US, “ee aac : Cag. Res. Gh Teck eg Cet

TECHNICAL REPORT CERC-89-10
US Army Corps ANNUAL DATA SUMMARY FOR 1987

of Engineers CERC FIELD RESEARCH FACILITY

Volume |
MAIN TEXT AND APPENDIXES A AND B

by

Michael W. Leffler, Kent K. Hathaway, Brian L. Scarborough
Clifford F. Baron, Herman C. Miller

Coastal Engineering Research Center

DEPARTMENT OF THE ARMY
Waterways Experiment Station, Corps of Engineers
3909 Halls Ferry Road, Vicksburg, Mississippi 39180-6199

Se
DOCUMENT ™.
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Woods Hae Oceanographic
inSiHULON -

September 1989
Final Report

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Technical Report CERC-89-10
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USAEWES, Coastal Engineering
Research Center
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3909 Halls Ferry Road
Vicksburg, MS 39180-6199

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321-6
11. TITLE (include Security Classification)

ELEMENT NO.
Annual Data Summary for 1987, CERC Field Research Facility; Volume I: Main Text and
Appendixes A and B; Volume II: Appendixes C-E

12. PERSONAL AUTHOR(S)
Seenreverse.

13a. TYPE OF REPORT | Final 136. TIME COVERED
report in 2 volumes FROM TO

16. SUPPLEMENTARY NOTATION

14. DATE OF REPORT (Year, Month, Day)
September 1989

5. PAGE COUNT
201

See reverse.

17. COSATI CODES
GROUP SUB-GROUP

18. SUBJECT TERMS (Continue on reverse if necessary identify by block number)
See reverse.

19. ABSTRACT (Continue on reverse if necessary idenufy by block number)
This report provides basic data and summaries for the measurements made during 1987 at

the US Army Engineer Waterways Experiment Station (WES) Coascal Engineering Research
Center's (CERC's) Field Research Facility (FRF) in Duck, NC. This report includes com-
parison of the present year's data with cumulative statistics from 1980 to the present.

Summarized in this report are meteorological and oceanographic data, monthly bathy-
metric survey results, samples of quarterly aerial photography, and descriptions of
sixteen storms that occurred during the year. The year was highlighted by an intense
Northeaster in March lasting 7 days. Waves with 4.9-m significant height were measured
at a gage located 6 km offshore.

This report is ninth in a series of annual summaries of data collected at the FRF
which began with Miscellaneous Report CERC-82-16, which summarizes data collected during

20. DISTRIBUTION / AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION
GduNciassiFicounumiteo CJ) same as Rpt. (Joric users Unclassified
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DD FORM 1473, a4mar Sa APG eortion maybe used neil exhacsed: SECURITY CLASSIFICATION OF THIS PAGE
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12. PERSONAL AUTHOR(S) (Continued).

Leffler, Michael W.; Hathaway, Kent K.; Scarborough, Brian L.;
Baron, Clifford F.; Miller, Herman C.

16. SUPPLEMENTARY NOTATION (Continued).

A limited number of copies of Volume II (Appendixes C-E) were published under
separate cover. Copies of Volume I (this report and Appendixes A-B) are
available from National Technical Information Service, 5285 Port Royal Road,

Springfield, VA 22161.

18. SUBJECT TERMS (Continued).

Meteorologic research--statistics (LC)

Oceanographic research--statistics (LC)

Oceanographic research stations--North Carolina--Duck (LC)

Water waves--statistics (LC)

19. ABSTRACT (Continued).

1977-1979. These reports are available from the WES Technical Report
Distribution Section of the Information Technology Laboratory, Vicksburg, MS.

Unclassified
SECURITY CLASSIFICATION OF THIS PAGE

PREFACE

This report is the ninth in a series of annual data summaries authorized
by the US Army Corps of Engineers (USACE), under Civil Works Research Work
Unit 321-6, Field Research Facility Analysis, Coastal Flooding Program. Funds
were provided through the US Army Engineer Waterways Experiment Station (WES)
Coastal Engineering Research Center (CERC), under the program management of
Dr. C. L. Vincent, CERC. Mr. John H. Lockhart, Jr. was USACE Technical
Monitor.

The data for the report were collected and analyzed at CERC’s Field
Research Facility (FRF) in Duck, NC. The report was prepared by
Mr. Michael W. Leffler, Computer Programmer Analyst, FRF, under direct
supervision of Mr. William A. Birkemeier, Chief, FRF Group, Engineering
Development Division (EDD), and Mr. Thomas W. Richardson, Chief, EDD; and
under general supervision of Dr. James R. Houston and Mr. Charles C. Calhoun,
Jrv., Chief and Assistant Chief, CERC, respectively. Mr. Kent K. Hathaway,
Oceanographer, FRF, assisted with instrumentation; and Brian L. Scarborough,
Amphibious Vehicle Operator, FRF, assisted with data collection. Messrs.
Herman C. Miller, Clifford F. Baron, John B. Strider, Jr., Daniel B. Hogan and
Ms. Deborah R. Heibel and Ms. Wendy L. Smith assisted with data analysis at
the FRF. The National Oceanic and Atmospheric Administration/National Ocean
Service maintained the tide gage and provided statistics for summarization.

This report was edited by Mrs. Joyce H. Walker, Information Products
Division, Information Technology Laboratory, WES.
Commander and Director of WES during the publication of this report was

COL Larry B. Fulton, EN. Dr. Robert W. Whalin was Technical Director.

CONTENTS

PREFACE .
PART I: INTRODUCTION .

Background :
Organization of Report
Availability of Data

PART II: METEOROLOGY .
Air Temperature
Atmospheric Pressure
Precipitation . 2
Wind Speed and Daeetion

PART III: WAVES

Measurement Instruments
Pressure Gage

Digital Data Amati and Suinmanincision ‘

Results
PART IV: CURRENTS

Observations
Results

PART V: TIDES AND WATER LEVELS

Measurement Instrument
Results

PART VI: WATER CHARACTERISTICS
Temperature .
Visibility
Density .

PART VII: SURVEYS

PART VIII: PHOTOGRAPHY .

Aerial Photographs
Beach Photographs

PART IX: STORMS

REFERENCES

Sti

73

APPENDIX A: SURVEY DATA .

APPENDIX B: WAVE DATA FOR GAGE 630
APPENDIX C*: WAVE DATA FOR GAGE 141
APPENDIX D: WAVE DATA FOR GAGE 625

APPENDIX E: WAVE DATA FOR GAGE 645

* A limited number of copies of Appendixes C-E (Volume II) were published
under separate cover. Copies are available from National Technical
Information Service, 5285 Port Royal Road, Springfield, VA 22161.

Al

Bl

Cl

D1

El

ANNUAL DATA SUMMARY FOR 1987
CERC FIELD RESEARCH FACILITY

PART I: INTRODUCTION

Background

1. The US Army Engineer Waterways Experiment Station (WES) Coastal
Engineering Research Center's (CERC’s) Field Research Facility (FRF), located
on 0.7 km? at Duck, NC (Figure 1), consists of a 561-m-long research pier and
accompanying office and field support buildings. The FRF is located near the
middle of Currituck Spit along a 100-km unbroken stretch of shoreline extend-
ing south of Rudee Inlet, VA, to Oregon Inlet, NC. The FRF is bordered by the
Atlantic Ocean to the east and Currituck Sound to the west. The Facility is
designed to (a) provide a rigid platform from which waves, currents, water
levels, and bottom elevations can be measured, especially during severe
storms; (b) provide CERC with field experience and data to complement labora-
tory and analytical studies and numerical models; (c) provide a manned field
facility for testing new instrumentation; and (d) serve as a permanent field
base of operations for physical and biological studies of the site and
adjacent region.

2. The research pier is a reinforced concrete structure supported on
0.9-m-diam steel piles spaced 12.2 m apart along the pier’s length and 4.6 m
apart across the width. The piles are embedded approximately 20 m below the
ocean bottom. The pier deck is 6.1 m wide and extends from behind the dune-
line to about the 6-m water depth contour at a height of 7.8 m above the
National Geodetic Vertical Datum (NGVD). The pilings are protected against
sand abrasion by concrete erosion collars and against corrosion by a cathodic
system.

3. An FRF Measurements and Analysis program has been established to
collect basic oceanographic and meteorological data at the site, reduce and
analyze these data, and publish the results.

4. This report, which summarizes data for 1987, continues a series of

reports begun in 1977.

CHESAPEAKE

wey

CAPE
HATTERAS

Figure 1. FRF location map

Organization of Report

5. This report is organized into nine parts and five appendixes.

Part I is an introduction; Parts II through VIII discuss the various data col-
lected during the year; and Part IX describes the storms that occurred.
Appendix A presents the bathymetric surveys, and Appendixes C through E
(published under separate cover as Volume II) contain wave data statistics.

6. In each part of this report, the respective instruments used for
monitoring the meteorological or oceanographic conditions are briefly
described along with data collection and analysis procedures and data results.
The instruments were interfaced with the primary data acquisition system, a
Digital Equipment Corporation (Maynard, MA) VAX-11/750 minicomputer located in

the FRF laboratory building. More detailed explanations of the design and the

operation of the instruments may be found in Miller (1980). Readers’ comments

on the format and usefulness of the data presented are encouraged.

Availability of Data

7. Table 1 summarizes the available data. In addition to the wave data
summaries in the main text, more extensive summaries for each of the wave

gages are provided in Appendixes B through E.

Table 1

1987 Data Availability

Gage Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
TO C2 ESE 4 NS MG 2N S34 IR SreDleZesr4 ae laceshanlecRsna Ucn GeO MCW Onaw lite OLA RCE 4 RO MMC ale iS 4,

Weather

Anenometer 632 ek kk i/ i i i i i a i i ee ee F / LTS Lie? Ct oe Led Ot os TP oP Ee? 43 / Pee eo Cees Lo! Ls bs

Atmospheric Pres 616 if * * / wKwKweK KKK KEKE KKK KKK KKK / KERR REE AK Ka eee Ke ne, / LF UF LP EP Por Tey

Air Temperature 624 wk wk / Kw KKK KE KKK KEKE KK KKK KK / Kak eek Ke kek / . a ae ae a ee a ed / ci i a a i a a a

Precipitation 604 kk * / KERR OKA EK, REKRAK REAR OR KOR Ke: / KORE KKK RARER IK KR aK ee / ti) PL? Lt he LS Le ee ee
Waves

Offshore Waverider 630 wk kk / wk kkk KK / Se i i i a a ad / * / * / weweweKe Ke Ke Ke KR KR KKK KKK / * / keke ke Ke kK ee eK

Pressure Gage 141 wk we * / i ee i ee a i ee ee i ee ad Hh * / * / Ce i i a a a a ee ed / RT PAP Ee Te LT? Eee oD Be

Pier End 625 CL? te ey / a a a i 2 i at / * / * / eee Ke Ke Ke KEK if if =a if * * / KEKRK KKK eK eK ee,

Pier Nearshore 645 kkk if eke KKK KEKE RAKE KKK EK if * / * / Ce i a i a i / wee KK KK Keke KK
Currents

Pier End we kK x week / wk weKeK / KRKRK KR KEKE KEKE KKK KKK KK KK KEK KK KK me Ls he Us Ley te *
Pier Nearshore wk kk if keke ka K / kerk / oe i i ee a i a Toft he ad
Beach x * / / x * / * / / / / / fi * / / xeKX*K / xx 5 a a 2 a ad / ete w: eek kK / eee KX,
Pier End Tide Gage wwe Ke KR KKK KKK / KERR OR RARER, RR RO RARAK, KRORSK A KAMAE CK KL KEK OK KN Reh e RULe ee, / PN eg.)
Water Characteristics

Temperature Se a eed / xxe«enk / ee ee ee i a a ad
Visibility * * keke we KEKE / kee / xeeaeae eee Hee Kea KK KR KKK KKK KKK KKK xe ke * x *
Density ewe we Ke KK KKK Hf KARL / / xt / kx / CHR eRe tet eh RS he Le RE SRR ES EIT CR? Pe Cy Pees Uy
7 *

Bathymetric Surveys bi mx td ‘3

Photography

Beach ee a a a ed
Aerial os ee a iW

Notes: ™* Full week of data obtained.
/ Less than 7 days of data obtained.
- No data obtained.

8. The annual data summary herein summarizes daily observations by
month and year to provide basic data for analysis by users. Daily measure-
ments and observations have already been reported in a series of monthly

Preliminary Data Summaries (Field Research Facility 1987). If individual data

for the present year are needed, the user can obtain detailed information (as
well as the monthly and previous annual reports) from the following address:

USAE Waterways Experiment Station
Coastal Engineering Research Center
Field Research Facility

SR Box 271

Kitty Hawk, NC 27949-9440

Although the data collected at the FRF are designed primarily to support
ongoing CERC research, use of the data by others is encouraged. The WES/CERC
Coastal Engineering Information and Analysis Center (CEIAC) is responsible for
storing and disseminating most of the data collected at the FRF. All data
requests should be in writing and addressed to:

Commander and Director

US Army Engineer Waterways Experiment Station

ATTN: Coastal Engineering Information Analysis Center
PO Box 631

Vicksburg, MS 39181-0631

Tidal data other than the summaries in this report can be obtained directly
from the following address:

National Oceanic and Atmospheric Administration
National Ocean Service

ATTN: Tide Analysis Branch

Rockville, MD 20852

A complete explanation of the exact data desired for specific dates and times
will expedite filling any request; an explanation of how the data will be used
will help CEIAC or the National Oceanic and Atmospheric Administration

(NOAA) /National Ocean Service (NOS) determine if other relevant data are
available. For information regarding the availability of data for all years
contact CEIAC at (601) 634-2012. Costs for collecting, copying, and mailing

will be borne by the requester.

PART II: METEOROLOGY

9. This section summarizes the meteorological measurements made during
the current year and in combination with all previous years. Meteorological
measurements during storms are given in Part IX.

10. Mean air temperature, atmospheric pressure, and wind speed and
direction were computed for each data file which consisted of data sampled two
times per second for 34 min every 6 hr beginning at or about 0100, 0700, 1300,
and 1900 eastern standard time (EST); these hours correspond to the time that
the National Weather Service (NWS) creates daily synoptic weather maps. Dur-
ing storms, data recordings were made more frequently. The data are summar-

ized in Table 2.

Table 2

Meteorological Statistics

Mean Mean Wind Resultants
Air Temperature Atmospheric Pres. Precipitation, mm 1987 1980-1987
deg C mb 1987 1978-1987 Speed Direction Speed Direction
Month 1987 1983-1987 1987 1983-1987 Total Mean Maxima Minima m/sec deg m/sec deg
Jan 5.6 5.2 1014.5 1017.1 140 97 180 44 3.6 322 2.6 338
Feb 4.2 5.9 1018.2 1017.1 44 70 84 20 3.6 5 1.9 353
Mar os 9.0 1016.8 1015.9 110 85 168 35 2.8 9 1.6 357
Apr 11.6 13.4 1011.4 1013.4 131 94 182 0 2.4 3 0.3 298
May 18.7 19.0 1018.6 1016.3 31 66 239 20 0.2 295 0.5 194
Jun 23.8 23.4 1015.9 1015.6 61 75 130 27 1.8 211 iteal 196
Jul 26.3 26.0 1016.9 1016.3 54 83 200 19 0.9 200 1.6 217
Aug 26.1 26.1 1016.3 1016.7 55 103 221 30 0.9 76 0.6 72
Sep 23.8 22.4 1016.0 1018.1 35 77 160 5 5 86 1.8 38
Oct 15.4 17.9 1019.6 1020.1 74 64 143 17 3.0 3 2.6 31
Nov 12.8 13.2 1020.6 1018.9 127 90 145 26 1.0 353 2.0 358
Dec 8.1 8.6 1017.5 1019.8 47 67 131 4 1.6 269 2.1 335
Average 15.3 15.8 1016.9 1017.1 76 80 1.1 352 1.0 359
Total 908 971

Air Temperature

ll. The FRF enjoys a typical marine climate which moderates the temper-

ature extremes of both summer and winter.

Measurement instruments

12. <A Yellow Springs Instrument Company, Inc. (YSI) (Yellow Springs,
OH) electronic temperature probe with analog output interfaced to the FRF’s
computer was operated beside the NWS's meteorological instrument shelter
located 43 m behind the dune (Figure 2). To ensure proper temperature read-
ings, the probe was installed 3 m above ground inside a "coolie hat" to shade
it from direct sun yet provide proper ventilation.
Results

13. Daily and average air temperature values are tabulated in Table 2

and shown in Figure 3.

Atmospheric Pressure

Measurement instruments

14. Electronic atmospheric pressure sensor. Atmospheric pressure was
measured with a YSI electronic sensor with analog output located in the
laboratory building at 9 m above NGVD. Data were recorded on the FRF com-
puter. Data from this gage were compared with those from an NWS aneroid
barometer to ensure proper operation.

15. Microbarograph. A Weathertronics, Incorporated (Sacramento, CA)
recording aneroid sensor (microbarograph) located in the laboratory building
also was used to continuously record atmospheric pressure variation.

16. The microbarograph was compared daily with the NWS aneroid
barometer, and adjustments were made as necessary. Maintenance of the
microbarograph consisted of inking the pen, changing the chart paper, and
winding the clock every 7 days. During the summer, a meteorologist from the
NWS checked and verified the operation of the barometer.

17. The microbarograph was read and inspected daily using the following

procedure:
a. The pen was zeroed (where applicable).
b. The chart time was checked and corrected, if necessary.
ce. Daily reading was marked on the chart for reference.
d. The starting and ending chart times were recorded, as
necessary.
e. New charts were installed when needed.

1:-6000 CERC

7 FEBRUARY, 1982)
48 SCALE 1:6,000 8 |

= ie 2 y
AERIAL PHOTOGRAPH TAKEN®:

PRESSURE GAGE
0.9 KM OFFSHORE

NO 141

METEOROLOGICAL

INSTRUMENTS ii » a "
ee is i BAYLOR GAGE
NO

c i TIDE GAGE

NO 865-1370

WAVERIDER BUOY
6 KM OFFSHORE NO. 630

WAVERIDER BUOY
a 7 KM OFFSHORE NO 640

Figure 2. FRF gage locations

10

Year Mean,°C

*—x 1987 15.3
Sat es eee @----© 1983-87 15.8

35

30
25
20

15

10 ‘ po 7. oe Pec Oe

be
+ eDes ose
Hire

Air Temperature, ee

°°

oe

TRIG GR Tey ke
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure 3. Daily air temperature values with monthly means

Results
18. Daily and average atmospheric pressure values are presented in

Figure 4, and summary statistics are presented in Table 2.

Precipitation

19. Precipitation is generally well distributed throughout the year.
Precipitation from midlatitude cyclones (northeasters) predominates in the
winter; whereas, local convection (thunderstorms) accounts for most of the
summer rainfall.

Measurement instruments

20. Electronic rain gage. A Belfort Instrument Company (Baltimore, MD)

30-cm weighing rain gage, located near the instrument shelter 47 m behind the

dune, measured daily precipitation. According to the manufacturer, the’

ia

1040 Year Mean, mb

»—-« 1987 1016.9
e----0 1983-87 1017.1

Atmospheric Pressure, mb

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure 4. Daily barometric pressure values with monthly means

instrument's accuracy was 0.5 percent for precipitation amounts less than
15 cm and 1.0 percent for amounts greater than 15 cm.

21. The rain gage was inspected daily, and the analog chart recorder
was maintained by procedures similar to those for the microbarograph.

22. Plastic rain gage. An Edwards Manufacturing Company (Alberta Lea,
MN) True Check 15-cm-capacity clear plastic rain gage with a 0.025-cm resolu-
tion was used to monitor the performance of the weighing rain gage. This
gage, located near the weighing gage, was compared daily; and very few dis-
crepancies were identified during the year.
Results

23. Daily and monthly average precipitation values are shown in
Figure 5. Statistics of total precipitation for each month during this year

and average totals for all years combined are presented in Table 2.

12

225 Year Total, mm

*—* 1987 908
@----© 1978-87 971

200

175

150

125

100

75

Precipitation, mm

50

25

“~

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure 5. Daily precipitation values with monthly totals

Wind Speed and Direction

24. Winds at the FRF are dominated by tropical maritime air masses
which create low to moderate, warm southern breezes; arctic and polar air
masses which produce cold winds from northerly directions; and smaller scale
cyclonic, low pressure systems, which originate either in the tropics (and
move north along the coast) or on land (and move eastward offshore). The
dominate wind direction changes with season, being generally from northern
directions in the fall and winter and from southern directions in the spring
and summer. It is common for fall and winter storms (northeasters) to produce
winds with average speeds in excess of 15 m/sec.

Measurement instrument

25. Winds were measured on top of the laboratory building at an ele-

vation of 19.1 m (Figure 2) using a Weather Measure Corporation (Sacramento,

CA) Skyvane Model W102P anemometer. Wind speed and direction data were

iL)

collected on the FRF computer as well as on a strip-chart recorder. The
anemometer manufacturer specifies an accuracy of +0.45 m/sec below 13 m/sec
and 3 percent at speeds above 13 m/sec, with a threshold of 0.9 m/sec. Wind
direction accuracy is +2 deg with a resolution of less than 1 deg. The ane-
mometer is calibrated annually at the National Bureau of Standards in
Gaithersburg, MD, and is within the manufacturer's specifications.
Results

26. Annual and monthly joint probability distributions of wind speed
versus direction were computed. Winds speeds were resolved into 3-m/sec
intervals; whereas, the directions were at 22.5-deg intervals (i.e. 16-point
compass direction specifications). These distributions are presented as wind
"roses," such that the length of the petal represents the frequency of occur-
rence of wind blowing from the specified direction, and the width of the petal
is indicative of the speed. Resultant directions and speeds were also deter-
mined by vector averaging the data (see Table 2). Wind statistics are pre-

sented in Figures 6, 7 and 8.

14

N
337.50.0 9595

315.0 45.0
67.5
292.5 "2,
a
W 570.0 S 90.0E
247.5 Ti oa 112.5
225.0 135.0

202.5 180.0 97-9
S

1987
Speed 1.1 m/s
Direction 352 deg

N
537251010 516
315.0
292.5 a is ee
Wiss avor Gee 90.0E
Se ii a 112.5
225.0 135.0
202.5 180.0 '97->
S
1980-1987

Speed 1.0 m/s
Direction 359 deg

0 Os 20 30 40
Frequency, %

Figure 6. Annual wind roses

iS)

N
337.50.0 995
315.0 f 45.0
Wes)
292.5 afl S
W : E
=e a= 90.0
a
“7 fic © 112.5
202.5 180.079
S
January
Speed 3.6 m/s
Direction 322 deg
N
Sie 22.5
315.0 45.0
67.5
292-9
Sug
RS
W5790.0 = call 90.0E
S
uf ey pry 112.5
225.0 135.0
202.5 180.0 97°
S
March
Speed 2.8 m/s
Direction 9 deg
Speed, m/s
nN © 0
nm T “f bad Sp
ae ee eo
(0) 10 20

Frequency, %

Figure 7.

N
337.
315.0
292.5 \ -
a&

45.0
67.5
ry %
Weare) a re al 90.0E
=. ae
247.5 per 112.5
225.0 135.0
202.5 180.0'°7°
S
February
Speed 3.6 m/s
Direction 5 deg
S57: 22.5
315.0 45.0
292.5 ally he
°
& o
W 570.0 =e al] 90.0E
— a
247.5 f/ |S 112.5
202.5 180.07">
S
April
Speed 2.4 m/s
Direction 3 deg
+
N
N
40

Monthly wind roses for 1987

(Sheet 1 of 3)

16

Frequency, %

Figure 7.

17

N N
337.50.0 995 337.50.0 995
45.0 315.0 45.0
~ is 67.5 a aS: g 67.5
eo
W ae EW is ae E
270.0 = a 20:0 270.0 = = poe
y* 112.5 ay ys 112.5
y) ,/ 135.0 135.0
202.5 180.0 ©7"> 202.5 180.0 ©”>
S S
May June
Speed 0.2 m/s Speed 1.8 m/s
Direction 295 deg Direction 211 deg
N N
337.5 0.0 22.5 337.5 0.0 22.5
45.0 315.0 45.0
1 f 67.5 y 67.5
292.5 ‘ VA 292.5 | 8 A A
QS Z*” . a
=< —
247.5 / si \S 112.5 OAT. a o’ 112.5
135.0 595.0 135.0
202.5180:02.> 202.5 180.07"
5 S
July August
Speed 0.9 m/s Speed 0.9 m/s
Direction 200 deg Direction 76 deg
Speed, m/sec
Noos
PIN ra Ale raT Al oat
te Se a
—— oe
OF THOM Mor son, 40

(Sheet 2 of 3)

N
337.50.0 995

315.0 45.0
2925 a8 7 QO aie
Pew, ea
eo Sy
247.5 ¢} o\ 112.5
225.0 135.0
202.5 180.0 7"
S
September
Speed 1.5 m/s
Direction 86 deg
N
337.50.0 995
315.0 45.0
2925 Q Qa Ww Base
De, =»
Wistolo |e all 90.0E
: si a
247.5 VA ii oS 112.5
225.0 | 135.0
202.5 180.0 7°
Ss
November
Speed 1.0 m/s

Direction 353 deg

N
337.5 0.0
315.0 45.0
292.5 A Td ore
ae —
Wl ora te o 90.0E
eo a
27.5 ¢ fy. 112.5
225.0 135.0
202.5 180.07"
S

October

Speed 3.0 m/s
Direction 3 deg

N
337.50.0 995
315.0 45.0
292.5 {409 L 67.5
a. >
W 970.0 a= ; HOE

ae O y”

ed 135.0

202.5 180.0 7"?
S

December
Speed 1.6 m/s
Direction 269 deg

0 10 20 30 40
Frequency, %

Figure 7. (Sheet 3 of 3)

18

N

N
337.50.0 99. = 337.50.0 995
315.0 315.0 , ne
292.5 a 44 be men 292.5 a 2, Nee
W 90.0E W 570 0 = s 90.0E
; of
247. S47, L o” 112.5 247.5 7, ry 1 112.5
225.0 155.0 225.0 135.0
202.5 180.0 97> 202.5 180.0 7°
S S
January February
Speed 2.6 m/s Speed 1.9 m/s
Direction 338 deg Direction 353 deg
N N
337.50.0 99. ey 337.50.0 995
315.0 i 315.0 45.0
292.5 a 2, nee 292.5 al 7 4 nee
“ g'
W 90.0E W ig 90.0
270.0 = 2 270.0 = are
247. C7, ws 112.5 247. Leg aN UWS)
225.0 135.0 225. f 135.0
202.5 180.0 "7" 202.5 180.0 °7*>
S S
March April
Speed 1.6 m/s Speed 0.3 m/s
Direction 357 deg Direction 298 deg
Speed, m/sec
i ie ee
Pot ega des
SS NS Sea SS Se
———
HAO 29 sor 20

Frequency, %
Figure 8.

Monthly wind roses for 1980

through 1987 (Sheet 1 of 3)

19

N N
337.50.0 995 337.50:0 555
315.0 45.0 315.0 45.0
2925 <ul y KE oie 292.5 .ati 9 ye
a ee ~& >
W s al 90.0E W oy = 90.0E
270.0 = : 270.0 = aa :
; WW 112.5 Tf 1\y 112.5
225. Vi 135.0 225.0 135.0
202.5 180.0'97- 202.5 180.0 '°7->
S S
May June
Speed 0.5 m/s Speed 1.1 m/s
Direction 194 deg Direction 196 deg
N N
3371510:0) oie 357, 51080) uoais
315.0 45.0 315.0 45.0
29255 L9 Ip a 292.5 Be te
a
W = = 90.0E W 90.0E
270.0 = ce 270.0 =
\Y
Ey / L\ 112.5 4, i = 112.5
an 135.0 poate 135.0
202.5 180.0 97" 202.5 180.079
S S
July August
Speed 1.6 m/s Speed 0.6 m/s
Direction 217 deg Direction 72 deg
Speed, m/sec
anon T
Coe pe MT Th le ee
HS Ss ee aS
——— on

0 10 20 30 40
Frequency, %

Figure 8. (Sheet 2 of 3)

20

N

N
337.50.0 995 337.50.0 995
315.0 45.0 315.0 } 45.0
292.5 wit i7, Sie 292.5 Al ish : Bee
a
W so Ea pe vu E
270.0 = eH ooo 270.0 F eco
¢/ y oY 112.5 247.5 oh J ny 112.5
225.0 135.0 225.0 135.0
202.5,180.0'"- 202.5 180.0979
S S
September October
Speed 1.8 m/s Speed 2.6 m/s
Direction 38 deg Direction 31 deg
N N
337.50.0 995 337.50.0 995
315.0 45.0 315.0 45.0
292.5 a f -. oe 292.5 Re } F4 we
W 570.0 = 90.0E W 970.0 po : 90.0E
‘ae
947.5 ¢/ ee 112.5 247. ¢/ ~ NS 112.5
225.0 135.0 225.0 135.0
202.5 180.0 '>/-> 202.5 180.0"
Ss S
November December
Speed Z0um/s Speed 2.1 m/s
Direction 358 deg Direction 335 deg
Speed, m/sec
NDE? 7 i i < ag
tem ome on
——
OPO meZORt sor 740

Frequency, %

Figure 8.

2A

(Sheet 3 of 3)

PART III: WAVES

27. This section presents summaries of the wave data. A discussion of
individual major storms is given in Part IX and contains additional wave data
for times when wave heights exceeded 2 m at the seaward end of the FRF pier.
Appendixes B through E provide more extensive data summaries for each gage,
including height and period distributions, wave direction distributions,
persistence tables, and spectra during storms.

28. Wave directions (similar to wind directions) at the FRF are
seasonally distributed. Waves approach most frequently from north of the pier
in the fall and winter and south of the pier in the summer, with the exception
of storm waves which approach twice as frequently from north of the pier.
Annually, waves are approximately evenly distributed between north and south

(resultant wave direction being almost shore-normal).
Measurement Instruments
29. The wave gages included one buoy (Gage 630), ome pressure (Gage

141) and two wave staff gages (Gages 625 and 645), as shown in Figure 2 and

located as follows:

Distance Offshore Water Depth Operational
Gage Type/Number from Baseline m Period
Accelerometer buoy (630) 6 km 18 11/78-12/87
Pressure gage (141) 1 km 9 09/86- 12/87
Continuous wire (625) 579 m 8 11/78-12/87
Continuous wire (645) 238 m o355) 11/84-12/87
Staff gages

30. Two Baylor Company (Houston, TX) parallel cable inductance wave
gages (Gage 645 at sta 7+80 and Gage 625 at sta 19+00 (Figure 2)) were mounted
on the FRF pier. Rugged and reliable, these gages require little maintenance
except to keep tension on the cables and to remove any material which may
cause an electrical short between them. They were calibrated prior to instal-
lation by creating an electrical short between the two cables at known dis-
tances along the cable and recording the voltage output. Electronic signal
conditioning amplifiers are used to ensure that the output signals from the
gages are within a O- to 5-V range. Manufacturer-stated gage accuracy is

about 1.0 percent, with a 0.1 percent full-scale resolution; full scale is

22

14 m for Gage 625 and 8.2 m for Gage 645. These gages are susceptible to
lightning damage, but protective measures have been taken to minimize such
occurrences. A more complete description of the gages’ operational charac-
teristics was given by Grogg (1986).
Buo age

31. One Datawell Laboratory for Instrumentation (Haarlem, The Nether-
lands) Waverider buoy gage (Gage 630) measures the vertical acceleration pro-
duced by the passage of a wave. The acceleration signal is double-integrated
to produce a displacement signal which is transmitted by radio to an onshore
receiver. The manufacturer stated that wave amplitudes are correct to within
3 percent of their actual value for wave frequencies between 0.065 and 0.500
Hz (corresponding 15- to 2-sec wave periods). The manufacturer also specified
that the error gradually increased to 10 percent for wave periods in excess of
20 sec. The results in this report were not corrected for the manufacturer's
specified amplitude errors. However, the buoy was calibrated semiannually to

ensure that it was within the manufacturer's specification.

Pressure Gage

32. One Senso-Metrics, Incorporated (Simi Valley, CA) pressure trans-
duction gage (Gage 141) installed near the ocean bottom measures the pressure
changes produced by the passage of waves creating an output signal which is
linear and proportional to pressure when operated within its design limits.
Pre- and post-deployment precision calibrations are performed at the FRF using
a static deadweight tester. The sensor's range is 0 to 25 psi (equivalent to
O- to 17-m seawater) above atmospheric pressure with a manufacturer-stated
accuracy of +0.25 percent. Copper scouring pads are installed at the sensor's
diaphragm to reduce biological fouling, and the system is periodically cleaned

by divers.

Digital Data Analysis and Summarization

33. The data were collected, analyzed, and stored on magnetic tape
using the FRF’s VAX computer. Data sets were normally collected every 6 hr.
During storms, the collection was at 3-hr intervals. For each gage a data set

consisted of 4 contiguous records of 4,096 points recorded at 0.5 Hz

23

(approximately 34-min long), for a total of 2 hr and 16 min. Analysis was
performed on individual 34-min records,

34. The analysis program computes the first moment (mean) and the
second moment about the mean (variance) then edits the data by checking for
"jumps," "spikes," and points exceeding the voltage limit of the gage. A jump
is defined as a data value greater than five standard deviations from the
previous data value; whereas, a spike is a data value more than five standard
deviations from the mean. If less than five consecutive jumps or spikes are
found, the program linearly interpolates between acceptable data and replaces
the erroneous data values. The editing stops if the program finds more than
five consecutive jumps or spikes or more than a total of 100 bad points or the
variance of the voltage is below 1 x 10-° squared volts. The statistics and
diagnostics from the analysis are saved.

35. Sea surface energy spectra are computed from the edited time
series. Spectral estimates are computed from smaller data segments obtained
by dividing the 4,096-point record into several 512-point segments. The
estimates are then ensemble-averaged to produce a more accurate spectrum.
These data segments are overlapped by 50 percent (known as the Welch (1967)
method) and have been shown to produce improved statistical properties than
from nonoverlapped segments. The mean and linear trends are removed from each
segment prior to spectral analysis. To reduce sidelobe leakage in the spec-
tral estimates, a data window was applied. The first and last 10 percent of
data points was multiplied by a cosine bell (Bingham, Godfrey, and Tukey
1967). Spectra were computed from each segment with a discreet Fast Fourier
Transform then ensemble-averaged. Sea surface spectra from subsurface pres-
sure gages were obtained by applying the linear wave theory transfer function.

36. Unless otherwise stated, wave height in this report refers to the
energy-based parameter H,, defined as four times the zeroth moment wave
height of the estimated sea surface spectrum (i.e., four times the square root
of the variance) computed from the spectrum passband. Energy computations
from the spectra are limited to a passband between 0.05 and 0.50 Hz for sur-
face gages and between 0.05 Hz and a high frequency cutoff for subsurface
gages. This high frequency limit is imposed to eliminate aliased energy and
noise measurements from biasing the computation of H,, and is defined as the
frequency where the linear theory transfer function is less than 0.1 (spectral

values are multiplied by 100 or more). Smoother and more statistically

24

significant spectral estimates are obtained by band-averaging contiguous
spectral components (3 components are averaged per band producing a
frequency band width of 0.0117 Hz).

37. Wave period T, is defined as the period associated with the
maximum energy band in the spectrum which is computed using a 3-point running
average band on the spectrum. The peak period is reported as the reciprocal
of the center frequency (i.e., T, = 1/frequency) of the spectral band with

the highest energy. A detailed description of the analysis techniques are

presented in a report by Andrew (1987).
Results

38. The wave conditions for the year are shown in Figure 9. For all
four gages, the distributions of wave height for the current year and all
years combined are presented in Figures 10 and 11, respectively. Distribu-
tions of wave period are presented in Figure 12.

39. Multiple year comparisons of data for Gage 141 actually incorporate
data for 1985 and 1986 from Gage 640, a discontinued Waverider buoy previously
located at the approximate depth and distance offshore as Gage 141.

40. Refraction, bottom friction, and wave breaking contribute to the
observed differences in height and period. During the most severe storms when
the wave heights exceed 3 m at the seaward end of the pier, the surf zone
(wave breaking) has been observed to extend past the end of the pier and
occasionally 1 km offshore. This occurrence is a major reason for the dif-
ferences in the distributions between Gage 630 and the inshore gages. The
wave height statistics for the staff gage (Gage 645), located at the landward
end of the pier, were considerably lower than those for the other gages. In
all but the calmest conditions, this gage is within the breaker zone. Con-

sequently, these statistics represent a lower energy wave climate.

25

Height, m
On FOND F OND FF ON FF OND FF ON F

Period, sec

Jan Jul

Feb Aug
so Sai abet =
Apr Oct
the eh Ena OO ee
May Nov
i was a
Jun Dec
EE DN Se Ot] SR

1 3° 5 7 9 1113715 17 19:21 23125)27:29) 12 3) eS a7 MISE I MShISi7 Su ih2si251270 29731
Day of the Month

Jul

Aug

1eSi150 799) 1A) 13615) 17) 1902023) 25027 29 ti 37S) 7S cit Ss15 17419) 2112392512729)
Day of the Month

Figure 9. Time-histories of wave height and period for Gage 630

26

Height, m

Height, m

108s On 10° 10 10°
Percent Greater Than Indicated

Figure 10. 1987 annual wave height distributions

Ong ON 10° 10 10
Percent Greater Than Indicated

Figure 11. Annual distribution of wave heights
for 1980 through 1987

2],

40
] Gage 625 1987 Gage 625 1980—87

al Z y
_ Jf --oeGf20o_]_.aBel2beo
g “4 Gage 630 1987 Gage oso 1980-87
ha se ie Brain
7) oad meee
a” Gage 141 1987 Gage 141 1985-87
2 20 y) =

Qe es ea an? hee eee eae AY nai | Aes

Gage 645 1980-87

20

Figure 12. Annual wave period distributions for all gages

41. Summary wave statistics for the current year and all years combined

are presented for Gage 630 in Table 3.

28

Table 3

Wave Statistics for Gage 630

1987 and 1980-1987 Mean, Standard Deviation and Extreme Hmo and Tp for Gage 630

1987 1980-1987
Height Period Height Period
Std. Std. E Std.
Mean Dev. Extreme Mean Dev. Number Mean Dev. Extreme Mean Dev. Number
Month mm ___m _ Date sec_ sec. Obs. mm _m_ __m__ Date sec_ sec_ _Obs._
Jan alge}! @G7/ 325) 26 Ssligees5 72 Tee Oln7: 4.5 NOB35 7 7719). 2/7 826
Feb Lesh 058 Gaal 17 Ugo deal 108 aS} QG7/ 5.1 1987) 8.16) 236 789
Mar Gi O39 4.7 10 Colealy 7258} LZ, DS2. 10)57) 4.7 1983 8.8 2.7 877
Apr 4s 028 3.8 26 oF 3 2.5 118 130). 0.6 a(3} Ke SEY CISA 725 7/ 859
May Ob 2.5 5 Sof 745(0) 103 OAS e015 353 1986 8.0 2.3 872
Jun 057, 710-3 1.6 24 Uses: Cot 114 0.7 0.4 Zell UCT ei e7/a7h 974572 826
Jul O26 VOR2 1.3 15 726% 159 121 O26 1053 cal 1985) Sed 235 827
Aug 029)" (0-5 2n3 15 Seliger ee4 124 0:8) 105 3.6 L981 5850) 215 830
Sep O59) 10c5 258) 5 Sigal Oo alee) 119 TOM (0:6 6.1 1985 8.6 2.6 849
Oct NE. (Wa7/ 3.0 13 oak = alae} 109 i726 7/ 4.3 aletsy 2 ts}a7/5 7457/ 931
Nov ilar) (5 7/ 2.7 12 Tisle Seal 119 iers (0)57/ 4.1 19815 (8s 258 767
Dec 1.0 0.6 B63 29 Se Sine sel 124 12s 2088 5.6 1980 8.4 2.9 769
Annual iat. Wer/ Bed Feb 8.2.) ~253' ~ 1348 1.0 0.6 6.1 Sep 1985 8.3 2.6 10022

42. Annual joint distributions of wave height versus wave period for
Gage 630 are presented for 1987 in Table 4, and for all years combined in
Table 5. Similar distributions for the other gages are included in Appendixes

B through E.

43. Annual distributions of wave directions (relative to True North)
based on daily observations of direction at the seaward end of the pier and
height from Gage 625 (or Gage 141 when data for Gage 625 were unavailable) are
shown in Figure 13. Monthly wave "roses" for 1987 and all years combined are

presented in Figures 14 and 15, respectively.

29

Annual 1987, Gage 63
Percent Occurrence(X100) of Heig
Height(m) Period(sec)

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0-

ZO) SO nner 9) 1559) 659) 79S Ole 99
0.00 - 0.49 7 22 22 22 Tek able Gal afl
0.50 - 0.99 590i) 163) 92370) 95930 S04 57 320653
1.00 - 1.49 G 22°) S148) 364) 92670 134, 341) 9163
1.50 - 1.99 ¢ : 37-208) 52525 104 111 4a
2.00 - 2.49 C 5 5 30 67 89 74 82
2.50 - 2.99 ; S C 15 37 22 7
3.00 - 3.49 6 C 6 C : 30 15 22
3.50 - 3.99 : : 6 O ; 7 7 :
4.00 - 4.49 6 : . . 6 é 5 15
4.50 - 4.99 . 6 : 0 . O 5 é
5.00 - Greater 8 6 . g 5 . 0
Total 66 207 444 1217 1179 1113 2409 1254

Table 4

Annual Joint Distribution of H,, versus T, for Gage 630

Table 5

0
ht and Period

10.0- 12.0- 14.0- 16.0-

Orceerveeve

Total

Annual Joint Distribution of H,, versus T, for Gage 630 (All Years)

Coe se eee

Height(m)

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0-
259) 21359) 149) 615.9) 26.9) 97/9) 11839

0.00 - 0.49 20 17 29 56 104 118 331
0.50 - 0.99 35 126 247 477 575 502 834
1.00 - 1.49 : 11 128 6 450 270 251

1.50 - 1.99 : 25 14S 2630114 7
2.00 - 2.49 : 6 2 26 78 78 49
2.50 - 2.99 C 6 C : 7/ 35 19
3.00 - 3.49 5 : . : 1 7 16
3.50 - 3.99 0 9 ; ; . 1 4
4.00 - 4.49 . : C 0 : : 1
4.50 - 4.99 : : . : 6 A é
5.00 - Greater 6 7 9 ° fe ° 1
Total 55 154 418 1086 1478 1125 1581

Annual 1980-1987, Gage 630
Percent Occurrence(X100) of Heigh

Period(sec)
10.0- 12.0- 14.0- 16.0-

30

9.0-

and Period

4
17

coco ee ee NWN

33

1987
Height 0.8 m
Direction 61 deg

N
337.59:0 995

1980-1987
Height 0.8 m
Direction 67 deg

Height, m

25 (Oe. SF), FEL AS RS
Oo = N » w+ wo

OM 2004540) 60 ‘60 100
Frequency, %

Figure 13. Annual wave roses

Sul

N
COR 225
45.0
"ha 67.5
D>
oll | 90.0E
&
S 112.5
135.0
S
January
Height 0.9 m

Direction 55 deg

N
0.0 92.5
45.0
67.5
i oe
\G | 90.0E
Se
112.5
S
March
Height 1.2 m

Direction 60 deg

2
S
0

Figure 14.

CO Om22"5
45.0
WV 67.5
a
>
s
ny
135.0
157.5
S
February
Height 1.0 m

Direction 54 deg

‘a on | 90.0E

S)
April
Height 0.9 m
Direction 53 deg

Height, m
Ono ae soe Oe LS
SN | ne) shee uD
20 40 60 80 100

Frequency, %

Monthly wave roses for 1987 (Sheet 1 of 3)

32

N
22S
67.5
Wee
SE
\ = 90.0E
SS
i225
S
May
Height 0.7 m

Direction 61 deg

S

July
Height 0.4 m
Direction 67 deg

22.9

S

June
Height 0.4 m

Direction 61 deg

S
August
Height 0.7 m
Direction 66 deg

Height, m
Oey get Wee een
) Chil eepogie See mle)

0 20

Figure 14.

40 60 80 100
Frequency, %

(Sheet 2 of 3)

33

72D USS)
45.0
oo 67.5
a
Pa
os i
we
112.5
S
September
Height 0.7 m

Direction 75 deg

S
November
Height 0.8 m
Direction 61 deg

Frequency, %

° °
oO —
0 20
Figure 14.

S
October
Height 0.9 m
Direction 66 deg

22.5

7 67.5
oa
= =) 90.08
&

112.5

S
December
Height 0.8 m
Direction 58 deg

2
Te

100

(Sheet 3 of 3)

0.0 99.5 0.0 92.5
45.0 45.0
=| 4 67.5 2 he 67.5
ef owl
x 112.5 ie 112.5
135.0 135.0
157.5
S )
January February
Height 0.9 m Height 1.0 m
Direction 56 deg Direction 64 deg
N N
02255 OrO 2235
45.0 45.0
67.5 67.5
i vA Ss
el] ey
. 112.5 2 112.5
135.0 135.0
S) S
March April
Height 0.9 m Height 0.7 m
Direction 69 deg

Direction 67 deg

Height, m
Se Sieh San ee ae Same ee
(oy REBORN RS ig PO)
0 20 40 60 80 100
Frequency, %
Figure 15. Monthly wave roses for 1980 through 1987
(Sheet 1 of 3)

3p)

ie 4, 67.5

-® 112.5

135.0
157.5
S
May
Height 0.7 m
Direction 74 deg

7

ay
=D
io —<o fl E
ei os 112.5
135.0
157.5

Ss
July
Height 0.4 m
Direction 78 deg

Height, m
> ro) ° 2
ro) = N bY)
0 20
Frequency, %
Figure 15.

36

112.5
135.0
S
June
Height 0.5 m

Direction 79 deg

112.5
135.0
S
August
Height 0.6 m

Direction 73 deg

° ro)
Te)
40 60 80 100

(Sheet 2 of 3)

September
Height 0.8 m
Direction 70 deg

N

337.50:0 99.5
45.0

4 » 2 67.5

November
Height 0.9 m
Direction 61 deg

October
Height 1.0 m
Direction 67 deg

December
Height 0.8 m
Direction 59 deg

Height, m
oo ee &
= Nn ~~ w

0

20 40 60 80 100

Frequency, %

Figure 15 (Sheet 3 of 3)

3i/

PART IV: CURRENTS

44. Surface current speed and direction at the FRF are influenced by
winds, waves, and, indirectly, by the bottom topography. The extent of the
respective influence varies daily. However, winds tend to dominate the cur-
rents at the seaward end of the pier; whereas, waves dominate within the surf

zone.

Observations

45. Near 0700 EST, daily observations of surface current speed and
direction were made at (a) the seaward end of the pier, (b) the midsurf
position on the pier, and (c) 10 to 15 m from the beach 500 m updrift of the
pier. Surface currents were determined by observing the movement of dye on

the water surface.

Results

46. Annual mean and mean currents for 1980 through 1987 are presented
in Table 6 and in Figure 16. Figure 16 shows the daily and average annual
measurements at the beach, pier midsurf, and pier end locations. Since the
relative influences of the winds and waves vary with position from shore, the
current speeds and, to some extent, direction vary at the beach, midsurf, and
pier end locations. Magnitudes generally are largest at the midsurf location

and lowest at the end of the pier.

38

Table 6
Mean Longshore Surface Currents*

Pier End, cm/sec Pier Midsurf, cm/sec Beach, cm/sec
1980- 1980- 1980-
Month 1987 1987 1987 1987 1987 1987
Jan 23 18 19 21 11 15
Feb 30 19 35 11 27 13
Mar 17 16 -3 16 -1 14
Apr 35 11 13 1 4 5
May 20 12 2 -3 6 -2
Jun 12 3 5 -11 6 -5
Jul 14 3 -9 -16 -4 -9
Aug 5 8 -16 -15 4 -6
Sep =i 10 -15 -3 -4 2
Oct 18 9 17 3 15 6
Nov 10 13 -4 9 1 11
Dec 12 14 6 14 16 8
Annual 16 11 4 2 7 6
* + = southward; —- = northward.

39

-200

Pier End

Year Mean, cm/s

-150 — 1987 16 =
@=---01980-87 11 =
-100 , #
-50 Z me Ee sh .
0 52 oye 1 ° rae * OIC IO ves ae Sree: dee or S35 aS bd
eee SG Be . 2 56 e ges COL SO Oo or ee ne < e 3 wee *
50-*.° ‘ aS Hearn ra) ae . ’ a Aim Sake
100 . + Me : =
° ° a
°o
150 mt
200 :
Pier Midsurf voutuaMGanttem/s
: -150 ——« 1987 4 eS |
se . . @=--01980-87 2 S
£ -100 : , ia aor =
(3)
om —-50
oO
®
fom 0
”)
=
2 50
oO
=
=) 100
=
oO
150
200 :
Beach (500 m Updrift) ,.,, Wecneenys
-—150

a —x« 1987 7
@=---0 1980-87 6

North

100 . : ws F

<£
_
* . J
°
"2)

150

200 T Filinsenie eens heeemoni Le ecaenr seria idl ihar Bese

Jan RD Nae Apr May Jun Jul iio Sep Oct Nee Dec
Month

Figure 16. Daily current speeds and directions with monthly means for 1987

40

PART V: TIDES AND WATER LEVELS
Measurement Instrument

47. Water level data were obtained from a NOAA/NOS control tide station
(sta 865-1370) located at the seaward end of the research pier (Figure 2) by
using a Leupold and Stevens, Inc. (Beaverton, OR) digital tide gage. This
analog-to-digital recorder is a float-activated, negator-spring, counterpoised
instrument that mechanically converts the vertical motion of a float into a
coded, punched paper tape record. The below-deck installation at pier
sta 19+60 consisted of a 30.5-cm-diam stilling well with a 2.5-cm orifice and
a 21.6-cm-diam float.

48. Operation and tending of the tide gage conformed to NOS standards.
The gage was checked daily for proper operation of the punch mechanism and for
accuracy of the time and water level information. The accuracy was determined
by comparing the gage level reading with a level read from a reference elec-
tric tape gage. Once a week, a heavy metal rod was lowered down the stilling
well and through the orifice to ensure free flow of water into the well.
During the summer months, when biological growth was most severe, divers
inspected and cleaned the orifice opening as required.

49. The tide station was inspected quarterly by a NOAA/NOS tide field
group. Tide gage elevation was checked using existing NOS control positions,
and the equipment was checked and adjusted as needed. NOS and FRF personnel
also reviewed procedures for tending the gage and handling the data. Any
specific comments on the previous months of data were discussed to ensure data
accuracy.

50. Digital paper tape records of tide heights taken every 6 min were
analyzed by the Tides Analysis Branch of NOS. An interpreter created a digi-
tal magnetic computer tape from the punch paper tape which was then processed
on a large computer. First, a listing of the instantaneous tidal height
values was created for visual inspection. If errors were encountered, a com-
puter program was used to fill in or recreate bad or missing data using cor-
rect values from the nearest NOS tide station and accounting for known time
lags and elevation anomalies. The data were plotted, and a new listing was
generated and rechecked. When the validity of the data had been confirmed,

monthly tabulations of daily highs and lows, hourly heights (instantaneous

Al

height selected on the hour), and various extreme and/or mean water level

statistics were computed.

Results

51. Tides at the FRF are semidiurnal with both daily high and low

tides approximately equal.

Tide height statistics are presented in Table 7.

Figure 17 plots the monthly tide statistics for all available data, and

Figure 18 compares the distribution of daily high and low water levels and

hourly tide heights.

the average of the hourly heights; whereas, the mean tide level is midway

The monthly or annual mean sea level (MSL) reported is

between mean high water (MHW) and mean low water (MLW) which are the averages

of the daily high and low water levels, respectively, relative to NGVD.

Mean

range (MR) is the difference between MHW and MLW levels, and the lowest water

level for the month is the extreme low (EL) water while the highest water

level is the extreme high (EH) water level.

Month Mean

or High
Year Water
1987

Jan 55
Feb 51
Mar 60
Apr 58
May 50
Jun 50
Jul 54
Aug 58
Sep 58
Oct 57
Nov 51
Dec -
1987 55

Prior Years

1986 60
1985 59
1984 64
1983 68
1982 58
1981 59
1980 59
1979 60
1979-=

1987 60

* Measurements are in centimeters.

Mean
Tide
Level

12

Mean
Sea
Level

Table 7

Mean

Low Mean
Water Range
-27 82
-27 78
-21 81
-20 78
-27 77
-27 77
-25 79
-22 80
-22 80
-23 80
-27 78
Gage Inoperative
-24 79
-35 95
-37 96
-32 97
-30 98
-42 99
-42 101
-43 102
-43 103
-36 97

42

Tide Height Statistics*

Extreme
High

Date

Dec
Dec
Oct
Jan
Oct
Nov
Mar
Feb

Nov 1981

-108
-93
-77
-73

-108

-110

-119
-95

-119

Mar 1980

Water Level, m

140

cS)
°

o
o

oo dal |

E
©: 40
3
& a MSL
is 0
3
= -20
“MLW
-40
-60 Me
-80
-100
-120 T aa <= == T T Sy 7 >
1979 1980 1981 1982 1983 1984 1985 1986 1987
Year
Figure 17. Monthly tide and water level statistics
relative to NGVD
1.50
1.25 1987
1979-87
1.00
0.75
0.50
0.25
0.00
tas |
-0.50
<M
panel SLUNG
=1.25
-1.50 +4~—_ Tr eelacy oe PT San ey ae Ps Teo
0.01 0.10 1.00 10.00 25.00 50.00 75.00 90.00 99.00 99.90 99.99
Percent Greater Than
Figure 18. Distributions of hourly tide heights and

high and low water levels

43

PART VI: WATER CHARACTERISTICS

52. Monthly averages of daily measurements of surface water tempera-
ture, visibility, and density at the seaward end of the FRF pier are given in
Table 8. The summaries represent single observations made near 0/00 EST and,
therefore, may not reflect daily average conditions since such characteristics
can change within a 24-hr period. Large temperature variations were common
when there were large differences between the air and water temperatures and
variations in wind direction. From past experience, persistent onshore winds
move warmer surface water toward the shoreline, although offshore winds cause
colder bottom water to circulate shoreward resulting in lower temperatures.

Table 8

Mean Surface Water Characteristics

Temper ature Visibility Density
deg C m g/cm

1980- 1980- 1980-
Month 1987 1987 1987 _ 1987 1987 1987
Jan 6.4 5.8 0.8 1.1 1.0228 1.0236
Feb 3.8 4.5 1.4 1.6 1.0221 1.0231
Mar Dar/ 6.5 1.3 1.4 1.0217 1.0228
Apr 10.2 10.9 1.6 2.0 1.0193 * 1.0224
May 15.5 15.2 2.0 2.3 1.0207 1.0223
Jun 19.1 19.3 3.2 3.5 1.0215 1.0215
Jul 22.7 21.8 4.3 3.9 1.0209 1.0215
Aug 24.4 23.3 3.4 3.0 1.0208 1.0205
Sep 24.2 22.8 3.8 2.2 1.0207 1.0209
Oct 18.0 19.1 2.4 1.5 1.0218 1.0216
Nov 14.0 14.7 1.3 0.9 1.0232 1.0227
Dec 9.8 10.1 1.1 1.0 1.0237 1.0232
Annual 14.6 14.5 ae: 2.1 1.0217 1.0222

*.Only 11 density measurements in April.

Temperature
53. Daily sea surface water temperatures (Figure 19) were measured with

an NOS water sampler and thermometer. Monthly mean water temperatures

(Table 8) varied with the air temperatures (see Table 2).

44

Temperature
30.0 C

Year ™) ideg

*—x 1987 14.6
@----© 1980-87 14.5

25.0

20.0

15.0

10.0

Water Temperature, deg C

5.0

0.0 ht. i eels he el

Nipareenratin
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure 19. Daily water temperature values with monthly means
Visibility

54. Visibility in coastal nearshore waters depends on the amount of
salts, soluble organic material, detritus, living organisms, and inorganic
particles in the water. These dissolved and suspended materials change the
absorption and attenuation characteristics of the water which vary daily and
yearly.

55. Visibility was measured with a 0.3-m-diam Secchi disk and, similar
to water temperature, variation was related to onshore and offshore winds.
Onshore winds moved warm clear surface water toward shore; whereas, offshore
winds brought up colder bottom water with large concentrations of suspended
matter. Figure 20 presents the daily and monthly mean surface visibility
values for the year. Large variations were common, and visibility less than

1 m was expected in any month. Monthly means are given in Table 8.

45

7.0

Water Visibility, m

Year Mean, m

*—* 1987 2.2
@----0 1980-87 2.1

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure 20. Daily water visibility values with monthly means

Density

56. Daily and monthly mean surface density values, plotted in

Figure 21, were measured with a hydrometer.

Table 8.

46

Monthly means are also given

in

Density, g/cm**3

Year Mean, g/cm**3

x— 1987 1.0217
@----© 1980-87 1.0222

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure 21. Daily water density values with monthly means

47

PART VII: SURVEYS

57. Waves and currents interacting with bottom sediments produce
changes in the beach and nearshore bathymetry. These changes can occur very
rapidly in response to storms or slowly as a result of persistent but less
forceful seasonal variations in wave and current conditions.

58. Nearshore bathymetry at the FRF is characterized by regular shore-
parallel contours, a moderate slope, and a barred surf zone (usually an outer
storm bar in water depths of about 4.5 m and an inner bar in water depths
between 1.0 and 2.0 m). This pattern is interrupted in the immediate vicinity
of the pier where a permanent trough runs under much of the pier, ending in a
scour hole where depths can be up to 3.0 m greater than the adjacent bottom
(Figure 22). This trough, which apparently is the result of the interaction
of waves and currents with the pilings, varies in shape and depth with chang-
ing wave and current conditions. The pier'’s effect on shore-parallel contours
occurs as far as 300 m away, and the shoreline may be affected up to 350m

from the pier (Miller, Birkemeier, and DeWall 1983).

nu

.
Oe
PSS

Figure 22. Permanent trough under
the FRF pier, 9 December 1987

48

59. To document the temporal and spatial variability in bathymetry,
surveys were conducted approximately monthly of an area extending 600 m north
and south of the pier and approximately 950 m offshore. Contour maps result-
ing from these surveys along with plots of change in elevation between surveys
are given in Appendix A.

60. All surveys utilized the Coastal Research Amphibious Buggy (CRAB),
a 10.7-m-tall amphibious tripod, and a Zeiss electronic surveying system
described by Birkemeier and Mason (1984). The profile locations are shown in
each figure in Appendix A. Survey accuracy was about +3 cm horizontally and
vertically. Monthly soundings along both sides of the FRF pier were collected
by lowering a weighted measuring tape to the bottom and recording the distance
below the pier deck. Soundings were taken midway between the pier pilings to
minimize errors caused by scour near the pilings.

61. A history of bottom elevations below Gages 645 and 625 is presented
in Figure 23 for their respective pier stations of sta 7+80 (238 m) and

sta 19+00 (579 m) along with intermediate locations, 323 and 433 m.

v Distance

;: ] (m)

=e 238

-3

- S235

é hi ees eee eG Gree eee fee

=18 0 a Pill ie) 579
pee

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Depth, m
!
a

Figure 23. Time-history of bottom elevations at
selected locations under the FRF pier

49

PART VIII: PHOTOGRAPHY

Aerial Photographs

62. Aerial photography was taken quarterly using a 23-cm aerial mapping
camera at a scale of 1:12,000. All coverage was at least 60 percent overlap,
with flights flown as closely as possible to low tide between 1000 and
1400 EST with less than 10 percent cloud cover. The flight lines covered are
shown in Figure 24. Figure 25 is a sample of the imagery obtained on 10 July

1987; the available aerial photographs for the year are:

Date Flight Lines Format

9 Jan 2 Color
3 B/W

27 Apr 2. Color
3 B/W
al B/W

10 Jul 2 Color
3 B/W

SOc 2 Color
3 B/W

Beach Photographs

63. Daily color slides of the beach were taken using a 35-mm camera
from the same location on the pier looking north and south (Figure 26). The
location from which each picture was taken, as well as the date, time, and a

brief description of the picture, was marked on the slides.

50

Ni RUOEE INLET

SCALE 1 12.000

CAPE
HATTERAS

FIELD RESEARCH
FACILITY

Figure 24. Aerial photography flight lines

oll

Figure 25. Sample aerial phctograph, 10 July 1987

52

North View South View

18 March 1987

Figure 26. Beach photos looking north and south from the FRF pier
(Sheet 1 of 4)

53

North View South View

18 June 1987

Figure 26. (Sheet 2 of 4)

54

North View South View

16 September 1987

Figure 26. (Sheet 3 of 4)

55

North View South View

6 November 1987

19 December 1987

Figure 26. (Sheet 4 of 4)

56

PART IX: STORMS

64. This section discusses storms (defined here as times when the wave
height parameter, H,,, equaled or exceeded 2 m at the seaward end of the FRF
pier). Sample spectra from Gage 630 are given in Appendix B. Prestorm and/or
poststorm bathymetry diagrams are given in Appendix A. NOAA Daily Weather
Maps (US Department of Commerce 1987) provided tracking information.

1-2 January 1987 (Figure 27)

65. This storm formed over the Gulf of Mexico and early on 1 January
was located off the Georgia coast. It increased in intensity and speed,
rapidly moved up the coast, and by 2 January was located off New England. On
1 January at 2000 EST, the atmospheric pressure dropped to 993 mb. Maximum
onshore winds exceeded 12 m/sec (ENE), and maximum H,, (Gage 141) of 3.81 m
(period = 10.24 sec) was recorded at 1900 EST also on 1 January.

1040 Atmospheric Pressure, mb Gage 616

1020
1010
1000

Wind Speed, m/sec Gage 632

1

Sw

: Wind Direction, Deg True N Gage 633

1

150 Wave Direction, Deg True N Gage 21
90 ————
30
-30
4 Wave Height, H,,5.™ Gage 141
3
2
1
0.

25 Wave Period, T,, sec Gage 141

0.

2 Water Level from NGVD, m Gage 1
1

°

LL I JR ULI |
1 2 3 4
JANUARY
1987

Figure 27. Data for 1-2 January 1987 storm

yi

17 January 1987 (Figure 28)

66. Following the passage of a cold front, strong onshore winds
generated by a large Canadian high-pressure system began to affect the FRF on
the afternoon of 16 January. Maximum wind speeds exceeded 14 m/sec (NNE), and
the largest H,, (Gage 141) of 2.32 m (period = 7.76 sec) was recorded at
1500 EST on 17 January. Total precipitation was 4 mn.

1030
1020
1010

1000

25 Wind Speed, m/sec Gage 632

20

15

10

5

0 4
360 Wind Direction, Deg True N Gage 633
270 PS
180

90

i) 4
150 Wave Direction, Deg True N Gage 21

a

3 Wave Height, H,,,,™m Gage 141
ne
1

Wave Period, Tp sec Gage 141

Water Level from NGVD, m Gage 1

JANUARY
1987

Figure 28. Data for 17 January 1987 storm

25-27 January 1987 (Figure 29

67. This low-pressure system formed on 23 January over the western
United States, later tracked over the southern United States, and early on 26
January moved offshore at Cape Hatteras, NC. On 25 January, onshore winds
peaked at 17 m/sec (NE) at 2200 EST. The minimum atmospheric pressure of
977.7 mb occurred on 26 January at 0300 EST. The maximum H,, (Gage 141) of
3.26 m (period = 9.85 sec) was recorded at 1400 EST on 26 January and remained

above 2 m for 33 hr. Total precipitation was 22 mm.

1040 Atmospheric Pressure, mb Gage 616
1030
1020 7
1010
1000
990 1
25 Wind Speed, m/sec Gage 632
20
15
10
5 ~
° =
360 Wind Direction, Deg True N Gage 633
270
180
90
0 — =]
150 Wave Direction, Deg True N Gage 21
90
30
-30:
a Wave Height, H,,,,m Gage 141
3
2 —~
1
° 1
25 Wave Period, T,, sec Gage 141
20
15
10. os alr ie E RC ee oe S
5
° 1
2 Water Level from NGVD, m Gage1
1
0
-1
-2
24 25 26 27 28 29
JANUARY
1987

Figure 29. Data for 25-27 January 1987 storm

59

16-18 February 1987 (Figure 30

68. Northeast winds generated by a strong Canadian high-pressure system
first affected the FRF early on 16 February following the passage of a cold
front. Maximum onshore winds approached 18 m/sec (NNE) at 0508 EST on
17 February, and the maximum H,, (Gage 141) of 4.30 m (period = 8.53 sec)

was recorded at 0808 EST on the same day. Total precipitation was 27 mn.

1040 Atmospheric Pressure, mb Gage 616
1030
1020
1010
1000
990 1
25 Wind Speed, m/sec Gage 632
20
15
10
5
0) 1
360 Wind Direction, Deg True N Gage 633
270
180
90
°
150 Wave Direction, Deg True N Gage 21
90
30
-30
5 Wave Helght, H,,,.™m Gage 141
4
3
2
1
tC) =a
25 Wave Period, T,, sec Gage 141

FU ee yi espe ian ea ara
5

o =<)
2 Water Level from NGVD, m Gage 1
1
°
+1
—2 Tatotalalate ola aletolotatntatalalolalalntalatatatatatat otal
15 16 7 18 19 20
FEBRUARY
1987

Figure 30. Data for 16-18 February 1987 storm

60

10-16 March 1987 (Figure 31)

69. Forming off Cape Hatteras, NC, on 10 March, this intense storm was
spawned from another low-pressure system which had developed over the Gulf of
Mexico and tracked northeast along the Appalachian Mountains. This storm
quickly moved well offshore and was replaced by a smaller storm which formed
off Virginia on 13 March and moved to the northeast. The minimum atmospheric
pressure of 1001 mb was recorded on 9 March at 2042 EST. Maximum onshore
winds exceeded 20 m/sec (NNE) at 0734 EST on 10 March with the maximum H,,
(Gage 141) of 4.52 m (period = 11.64 sec) recorded at 1300 EST on the same
day. The H,, remained above 3 m for 28 consecutive hr and above 2 m for 159

hr. Total precipitation was 22 mm.

1040 Atmospheric Pressure, mb Gage 616
1030
1020
1010
1000
990 1
26 Wind Speed, m/sec Gage 632

Direction, Deg, In

150 Wave Direction, Deg True N Gage 21
90
30
-30
5 Wave Height, H,45,™ Gage 141
4
3
2
1
0 =a
25 Wave Period, Tp sec Gage 141
20
15
10
5
0 =
2 Water Level from NGVD, m Gage1
1
0
“1
-2
9 10 1 12 13 14 15 16 7 18
MARCH
1987

Figure 31. Data for 10-16 March 1987 storm

61

23-24 March 1987 (Figure 32)

70. Onshore winds generated by a Canadian high-pressure system produced
storm waves at the FRF early on 23 March. Maximum winds exceeded 10 m/sec
(N), and maximum H,, (Gage 141) was 3.15 m (period = 11.64 sec); both values
were recorded at 1300 EST on 22 March.

1040 Atmospheric Pressure, mb Gage 616
1030
1020 =
1010
1000
990 7
25 Wind Speed, m/sec Gage 632

150 Wave Direction, Deg True N Gage 21
90
30
-30
4 Wave Height, H,,,, m Gage 141
3
2
1 e ~
0 a
25 Wave Period, Tp, sec Gage 141
20
15
iS by pee a era Pee en hs aa ey, Bx
5
0 al
2 Water Level from NGVD, m Gage 1
1
0)

Figure 32. Data for 23-24 March 1987 storm

62

30-31 March 1987 (Figure 33)

71. Onshore winds produced by a combination of a Canadian high-pressure

system and a storm traveling along a cold front over the Appalachian Mountains

briefly produced storm waves at the FRF. Maximum onshore winds in excess of

11 m/sec (SSE) were recorded at 0842 EST on 31 March. The minimum atmospheric

pressure of 997 mb occurred at 0842 EST, and the maximum Hi. (Gage 141) of

2.35 m (period = 9.48 sec) was recorded at 1000 EST the same day. Total

precipitation was 21 mn.

ie ees ee

25 Wind Speed, m/sec Gage 632
20
15
10
5
1}

2 Atmospheric Pressure, mb Gage 616

360 Wind Direction, Deg True N Gage 633
270
180
90
C) 1
150 Wave Direction, Deg True N Gage 21
90
30
-30
3 Wave Height, Ho» M Gage 141
2
1
0) SI
25 Wave Period, T,, sec Gage 141
20
15
10
5
° 1
2 Water Level from NGVD, m Gage 1
1
t)
“1
-2
29 30 3
MARCH
1987

Figure 33. Data for 30-31 March 1987 storm

16 April 1987 (Figure 34)

72. This storm originated over the central United States and was
located over western South Carolina by 16 April. It rapidly weakened and
moved offshore on 18 April. On the 16th, maximum wind speeds exceeded 12
m/sec (ESE), peaking at 1108 EST. The maximum H,, (Gage WAI) ie 255)s) inl
(period = 8 sec) was recorded at 1600 EST, and the lowest atmospheric pressure

of 1000 mb occurred at 1416 EST. Total precipitation was 7 mn.

1040 Atmospheric Pressure, mb Gage 616
1030
1020
1010 iii ee My lowe Fe
1000
990 ———y
25 Wind Speed, m/sec Gage 632
20
15
10
5
0 1
360 Wind Direction, Deg True N Gage 633
270
180
90
0) 1
150 Wave Direction, Deg True N Gage 21
90
30
-30
3 Wave Height, H,,.,m Gage 141

2 Ue ey eRe Lae (pt OU at SRG

25 Wave Period, T,, sec Gage 141

()
2 Water Level from NGVD, m Gage 1
1
°

ALL SLA LG SLL aL IY FU SU PL I]
15 16 7 18
APRIL
1987

Figure 34. Data for 16 April 1987 storm

64

25-28 April 1987 (Figure 35)

73. This storm developed over Georgia on 23 April, slowly traveled to
the northeast, and became almost stationary off Cape Hatteras, NC. By
25 April the low developed into a major storm and moved well offshore on
27 April. On the 26th, maximum onshore winds exceeded 18 m/sec (N to NNE) at
1442 EST. The maximum H,, (Gage 625) of 3.14 m (period = 11.14 sec)
occurred 5 hr later, and the lowest atmospheric pressure of 1012 mb was

recorded at 1408 EST. Total precipitation was 27 mm.

1040 Atmospheric Pressure, mb Gage 616

1010 pee

25 Wind Speed, m/sec Gage 632

20
15
10
5
i) =)
360 Wind Direction, Deg True Gage 633

150 Wave Direction, Deg True N Gage 21
90
30
-30
4 Wave Height, H,,,,™m Gage 625
3
‘ fo ee
1 ed
0 1
25 Wove Period, Tp» sec Gage 625
20
15
Sea AUN 6S gee or naar ate Sein Miata ec EE TM
5
0 4
2 Water Level from NGVD, m Gage 1
1
0)
-1
-2
24 25 26 27 28 29 30
APRIL
1987

Figure 35. Data for 25-28 April 1987 storm

65

4-5 May 1987 (Figure 36

74. Strong onshore winds generated by a large Canadian high-pressure
system along with a weak low-pressure system developed on 4 May. That day,
maximum onshore winds exceeded 16 m/sec (NNE) at 1742 EST, and maximum H,,
(Gage 141) of 2.69 m (period = 7.31 sec) was recorded at 2008 EST. The

atmospheric pressure did not drop, and there was no precipitation.

1040 Atmospheric Pressure, mb Gage 616
1030
1020
1010
1000
990 1
25 Wind Speed, m/sec Gage 632
20
15
10
5
i) 7
360 Wind Direction, Deg True N Gage 633
270
180
90
C) 1
150 Wave Direction, Deg True N Gage 21
90
30
-30
3 Wave Height, H,,..™ Gage 141
2
1
° ———sat
25 Wave Period, T,, sec Gage 141
20
15
10
5
C) 1
2 Water Level from NGVD, m Gage 1
1
0)
-1
-2
3 4 5 6 7
MAY
1987

Figure 36. Data for 4-5 May 1987 storm

66

14-16 August 1987 (Figure 37)

75. A Canadian high-pressure system affected onshore winds at the FRF
on 11 August. Augmented by a weak storm that developed off Florida's east
coast on 14 August, onshore winds continued through 16 August. Maximum wind
speeds exceeding 10 m/sec (NE) and H,, (Gage 141) of 2.46 m (period =
11.13 sec) were recorded at 0734 EST on 15 August. Because the winds were

produced by a high-pressure system atmospheric pressure never declined, and
there was no precipitation.
1040 Atmospheric Pressure, mb Gage 616

eae a eneeee eee
1010 ERS EMT

25 Wind Speed, m/sec Gage 632

360 Wind Direction, Deg True N Gage 633

180
80

Wave Direction, Deg True N Gage 21

‘I See a
Wave Period, Tp. sec Gage 141

Wave Height, H,,,,™m Gage 141

2 Water Level from NGVD, m Gage 1

13 14 15 16 7 18
AUGUST
1987

Figure 37. Data for 14-16 August 1987 storm

67

4-5 September 1987 (Figure 38)

76. Strong onshore winds generated by a strong Canadian high-pressure

system briefly produced storm waves at the FRF. The maximum wind speed of

13 m/sec (NE) was recorded at 2200 EST on 4 September.

That same day, the
maximum Hy,

(Gage 141) of 2.38 m (period = 7.11 sec) occurred at 2042 EST.

1040 Atmospheric Pressure, mb Gage 616
1030
1020
1010
1000
990 - wo - - <= -=-----— + 1
25 Wind Speed, 1n, sec Gage 632
20
15
10
5
0 = = 1

360 Wind Direction, Deg True N Gage 633

ee

+

w

Wave Height, H,,5. Mm Gage 141

| in po cies

25 Wave Period, Tp. sec

=)
Gage 141

Cpa.

Water Level from NGVD, m

SLES La LLL) FL LR) FU SU a aL
3 4 5 6 7
SEPTEMBER
1987

Figure 38. Data for 4-5 September 1987 storm

68

12-15 October 1987 (Figure 39)

77. Following the passage of a cold front late on 11 October, strong
onshore winds generated by a huge high-pressure system located in the central
US rapidly produced storm waves at the FRF. Onshore winds exceeded 10 m/sec
(N to NNE) for 86 consecutive hr with the peak wind speed of 17 m/sec (NNE)
occurring at 1934 EST on 13 October. Waves above 2 m were recorded for 80

consecutive hr with the maximum H,, (Gage 141) of 3.28 m (period = 9.14 sec)
occurring on 14 October at 0542 EST.

1040 Atmospheric Pressure, mb Gage 616

1020 Be ee a a EE

ees Te = eat!
25 Wind Speed, m/sec Gage 632
20
15
: ee
5
o4—™=--- “--- ~——- - - sn --== si
Wind Direction, Deg True N Gage 633

150 Wave Direction, Deg True N Gage 21
90
30
-30
4 Wave Height, H,,,,m Gage 141
3
2
1
0 = eee Ue oe : 2
25 Wave Period, Tp» sec Gage 141

14
OCTOBER
1987

Figure 39. Data for 12-15 October 1987 storm

69

11-12 November 1987 (Figure 40)

78. On 9 November, this storm developed off the Texas coast, moved
rapidly to the northeast, and by 11 November was located off the Virginia
coast. The storm intensified and continued its rapid movement up the east
coast, reaching New England on 12 November. Maximum onshore winds exceeded
13 m/sec (E) at 2200 EST on 11 November; maximum H,, (Gage 141) of 2.63 m
(period = 10.24 sec) occurred at 0400 EST on 12 November. The lowest atmo-
spheric pressure, 1007.2 mb, was recorded on 10 November at 1634 EST. Total

precipitation was 11 mn.

1040 Atmospheric Pressure, mb Gage 616

ran qd

25 Wind Speed, m/sec Gage 632

20

15

: ieee a ne

5

0 ——-----— = —=—-— -— 1
360 Wind Direction, Deg True N Gage 633

150 Wave Direction, Deg True N Gage 21

90 : 3 ki ee
30
-30
3 Wave Height, H,45,m Gage 141
2
1
0 a = eee = See : ,
25 Wave Period, T,, sec Gage 141

LLL SL RSL ae SUL eR LU IE LLL LE]
10 a 12 13 14
NOVEMBER
1987

Figure 40. Data for 11-12 November 1987 storm

70

27-29 November 1987 (Figure 41)

79. Winds caused by a strong Canadian high-pressure system began to

generate storm waves at the FRF on 27 November. The additional development of

a storm over Tennessee that moved to the North Carolina coast on 29 November
prolonged the onshore winds through 30 November. The maximum H,, (Gage 141)
of 2.44 m (period = 7.53 sec) occurred on 27 November at 1300 EST. Maximum
onshore winds approaching 12 m/sec (NE) were recorded at 1900 EST on the 27th.
The lowest atmospheric pressure was 998.9 mb on 30 November at 1442 EST.

Total precipitation was 34 mn.

1040 Atmospheric Pressure, mb Gage 616

25 Wind Speed, m/sec Gage 632

Wind Direction, Deg True N

150 Wave Direction, Deg True N Gage 21

3 Wave Height, H,,,,™ Gage 141

2

1

0 = am <= 1
25 Wave Period, Tp. sec Gage 141

2 Water Level from NGVD, m Gage 1

26 27 28 29 30
NOVEMBER
1987

Figure 41. Data for 27-29 November 1987 storm

71

29-30 December 1987 (Figure 42)

80.

This storm formed off Cape Hatteras, NC, early on 29

rapidly strengthened as it quickly moved up the east coast. It

off Nova Scotia, Canada, by 30 December. Maximum onshore winds
14 m/sec (NNE) at 2042 EST on the 29th; 5 hr later the maximum
(Gage 625) of 2.79 m (period = 11.13 sec) was recorded; and the

December and
was located
approached
Ho

minimum

atmospheric pressure of 1001.8 mb occurred on the 29th at 0434 EST.

Precipitation totalled 16 mn.

1040 Atmospheric Pressure, mb Gage 616
1030
1020
1010
1000
990-+—- - --
=
25 Wind Speed, m/sec Gage 632

oO = — os = a —

Wind Direction, Deg True N Gage 633

0 Sey =
150 Wave Direction, Deg True N Gage 21 i
90
be TIS
-30
3 Wave Height, H,,,, m Gage 625
2 Ne ee a
1
te) =
25 Wave Period, T,, sec Gage 625

SUL SUS LL UT Lae] eae LLU Le Pe ULL
28 29 30 31
DECEMBER
1987

Figure 42. Data for 29-30 December 1987 storm

72

REFERENCES

Andrew, M. E. 1987. "Standard Wave Data Analysis Procedures for Coastal
Engineering Applications," Unpublished report to The US Army Engineers
Waterways Experiment Station, Vicksburg, MS.

Bingham, C., Godfrey, M. D., and Tukey, J. W. 1967. "Modern Techniques of
Power Spectrum Estimation," IEEE Transactions Audio Electroacoustics, AU-15,
pp 56-66.

Birkemeier, W. A., and Mason, C. 1984. "The CRAB: A Unique Nearshore

Surveying Vehicle," Journal of Surveying Engineering, American Society of
Civil Engineers, Vol 110, No. 1.

Field Research Facility. 1987 (Jan-Dec). "Preliminary Data Summary," Monthly
Series, Coastal Engineering Research Center, US Army Engineer Waterways
Experiment Station, Vicksburg, MS.

Grogg, W. E., Jr. 1986. "Calibration and Stability Characteristics of the
Baylor Staff Wave Gage," Miscellaneous Paper CERC-86-7, US Army Engineer
Waterways Experiment Station, Vicksburg, MS.

Miller, H. C. 1980. "Instrumentation at CERC’s Field Research Facility,
Duck, North Carolina," CERC Miscellaneous Report 80-8, US Army Engineer
Waterways Experiment Station, Vicksburg, MS.

Miller, H. C., Birkemeier, W. A., and DeWall, A. E. 1983. "Effect of the
CERC Research Pier on Nearshore Processes," Coastal Structures '83, American
Society of Civil Engineers, Arlington, VA, pp 769-785.

US Department of Commerce. 1987. "Daily Weather Maps," Weekly Series,
Washington, DC.

Welch, P. D. 1967. "The Use of Fast Fourier Transform for the Estimation of

Power Spectra: A Method Based on Time Averaging Over Short Modified
Periodograms," IEEE Transactions Audio Electroacoustics, AE-15, pp 70-73.

73

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be me

a a in.

APPENDIX A: SURVEY DATA

1. Contour diagrams constructed from the bathymetric survey data are
presented in this appendix. The profile lines surveyed are identified on each
diagram. Contours are in half meters referenced to National Geodetic Vertical
Datum (NGVD). The distance offshore is referenced to the Field Research
Facility (FRF) monumentation baseline behind the dune.

2. Change in FRF bathymetry diagrams constructed by contouring the dif-
ference between two contour diagrams are also presented with contour intervals
of 0.25 m. Wide contour lines show areas of erosion. Other areas correspond
to areas of accretion. Although these change diagrams are based on consider-
able interpolation of the original survey data, they do facilitate comparison

of the contour diagrams.

Al

5 Dec 86
(0.25 m Contours)

0)
VOOR Ss ‘\
OSH

®
Ss)
S
2)
Op)
®
1e7)
iS
lo}
Js
O

SS
=0.50=05°0
oS + as
w
lw ‘90UD\sIq
SIBQUINN SUI] 9}!JO4q
ps - NM HN OR DODO
oo N © » Boe re PCP wand DDD HDDAD
Te) o NS - ee a
Ps i Err ser alin Ugg ty Une eal aapale ol era apelin oe

1100
1000
900
800
700
600
500
400
300
200
100

WW ‘9dUD}SIq

A2

—100

450 650 850

Distance, m

250

50

Distance, m

FRF bathymetry, 4 February 1987

(depths relative to NGVD)

Figure Al.

“— to}
oO 0
1) os o
oO a re
O° oO
YOs§s a
Bae :
ir
ouWwe fe
[Ss uO 6
oYa g
=) ©
(®) we ae
0+
vB
Q
°
10
nN
°
3)
° °
° °
o =
= 1
ww ‘90uUD}sSIq
SJOQUINN OUIT a{!JO4d4
oO 0 Oo -+0n0 <- NM DO RK ODO
DON + © momo OO WwW
oon ooo SBKRRDOO MD HO SSS Ss) eo Ge) 9) 9)
(era |i Fears ae ae lea | ] [acl claret ]
o-s- °
re)
Ce)
O°Z- Ove=
°
Sp As bet ERE WOE Ts)
ie en ee SS SB Paton | a ee eo Tr IR | eles kre oS Sec Bi a o
2 ae Ne | ea rigs SI A Oa. emectliegh ane oY me
0'9~ A ees ) ripe
MDP L/- ia E
Se a a >. ! if! ENR IS oO
Pe een pea SR Wika Ries ee eee O
0°S— 7 ae = (Ss
— ; 0°¢ 5
ae
(S)

1100
1000
900
800
700
600
500
400

lu ‘90UuD}sIq

A3

300

200
100

FRF bathymetry, 3 March 1987

(depths relative to NGVD)

Figure A2.

850

ao
oO cS
oO =)
£ne
YNOrc
ao
oe °
OLSeE @
Cw =
HSS Ne ie) iN o
RS) ie Oo Oo
[Ss
(©) wa ae
0)
+ Oo
ja)
r
NSE
—- BB
=> eZ oO
TD = D
o Oo o Oo Oo oO oO Oo
= 2° @ co) n © re) + m nN = =
ae |
ud ‘89UD\sIq
SJOQGUINN Urq e}!JO4Ug
LODO NO pCO) 00) Wes CN) BL) CO COO.)
COO ION shee COR I NO COM LO MILO) x
19) (LOCO) OE COM COMISeuIet Connon one ne SS Ss See 2 ew ee @
o's—
°
9)
oo
Tries ©
—_- —_—§— 0'7- 96
L 6
EN I IS ee ie eee Sse oa eee ite}
Dee Fo nh ee ae NI es hoch 5 home Com Tes a ©
o
oO
iS
Lo}
2)
ow)
Qa

1100

1000
900
800
700
600
500
400
300
200
100
—100

WW ‘a9dUD}SIqg

A4

FRF bathymetry, 2 April 1987

(depths relative to NGVD)

Figure A3.

58

1100

62

1000

900

76

800

9)
o

700

4

Changes Since
2 Apr 87
(0.25 m Contours)

1100
1000
900
800

SJOQUINN Sul] 9]1JO4q

om 0 Oo
Mm oo RNR
2S

600
500
400

WW ‘89UD}SIq

A5

600
500
400

lu ‘e0uD\sIq

185

188

189

190

-—100

450 650 850

Distance, m

250

Distance, m

Figure A4. FRF bathymetry, 19 May 1987

(depths relative to NGVD)

a Oo
ORS 2
nm
= oo 2
Y SiG
gs° °
o)
ep Dts
cAw =
ON o
= ()
(>) 2 ae
o+
OD
a
fo}
w
N
Oo
ite}
fo} fo}
Oo oO
5 =
= |
WW ‘89UD}SIq
SJOQUINN SUlT 2I1JOud
Oo
ie)
oO
Oo
i's)
o
£
o
6)
S
4g
Oo
» 2
Se)

1100
1000
900
800
700
600
500
400
300
200
100
—100

W ‘99UD}sIg

A6

FRF bathymetry, 17 June 1987

(depths relative to NGVD)

Figure A5.

FRF Pier
Changes Since
17 Jun 87
(0.25 m Contours)

o

° ° ° ° ° ° ° °
w ° ° ° ° ° ° fo} °
a S ro) t) 6 o Te) +
wi ‘99UD}sIq

SJOGUINN SUIT 2]1fOId
eye {Voy k=) oe Ge) Wo) See he
DOAN Tt CO yoo oO WW oO oOo oO
Ta 2 eo NS Ge 24 2 © PS BS aes ES ge ee

1100
1000
900
800
700
600
500
400
300
200

uw ‘90uD}sIq

A7

185

186

100

187

100

188

189

450 650 850
Distance, m

250

50

-100

190

—100

850

450

Distance, m

FRF bathymetry, 22 July 1987

(depths relative to NGVD)

Figure A6.

“——
a °
> SS @
re NO
o WN £Neg
oa WON (Y © 2
(iris WRK QOO: —
fa SONOS % Bac °
(irae MNQOKNO
Xd RR Wa £ o E
ROARK)
IR RO ORO» Cc ite)
RSTIIRRY Sic >
’ sabaheraianen oO is) 6
S
» oo
wow
+ Oo
(a)
°
0
N
<x
o Ss s °
° ° ° ° ° 2
w o ro) ° o ° 3 = = 2 ° ° °
= =] a o iS 0 + pay N S 2
I
WW ‘9DuUDjsSIG
SIOQUINN SUIT a|!Joug
0 0 O Oe iep CO - VN) 0» © KR ODO
Doan +t OR MN O HN WwW
no O0oOoOKOKR ROG PM LL EES bs Gsh 9 Ge G2) ED G9) “CD Cy
O*g— fo)
re)
L (oe)
ESS ees aie
“ Boe
Mo Soe
cr _7.0
°
| Rr Fae ee | Ih o Be S HR m ee E re
STN Soar? o
| pes oe :
O'9— \ ’ - O'9~
iar pemeees res Ngee oT E
pe re a oe 1 v be [SSS =
ro Soe eS) n Ss oO
Pe \ Jz ake Oo°S— iS
~ 4
O"s— \ / art Boe enn eee o
\\\ a a re (mnt Bon
I eae Rn WE Wy RN raya ie San LO
PSK 4 BS a +O
ee \\ fy, O'p~
\ 1
ana) Seco
1/¢q \ Fe KS
ne). I A ?
ee | sae \ /
\ - l /
Sx] A Sie MS
ee Le o'r eee Seal °
aircon omer eee aah N

_ SS
d eee

° ° ° ° ° fo) °

° ° ° ro) ° ° °

= °o ro) o nS o re)

lw ‘aduD}sIqg

A8

400

300

200
100

—100

FRF bathymetry, 1 September 1987

(depths relative to NGVD)

Figure A7.

1100

\ \)
\y
= POOR ‘S CH ) X)
Gs REIS <\%
STORMS
—' EK SNM OOXY

ORS

rv

os

SS OSS SO
‘7 Ss

4,

AY
ys
x

SN

1 Sep 87
(0.25 m Contours)

®
)
S
2)
i)
©
D
fe
S)
ic
O

~~
\
Oo Oo lo} Oo Co
w ° ° ° ° °
= ° ro ro) i
SIOQUINN eUlq eI1ZO1q
oOo 0 Oo - + ©
Cr) 1) Spr Cob TS. fed Coy Ue Le)
nooo GKR ROG PKL jst ie Bs
o°'s-—
UT ers a
Se
SSH:
On
FS ee rer ae oe a SK
! nN 2
O'9— Sah a
\ } / Q
ee SS eye aree Ios /
Say, 1 P;
Six, os Be
O's~ \ 7 on
4 /
---- LL \ TA Ke
res \\V As Za
SS
| / /
BS 1 n 1
ANS \
I 1 \
{ \ 5 \
> Wea x

1000
900
800
700

600
500
400

WW ‘aduUD}SIq

A9

FRF Pier

500

lw *99UuD\sIqg

178
181

300

189

-100

190

° ° ° °
° ° ° °
+ m a =
Qyebe (ey Ce TS le)
oOo o oO © 0O ®WO
a
25/0)
O'9~
—5.0
O'4

200

100

—100

650 850

450
Distance, m

250

50

450 650 850
Distance, m

250

50

FRF bathymetry, 29 September 1987

(depths relative to NGVD)

Figure A8.

| Tp °
J oO L ire)
ne J] On 32 nh o
© / £08 o
a ! Nas o
LL i ay 1?) DO oO fe S
fe ARS oO e He e
ERY oO) E
rae Cq 0
Ne le) N o
is (S) oO
OR — c
Nie ae
\
a AX a
ss aaa
eT ho \atraes 9
FFA SSO 9 3
eS SONGS x) iP]
es Gs 0), N
So se
EEN,
ie 2 2
ig Ve ‘ \ \ °
Ww
lu ‘99uD,sIq
SIOQUINN SUlT eI1fO1d
oOo MO See Cy a), SOQ) be 1) Cs TS CG) ©)
oOnN + m o O Mm
Wii 2 oO Ss & oo 2 22 St BS Se TSS Ce Gs) ek) eS
O°8—
fo)
Te)
©
iS
)
1o)
Cc
ie}
oes)
a
a

1100
1000
900
800
700
600
500
400
300
200
100
—100

WwW ‘99UD}SIq

A10

FRF bathymetry, 9 December 1987

(depths relative to NGVD)

Figure A9.

APPENDIX B: WAVE DATA FOR GAGE 630

1. Wave data summaries for Gage 630 are presented for 1987 and for 1980
through 1987 in the following forms:

Daily H,, and T,

2. Figure Bl displays the individual wave height and peak spectral wave

period values along with the monthly mean values.

Joint Distributions of H,, and T,

+3. Annual and monthly joint distributions tables are presented in Tables
Bl and B2, and data for 1980 through 1987 are in Tables B3 and B4. Each table
gives the frequency (in parts per 10,000) for which the wave height and peak
period were within the specified intervals; these values can be converted to
percent by dividing by 100. Marginal totals are also included. The row total
gives the total number of observations out of 10,000 which fell within each
specified peak period interval. The column total gives the number of observa-

tions out of 10,000 which fell within each specified wave height interval.

Cumulative Distributions of Wave Height

4. Annual and monthly wave height distributions for 1987 are plotted in
cumulative form in Figures B2 and B3. Data for 1980 through 1987 are in
Figure B4.

Peak Spectral Wave Period Distributions

5. Annual and monthly peak wave period, T distribution histograms

p’?
for 1987 are presented in Figures B5 and B6. Data for 1980 through 1987 are

in Figure B7.

Bl

Persistence of Wave Heights

6. Table B5 shows the number of times in 1987 when the specified wave
height was equaled or exceeded at least once during each day for the duration
(consecutive days). Data for 1980 through 1987 are given in Table B6. An

example is shown below:

Height Consecutive Day(s) or Longer

eekmis Dee FS 26 1 5) Gi EZ, 28 AO ON AN de OS eG eIS 1G ie eo.
18 15 a Wo | 8 v/
ty) 4 ye RB 8 2

A WO GO - 2 A
gO Be

3) 72
G4

1

WWD] Oo
fe tet OL OO OL 6
ouMouwouowu
af
oO

This example indicates that wave heights equaled or exceeded 1.0 m 50 times
for at least 1 day; 34 times for at least 2 days; 24 times for at least 3
days, etc. Therefore, on 16 occasions the height equaled or exceeded 1.0 m
for 1 day exactly (50 - 34 = 16); on 10 occasions for 2 days; on 3 occasions
for 3 days, etc. Note that the height exceeded 1 m 50 times for 1 day or
longer, while heights exceeded 0.5 m only 18 times for this same duration.
This change in durations occurred because the longer durations of lower waves
may be interspersed with shorter, but more frequent, intervals of higher
waves. For example, one of the times that the wave heights exceeded 0.5 m for
16 days may have represented 3 times the height exceeded 1 m for shorter

durations.

Spectra

7. Monthly spectra for the offshore Waverider buoy (Gage 630) are
presented in Figure B8. The plots show "relative" energy density as a
function of wave frequency. These figures summarize the large number of
spectra for each month. The figures emphasize the higher energy density
associated with storms as well as the general shifts in energy density to
different frequencies. As used here, "relative" indicates the spectra have
been smoothed by the 3-D surface drawing routine. Consequently, extremely

high- and low-energy density values are modified to produce a smooth surface.

B2

The figures are not intended for quantitative measurements; however, they do
provide the energy density as a function of frequency relative to the other
spectra for the month.

8. Monthly and annual wave statistics for Gage 630 for 1987 and for 1980
through 1987 are presented in Table B/7.

9. Figure B9 plots monthly time histories of wave height and period.

Year Mean, m
5.0 %—x 1987 tel

Wave Height, m

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Wave Period, sec

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month

Figure Bl. 1987 daily wave period values with monthly means
for Gage 630

B3

Table Bl

Annual Joint Distribution of H,, versus T,

Height(m)

DEPWWNNERrOO
e@ 0 0 © © Oo
ow

eo © © eo

SOMNOMOMoUOWS
Acocooooco°oceeo

°o

DOWNOWONUOWOW

—$OPPWWNNPROO
Je e

GUO Oost G0 a0 0

fs)

ter

Annual 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Per iod(sec)

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
5) oO): IC) Sc) eG) 7/08) Bob) So) at

. . 30 67 89 74 82 126 ° 59
° ° : 15 37 22 7 89 15
5 . ao 15 22 27 7

Ge) el oi ene) (oteyie) ekelixe

; ‘ : : : 3 7 5 é :
66 207 444 1217 1179 1113 2409 1254 1527 126 45

Total

B4

Height(m)
0.00 - 0.49
0.50 - 0.99
1.00 - 1.49
1.50 - 1.99
2.00 - 2.49
2.50 - 2.99
3.00 - 3.49
3.50 - 3.99
4.00 - 4.49
4.50 - 4.99
5.00 - Greater

Total

Height(m)
0.00 - 0.49
0.50 - 0.99
1.00 - 1.49
1.50 - 1.99
2.00 - 2.49
2.50 - 2.99
3.00 - 3.49
3.50 - 3.99
4.00 - 4.49
4.50 - 4.99
5.00 - Greater

Total

Height(m)
0.00 - 0.49
0.50 - 0.99
1.00 - 1.49
1.50 - 1.99
2.00 - 2.49
2.50 - 2.99
3.00 - 3.49
3.50 - 3.99
4.00 - 4.49
4.50 - 4.99
5.00 - Greater

Total

Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
Cot Siete A Sos GeO as ick) ADEE) ab oss JSC) es i eal oo ete
5 5 Q O 417 278 5 5 é 139 139 6 973
139) 95:278) 7139) 239 0 556 972 694 694 G O O 3611
6 278 278 278 9 417, (e139) 556 0 . 0 1946
6 2 O 417 694 278 139 278 5 o O 1806
O . 4 139 139 417 139 O 139 3 139 5 1112
O 6 Q 3 6 139 6 O O 139 5 278
d 6 A 6 6 O 6 139 139 6 ° 5 278
G 3 O ° 7 6 G 0 O 6 o 0
0 5 5 - O 0 5 5 6 5 5 O 0
O . 5 6 5 G Q 0 . 3 ‘s fo
139 556 417 973 1250 1390 1806 1111 1806 139 417 0
February 1987, Gage 630
Percent Occurrence(X100) of Height and Period
Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
D0 na Sot) eats) 6 Bo) O20 eo Bc Oo) Sait) aa ioo slat) [loner
é . 6 93 93 93 185 0 5 6 A 464
93 ; - 463 648 463 833 648 926 6 ‘ 5 4074
: 5 - 833 1204 93 278 278 o Rk ; 2964
: é 93 370 463 93 93 370 6 5 ; 1482
6 O 7 93 93 9 185 93 O 0 3 464
: - 6 6 93 : 6 6 93 ; 6 6 186
6 6 O 6 c 93 0 93 0 0 5 5 186
; : : : ; E L993 : : 5 ; 93
Q 0 5 5 O 5 O 6 O é & 0
5 6 : i 9 A 93 5 : 5 6 ; 93
93 0 93 1852 2594 835 1111 1390 1760 0 278 0
March 1987, Gage 630 -
Percent Occurrence(X100) of Height and Period
Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
39) 359) 4 Ol 5.9) Ge Oi e709) 89 99 119) 21339 a15<9 "Longer
5 : 6 5 oe 342: 9 ; ; 6 5 342
: 85 Lae 7) a2 7 OG 4 2505 42. ; 6 s 2392
a BSye 7AM sa 2a S42 85 171 427 940 6 85 O 2648
6 5 O 2565) Al7l 256, 85 256 598 0 V7 3 1793
o O 9 0 85 3 256 85 855 6 427 6 1708
a 5 b 3 0 5 6 427 ° 85 C 512
5 s 3 A 5 A ; 85 & 85 4 170
5 6 Fs G O Q 7 85 6 5 5 85
: s 6 5 6 6 5 85 85 : 85 ; 255
0 6 6 5 . O 5 85 5 5 0 88
6 170 171 769 1025 1110 1196 1109 3502 0 938 0

Monthly Joint Distribution of H,, versus a

Table B2

Percent Occurrence(X

January 1987, Gage 630
00) of Height and Period

(Continued)

B5

(Sheet 1 of 4)

Table B2 (Continued)

April 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Per iod(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- ao0F 10.0- 12.0- 14.0- 16.0-
2.9) 13.9 4.9) 1 5).9 6-59) © 7.9) 1 8.9 1959 F119) 13-9159 “Longer:

0.00 - 0.49 5 5 2 6 85 169 85 424 169 85 O 1017
0.50 - 0.99 - 254 85 169 254 254 254 339 847 - 678 5 3134
1.00 - 1.49 o 6 85 8 254 932 6 169 e254: . 1779
1.50 - 1.99 ° 6 - 424 169 - 508 339 508 169 254 O 2371
2.00 - 2.49 G 0 0 169 85 85 85 85 O 85 : 594
2.50 - 2.99 5 5 0 5 85 85 85 254 f° Q 5 509
3.00 - 3.49 . 6 ; 85 85 ee 254. 6 5 424
3.50 - 3.99 : 0 . . 85 85 . J : c 6 170
4.00 - 4.49 9 . 0 O c 5 9 O 9 . O - 0
4.50 - 4.99 5 ° O O o O 5 C b 5 2 2 0
5.00 - Greater 9 2 Q O 9 C 9 6 5 6 0
Total 0 254 170 847 508 933 2203 933 2456 338 1356 0
May 1987, Gage 630
Percent Occurrence(X100) of He ght and Period
Height(m) Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer
0.00 - 0.49 5 97 ° 7 0 194 777 S 97 6 97 9 1262
0.50 - 0.99 : oO mses 97. 777 845) 583) 21971 97 485 : 5243
1.00 - 1.49 : : 97 388 194 291 1262 97 0 6 6 2329
1.50 - 1.99 6 0 5 9 0 3 6) eek) O G 7 5 680
2.00 - 2.49 . S 0 : : - 194 97 6 : O 291
2.50 - 2.99 3 O ‘ 97 97 6 5 C 6 - Q 194
3.00 - 3.49 o : : C 5 : 0 5 0 0 : : 0
3.50 - 3.99 o 6 ; é . 6 é 5 6 : 0
4.00 - 4.49 3 6 6 c O 5 O . 5 2 5 0
4.50 - 4.99 é 5 O : 5 5 } . : 6 ° 0
5.00 - Greater 3 5 6 a 7 6 3 3 6 5 6 0
Total 97 97 873 388 1359 3884 1457 1165 97 582 0

June 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 A 9 ° Bo aS 8892789)" 3515263)" A175 A 3 1841
0.50 - 0.99 263 789 175 1053 965 965 2632 263 263 é : 6 7368
1.00 - 1.49 : eel 7 5 ets 5 88 175 88 ; : ‘ 0 . 701
1.50 - 1.99 6 : : 88 : : : 6 . : : 5 88
2.00 - 2.49 ; : : 6 5 . 0 ; : . 0
2.50 - 2.99 6 é 6 : : 3 ' ; : ‘ : 0
3.00 - 3.49 5 6 ; - i : A : 0 é 0
3.50 - 3.99 3 : 3 : é : : : 0
4.00 - 4.49 : : : c . : é ; 6 : : 6 0
4.50 - 4.99 3 5 : 6 6 . : 6 3 6 : : 0
5.00 - Greater 4 ; 7 O 6 . J 6 : 5 9 A 0
Total 263 789 350 1316 1228 1228 3509 614 526 175 0 0
(Continued)

(Sheet 2 of 4)

B6

Table B2 (Continued)

July 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 : . 83 165 83 331 2314 248 83 . 83 ° 3390
0.50 - 0.99 83 83 744 1322 413 992 1983 248 413 . 83 . 6364
1.00 - 1.49 . - 165 8 . ° . . . . . . 248
1.50 - 1.99 . . . . . ° . ° . . . ° 0
2.00 - 2.49 . . . . . . . . . ° ° . 0
2.50 - 2.99 . . . ° . . . ° . ° ° ° 0
3.00 - 3.49 ° . ° . . . . . . . . . 0
3.50 - 3.99 . . . . . . . . . . . . 0
4.00 - 4.49 . . . . . . . . . . . . 0
4.50 - 4.99 . . . ° . ° . ° . . . . 0
5.00 - Greater : ° ° ° . ° . : . . . . 0
Total 83 83 992 1570 496 1323 4297 496 496 0 166 0

August 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 81 2 ° 3 81 242 484 484 81 8 9 1453
0.50 - 0.99 81 242 161 645 968 161 1452 1210 968 ee 161 5 6049
1.00 - 1.49 : 273238726 161 Q - 161 # 161 : : : 1532
1.50 - 1.99 G 5 6 81 81 242 81 161 81 é : : 727
2.00 - 2.49 S O O : : : eee 24.2) C o : 242
2.50 - 2.99 3 0 O oO : C ° ° : 0 5 . 0
3.00 - 3.49 O O 5 : C : ; 5 5 O 6 0
3.50 - 3.99 a 5 : 0 : 6 5 o 6 O A 0
4.00 - 4.49 3 5 2 3 : 6 b é 5 O ' 0
4.50 - 4.99 6 9 ° O 0 < : O 5 . O é 0
5.00 - Greater 6 2 6 ° 2 6 G 6 o 7 3 6 0
Total 162 242 484 1452 1210 484 1775 2016 1936 81 161 0

September 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
259 3594590 5 9 6.9 79 869m 95921139 13599) 1529)nitonger:

0.00 - 0.49 5 6 5 5 84 84 252) 252 ‘ ee LOS ° 840
0.50 - 0.99 O 84 420 588 840 840 1513 1513 840 G 84 5 6722
1.00 - 1.49 O G O A Aa lalletey syed Pialeteh | 3} 5 G 6 1428
1.50 - 1.99 5 . 84 168 168 168 . 84 C 0 O 672
2.00 - 2.49 6 a 5 168 84 6 o d 9 6 336
2.50 - 2.99 6 . O . 5 a 5 G 3 5 6 O 0
3.00 - 3.49 6 5 3 6 O O 7 o 5 5 5 6 0
3.50 - 3.99 7 3 O : 6 C . 2 . ; : 5 0
4.00 - 4.49 6 3 7 . 2 . ° 6 6 0 0
4.50 - 4.99 5 6 o C b 3 . 5 6 6 3 0
5.00 - Greater 3 9 5 S O 9 re G 0 : 3 9 0
Total 0 84 420 672 1428 1428 2689 1933 1092 OMm.252 0

(Continued)
(Sheet 3 of 4)

B7

Table B2 (Concluded)

October 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Per iod(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 89 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 5 O 4 3 5 9 92 5 5 0 184
0.50 - 0.99 ° } 92 459 275 642 2294 1284 367 92 5 ° 5505
1.00 - 1.49 } oO kl 740 92 183 183 550 459 5 O 5 1925
1.50 - 1.99 6 6 Ad Sl CE) 92 5 5 ask) 9 . O 1376
2.00 - 2.49 O O 5 6 92 3 5 AS 7 3 0 5 367
2.50 - 2.99 6 6 0 0 los eros 5 92 ° C Z 458
3.00 - 3.49 3 6 5 ; etLOS O 0 : 6 C 5 183
3.50 - 3.99 5 0 6 ~ z 6 7 O C 5 5 6 0
4.00 - 4.49 5 } o . O O ° 6 5 ° O 0
4.50 - 4.99 5 O 5 5 6 6 c 5 O 7 0
5.00 - Greater 5 9 5 2 9 9 9 = z Q 0
Total 0 550 1101 918 1283 2752 2201 1101 92 0 0

November 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
239 013.39 00459) 1559)) 1659) 729) 1859 OSS 11 os 39e15 39 Longer

0.00 - 0.49 - 168 168 <el 6BmamloO en 640.) 336 4 5 \rky2 2100
0.50 - 0.99 0 84 252 336 756 588 588 336 168 84 : 6 3192
1.00 - 1.49 6 6 64 Oxi336im* 158810") 252251336 - 168 84 0 1848
1.50 - 1.99 6 84 252 504 168 252 168 # 168 6 O 1596
2.00 - 2.49 a O = 168\2 5045 “336 0a0168 G : 5 1176
2.50 - 2.99 5 é 6 0 7 4 84 J 84
3.00 - 3.49 : a . 0 6 6 9 é : 5 0
3.50 - 3.99 : 5 : 6 fs A 5 5 : : 5 0
4.00 - 4.49 : 6 : 6 : 5 5 3 5 0
4.50 - 4.99 : 6 : o . 0 3 z 5 O 0 0
5.00 - Greater 5 ; 5 6 5 O O 6 5 a 9 5 0
Total 0 252 588 924 2184 1680 2352 1008 588 168 252 0

December 1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
ol) FORE)

2.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer
0.00 - 0.49 . ° 5 5 - 242 81 LOL 81 : 565
0.50 - 0.99 81 81 645 1129 161 242 806 484 1290 242 726 G 5887
1.00 - 1.49 ° e242 806) 71242 81 161 161 403 : 6 2096
1.50 - 1.99 : - 161 484 «161 : 5 81 C 81 3 968
2.00 - 2.49 : c : 6 81 J d : 81 : 81 C 243
2.50 - 2.99 5 C 6 ° q 3 ° . 81 6 6 é 81
3.00 - 3.49 4 é 4 Q 81 81 é 6 O C 162
3.50 - 3.99 a : 4 O & : 6 é d 0
4.00 - 4.49 ; 5 . 5 : 0 3 a 5 G 0
4.50 - 4.99 6 5 : 3 ‘ f : a é 6 : 0
5.00 - Greater 9 ; 6 3 A ‘ 4 5 6 5 9 6 0
Total 81 81 887 2096 968 484 1290 807 1936 403 969 0

nn

(Sheet 4 of 4)

B8

Table B3

Annual Joint Distribution of H,, versus T, (All Years)

Annual 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec)
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2b 36Gb VA Obes 596 Sin 7 Op Ono OemaleO) 213-9) 529 Longer
0.00 - 0.49 20 17 29 S6penl04e 11 Sree S31 27 Oa ele 80 138 4
0.50 - 0.99 S5ee 126ne 247s A/a O75 O02ee moss GOlemees2ue 156 12417; 17
1.00 - 1.49 6 Tis (128 S86. 450i 270i cole 20len sre 40 134 5
1.50 - 1.99 ° Q 2 14h 263i a 114 75 70) 137. 37 83 5
2.00 - 2.49 ° 6 2 26 78 78 49 45 77 33 46 2
2.50 - 2.99 O c Oi 6 i 35) 19 16 43 12 25 3
3.00 - 3.49 5 O 5 G 7 16 15 19 5 10 é
3.50 - 3.99 c 5 6 . A al 4 8 11 5 4
4.00 - 4.49 3 O 3 5 5 6 1 2 8 1 2 6
4.50 - 4.99 9 O 2 6 O 5 6 6 3 Q ° O
5.00 - Greater ° 5 : 5 4 9 6 5 5
Total 5 154 418 1086 1478 1125 1581 1326 1716 371 #4660 33

B9

Percent Occurrence(X100) of Height and Period
Height(m) Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer
0.00 - 0.49 121 12 9 > a) 97 eis asp 97. 230 36 85 : 1005
0.50 - 0.99 Tf} LD PN > ei) Ey) - EY Y/Y ~ GY/2 97 254 z 3777
1.00 - 1.49 G 24 S7ae 508 fe Oo en 242 eee 4 Ome? Lem O57, : 73 12 2396
1.50 - 1.99 0 5 24) 278) ee 0G m2 4 2) 97 97 254 12 48 6 1560
2.00 - 2.49 O 9 O 36 194 230 109 24 145 48 36 12 834
2.50 - 2.99 0 3 6 : 12 97 61 24 48 24 61 6 327
3.00 - 3.49 O 6 6 6 ' 6 24 12 36 . 5 6 72
3.50 - 3.99 6 C 5 6 0 ° ° 5 5 5 O 2 0
4.00 - 4.49 O 0 5 5 O 5 6 5 12 ° 5 5 12
4.50 - 4.99 5 5 Q 0 6 A 5 ° 12 ° . 5 12
5.00 - Greater 9 ° O 5 O O 0 a O O 3 0
Total 194 278 435 1294 1755 1222 945 908 2166 217 557 24
February 1980-1987, Gage 630
Percent OccurrenceyX100) of Height and Period
Height(m) Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer.
0.00 - 0.49 6 3 5 13 38 25 101 38 2527, P 367
0.50 - 0.99 25 63 89 380 494 266 520 621 1166 257165 13 3827
1.00 - 1.49 : 13 89 634 710 228 317 368 596 101 253 0 3309
1.50 - 1.99 6 A 13) 7190) 93425) 203 89) 101) 215 76 127 0 1356
2.00 - 2.49 : 6 . 89 114 25 38 89 114 63 114 6 646
2.50 - 2.99 ; 0 6 ‘ 13 38 é - 139 25 76 : 291
3.00 - 3.49 C : 6 : : 13 : 25 38 13 25 , 114
3.50 - 3.99 3 OC O fc . D = 13 13 : é 5 26
4.00 - 4.49 c é O 3 2 - 6 13 38 5 6 c 51
4.50 - 4.99 o o J O 6 © 7 0 6 5 } 0 0
5.00 - Greater O 5 6 3 Q 7 13 6 6 5 } 5 13
Total 5 76 191 1306 1711 798 1078 1230 2357 328 887 13
March 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period
Height(m) Per iod(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
229) 80369) 429) 559) 21659) 7/59) 859) 959 S119) 91329 1559) Longer:
0.00 - 0.49 11 2 P 11 57 57 80 46 137 68 68 0 535
0.50 - 0.99 11 91 205 365 433 422 513 639 787 171 205 : 3842
1.00 - 1.49 : 11 194 376 525 331 274 319 764 68 376 6 3238
1.50 - 1.99 J 6 2. 228) (2395-103 91 114 285 103 160 0 1323
2.00 - 2.49 5 é 11 57 34 80 57 182 46 125 ; 592
2.50 - 2.99 : 5 6 6 23 11 11 11 68 23 57 6 204
3.00 - 3.49 6 : : : 11 0 11 23 Ly/ 11 11 ; 124
3.50 - 3.99 o 6 4 6 ; : 3 23 23 C 11 : 57
4.00 - 4.49 : : . 6 C 11 11 11 : 23 : 56
4.50 - 4.99 c 5 2 0 > - ° ° 23 o S 0 23
5.00 - Greater 6 5 ° 2 0 2 9 S 5 O fe 9 0
Total 2 102 399 991 1345 958 1071 1243 2337 490 1036 0

Table B4

Monthly Joint Distribution of H,, versus T, (All Years)

January 1980-1987, Gage 630

(Continued)

B1O

(Sheet 1 of 4)

Table B4 (Continued)

April 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 5 12 23 23 35 23) 9349) §233)) #210) S105) e116 5 1129
0.50 - 0.99 93) S175) 9221) 396° =477. 8501) W7578 B617, 1141, 5279) 373 O 5030
1.00 - 1.49 6 12162331) S84 e326) Ol) 256) 396 70 175 O 2329
1.50 - 1.99 . 5 ope 40140 93> 91052 4105) 198 35)772128 6 944
2.00 - 2.49 5 2 2 47 35 12 35 70 35 35 12 7 281
2.50 - 2.99 ° 5 ° ° 6 23 35 12 47 35 12 7 164
3.00 - 3.49 5 é 3 6 - 12 23 23 35 O O 6 93
3.50 - 3.99 5 3 : . 6 12 2 c 6 3 5 ° 35
4.00 - 4.49 5 5 2 } 6 c ° ° J . 3 5 0
4.50 - 4.99 9 0 - O 7 5 0 c iS é 7 O 0
5.00 - Greater 3 A . 6 3 6 5 . 6 3 6 6 0
Total 93 199 360 839 1071 1002 1688 1316 2062 559 816 0

May 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 11 23 34 92. 149 183 447 252 172 23 69 . 1455
0.50 - 0.99 23) 9172) e367, 665) (9585722) 1250) 1078) e711 34 =172 : 5779
1.00 - 1.49 ° =» 103° 6229) 9344; 7195) 7413) 7195) 7310 Ly £103 . 1903
1.50 - 1.99 . . 11 57 80 23. 103 69 69 34 80 . 526
2.00 - 2.49 . . 23 11 57 : 46 11 34 34 . 216
2.50 - 2.99 ° . ° alal 11 11 11 11 23 11 . 89
3.00 - 3.49 . . ° . . . . . 11 11 . 22
3.50 - 3.99 5 . . . . . . . . . : 0
4.00 - 4.49 : ° : . ° ° . ° ° . . . 0
4.50 - 4.99 ° ° . . . . . ° ° : : . 0
5.00 - Greater ° 5 ° ° ° ° ° ° ° ° ° 0
Total 34 195 515 1066 1180 1191 2224 1651 1284 170 480 0

June 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 24 36 61 97 242 339 605 557 230 48 12 ; 2251
0.50 - 0.99 61 242 363 738 738 +$702 1610 9884 605 194 36 : 6173
1.00 - 1.49 : 6 73 230 206 206 218 121 #4109 : 61 3 1224
1.50 - 1.99 6 6 12 48 73 73 24 12 61 : : : 303
2.00 - 2.49 é 6 : 6 12 12 12 12 : 0 : : 48
2.50 - 2.99 o 6 6 0 5 6 . 6 © 6 6 0
3.00 - 3.49 ° 5 J ts 5 6 . 6 ° 0
3.50 - 3.99 : : ; 6 6 : é é 6 3 : é 0
4.00 - 4.49 6 ( e 6 é : C é 6 é 6 6 0
4.50 - 4.99 6 s 6 O 6 ° c é 6 3 6 6 0
5.00 - Greater : S é : ; 3 5 : : 6 ; 0
Total 85 278 509 1113 1271 1332 2469 1586 1005 242 109 0
(Continued)

(Sheet 2 of 4)

Bll

Table B4& (Continued)

Height(m) Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
(pe) elon) La): Se) (6) AS) aC a) tala tote) vinleJa) saya) Tey fee
0.00 - 0.49 12 24 60 109 278 302 1137 798 339 145 290 24 3518
0.50 - 0.99 36 121 351 617 762 689 1330 907 447 254 73 73 5660
1.00 - 1.49 9 24 60) ely esl 97 60 48 O ° . fe 651
1.50 - 1.99 : : : 60 12 24 36 6 : : : : 132
2.00 - 2.49 0 : 6 12 ° 3 12 : O : 0 : 24
2.50 - 2.99 O c © o ° 2 O ° 5 ° ° 0 0
3.00 - 3.49 O 5 : O O ° 0 O O 5 © O 0
3.50 - 3.99 2 o 6 2 0 5 0 5 5 6 0 C 0
4.00 - 4.49 c O O 9 . 6 0 6 - 2 O 0
4.50 - 4.99 O 5 6 5 6 3 O 5 : 6 Q 7 0
5.00 - Greater 6 5 : 5 5 Q ° 2 Z 3 C 5 0
Total 169 471 979 1233 1112 2575 1753 786 399 363 97
August 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period
Height(m) Per iod(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
Dee) SEY SC) Bot), Bat) 7/6) A Bee) able) eee) alae): Merete
0.00 - 0.49 24 36 72 108 193 241 494 554 422 84 120 O 2348
0.50 - 0.99 36 108 241 578 795 699 1313 795 614 169 301 O 5649
1.00 - 1.49 O 12157 es lich 265) el 57 e108 72 12 5 O 1325
1.50 - 1.99 O O 9 60m e157, 84 36 24 24 6 36 O 421
2.00 - 2.49 A 5 o 24 24 12 24 5 48 3 12 és 144
2.50 - 2.99 O ° 5 0 12 9 24 ° 12 5 12 6 60
3.00 - 3.49 : 3} 5 5 12 12 6 12 Q 5 : 36
3.50 - 3.99 3 : O ° 5 3 12 2 5 O & 12
4.00 - 4.49 9 2 6 o 5 6 3 6 6 0 0 © 0
4.50 - 4.99 5 c 3 ° : 6 . C 5 5 0 O 0
5.00 - Greater 7 j 6 c : . 9 5 6 - - 0
Total 60 156 470 1071 1422 1313 2060 1493 1204 265 481 0
September 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period
Height(m) Period(sec) Total
2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
3 3.9" 4.9 5.9 6.9 97.9 8.9 (9.9 11.9 13.9 15.9 Longer
0.00 - 0.49 0 12 12 35 24 24 94 330 294 141 118 12 1096
0.50 - 0.99 ° 59 177 318 601 459 824 766 1143 165 236 6 4748
1.00 - 1.49 6 12 82 412 589 353 471 247 389 59 153 12 2779
1.50 - 1.99 O 12 71 283 #130 7-130 59 12 82 : 850
2.00 - 2.49 5 é 35 82 47 24 35 82 35 24 6 364
2.50 - 2.99 6 ‘ é 6 35 24 12 9 ; 71
3.00 - 3.49 6 5 5 0 2 3 . 12 12 12 12 Q 48
3.50 - 3.99 9 ° 5 - ° . ° 12 12 12 O 36
4.00 - 4.49 A 3 9 O 5 2 S 6 0 5 - O 0
4.50 - 4.99 0 5 3 C O 5 C - 6 7 7 c 0
5.00 - Greater 7 5 9 : ° 5 O a 6 12 O fe 12
Total 0 83 283 871 1579 1048 1508 1532 1991 448 637 24

July 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

(Continued)

B12

(Sheet 3 of 4)

Table B4 (Concluded)

October 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 21 6 0 fe 54 64 193 150 226 43 129 e 880
0.50 - 0.99 : 43 150 333 430 419 677 462 902 161 322 11 3910
1.00 - 1.49 6 6 abt) Pep) ch 7A SI pal LIA} 97 161 2449
1.50 - 1.99 ; oC 32 193 451 86 54 64 183 97 236 43 1439
2.00 - 2.49 b 6 : 11 118 204 54 86 161 54 97 11 796
2.50 - 2.99 . O 0 O 11 140 43 64 54 11 43 fs 366
3.00 - 3.49 . 6 O 5 6 43 11 4 ata 5 32 97
3.50 - 3.99 é Z ° 6 O eS 9 21 ; 21 : 6 42
4.00 - 4.49 : ; 5 é gj 5 é 21 ; : , 21
4.50 - 4.99 6 : 5 ; ; 6 6 : 6 6 6 0
5.00 - Greater 5 6 5 Q 9 5 3 2 ° 7 6 0
Total 21 43 332 1128 1429 1192 1172 1083 2031 484 1020 65

November 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Per iod(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 11.9 13.9 15.9 Longer

0.00 - 0.49 13 39 39 26 65 91 169 169 104 65 183 963
0.50 - 0.99 26 52 352 508 587 508 456 495 639 169 156 65 4013
1.00 - 1.49 . 26 196 469 743 443 235 248 352 2 91 39 2868
1.50 - 1.99 . . 26) 91222) 365)= 7209) 6130 65 143 65 13 13 1251
2.00 - 2.49 . . . 26 78 143 169 52 26 26 13 . 533
2.50 - 2.99 : 2 . : : 26 13 26 65 . 13 : 143
3.00 - 3.49 : : . : . 26 65 13 13 . 117
3.50 - 3.99 . . . ° . . . . 52 26 13 . 91
4.00 - 4.49 . . . . . . . . . 13 ° : 13
4.50 - 4.99 . . . ° . . . ° ° . ; . 0
5.00 - Greater : . : . ° . . . . . 0
Total 39 117 613 1251 1838 1420 1198 1120 1381 403 495 117

December 1980-1987, Gage 630
Percent Occurrence(X100) of Height and Period

Height(m) Period(sec) Total

2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-
2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9) 11.9 13.9 15.9 Longer

0.00 - 0.49 . 13 52 52 13 26 7117" 156 143). 162; 364 13 1131
0.50 - 0.99 39 143 208 481 637 234 377 481 949 143 286 52 4030
1.00 - 1.49 . 6 Pal CERT Gail skis ht ake) Cee) 26 86143 . 2535
1.50 - 1.99 ° . S143 533" ell 7, 65 52 143 52 e 1118
2.00 - 2.49 . . 26 - 221 156 39 65 104 52 78 ° 741
2.50 - 2.99 . ° . ° ° 26 ° 26 78 ° 13 ° 143
3.00 - 3.49 . : . . . . 91 26 26 13 . 156
3.50 - 3.99 . . ° . . . 26 26 39 . 13 . 104
4.00 - 4.49 . S . ° . : : . 13 . . . 13
4.50 - 4.99 ° ° ° ° . ° . : . . ° 0
5.00 - Greater . . ° ° ° ° : . 1 13 26
Tota 39 156 455 1157 2015 897 936 962 1924 416 975 65

(Sheet 4 of 4)

B13

Height, m

2 )

10 | 10 10°
Percent Greater Than Indicated

10°

Figure B2. Annual cumulative wave height distributions
for Gage 630

B14

Height, m

=

Ww
rape een ana ere Nene enn

)

10° 10)
Percent Greater Than Indicated

Figure B3. 1987 monthly wave height distributions
for Gage 630

B15

Height, m

to w -

Panes) nee) ear rnrnefiin

a

10% Om 10° 10 10°
Percent Greater Than Indicated

Figure B4. 1980-1987 monthly wave height distributions
for Gage 630

B16

Frequency of Occurance, %

40-7
1
a

o-
40-7

|
2044

oa
;

20+

=a

Gage 625

aon o_|

Gage 630

Gage 141

Gage 645

Figure B5.

1987

1987

| -Banda

4
|

|

4

ai

Gage 625 1980-87

ey
__.aeadden

Gage 630 1980-87

__ AoA

Gage 141 1985—87

6
Period, sec

Annual wave period distributions for all gages

B17

Frequency of Occurrence, %

40 g
: Jan | Jul Z
PMO V4 >
0 aol Ae “See

40

‘ Feb _¢ ; Aug :
|" oowe | en BA

4074

1 Mar

7 |
MME GARB AG AN

"A
angio...

40-
| Apr
20-4

ace y
4 paoeer Dp" —_ aote.__

Figure B6. 1987 monthly wave period distributions for Gage 630

B18

Frequency of Occurrence, %

Jul

Z,
eas oad

ae os __ At AAAB A oo

a a et : eel Es es ee er ree

alla
nba

Oct

__panbefen. __ .oBaead

Nov
20

:
Tae
4
|

ore Wi __ Alba.

0)
40

Figure B7. 1980-1987 monthly wave period distributions
for Gage 630

B19

0.5

1980 through 1987 Persistence of H,, for Gage 630

Height Consecutive E16) or Longer
(m) aces meee ass Si Oe] Ole ee 2h 3 el 4a 1 8 19+

19
35
22
12

5

1987 Persistence of H,, for Gage 630

4
14
24 17 12 10
14 8 6 2
By cy 7
ea
1

17
25
11

5

Consecutive Da

13
5

1

Table B5

110
3 2
a
Table B6

15 14 13 12 11 10

18 14 10
(ied A4
ened

7

5
1

4

B20

or Longer

eb a ee a ie eee

3

2

9

9

8

7

8

6

1

5

1

3

WAVE GAGE 630

ALISN3G AD

WAVE GAGE 630
1987

in NS

NY

\}

1987 monthly spectra for Gage 630

Figure B8.

(Sheet 1 of 6)

B21

top)

[-e)

KLISNS

wo

NY
RM a) oe
Nt ai

Ny oy =
Pies eo.

a

~ =x

q xouans 4

(Sheet 2 of 6)

Figure B8.

B22

Figure B8. (Sheet 3 of 6)

B23

|

aim
SAS RSS ST
ERA RAL SSS 2 S
0 SOS LPS FRE LS 2 &
%.9 SEER ETS RRS
Soe eR S
LZ ES fp
PREG) O29 PORREERG Re
EN GN 25 phe ah
eae Orgs
Figure B8.

(Sheet 4 of 6)

B24

WAVE GAGE 630 i
! 1987 R

i

0)

| Wave GiGE 630
Ss | H 1987
ss ee eee a ee
va)
Z.
im)
e
Wa
@)
4
w
Se
0)
w
Zs
4
wu
(67

1987

4
q

[ese Nees]
WAVE GAGE 630
\]

=) =e
JSF LT} ty SSS Sy
Sese —— rae fos
Sed) oe LES As ay
= oS

0.9 sy OS eS
3 Vitis air NY, Sy

Figure B8. (Sheet 5 of 6)

B25

!
|

= Fel OW =
® oS Eee ee Mh Ae i £1 SOW S| pas thee HP Tp Ey 0
a8 HN es LPN |
oe ee ETM LITA) é oe 7 NH) é
s il Hi fi} He 1) * : An Hi ee
ESN Hilo ee
Wee I Mle —— Sy eee Ly i :
RA MOLY! E SS ©
ea a Ni INL”
yy) Oy K/ M} fo)
Sa ez Be
UK [ez i =
= Wen en (1 a
ree pp AAA? =,
iin eeee oo ae 2o
We ek eee Pee ae
RRS LS ; B
\eee o 1 YY. 2
nia BNE o =: 5 me ANSE

(Sheet 6 of 6)
B26

Figure B8.

Table B/7
Wave Statistics for Gage 630

198. 1980-

Height Period Height Period

Std. Std. Std. Std.
Mean Dev. Extreme Mean Dev. Number Mean Dev. Extreme Mean Dev. Number
_ m_ _m__ Date sec sec Obs. .™m_ m_ __m__ Date sec_ sec_ _Obs.
Ge} (G7/ 355 26 Cla 7465) 72 Gk. sOpz/ 4.5 1983 7.9 2.7 826
AS} OEE} bert 17 Hoey Banh 108 es} e527 Eyg2h 1987 8.6 2.6 789
1.6 0.9 4.7 10 Cert a745e} 117 Wer. | Wez/ 4.7 1983 8.8 2.7 877
1.4 0.8 3.8 26 CHE} 4255) 118 1.0 0.6 3.8 1985— (8.7) 227 859
st) Oak) a5) 5 85755) 230 103 O59 0.5 3.3 1986 8.0 2.3 872
(}o7/= (sé) 1.6 24 Uo) C52 114 0.7 0.4 2.1 198 lle 7si/eueme ave. 826
O36) 1052: 1.3 15 oye eat) 121 O56: 023 2.1 O85 eS leo) 827
029) 51025 a8} 15 Bole wee4. 124 038) (025 3.6 1981 1820) 255 830
Qs9-> 50-5 2.3 5 Ba1y 139 119 To), aS 6.1 1985057836" 4206 849
ae 1 (a7/ 3.0 13 Gay hats} 109 s72, iO G7/ 4.3 198 Qe Sez eed: 931
eV WG7/ 2.7 12 Ui “75st 119 a4) Osz/ 4.1 1981 8.1 2.8 767
1 On 0)26 3.2 29 Go Eft 124 1825 058 5.6 1980 8.4 2.9 769
aba Wsy/ 5.1 Feb Goran pep keh 10 4026 6.1 Sep 1985 8.3 2.6 10022

B27

Height, m
ON FON F ON FON FOOH FON BB

1 3 5 17 git 1515) 17, 19) 21/25 25'27 29) 9 S350 7. 913) 15917, 19) 21)25)25)27, 29131
Day of the Month

= N
o oOo

Period, sec
3S So

N
oo

13.5 7 9 1113 15 17 19 2123252729 1 3 5 7 9 1113 15 17 19 2123 25 27 29 31
Day of the Month

Figure B9. Time-histories of wave height and period
for Gage 630

B28

i
wa ah
Dy ee fl
ane
ae

aie

POE Cia

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