 97271 . 97199 . 97103 . 96979 187 143 99 55 42 37 33 192 135 98 55 42 36 35 230 205 171 132 64 53 43 207 1(0 93 61 50 43 53 ItO 144 130 92 67 207 177 107 64 46 40 42 201 154 46 57 39 44 48 54 186 160 122 101 58 40 60 210 158 100 62 44 47 48 187 108 82 63 47 41 50 0 24. 35587 48. 69799 121. 67449 243. 21011 437.50311 728. 59461 0 24. 35550 48. (.9650 121. 67262 243. 20824 437. 50024 728. 59324 0 24. 36900 48. 72787 121. 76024 243. 35773 437. 68873 728. 81924 0 24. 3r050 4S. 70400 121. 68050 243. 22487 437. 53187 728. 66237 0 24. 35262 48. 69874 121. 70074 243.27511 0 24. 36262 48. 70999 121. 69286 243. 23661 437. 53661 728.64611 0 24. 35900 48. 69587 121. 65324 243. 188.24 437. 48524 728. 60974 970. 92224 1454. 74724 1647. 96324 0 24. 35787 48. 70499 121. 70736 243.28173 437. 59373 680. 20748 0 24. 36062 48. 70474 121. 68424 243. 22549 437. 53049 728. 65949 0 24. 35150 48.68712 121. 66024 243. 20399 437. 50599 728. 62899 Interpolated. Exterpolated. 139 Oceanographic station data and dynamic calculatioyis, 1929 — Continued a = meters Ol = pressure in decibars Date Lati- tude N. Longi- tude W. a Depth of water Depth sta- tion Tem- pera- Salin- ity Si V 1 V-V E E-Ei ture o / o , ° C. 0100 1 :069 June 19 41 57 48 00 3,749 0 11.4 33. 15 25.29 0. 97533 269 0 0 25 5.9 33.42 ' 26.33 . 97423 170 24. 36950 .05485 50 3.7 33. 76 ! 26. 85 . 97362 120 48. 71762 .09112 125 4.2 34.48 27.37 . 97281 73 121. 70874 . 16362 250 4.7 34.85 27.61 . 97204 ' 96 243. 26186 . 24187 450 4.2 34.91 27.71 .97106 44 437. 57186 . 33837 750 4.0 34.95 ' 27.77 . 96969 1 40 728. 68436 . 46487 1070 June 21 42 45 49 11 2,378 0 6.2 33. 28 26. 19 . 97488 184 0 0 25 3.3 33. 56 26. 73 . 97385 132 24. 35412 . 03947 50 2.9 34. 03 27. IS . 97333 91 48. 69387 . 06737 125 2.8 34.54 1 27.56 . 97263 55 121. 66737 . 12225 250 2.8 34. 81 27. 78 . 97186 1 34 243. 19799 . 17800 450 3.6 34. 87 27. 75 .97102 40 437. 48599 .25250 750 3.6 34. 91 27. 79 . 96966 37 728. 58799 . 36850 1071 June 25 43 07 48 53 2,269 0 9.0 33.35 ' 25.85 . 97480 216 0 0 25 5.0 33.41 26.44 . 97413 160 24. 36162 . 04697 50 2.4 33.90 27.08 . 97341 99 48. 70.587 . 07937 125 3.2 34. 55 27.53 . 97266 58 121. 68349 . 13837 250 4.2 34.83 27.65 . 97200 48 243. 22474 . 20475 450 3.8 34.88 27.73 . 97104 42 437. 52784 . 29435 750 3.6 34 88 27.75 . 96970 41 728. 63974 .42025 1072 June 26 42 13 48 40 3,199 0 17.4 34.81 25. 30 . 97532 268 0 0 25 13.9 34 82 26.09 . 97446 193 24. 37225 . 05760 50 13.2 34.96 26.34 .97411 169 48. 72937 .10287 125 11.8 35.21 26.81 . 97335 127 121. 75912 . 21400 250 7.8 35.39 27.63 . 97203 51 243. 34537 . 32538 450 7.6 35.42 27.69 .97112 50 437. 66037 .42688 750 4.2 35 43 28.12 . 96936 7 728. 73237 .51288 1073 June 28 42 03 49 40 3, 247 0 6.1 32.63 25 68 . 97496 232 0 0 25 2.5 32.92 26.29 . 97427 174 24. 36537 . 05072 50 .2 33.29 26.74 . 97372 130 48. 71524 . 08874 125 2.0 33.98 27.18 . 97299 91 121. 71686 . 17174 250 2.6 34.52 27.56 . 97207 55 243.28311 . 26312 450 3.0 34.72 27.69 .97107 45 437. 59711 . 36362 750 3.2 34.82 27.75 . 96969 40 728.71111 . 49162 1074 June 30 43 08 50 50 101 0 10.8 32.96 25.25 . 97437 173 0 0 25 3.0 33.03 26.34 . 97422 169 24. 35737 . 04272 50 -.3 33.23 26.71 . 97375 133 48. 70699 . 08049 75 2.0 33.88 27.10 . 97328 97 73. 04486 . 10932 100 3.4 34. 20 27. 23 . 97305 86 97. 37372 . 13217 1075 July 1 42 05 50 20 3,290 0 19.8 34.73 24.66 . 97594 330 0 0 25 18.4 35.00 25.20 . 97532 279 24. 39075 . 07610 50 15.2 35.41 26.27 . 97418 176 48. 75950 .13300 125 13.0 35.44 26.75 . 97342 134 121. 79450 .24938 250 11.8 35.48 27.02 . 97263 111 243. 42262 . 40263 450 7.2 35.60 27.89 . 97092 30 437. 77762 .54413 750 3.4 35.66 28.39 . 97909 -20 728. 77912 . 55963 1076 July 5 42 32 49 04 2,779 0 11.2 32.96 25.18 . 97544 280 0 0 25 2.8 33.46 26.70 . 97388 135 24. 36650 . 05185 50 1.6 33.59 26.89 . 97358 116 48. 70975 . 08325 125 3.0 34.51 27.51 .97268 60 121. 69450 .14938 250 4.0 34.84 27.68 .97197 45 243. 23512 .21513 450 4.0 34.94 27.76 .97101 39 437. 53312 . 29963 750 4.0 34.94 27.76 . 96970 41 728. 63962 . 42013 1077 July 6 43 00 49 05 2,560 0 11.8 33.00 25. 10 . 97551 287 0 0 25 2. 1 33.50 26.78 . 97381 128 24. 36650 .05185 50 4.0 34.22 27.19 . 97330 88 48. 70537 .07887 125 1 4.0 34 63 27.51 . 97268 60 121. 67962 . 13450 250 4.0 34.78 27.63 . 97201 49 243. 22274 . 20275 450 4.1 34.89 27.71 . 97106 44 437. 5.:974 . 39625 750 4.0 34.91 27.74 . 96972 43 728. 64674 . 42735 1078 July 7 43 20 49 17 915 0 i 7.5 32.81 25.64 .97500 236 0 0 25 I 7.5 33.81 26.44 . 97413 160 24. 36412 .04947 50 5.4 34.34 27.13 . 97336 94 48. 70774 .08124 125 5.2 34. 71 27.45 . 97273 65 121.68611 . 14099 250 1 4.5 34.84 27.63 . 97201 49 243. 23236 . 21237 450 1 3.4 34.84 27.74 . 97102 40 437. 53536 . 30187 750 1 2.3 34. 85 27.85 . 96958 29 728. 62536 . 40587 1079 July 8 41 44 49 00 3, 290 0 ' 10.8 33.19 25. 45 . 97518 254 0 0 25 ! 8.8 33.42 25.93 . 97461 208 24. 37237 . 05772 50 1 3.8 33.75 26.84 . 97363 121 48. 72537 . 09887 125 1 2.7 34.33 27.40 . 97278 70 121.71574 . 17062 250 I 2.8 34.62 27.62 . 97201 49 243.26511 . 24512 450 3.5 34.86 27.75 .97101 39 437.56711 . 33362 750 1 3.8 1 34.92 27.77 . 9(i969 40 728. 67211 . 45262 140 Oceanographic station data and dynamic calculations, 1929 — Continued Lati- tude N. Longi- tude W. a a = meters ai= pressure in decibars Sta- tion Date Depth of Depth Tem- Salin- ity water pera- ture at V V-Vi E E-Ei o , o , ° C. OjOO 1080 July 9 41 36 48 32 3,430 0 11.4 32. 82 25.03 0. 97558 294 0 0 25 8.9 33.20 25.74 . 97479 226 24. 37962 . 06497 50 4.2 33.44 26.56 . 97390 148 48. 73824 .11174 125 2.7 34.16 27.26 . 97292 84 121. 74399 . 19887 250 4.4 34.71 27.54 . 97210 58 243. 30774 . 28775 450 3.9 34.87 27.72 . 97105 43 437. 62274 . 38925 750 2 3 9 34.91 27. 75 . 96971 42 728. 73674 . 51725 1031 July 13 42 00 48 40 3,239 0 11.9 32.92 25.02 . 97559 295 0 0 25 6.0 33.24 26.19 . 97437 184 24. 37450 . 05985 50 4.2 33.74 26.79 . 97368 126 48. 72512 . 09862 125 2. 1 34.36 27.47 . 97272 64 121.71512 . 17000 250 3.2 34.65 27.61 . 97202 50 243. 26137 . 24138 450 4.0 34.85 27.69 . 97108 46 437. 57137 . 33788 750 4.0 34.92 27.73 . 96973 44 728. 69287 . 47338 1082 July 14 41 34 48 11 3,381 0 17.7 34.26 24.80 . 97580 316 0 0 25 17.3 34.57 25.40 . 97512 259 24. 38650 . 07185 50 14.8 34.65 25.70 . 97472 230 48. 75950 . 13300 125 '3.6 34.64 27.56 . 97263 55 121. 78512 . 24000 250 3.8 34.64 27.54 . 97210 58 243. 33074 . 31075 450 4.4 34.71 27.54 . 97122 60 437. 66274 . 42925 750 4.4 34.95 27.73 . 96974 45 728. 80624 . 58675 1083 July 15 41 32 49 07 3,327 0 13.2 33.07 24.88 . 97572 308 0 0 25 6.7 33.22 26.08 . 97447 194 24. 37737 . 06272 50 2.6 33.83 27.00 . 97348 106 48. 72674 . 10024 125 3.1 34.49 27.49 . 97270 62 121. 70849 . 16337 250 3.7 34.76 27. 65 . 97199 47 243. 25161 . 23162 450 4.3 34.93 27.72 . 97105 43 437. 55561 .32212 750 4.2 34.95 27.75 . 96971 42 728. 66961 .45012 1084 July 16 41 45 48 50 3,107 0 13.4 33.06 24.81 . 97579 315 0 0 25 6.8 33.38 26.20 . 97436 183 24. 37687 . 06222 50 3.4 33.94 27.02 . 97346 104 48. 72462 . 09812 / 125 2.9 34.46 27.48 . 97271 63 121. 70599 . 16087 250 3.5 34.70 27. 62 . 97202 50 243. 25162 . 23163 450 3.7 34.83 27.70 . 97107 45 437. 56062 .32713 750 3.7 34.89 27.75 . 96971 42 728. 67762 . 45813 1085 July 18 42 01 49 29 3,290 0 14.0 32.89 24. 59 . 97600 336 0 0 25 4.2 33.31 26. 45 . 97412 159 24. 37650 . 06185 50 1.9 33.91 27.13 . 97336 94 48. 72000 . 09350 125 2.8 34.42 27.46 . 97273 65 121. 69837 . 15325 250 4.0 34.73 27.59 . 97205 53 243. 24712 . 22713 450 3.6 34.75 27.65 .97115 53 437. 56312 . 32963 750 3.6 34.73 27.63 . 96981 52 728. 70112 . 48163 1086 July 20 41 18 48 43 3,343 0 14.6 32.96 24.51 . 97608 344 0 0 25 6.4 33.30 26.19 . 97437 184 24. 38062 . 06.597 50 2.6 33.69 26.90 . 97357 115 48. 72987 . 10337 125 3.7 34.45 27.41 . 97277 69 121. 71762 . 172.'-)0 250 3.5 34.61 27. 55 . 97209 57 243. 27137 . 25138 450 3.5 34.73 27.64 . 97112 50 437. 59267 . 3591S 750 3.4 34.77 27.69 . 96976 47 728. 72437 .50488 1087 July 21 40 57 48 55 3,290 0 13.3 32.84 24.68 . 97592 328 0 0 25 9.8 33.37 25.73 . 97480 227 24. 38400 . 06935 50 5.7 33.01 26.05 . 97438 196 48. 74875 . 12225 125 2.3 33.11 26. 46 . 97367 159 121. 80062 . 25550 250 4.8 34.80 27. 56 . 97209 57 243. 41062 . 39063 450 4.7 34.70 27.49 .97128 66 437. 74762 .51413 750 4.2 34.90 27.71 . 96975 46 728. 90212 . 68203 1088 July 23 41 48 49 15 3,290 0 15.5 32.88 24.66 . 97594 330 0 0 25 2.4 32.94 26.32 . 97424 171 24. 37725 . 06260 50 2.2 33.60 26.85 .97362 120 48. 72550 . 09900 125 5.1 33.96 26.85 . 97330 122 121. 73500 . 18988 250 4.0 34.67 27.54 . 97210 58 243. 32250 . 30251 450 3.8 34.77 27.65 .97111 49 437. 64350 .41001 750 3.5 34.74 27. 65 . 96979 50 728. 77850 . 55901 1089 July 24 42 11 49 29 3,109 0 15.3 33.34 24.63 . 97596 332 0 0 25 5.0 33.49 26.51 . 97406 153 24. 37525 . 06060 50 4.8 33.75 26.73 . 97373 131 48. 72262 . 09612 125 4.7 34. 55 27.38 . 97280 72 121.71749 . 17237 250 5.0 34.86 27.59 . 97206 54 243. 27124 . 25125 450 5.0 34.80 27.56 .97121 59 437. 59824 . 36475 750 3.8 34.73 27.62 . 96983 54 728. 75424 . 53475 1090 July 26 42 20 49 45 3, 019 0 14.9 32.80 24.32 . 97626 362 0 0 25 7.4 33.12 25.90 .97464 211 24. 38625 . 07160 50 4.8 33.90 26.85 . 97362 120 ' 48.73950 . 11300 125 2.4 34.41 27.48 . 97271 63 121. 72687 . 18175 250 2.4 34. 54 27.59 . 97204 52 243. 27374 . 25375 450 3.4 34. 75 27.67 .97109 47 437. 58674 . 35325 750 4.2 .34. 78 27.62 . 96983 54 728. 72474 . 50525 1 Interpolated. ' Exterpolated. 141 Oceanographic station data and dynamic calculations, 1929 — Continued 1 Lati- tude N. Longi- tude W. a di a = meters 01 = pressure in decibars tion "^^® Depth of Depth Tem- Salin- water pera- ity it V V-Vi E E-E, ture o / o , " C. 0100 1091 July 28 43 26 49 10 1,096 0 14.2 32.92 24.53 0. 97606 342 0 0 25 7.0 33.36 26.16 . 97440 187 24. 38075 .06610 50 7.3 33.68 26.36 . 97410 168 48. 73700 . 10050 125 7.7 34.27 26.75 . 97340 132 121. 76825 . 22313 250 4.9 34.85 27.61 .97204 52 243. 35825 .33826 450 13.1 34.63 27.60 .97115 53 437. 67725 .44376 750 3.4 34.65 27.59 . 96985 56 728. 82725 . 60776 1092 July 29 43 40 49 03 913 0 14.8 33.73 25.05 . 97556 292 0 0 25 11.6 35.03 26.71 . 97387 134 24. 36787 . 05322 50 11.8 35.22 26.84 . 97364 122 48. 71174 .08524 125 10.2 35.17 27.07 .97311 103 121. 71486 . 16974 250 8.6 34.77 27.02 . 97262 110 243. 32298 . 30299 450 4.3 34.84 27.65 .97111 49 437. 69598 .46249 1093 July 30 43 47 49 02 1,280 0 10.3 32.33 24.83 . 97577 313 0 0 [ 25 5.3 32.56 25.72 . 97481 228 24. 38225 . 06760 50 5.3 32.59 25.75 . 97466 224 48. 75062 .12412 125 4.8 33.27 26.36 . 97377 169 121.81674 . 27162 250 4.0 34.71 27.58 . 97206 54 243. 43111 .41112 450 4.3 34.83 27.65 .97111 49 437. 74811 . 51462 750 3.8 34.82 27.69 . 96977 48 728. 88011 . 66062 1094 July 31 43 40 49 00 982 0 11.0 32.61 24.94 . 97566 302 0 0 25 3.9 33.79 26.85 . 97374 121 24. 36750 .05285 50 4.6 34.50 27.34 . 97316 74 48. 70375 . 07725 125 4.5 34.55 27.40 . 97278 70 121. 67650 . 13138 250 4.6 34.82 27.60 . 97205 53 243. 22837 .20838 1095 Aug. 2 43 41 49 05 783 0 10.7 32.35 24.79 . 97581 317 0 0 25 5.0 32.96 26.09 . 97446 193 24. 37837 . 06372 50 -.4 33.21 26.70 . 97376 134 48. 73112 .10462 125 2.5 34.33 27.42 . 97278 70 121. 72637 . 18125 250 2.9 34.51 27.52 . 97211 59 243. 28199 . 26200 450 3.7 34.64 27.55 . 97121 59 437. 61399 . 38050 750 4.2 34.68 27.58 . 96987 58 728. 77599 . 65650 > Interpolated. o TREASURY DEPARTMENT :: UNITED STATES COAST GUARD A PRACTICAL METHOD FOR DETERMINING OCEAN CURRENTS COAST GUARD BULLETIN No. 14 :: :: :: DECEMBER, 1925