High-Resolution Topographic, Bathymetric, and

Oceanographic Data for the Pleasure Point Area,

Santa Cruz County, California: 2005-2007

By Curt D. Storlazzi, Patrick L. Barnard, Brian D. Collins, David P. Finlayson, Nadine E. Golden,

Gerry A. Hatcher, Robert E. Kayen, and Peter Ruggiero.

Oblique aerial photograph of the Pleasure Point area

Open-File Report 2007-1270

U.S. Department of the Interior

U.S. Geological Survey
Other than this note, this page intentionally left blank.
High-Resolution Topographic, Bathymetric, and

Oceanographic Data for the Pleasure Point Area,

Santa Cruz County, California: 2005-2007

Curt D. Storlazzi1, Patrick L. Barnard1, Brian D. Collins2, David P. Finlayson1, Nadine E. Golden1,

Gerry A. Hatcher1, Robert E. Kayen2, and Peter Ruggiero3.

1

U.S. Geological Survey, Pacific Science Center, Santa Cruz, CA

2

U.S. Geological Survey, Western Region Headquarters, Menlo Park, CA

3

Oregon State University, Department of Geosciences, Corvallis, OR

Open-File Report 2007-1270

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Dirk Kempthorne, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

This report and any updates to it are available at:

http://pubs.usgs.gov/of/2007/1270/

For product and ordering information:

World Wide Web: http://www.usgs.gov/pubprod

Telephone: 1-888-ASK-USGS

For more information on the USGS – the Federal source for science about the Earth, its natural

and living resources, natural hazards, and the environment:

World Wide Web: http://www.usgs.gov

Telephone: 1-888-ASK-USGS

Manuscript approved for publication, September 5, 2007

Any uses of trade, product, or firm names is for descriptive purposes only and does not imply

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual

copyright owners to reproduce any copyrighted materials contained within this report. 
iii

LIST OF FIGURES

FIGURE 1. Map of the study area location. 6

FIGURE 2. Schematic showing the elliptical scan pattern of the ATM. 9

FIGURE 3. Topographic lidar data acquisition and an example scan. 10

FIGURE 4. Region oftopographic lidar data coverage in the study area. 11

FIGURE 5. Coastal Profiling System being prepared for data collection. 12

FIGURE 6. Coastal Profiling System survey track lines in the study area. 12

FIGURE 7. View of the data processing shed onto the fantail of the R/V Paragon. 13

FIGURE 8. Underway view of the starboard gunnel of the R/V Paragon. 14

FIGURE 9. Color-coded swath bathymetry of the study area. 14

FIGURE 10. Location and image of the AWAC deployed off Pleasure Point. 15

FIGURE 11. Variation in the incident wave field during the periods of data acquisition. 16

FIGURE 12. Components of the digital imaging system. 17

FIGURE 13. Two merged 8 mega-pixel digital stills taken of the Pleasure Point surf breaks. 18

FIGURE 14. Video camera data from a period with small waves. 18

FIGURE 15. Video camera data from a period with large waves. 18

LIST OF TABLES

TABLE 1. AWAC deployment log. 15

TABLE 2. Digital imaging system data acquisition statistics. 17

LIST OF APPENDICES

APPENDIX 1. Terrestrial Lidar System Information. 21

APPENDIX 2. Coastal Profiling System Information. 23

APPENDIX 3. Swath Bathymetry System Information. 24

APPENDIX 4. Acoustic Doppler Profiler Information. 26

APPENDIX 5. Digital Imaging System Information. 27

APPENDIX 6. Experiment Personnel. 28
ADDITIONAL DIGITAL INFORMATION 

For additional information on the instrument deployments, please see: 

http://walrus.wr.usgs.gov/infobank/a/a198pc/html/a-1-98-pc.meta.html

http://walrus.wr.usgs.gov/infobank/w/w105mb/html/w-1-05-mb.meta.html

http://walrus.wr.usgs.gov/infobank/p/p105mb/html/p-1-05-mb.meta.html

http://walrus.wr.usgs.gov/infobank/p/p106mb/html/p-1-06-mb.meta.html

http://walrus.wr.usgs.gov/infobank/p/pp106mb/html/p-p1-06-mb.meta.html

http://walrus.wr.usgs.gov/infobank/f/f106mb/html/f-1-06-mb.meta.html

http://walrus.wr.usgs.gov/infobank/f/f206mb/html/f-2-06-mb.meta.html

http://walrus.wr.usgs.gov/infobank/f/f306mb/html/f-3-06-mb.meta.html

http://walrus.wr.usgs.gov/infobank/f/f107mb/html/f-1-07-mb.meta.html

http://walrus.wr.usgs.gov/infobank/p/p107mb/html/p-1-07-mb.meta.html

For an online PDF version of this report, please see: 

http://pubs.usgs.gov/of/2007/1270/ 

For more information on the U.S. Geological Survey Western Region’s Coastal and Marine 

Geology Team, please see: 

http://walrus.wr.usgs.gov/

For data files described in this report, please contact: 

Dr. Curt D. Storlazzi (Project Chief) 

USGS Pacific Science Center 

400 Natural Bridges Drive 

Santa Cruz, CA 95060 

cstorlazzi@usgs.gov

 

 

SUGGESTED CITATION 

C.D. Storlazzi, Barnard, P.L., Collins, B.D., Finlayson, D.P., Golden, N.E., Hatcher, G.A., Kayen, R.E., 

and Ruggiero, Peter, 2007, High-resolution topographic, bathymetric, and oceanographic data for 

the Pleasure Point area, Santa Cruz County, California; 2005-2007: U.S. Geological Survey OpenFile Report 2007-1270, 28 p. 

iv 
1

INTRODUCTION

The County of Santa Cruz Department of Public Works and the County of Santa Cruz

Redevelopment Agency requested the U.S. Geological Survey (USGS) Western Coastal and

Marine Geology Team (WCMG) to provide baseline geologic and oceanographic information on

the coast and inner shelf at Pleasure Point, Santa Cruz County, California. The rationale for this

proposed work is a need to better understand the environmental consequences of a proposed

bluff stabilization project on the beach, the nearshore and the surf at Pleasure Point, Santa Cruz

County, California (FIG. 1). To meet these information needs, the USGS-WCMG Team collected

baseline scientific information on the morphology and waves at Pleasure Point. This study

provided high-resolution topography of the coastal bluffs and bathymetry of the inner shelf off

East Cliff Drive between 32nd Avenue and 41st Avenue. The spatial and temporal variation in

waves and their breaking patterns at the study site were documented. Although this project did

not actively investigate the impacts of the proposed bluff stabilization project, these data provide

the baseline information required for future studies directed toward predicting the impacts of

stabilization on the sea cliffs, beach and nearshore sediment profiles, natural rock reef

structures, and offshore habitats and resources. They also provide a basis for calculating

potential changes to wave transformations into the shore at Pleasure Point.

FIGURE 1. Location of the study area.

Background

The Pleasure Point area in northern Monterey Bay is a complex coastal setting of sea cliffs and

small pocket beaches that are influenced by a variable wave climate due to its south-facing
2

orientation. Large winter swells typically arrive from the northwest and west; however, this area

also experiences un-refracted waves out of the southwest during the summer. Spatially and

temporally variable wave conditions and the complex, shallow, rocky seafloor at this site have

restricted comprehensive field surveys in the past. Recent innovations in field techniques and

equipment, as well as remote-sensing techniques, now make it possible to perform a detailed

analysis of the morphology and physical processes operating on this type of complex coastline.

Understanding the morphology and waves off Pleasure Point is important because it is part of the

Monterey Bay National Marine Sanctuary and the seacliffs in this area protect infrastructure

(road, water and sewage lines) that is crucial to Santa Cruz County. Continuing erosion has

threatened this infrastructure, and thus it has become increasingly important to provide scientific

data that will allow the various government agencies involved with the area to make the best

informed management decisions.

Project Description and Objectives:

The USGS Pleasure Point Study provided baseline information for future studies of impacts of the

proposed East Cliff Drive Stabilization Project. An integrated study to document both the coastal

and nearshore morphology and the spatial and temporal variation in waves at the study site was

conducted. These data were collected by means of three-dimensional beach and seacliff

mapping, nearshore bathymetric surveys, video monitoring and oceanographic instrumentation.

All of the data were collected to USGS standards and thus are the foundation for any future

surveys conducted to investigate change in morphology or processes at the study site. These

surveys, initiated in October, 2005, and extending through May, 2007, were required to determine

future long-term impacts by the proposed bluff stabilization project on the study area.

Task 1 – Mapping

High-resolution maps of the Pleasure Point area were compiled for both the terrestrial and

subaqeous parts of the study area from a combination of historical and newly collected data. The

morphology of the seacliffs was documented using historic airborne lidar (Light Detection and

Ranging) data and terrestrial lidar data. The bathymetry of the inner shelf was collected using

single-beam fathometers and an interferometric side-scan swath bathymetric sonar. This

topographic and bathymetric data will provide the baseline data for any future survey efforts

trying to detect change and a valuable resource for management decisions for Pleasure Point.

Furthermore, these data will provide the necessary topographic and bathymetric boundary

information for any future numerical modeling efforts attempting to predict coastal erosion or

changes to wave breaking patterns under different future scenarios (climate change, sea level

rise, seawall construction, etc.).

Subtask 1.1 - Historical Data

Historic airborne scanning lidar survey data provided topographical coverage for determining

regional shoreline position and seacliff morphology for comparison with the higher-resolution

survey work described here.

Subtask 1.2 – Terrestrial Lidar

The terrestrial portion of the study area, from the top of the seacliffs down to the beach and

intertidal bedrock reefs were surveyed at very high resolution (typical point to point spacing of

several centimeters) using a terrestrial lidar scanner. Because ground-based lidar scanning can

be performed with a horizontal look angle, not only is the cliff topography point density much

higher that from an airborne platform, but geologic features such as sea caves and wave cut

notches can also be captured. The terrestrial lidar collected along the Pleasure Point study area
3

was used to create a high-resolution digital elevation model of the terrestrial portion of the study

area. The fieldwork component of this subtask was conducted from the fall of 2005 through the

winter of 2006.

Subtask 1.3 – Shallow Nearshore Bathymetry

To map the bathymetry in very shallow water (depths < 5 m/16 ft) where larger traditional survey

vessels cannot operate, the single-beam USGS Coastal Profiling System (CPS) with real-time

kinematic differential global positioning system (RTK-DGPS) and echo sounder equipment was

employed to collect single beam bathymetry over the shallow nearshore off Pleasure Point. The

fieldwork component of this subtask was conducted in the fall of 2005.

Subtask 1.4 – Deeper Nearshore Bathymetry

An interferometric side-scan swath bathymetric sonar survey was run offshore Pleasure Point,

the first ever high-resolution swath bathymetric survey in this region, to complement the

shallower single-beam CPS survey discussed above. This provided broad spatial coverage from

approximately 0.5 km offshore into water depths of 3-4 m; the shallower portion of the swath

bathymetry thus overlapped the deeper portion of the CPS survey. The fieldwork component of

this subtask was conducted in the fall of 2005.

Task 2 – Wave Characterization

The spatial and temporal variation in the incoming waves and the resulting breaking wave

patterns at Pleasure Point area were documented from a combination of in situ instrumentation

and remote sensing techniques. The information on the incident wave and current field at the

study site was collected by way of oceanographic instrumentation deployed just offshore of the

coast at a depth of 14 m. Wave breaking patterns were documented using a web-based camera

system deployed at a private residence on East Cliff Drive. These data will provide the baseline

data for any future survey efforts trying to detect change and be a valuable resource as

management decisions for Pleasure Point are being made. Furthermore, these data will provide

the necessary incident forcing parameter boundary information for any future numerical

modeling efforts attempting to predict coastal erosion or changes to wave breaking patterns

under different future scenarios (climate change, sea level rise, seawall construction, etc.).

Subtask 2.1 – Temporal Variation in Currents and the Incident Wave Field

An acoustic Doppler current profiler (ADCP) was deployed for 12 months offshore Pleasure Point

to document the range of tide, wave and current conditions observed over a single year. This

sensor will make it possible to determine the link between the offshore wave conditions

measured by the deep-water NDBC Monterey Bay #46042 (NDBC, 2007) directional wave buoy

and the resulting wave breaking patterns at Pleasure Point imaged by the web-based camera

system. The fieldwork component of this subtask was initiated in the late spring of 2006 and data

were collected through the late spring of 2007.

Subtask 2.2 – Spatial and Temporal Variation in Breaking Wave Patterns

A digital camera system was installed to document the patterns of breaking waves across the

study area in real-time. This video monitoring made it possible to track wave breaking patterns,

rip-channel development and potentially infer rock reef and/or sand-bar location(s) under a range

of wave and tide conditions. These data can then be compared to offshore deep-water offshore

wave conditions measured by the deep-water National Data Buoy Center (NDBC) Monterey Bay

#46042 (NDBC, 2007) directional wave buoy and the ADCP discussed above. The fieldwork
4

component of this subtask was initiated in late spring 2006 and data were collected through the

late spring of 2007.

DATA ACQUISITION

Subtask 1.1 - Historical Data

The Airborne Topographic Mapper (ATM) lidar data were collected in partnership with the

National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center, the NASA

Wallops Flight Facility, the USGS Center for Coastal and Regional Marine Geology, and the NOAA

Aircraft Operations Center. The ATM can survey beach topography along hundreds of kilometers

of coast in a single day with data densities that cannot be achieved with traditional survey

technologies (FIGURE 2). For each pass along the coast, the ATM lidar scanned a 375-m wide

swath along the aircraft flight line. For most of the study area, four overlapping passes were

flown yielding a typical surveyed swath approximately 700-m wide with laser spot elevations

every 3 m2. The aircraft pitch, roll, and heading were obtained with an inertial navigation system

and the positioning of the aircraft was determined using kinematic Global Positioning System

(GPS) techniques. The twin-engine turboprop aircraft, a De Havilland Twin Otter, was provided

and operated by NOAA's Aircraft Operations Center, McDill Air Force Base, Tampa, FL. The local

topography of the area was derived from ATM data acquired on 04/17/1998 and 04/18/1998

following the intense storms of the 1997-1998 winter; these data were obtained from the Coastal

Services Center (2006) website. More than 918,100 data points were acquired during the two

days of surveying, extending from the water line up to the top of the seacliffs and some distance

landward. See http://coastal.er.usgs.gov/lidar/AGU_fall98/ for more information.

FIGURE 2. Schematic showing the elliptical scan pattern of the ATM.

Image from http://coastal.er.usgs.gov/lidar/AGU_fall98/

Subtask 1.2 – Terrestrial Lidar

Terrestrial lidar data were collected of the seacliffs, beaches, and intertidal bedrock reef platform

areas. Terrestrial lidar is the newest and most accurate technology being used to map and

monitor coastal bluff stability (Collins and Sitar, 2004, 2005). The data collection technique

consists of sending and receiving laser pulses to build a point file of three-dimensional

coordinates of virtually any reflective surface. The time of travel for a single pulse reflection is

measured along a known trajectory such that the distance from the laser and consequently the

exact location of a point of interest is computed. The USGS WCMG terrestrial lidar system
5

consists of a Riegl Z210 instrument mounted on a tripod platform (FIGURE 3). The instrument

captures data at approximately 8,000 points per second with a typical range of 100’s of m and at

an accuracy of 25 mm for each point. Additional specifications of the unit are provided in

APPENDIX 1.

Data collection consisted of setting up the instrument with the best possible field of view for each

location along and above the seacliffs (FIGURE 4). The unit was then moved to the next scan

location, which was determined by the required data density and the relative irregularity of the

seacliffs (i.e. cliffs with many caves or inlets require more scans to capture all aspects of the

features). In October, 2005, data were collected from the seacliff crest during high tide, capturing

topographic data of the crest area to some 50 m back from the cliff edge along with some seacliff

data captured from key vantage points near the edge. In January, 2006, data were collected from

the intertidal bedrock platform during a period of extremely low tides. This field effort collected

data of the seacliff, beach, and intertidal reef. In February, 2006, data were collected of a section

of cliff immediately adjacent to Pleasure Point (Opal Cliffs area) again, at a low tide from the

intertidal bench. Additional data were collected of this area in January, 2007, to improve final

data accuracy.

In total, scans from 54 individual locations were performed, collecting a total of 38.1 million points

of ground topographic data and an additional 6.6 million points of cultural features such as

houses, signs, fences, etc. Several post-processing steps were necessary. The data were

filtered to remove non-terrain objects (people, cars, etc.). Adjacent scans were registered to one

another through a local fit of overlapping points, and georeferenced to geodetic coordinates

through the use of control points visible in the scan data and locatable in the field. Field survey of

the control points was performed in June, 2006, and consisted of a post-processed differential

FIGURE 3: Topographic lidar data acquisition and an example scan. LEFT: Photograph of the lidar scanner during data

acquisition on the intertidal bedrock reefs at low tide. Laser pulses exit and enter the scanner through the two

vertical windows on the panning unit; the data acquisition computer is in the baby jogging stroller. RIGHT: Individual

scan taken just east of the stairwell at 36th Avenue. Houses, rip-rap, people and even individual power lines are

clearly identifiable in the data.

beach

power line

rip-rap
6

GPS survey on 30 control points. In some cases, a differential RTK GPS unit was placed directly

on the lidar instrument to achieve an increased level of accuracy. The georeferenced points

were then filtered to obtain a consistently dense data set for surface modeling. The final digital

elevation model (DEM) was created from a point set with a typical point-to-point spacing of 20

cm.

FIGURE 4: Region oftopographic lidar data coverage in the study area.

Subtask 1.3 – Shallow Nearshore Bathymetry

The Coastal Profiling System (CPS), a hydrographic surveying system mounted on a Personal

Watercraft (PWC), was used to collect shallow-water bathymetric data off Pleasure Point

(FIGURE 5). Combining the high accuracy positioning of Differential Global Position System

(DGPS), the efficiency of an acoustic echo sounder, and the mobility of a personal watercraft, the

CPS provides a fast and accurate method to achieve sub-decimeter accuracy; reasonable

variations in water temperature and salinity (not measured), however, can affect depth estimates

by as much as 3% of the water depth. The CPS collected data at 5 Hz and, while traveling at 3 m/s,

generated a depth sounding every 0.6 m along the sea floor. These data were collected assuming

a sound velocity of 1500 m/s. A more complete discussion of the CPS can be found in MacMahan

(2001), Ruggiero et al. (2005) and APPENDIX 2.

Twenty-five shore-normal and 23 shore-parallel track lines were collected (FIGURE 6). Due to

heavy kelp coverage in some locations and RTK-GPS problems, data coverage was sometimes

intermittent. In general, however, data quality was extremely high and more than 90% of the

planned study area was covered. Data was collected into water depths less than 1 m and out

into depths of more than 12 m.

To eliminate bed data or data outliers, each individual transect was examined, typically using a

Perl script and HYPACK software (the program used to collect the data), to detect and remove

any data points collected when the GPS receiver was not initialized in kinematic mode. This
7

FIGURE 5. A Coastal Profiling System acquiring data. The black waterproof case by the handlebars holds the

navigation display and quick keyboard, the white circular GPS antenna and black RTK whip antenna are mounted

directly over the fathometer on a pole attached to the stern, and the waterproof cases on the stern hold the batteries

and electronics for the computer, GPS and fathometers.

script also eliminated any obvious outliers from the raw files that are either shallower than the

echo sounder blanking interval or deeper than a user defined cutoff value. The individual files

were then exported in UTM Zone 10 Easting, Northing, Elevation ASCII triplets with one data file

per transect. A smoothing operation was then performed using a median filter on the zFIGURE 6. Coastal Profiling System survey track lines in the study area.
8

coordinate in the alongline direction to reduce high frequency fluctuations. Varying window sizes

were used to obtain a smooth profile while maintaining the integrity of the actual data points. In

total, more than 103,033 data points were acquired during the one day of surveying, extending

from mean sea level down to water depths just less than 12 m.

Subtask 1.4 – Deeper Nearshore Bathymetry

The deeper nearshore bathymetric survey was conducted aboard the R/V Paragon, a 10 m (32 ft)

Radon-style, twin outboard vessel owned and operated by the University of California, Santa Cruz

(FIGURE 7). A temporary data processing shed was placed on the fantail to protect the

acquisition computers and operator from the weather, and the SEA SWATHplus interferometric

side-scan swath bathymetric sonar was pole-mounted to the starboard gunnel (FIGURE 8).

SWATHplus is a 234 kHz side scan system that simultaneously collects bathymetry and

backscatter information using amplitude and phase difference information from multiple

transducers (APPENDIX 3).

FIGURE 7. Loading the temporary data processing shed onto the fantail of the R/V Paragon.

No direct vertical control was available in the study area during the survey. Instead, vertical

control was established using observed water levels from the National Ocean Service (NOS,

2007) Tide Station #9413450 located in Monterey Harbor (36° 36.3' N, 121° 53.3' W). NOAA has

established tidal harmonics for Santa Cruz that deviate slightly from the Monterey Bay reference

station, however, the maximum deviation between the reference station and Santa Cruz is

approximately 10 cm at full tide range. This difference is the same as the theoretical maximum

precision of the SWATHplus system (~10 cm) under ideal conditions, so the Monterey Bay

observed tides were used without adjustment during post processing.

The time series of observed water levels at Monterey Bay was downloaded from the NOS web

site (NOS, 2007) prior to post processing. These data were then entered into the SEA Swath

Processor acquisition software to establish Mean Lower Low Water (MLLW) as the vertical

datum of the survey. This survey can be converted to other vertical datums (such as NAVD 88) by
9

FIGURE 8. Underway view of the starboard gunnel of the R/V Paragon

showing the pole mount used to deploy the transducers.

referring to the tidal benchmark sheet for NOS Station 9413450 (Epoch 1983-2001). For reference,

NAVD 88 is 0.04 cm below MLLW at the benchmark.

Sound velocity profiles (SVP) for the survey were estimated by manually dropping a sound

velocity profiler. SVPs were collected at the beginning of each day and periodically during the

day as dictated by the environment. Overall, 11 SVPs were collected over five survey days. In

FIGURE 9: Color-coded swath bathymetry of the study area overlaid

on a 2005 black and white digital orthophotograph.
10

total, more than 3,242,199 soundings were acquired during this survey, extending from water

depths just less 2 m to more than 21 m (FIGURE 9).

Subtask 2.1 – Temporal Variation in Currents and the Incident Wave Field

An upward-looking 1-MHz Nortek AWAC ADCP was deployed for 12 months offshore Pleasure

Point to document the range of wave energy conditions observed over a year. The AWAC

(FIGURE 10, TABLE 1) collected a vertical profile of current velocity and acoustic backscatter (a

proxy for suspended sediment) through the water column, along with water depth and

temperature data, once a second for 6 min. These 3,600 samples were averaged to produce one

sample per parameter every 20 min (APPENDIX 4). Every hour, the AWAC collected current and

pressure (water depth) data twice a second for 8.5 min; these data were then used to compute

wave height, wave period, wave direction, and directional wave energy spectra once an hour.

This sensor will make it possible to determine the link between the offshore wave conditions

measured by the deep-water NDBC Monterey Bay (#46042) directional wave buoy and the

resulting wave breaking patterns at Pleasure Point imaged by the web-based camera system

(see below). These data, in conjunction with the proposed nearshore bathymetry, are crucial if

accurate modeling of waves in the study area under a range of scenarios (engineering, climate,

etc.) is desired by resource managers in the future. The fieldwork component of this subtask was

initiated in the late spring of 2006 and data were collected through the late spring of 2007.

FIGURE 10: Location and image of the AWAC deployed off Pleasure Point from 05/2006-06/2007.

LEFT: Location of the AWAC and the camera system relative to the shoreline.

RIGHT: Underwater photograph of the AWAC deployed at a depth of 13 m.

TABLE 1: AWAC deployment log.

Deployment Deployment Date

[MM/DD/YYYY]

Recovery Date

[MM/DD/YYYY]

Current

Measurements

Wave

Measurements

1 05/19/2006 08/21/2006 6769 2255

2 08/24/2006 11/29/2006 6985 2327

3 12/04/2007 03/12/2007 7059 2352

4 03/14/2007 06/05/2007 5981 1993

Overall, 8,927 wave bursts (>400,000 individual waves) and 26,794 current profiles were collected

(FIGURE 11). The minimum, mean ± one standard deviation wave heights during the period were
11

0.34 m, 0.92 ± 0.27 m, and 5.10 m, respectively. The minimum, mean ± one standard deviation, and

maximum wave periods during the study period were 3.2 s, 12.3 ± 2.1 s, and 23.8 s, respectively;

the mean ± one standard deviation wave direction during the study period was 211.3 ± 8.6°, with a

range of 182.7° – 240.6°.

FIGURE 11: Variation in the incident wave field during the periods of data acquisition. TOP: Significant wave height, in

meters. MIDDLE: Dominant wave period, in seconds. BOTTOM: mean wave direction, in degrees true. The lines

denote the monthly mean values while the error bars denote ± one standard deviation.

Subtask 2.2 – Spatial and Temporal Variation in Breaking Wave Patterns

The web-based camera system was comprised of an analog video camera and a digital still

camera, housed in a single pan and tilt unit (FIGURE 12), and linked to a computer and DSL

connection such that the camera could be controlled remotely from the USGS office in Santa Cruz

(APPENDIX 5). Data from various sections of the study area were therefore collected (TABLE 2).

Since these data were posted automatically to the web, the Santa Cruz County Redevelopment

Agency, Santa Cruz County Department of Public Works and the California Department of Boating

and Waterways and other agencies were able to access the data in real time. The video

monitoring makes it possible to track wave breaking patterns (FIGURE 13-15), rip channel

development and potentially infer sand-bar location(s) under a range of wave conditions. When

considering the cultural usage of the Pleasure Point area, these data could also be used to

document number of individuals in the imagery, either for (a) simply documenting the number of

people who actually surf, or (b) for determining carrying capacity for any new infrastructure (new
12

bathrooms, stairs, etc). The digital imagery can be compared to offshore deep-water offshore

wave conditions measured by the deep-water NDBC Monterey Bay directional wave buoy and

FIGURE 12: Components of the digital imaging system. LEFT: The front of the camera housing, with the Sony Block

video camera on the left and the Olympus 8 mega-pixel still camera on the right. RIGHT: Weatherproof enclosures

containing the power supply, data acquisition computer, pan/tilt controller, DSL modem and windshield washer tank.

See FIGURE 10 for location information.

the USGS ADCP measurements to understand the relationships between the incident wave field

and breaking patterns in the field area. The fieldwork component of this subtask was initiated in

the late spring of 2006 and data were collected through the late spring of 2007. Overall, 30,317

digital stills and 12,744 digital video time averages were collected (TABLE 2).

TABLE 2: Digital imaging system data acquisition statistics.

Scene Type Description Images

p1 Still Hook 3,027

p2 Still 38th Avenue 3,027

p3 Still Jack's 3,027

p4 Still Pleasure Point 3rd peak 3,027

p5 Still Pleasure Point 1st peak 3,027

p10 Still Hook zoom 1,326

p11 Still 38th Avenue zoom 1,355

p20 Still Pleasure Point 3rd peak zoom 1,355

p21 Still Pleasure Point 1st peak zoom 1,398

d12 Still Pleasure Point composite 3,443

d14 Still Hook-38th Avenue composite 3,427

d38 Still Study Area panoramic 2,878

s5 Video Pleasure Point 1st peak 3,257

s18 Video Pleasure Point 3rd peak 3,173

s23 Video 38th Avenue-Jack's 3,166

s32 Video Hook-38th Avenue 3,148

Total Still 30,317

Total Video 12,744
13

FIGURE 13. Two merged 8 mega-pixel digital still photographs taken of the Pleasure Point surf breaks.

FIGURE 14: Video camera data from a period with small (0.5 m) waves (08/15/2006). LEFT: Average of more than 3,000

images taken at 5 Hz. RIGHT: Variance of more than 3,000 images taken at 5 Hz. Note that, due to the sun angle, it is

difficult to delineate the region of wave breaking and whitewater (wave bores); however, these areas are easily

identifiable as white regions in the variance data. “Ghosts” in the imagery are where people were in the field of view

for a part of the 10 min period of data acquisition.

FIGURE 15: Video camera data from a period with larger (1.5 m) waves (09/20/2006). LEFT: Average of more than 3,000

images taken at 5 Hz. RIGHT: Variance of more than 3,000 images taken at 5 Hz. Note the much larger regions of

wave breaking and whitewater (wave bores) as compared to the period of smaller waves shown above in FIGURE 14.

“ghost”
14

SUMMARY

The USGS conducted an integrated study to document both the coastal and nearshore

morphology and the spatial and temporal variation in waves at Pleasure Point, Santa Cruz County,

California. These data were collected by means of three-dimensional beach and seacliff mapping

using airborne and terrestrial lidar scanners, nearshore bathymetric surveys using single-beam

fathometers and an interferometric side-scan swath bathymetric sonar, video monitoring using a

digital still camera and digital video camera and in situ oceanographic measurements using a

acoustic Doppler current profiler and directional wave gauge. In all, more than 39 million points

of ground topographic data, 3.3 million points of seafloor bathymetric data, 40,000 images of wave

breaking patterns and 8,900 in situ directional wave spectra measurements were collected.

These data provide the baseline information needed for future studies directed toward predicting

the impacts of stabilization on the seacliffs, beach and nearshore sediment profiles, natural rock

reef structures, and offshore habitats and resources.

ACKNOWLEDGEMENTS

This work was funded by the Santa Cruz County Redevelopment Agency, Santa Cruz County

Department of Public Works and the California Department of Boating and Waterways, and the

USGS WCMG. The USGS funds were allotted as part of an effort by the Benthic Habitats Project

to better understand the affect of geologic and oceanographic processes on nearshore

ecosystems. Paul Rodriguez (Santa Cruz County Redevelopment Agency), Ralph Norberg (Santa

Cruz County Department of Public Works), and Kim Sterrett (California Department of Boating and

Waterways) were the county and state liaisons, and provided support and advice throughout the

experiment. We would like to thank residents Liz and Don Darst, who graciously donated their

time and effort during our numerous survey operations. Annie, Jim and Joel Marshall

overextended themselves by hosting our digital imaging system at their house for 12 months, and

for that we owe them great thanks. Brian Foss and the staff at Santa Cruz Small Craft Harbor

provided us with launching and loading facilities. We would also like to thank Amy Draut (USGS)

and Jon Warrick (USGS), who contributed numerous excellent suggestions and a timely review of

our work. Use of trademark names does not imply USGS endorsement of products.
15

REFERENCES

Coastal Services Center, National Oceanographic and Atmospheric Administration, 2006. Online

digital data. ftp://ftp.csc.noaa.gov/crs/lidar/load_lid.avx 

CodaOctopus, 2006. Octopus F180. Technical Brief. Edinburgh, UK

Collins, B.D. and Sitar, N., 2004. Application of High Resolution 3D Laser Scanning to Slope

Stability Studies, Proceedings of the 39th Symposium on Engineering Geology and Geotechnical

Engineering, Butte, Montana, May 18-21, 2004, pp. 79-92.

Collins, B.D. and Sitar, N., 2005. Monitoring of Coastal Bluff Stability Using High Resolution 3D

Laser Scanning, ASCE Geo-Frontiers Special Publication 138:- Site Characterization and

Modeling, Remote Sensing in Geotechnical Engineering, E.M. Rathje, ed., ASCE, Austin, Texas,

Jan 24-26, 2005.

MacMahan, J., 2001. Hydrographic surveying from a personal watercraft. Journal of Surveying

Engineering, 127(1), 12-24.

National Data Buoy Center, National Oceanographic and Atmospheric Administration, Monterey

Buoy #46042, 2007. Online digital data.

http://www.ndbc.noaa.gov/station_page.php?station=46042

National Ocean Service, National Oceanographic and Atmospheric Administration, Monterey tide

station #9413450, 2007. Online digital data.

http://tidesandcurrents.noaa.gov/data_menu.shtml?stn=9413450%20Monterey,%20CA&type=Hist

oric%20Tide%20Data

Ruggiero, P., Kaminsky, G.M., Gelfenbaum, G., and Voigt, B., 2005. Seasonal to interannual

morphodynamic variability along a high-energy dissipative littoral cell. Journal of Coastal

Research, 21(3), 553-578.

SEA(AP) Ltd., 2005. SWATHplus training pack. Beckington Castle, PO Box 800, Frome England,

BA11 6TB.
16

APPENDIX 1

Terrestrial Lidar System Information

Riegl LMS-Z210 3D Laser Mirror Scanner (S/N: 9992980) Terrestrial Lidar System

( http://www.riegl.com/terrestrial_scanners/lms-z210i_/210i_all.htm )

Technical Description: Near infrared, Laser Class 1 (eye safe) pulsed laser diode with true

color channel operating on time-of-flight measurement principle with

panning head and rotating triangular mirror.

Technical Specifications:

Physical Dimensions: 0.5 m in height, 0.2 m in diameter, and 13 kg in mass.

Range Information Up to 200 m typical, up to 700 m under optimal atmospheric conditions.

Angular extents: 0° to 336° horizontally, 0° to 80° vertically

Measurement Accuracy: Typically 15 mm to 25 mm

Measurement Resolution: 5 mm

Measurement Rate: Up to 8000 points/s

Power: One gel cell 12-volt battery running at 6.5 amps (typ.) and 78 watts (typ.).

Survey Description: The lidar unit is set-up on a 1.5 m adjustable tripod and leveled with a tribrach.

Typically, the tripod is located on the beach or intertidal platform and aimed at

the seacliffs or located on the seacliff top and aimed over or along the seacliffs.

A laptop computer controls the lidar instrument via parallel and serial cables.

Each scan typically obtains 1 million data points; collected in approximately 5

min. The equipment is moved along the beach every 50 to 100 m and the survey

is repeated.

Survey Schedule: Data were collected from the top of the seacliff on October 5-6, 2006, consisting

of 37 scans. Data was collected from the beach and intertidal bedrock reef

platform on January 27, 2006, consisting of 17 scans. Due to differing beach

conditions between these two efforts, only beach data of the lowest beach

geometry (January 27, 2006) was utilized in the processed data set. Of these 54

scans, only 46 were utilized due to existing overlapping data or poor registration

fit with some of the scans. Additional data adjacent to the Pleasure Point study

area (Opal Cliffs area) was collected on February 9, 2006, and January 31, 2007,

consisting of 8 additional scans and were utilized in the final georeferencing of

the data set.

Position Information: Data were registered to geodetic coordinates through the collection of 30 local

control points visible in the scan data. The local control points were surveyed

using a pair of Ashtech Z-Xtreme geodetic quality, dual frequency (L1/L2) GPS

receivers. One receiver acted as a base station and the other as a rover located

over each control point. The data was post processed differentially using

Ashtech’s proprietary software in a Stop-and-Go methodology.

Lidar data in January, 2007, were collected using a pair of Topcon Hyper+ RTK,

dual frequency GPS/GLONASS receivers using a similar base-rover

methodology, but processed in real-time using a Pacific Crest radio link.

Position Accuracy: The GPS equipment used in the survey program provided local control point

accuracies on the order of less than 5 cm.

The GPS/GLONASS equipment used for the January, 2007, lidar surveys provided

point accuracies on the order of less than 6 mm.

Processing Information: Data processing was performed using I-SiTE Studio 2.4 and 3.0 software,

specifically designed for terrestrial Lidar data processing. Scans were filtered,

registered, and georeferenced according to standard post-processing
17

techniques. Three-dimensional surfaces and digital elevation models (DEMs)

and grids were then extracted from the data. ArcGIS was utilized for final

extraction of DEMs using data filtered to a minimum individual point to point

separation of 20 cm.

Processing Accuracy: Individual scans each have an internal accuracy of 2.5 cm. Adjacent scans were

registered to one another through local fit of overlapping data typically

consisting of several hundred thousand points. Measurements between

adjacent scans have an internal accuracy of 5 cm. The internal accuracy of the

data for measurements made within the lidar data set is 2.5 + 5 = 7.5 cm or

approximately 0.08 m. All scans were georeferenced to NAD83 UTM Zone 10N

and NAVD88 coordinates using surveyed control points visible in the scan data.

Measurement fit of all data to georeferenced coordinates is 0.5 m.

Internal Horizontal and Vertical Positional Accuracy Assessment: ±0.08 m

Georeferenced Horizontal and Vertical Positional Accuracy Assessment: ±0.50 m
18

APPENDIX 2

Coastal Profiling System Information

Vessel Specifics

Description: 2003 Honda AquaTrax F-12 4-stroke PWC

Dimensions: 3.2 m in length, 1.3 m in width, and 1.1 m in height

Survey speed: 3 m/s (6 knots); can operate for ~5 hours on 60-L fuel tank

Instruments: The instruments are placed on a bracket at the stern of the vessel, and forward

upper part of the vessel in front of the handlebars. On the stern bracket are

three large watertight cases, which house the GPS, computer, echo sounder

electronics and batteries.

Power: Two gel cell 12-volt marine batteries, configured in parallel and housed in a

Pelican box mounted on the PWC’s stern.

Position Information: Trimble 4700 GPS receiver, with Pacific Crest GPS radio modem to communicate

with the shore base station. The L1/L2 microcentered GPS antenna and the radio

antenna were mounted directly above the echo sounder transducer.

Depth Information: ESE-50 single frequency echo sounder with a 200 kHz transducer manufactured

by Flash Fire Technology, Inc. The transducer has a 10o conical beam width and

generates a pulse at 200 kHz. The CPS collected data at 5 Hz and while traveling

at 3 m/s, generated a depth sounding every 0.6 meters along the sea floor.

Navigation: HYPACK hydrographic surveying software was used as the data synchronization

software and navigation system. Navigation and surveying are aided by a 12

inch Big Bay Technologies outdoor monitor that is mounted in a watertight case

on a bracket forward of the PWC’s handlebars. A small 17-button programmable

Logic Controls keypad is placed in a waterproof radio bag mounted on the

handlebars.

Survey Accuracy: The survey-grade GPS equipment used in the monitoring program have

manufacturer reported Root Mean Square (RMS) accuracies of approximately ±3

cm + 2 ppm of baseline length (typically 10 km or less) in the horizontal while

operating in Real Time Kinematic surveying mode. The horizontal uncertainty of

individual data points is ~0.05 m.

Quantitative Horizontal Positional Accuracy Assessment: ±0.05 m

Quantitative Vertical Positional Accuracy Assessment: ±0.15 m
19

APPENDIX 3

Swath Bathymetry System Information

SEA Group Ltd 234 kHz Interferometric Submetix SWATHplus-M Bathymetric Sonar System

( http://www.sea.co.uk/swathplus.aspx?nav=products)

Dimensions (cm): 16H x 35W x 6D

Maximum Water Depth: 100 m

Maximum Swath Width: 300 m

Maximum Range/Depth Ratio: 15:1

Across-track resolution: 7.5 cm maximum, 1.1o azimuth beamwidth

Accuracy: 0.1 m or 1% accuracy versus water depth

Operating Environment: Microsoft Windows NT

Data Processors: SEA Swath Processor, v. 2.05

SEA Grid Processor v. 2.05

Navigation: CodaOctopus, Model F180, Differential Global Positioning

System (DGPS)

Navigation Logging: Yo-Nav version 1.19

Heading Information: KVH Industries Inc. azimuth digital gyro

compass provided ship headings with 0.5o accuracy

Spatial Resolution: 0.2 m raw, 1.0 m processed

Data Format: Correct x-position, y-position, depth, and acoustic amplitude data

Data Processing:

Started with SXP files that were the output from A 234 kHz Interferometric Submetix Swath Bathy

Sonar System. Imported these SXP files on at a time into a SEA Grid Processor v. 2.05, environment

with a bin size of 1 (bin size is in meters). In SEA Grid Processor environment ran the following

filter on each bathymetry file: Standard deviations > 0.5. Individually exported each bathymetry file

from SEA Grid Processor environment which converts the SXP file to an ASCII grid text file.

Imported bathymetry ASCII grid text files into Fledermaus v.6.2.0a, Build 45 Professional, using the

Fledermaus Data Magic extension. Exported bathymetry files from Fledermaus Data Magic to ASCII

ArcView grid format. In ArcGIS v. 9.1, Toolbox environment, converted ASCII ArcView grid files

from ASCII to ArcGIS Raster; defined projection for each raster as NAD_1983_UTM_Zone_10N;

and built ArcGIS pyramids for each raster file. In ArcGIS v. 9.1, Toolbox environment, Spatial

Analysis Tools-->Math-->Plus tool, added 0.043 to grid depth in order to correct for difference

between MLLW and NAVD 88.

Vessel Information:

University of California at Santa Cruz R/V Paragon

32' Radon style, twin 250HP diesels, radar, fathometer, autopilot and davit.

SWATHplus-M data acquisition and real-time processing van was installed on the aft

deck.

SWATHplus-M transducer was mounted on the starboard side aft quarter.

Sound Velocity Profile (SVP) casts were made using an Applied Microsystems SV-Plus V.2

sound velocity profiler off the port side aft quarter. Navigation was provided using the

YoNav software package, which allowed for the creation of sets of parallel survey lines of

a given length at a given line spacing. The navigation information, including position,

speed, heading and distance along the transect line, were provided to the vessel captain

via a LCD display.

Survey Information:

Number of Lines: 97 (89 ~straight, 8 shore-parallel)

Water depths: 1-22 m

Sound Velocity Profiles: 11 sound velocity profiles (minimum = 1/day)

Dates:

Mobilization: 10/12/2005 YD285

Survey: 10/13/2005 YD286 - 10/14/2005 YD287, 10/17/2005 YD290 - 10/19/005 YD292

Demobilization: 10/20/2005 YD293
20

Quantitative Horizontal Positional Accuracy Assessment: ±0.2 m

Quantitative Vertical Positional Accuracy Assessment: ±0.3 m
21

APPENDIX 4

Acoustic Doppler Current Profiler

Nortek 1 MHz AWAC (S/N: 2074) Acoustic Doppler Current Profiler and Directional Wave Gauge

( http://www.nortekusa.com/hardware/AWAC.html)

Transmitting Frequency: 1 MHz

Depth of Transducer: 13 m

Blanking Distance: 0.4 m

Height of First Bin above Bed: 1.0 m

Bin Size: 0.5 m

Number of Bins: 34

Sampling Frequency: 2 Hz surface tracking, 1 Hz currents

Profile Ensemble Interval: 0:20:00.00

Profile Averaging interval: 0:06:00.00

Wave Ensemble Interval: 1:00:00.00

Number of Wave Samples: 1024

Sound Speed Calculation: Set salinity (35 PSU), updating temperature via sensor

Velocity Precision: horizontal: 0.5 cm/s, vertical: 1.4 cm/s

Coordinate System: East-North-Up

Compass Update Rate: 0:20:00.00

Magnetic Compass: Set to –10o magnetic offset

Location Latitude: N 36o 56.907'

Longitude: W 121o 58.722'

Data Processing:

The data were averaged into 1 hour ensembles, all of the spurious data above the water surface

were removed and all of the data in bins where the beam correlation dropped below 70% were

removed for visualization and analysis.

Position Information: Garmin GPS-76 GPS; s/n: 80207465
22

APPENDIX 5

Digital Imaging System Information

Erdman Video Systems, Inc. C5050-PT Biscut with Real-Time Video Upgrade

( http://www.video-monitoring.com/allinone.htm )

Digital Camera: Olympus SP-350 Ultra Zoom camera

Digital Video: Sony FCB-EX480A Block camera

Control Interface: 667 megahertz embedded PC with 256 megabytes

PC133 memory and 100 gigabyte hard drive

Camera Scene Sampling Frequency: 1 per hour

Number of Camera Scenes: 9

Video Scene Sampling Frequency: 5 frames/s for 10 min

Number of Video Scenes: 4

Location Latitude: N 36o 57.407'

Longitude: W 121o 58.254'

Position Information: Garmin GPS-76 GPS; s/n: 80207465
23

APPENDIX 6

Experiment Personnel

Person Affiliation Responsibilities

Curt Storlazzi USGS Chief Scientist

Patrick Barnard USGS CPS Survey

Michael Boyle USGS Swath Bathymetry Acquisition

Bradley Carkin USGS Terrestrial Lidar Survey Assistant

Brian Collins USGS Terrestrial Lidar Survey

Jodi Eshleman USGS CPS Survey Processing

Jared Figurski UCSC Vessel Captain, R/V Paragon

David Finlayson USGS Geospatial Data Processing

Nadine Golden USGS Geospatial Data Processing

Dave Gonzales USGS Oceanographic Instrumentation

Jamie Grover UCSC Vessel Captain, R/V Paragon

Gerry Hatcher USGS Swath Bathymetry Acquisition

Robert Kayen USGS Terrestrial Lidar Survey

Joshua Logan USGS Geospatial Information, diver

Diane Minasian USGS Terrestrial Lidar Survey Assistant

Kevin O'Toole USGS Mechanical Fabrication/Field Support

Kathy Presto USGS Oceanographic Instrumentation

Tom Reiss USGS Dive Safety Officer, Geodetic Survey

Peter Ruggiero OSU CPS Survey

Randy Russell USGS Computer Support

Randolf Skovan UCSC Vessel Captain, R/V Paragon

Andrew Stevenson USGS Geospatial Data Processing