Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the 

U.S. Government

This map was printed on an electronic plotter directly from digital files. Dimensional calibration may vary between electronic plotters 

and between X and Y directions on the same plotter, and paper may change size due to atmospheric conditions; therefore, scale and 

proportions may not be true on plots of this map.

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225, 1–888–ASK–USGS

Digital files available at http://pubs.usgs.gov/of/2014/1214/

Suggested Citation: Golden, N.E., Cochrane, G.R., Erdey, M.D., and Krigsman, L.J., 2014, Ground-truth studies, Offshore of Half Moon 

Bay map area, California, sheet 6 in Cochrane, G.R., Dartnell, P., Greene, H.G., Johnson, S.Y., Golden, N.E., Hartwell, S.R., Dieter, B.E., 

Manson, M.W., Sliter, R.W., Ross, S.L., Watt, J.T., Endris, C.A., Kvitek, R.G., Phillips, E.L., Erdey, M.D., Chin, J.L., and Bretz, C.K. (G.R. 

Cochrane and S.A. Cochran, eds.), California State Waters Map Series—Offshore of Half Moon Bay, California: U.S. Geological 

Survey Open-File Report 2014–1214, pamphlet 37 p., 10 sheets, scale 1:24,000, http://dx.doi.org/10.3133/ofr20141214.

ISSN 2331-1258 (online)

http://dx.doi.org/10.3133/ofr20141214

Figure 5. USGS-designed camera sled being 

loaded onto research vessel in preparation for 

ground-truth studies. Components onboard sled 

include four digital video camcorders, one 

8-megapixel digital SLR camera, lasers for scale, 

and various strobe and video lights, as well as 

telemetry instrumentation that records depth, 

altitude, and compass heading.

#

^

^

^

^

!

!

!

!

DISCUSSION

Between 2006 and 2007, the seafloor in the Offshore of Half Moon Bay map area in northern California was mapped by Fugro Pelagos and California State 

University, Monterey Bay (CSUMB), using multibeam echosounders (see sheets 1, 2, 3). These mapping missions combined to collect bathymetry and acousticbackscatter data from about the 10-m isobath to out beyond the 3-nautical-mile limit of California’s State Waters. In order to characterize the bathymetry and 

acoustic-backscatter data into geologically and biologically useful information, the USGS ground-truth-surveyed the data by towing a camera sled (fig. 5) over specific 

locations throughout the map area in 2007.

During the ground-truth-survey cruise, the camera sled was towed 1 to 2 m over the seafloor, at speeds of between 1 and 2 nautical miles/hour. The sled housed 

two standard-definition (640×480 pixel resolution) video cameras (one forward looking, the other downward looking), a high-definition (1,080×1,920 pixel resolution) 

video camera, and an 8-megapixel digital still camera, which captured a digital still photograph once every 30 seconds. The video was relayed in real time to the 

research vessel, where USGS and National Oceanic and Atmospheric Administration (NOAA) scientists recorded both the geologic and biologic character of the 

seafloor once every minute, using programmable keypads. The location and directions of the camera-sled tracklines were chosen in order to visually inspect areas 

thought to represent the full range of bottom hardness and rugosity in the map area.

In the context of marine-fisheries management, benthic-habitat complexity can be divided into abiotic (geologic) and biotic (biologic) components. Benthichabitat complexity refers to the visual classification of local abiotic and biotic vertical relief and structure that may provide potential refuge for both juvenile and adult 

forms of various species. Only abiotic attributes (primary- and secondary-substrate composition) were used in the production of the seafloor-character map on sheet 5. 

Classifications of primary and secondary substrate are based on the Wentworth (1922) scale of sediment grain-size categories, and the sand, cobble, and boulder sizes 

are classified as in Wentworth (1922). However, the difficulty in distinguishing the finest divisions in the Wentworth (1922) scale during video observations made it 

necessary to aggregate some grain-size classes: the granule and pebble sizes have been grouped together into a class called “gravel,” and the clay and silt sizes have 

been grouped into a class called “mud.” In addition, hard bottom and clasts larger than boulder size are classified as “rock.” Primary and secondary substrate, by 

definition, constitute greater than 50 and 20 percent of the seafloor during an observation, respectively. 

This sheet contains a smaller, simplified (depth-zone symbology has been removed) version of the seafloor-character map (sheet 5), on which the camera-sled 

tracklines used to ground-truth-survey the sonar data are indicated by aligned colored dots, each dot representing the location of a recorded observation. Primary- and 

secondary-substrate compositions are shown by differently colored dots. The map also shows the locations of the detailed views of seafloor character along some of 

the tracklines (Boxes A through D) that are highlighted on this sheet (figs. 1A, 2A, 3A, 4A). Also shown are locations of samples (triangles) from usSEABED (Reid 

and others, 2006) that were used to supplement the ground-truth surveys. 

The seafloor-character map shows that this area is dominated by sedimentary-rock outcrops (see, for example, figs. 2E, 2I, 3G, 3H). At deeper depths in the 

northern part of the map area, the seafloor is covered predominantly by sandy sediment (see, for example, figs. 1B, 1C, 1D) that is characterized by sharp-crested, 

oscillatory ripple patterns (typical wavelengths, 5 to 15 cm). The general absence of burrows documents sparse populations of mega-infauna capable of bioturbating 

the sandy seafloor at a scale observable by our camera systems and (or) a dynamic environment of mobile sediment that degrades or destroys evidence of burrowing. 

The sandy-shelf areas are typified by low abiotic complexity, low biotic complexity, and low biocover.

Rocky outcrops and areas of moderately to poorly sorted, coarse sand and gravel are located along the entire length of the shallow areas and are the dominant 

substrate in the central part of the map area. These areas are characterized by moderate to high abiotic complexity created by steep rocky outcrops projecting dramatically above the adjacent sandy seafloor (see, for example, figs. 2D, 2F, 3I, 4D). Here, epifauna can be diverse, and urchins, starfish (asteroids), and schools of rockfish, 

as well as numerous attached fauna (for example, sponges, cup corals), provide moderate to high biocover.

Scour depressions are found at all water depths, and they are both adjacent to, and distant from, rocky areas. Moderately to poorly sorted, coarse sand and gravel 

located in these areas typically form shallow depressions relative to the adjacent sandy seafloor. Many of these depressions are characterized by large ripples and 

megaripples composed of coarse sand, fine gravel, and scattered shells (see, for example, figs. 1B, 1C). These features provide low abiotic complexity, low biotic 

complexity, and low biocover. 

Each detailed view (figs. 1A, 2A, 3A, 4A) shows the locations of camera-sled tracklines (aligned colored dots), as well as of the photographs (colored stars) taken 

along the tracklines. These photographs, which are representative of the seafloor, are displayed with a description of the observed seafloor characteristics recorded by 

USGS and NOAA scientists (figs. 1B through 1E; 2B through 2I; 3B through 3I; 4B through 4E). Only primary and secondary substrates are reported, although 

individual photographs may show more substrate types. Organisms, when present, are labeled on the photographs.

Ground-truth surveys in the Offshore of Half Moon Bay map area include approximately 23 trackline kilometers of video and 2,000 still photographs, in addition 

to 1,086 seafloor observations of abiotic and biotic attributes. A visual estimate of slope was also recorded.

GLOSSARY

Rugosity—A GIS-derived characterization of seafloor roughness, calculated as the ratio of the three-dimensional surface area of seafloor to the two-dimensional 

planar-base area, for each cell in the bathymetry grid.

Backscatter intensity—The amplitude of the reflected sonar signal (see sheet 3) used to infer the hardness of the bottom, determined after sonar-data processing 

has removed (as much as possible) the effects of water depth, angle of reflection, and bottom roughness.

Biocomplexity—The assessment of the presence or absence of biological structures that have the potential of providing shelter for fauna, determined by estimating the scale, the amount, and the morphology of biological relief (as described by Tissot and others, 2006).

Biocover—The visual estimate of the proportion of biologic cover by encrusting organisms: high, greater than 50 percent; moderate, between 50 percent and 10 

percent; low, less than 10 percent.

REFERENCES CITED

Reid, J.A., Reid, J.M., Jenkins, C.J., Zimmerman, M., Williams, S.J., and Field, M.E., 2006, usSEABED—Pacific Coast (California, Oregon, Washington) offshore 

surficial-sediment data release: U.S. Geological Survey Data Series 182, available at http://pubs.usgs.gov/ds/2006/182/.

Tissot, B.N., Yoklavich, M.M., Love, M.S., York, K., and Amend, M., 2006, Benthic invertebrates that form habitat on deep banks off southern California, with special 

reference to deep sea coral: Fishery Bulletin, v. 104, p. 167–181.

Wentworth, C.K., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology, v. 30, p. 377–392.

EXPLANATION

Substrate class

Fine- to medium-grained smooth sediment—Low backscatter, low rugosity; typically mud to medium-grained sand; often rippled and (or) burrowed

Mixed smooth sediment and rock—Moderate to very high backscatter, low rugosity; typically coarse-grained sand, gravel, cobbles, and bedrock

Rock and boulder, rugose—High backscatter, high rugosity; typically boulders and rugose bedrock

Medium- to coarse-grained sediment—Very high backscatter, low rugosity; typically medium- to coarse-grained sediment, with varying amounts of 

shell hash; in scour depressions

Location of real-time video observation and interpreted substrate class of seafloor

Fine- to medium-grained smooth sediment—Low backscatter, low rugosity; typically mud to medium-grained sand; often rippled and (or) burrowed

Mixed smooth sediment and rock—Moderate to very high backscatter, low rugosity; typically coarse-grained sand, gravel, cobbles, and bedrock

Rock and boulder, rugose—High backscatter, high rugosity; typically boulders and rugose bedrock

Medium- to coarse-grained sediment—Very high backscatter, low rugosity; typically medium- to coarse-grained sediment, with varying amounts of 

shell hash; in scour depressions

Location of digital still photograph and interpreted substrate class of seafloor

Fine- to medium-grained smooth sediment—Low backscatter, low rugosity; typically mud to medium-grained sand; often rippled and (or) burrowed

Mixed smooth sediment and rock—Moderate to very high backscatter, low rugosity; typically coarse-grained sand, gravel, cobbles, and bedrock

Rock and boulder, rugose—High backscatter, high rugosity; typically boulders and rugose bedrock

Medium- to coarse-grained sediment—Very high backscatter, low rugosity; typically medium- to coarse-grained sediment, with varying amounts of 

shell hash; in scour depressions

Interpreted substrate class depicted in digital still photograph—Indicated by colored frame around photograph (not shown on map; shown in figures 

only)

Fine- to medium-grained smooth sediment—Low backscatter, low rugosity; typically mud to medium-grained sand; often rippled and (or) burrowed

Mixed smooth sediment and rock—Moderate to very high backscatter, low rugosity; typically coarse-grained sand, gravel, cobbles, and bedrock

Rock and boulder, rugose—High backscatter, high rugosity; typically boulders and rugose bedrock

Medium- to coarse-grained sediment—Very high backscatter, low rugosity; typically medium- to coarse-grained sediment, with varying amounts of 

shell hash; in scour depressions

Sample localities

From usSEABED (Reid and others, 2006)

Area of “no data”—Areas near shoreline not mapped owing to insufficient high-resolution seafloor mapping data; areas beyond 3-nautical-mile limit of 

California’s State Waters were not mapped as part of California Seafloor Mapping Program

3-nautical-mile limit of California’s State Waters

Kilometers 0 5 10

0 5 10Nautical Miles

122°40' 122°20'

38°

37°40'

37°20'

San

Francisco

Bay

Area of

Map

Limit of California’s

State Waters

CALIF.

MAP LOCATION

1

U.S. Geological Survey;

2

National Oceanic and Atmospheric Administration, National Marine Fisheries Service

Ground-Truth Studies, Offshore of Half Moon Bay Map Area, California

By

Nadine E. Golden,1 Guy R. Cochrane,1 Mercedes D. Erdey,1 and Lisa M. Krigsman2

2014

^_ ^_

^_

^_

D4 D3

D2

D1

Box D Figure 4A. Detailed view of seafloor character mapped southwest of Martins 

Beach, approximately 4 km offshore (see Box D, on map, for location), showing 

locations of periodic real-time video observations (dots) and digital still 

photographs (stars; see figs. 4B through 4E) from camera line CAM2, cruise 

F–3–07–NC.

4 Cam2_Tape3 Image 1519 -39m 15 cm

Figure 4E. Digital still photograph no. D4 (see fig. 4A for location). 

Unconsolidated, fine- to medium-grained sand with oscillatory ripples in 

confused pattern (water depth, 39 m). Abiotic complexity is low, biotic 

complexity is absent, and biocover is low. Biocover includes flatfish (ff), brittle 

star arms (bs), and sea pen (sp). Distance between lasers (red dots are just out 

of view in this image but are visible in previous video frame) is 15 cm.

ff

sp

3 Cam2_Tape3 Image 1468 -36m 15 cm

cc

sa

bas

lc

Figure 4D. Digital still photograph no. D3 (see fig. 4A for location). Mixed 

boulder with sand and scattered shells (water depth, 36 m). Abiotic complexity 

is moderate, biotic complexity is absent, and biocover is moderate. Biocover 

includes cup corals (cc), bat star (bas), sea anemones (sa), and lingcod (lc). 

Distance between lasers (red dots are just out of view in this image but are 

visible in previous video frame) is 15 cm. 

2 Cam2_Tape2 Image 1403 -34m 15 cm

cs

sa

Figure 4C. Digital still photograph no. D2 (see fig. 4A for location). 

Unconsolidated, fine- to medium-grained sand with oscillatory ripples in 

confused pattern (water depth, 34 m). Abiotic complexity is low, biotic 

complexity is absent, and biocover is high. Biocover includes sea anemone 

(sa) and clam siphons (cs). Distance between lasers (red dots) is 15 cm.

1 Cam2_Tape2 Image 1355 -32m 15 cm

ff

Figure 4B. Digital still photograph no. D1 (see fig. 4A for location). 

Unconsolidated, fine- to medium-grained sand with sharp-crested, oscillatory 

ripples in confused pattern (water depth, 32 m). Abiotic complexity is low, biotic 

complexity is absent, and biocover is low. Biocover includes flatfish (ff). 

Distance between lasers (red dots) is 15 cm.

bs

^_

^_

^_

^_

^_

^_

^_

^_

C8

C7

C6

C5

C3 C4

C2

C1

Figure 3A. Detailed view of seafloor character mapped southwest of city of Half 

Moon Bay, approximately 1 km offshore (see Box C, on map, for location), 

showing locations of periodic real-time video observations (dots) and digital still 

photographs (stars; see figs. 3B through 3I) from camera line CAM18, cruise 

F–3–07–NC.

Box C

8 Cam18_Tape23 Image 1686 -9m 15 cm

spo

kg

ra

Figure 3I. Digital still photograph no. C8 (see fig. 3A for location). Mixed gravel, 

cobbles, and rugose rock outcrop with scattered shells (water depth, 9 m). 

Abiotic complexity is moderate, biotic complexity is absent, and biocover is 

high. Biocover includes encrusting sponges (spo), red algae (ra), cup coral 

(cc), and kelp greenling (kg). Distance between lasers (red dots) is 15 cm.

cc

7 15 cm Cam18_Tape22 Image 1572 -19m

spo

Figure 3H. Digital still photograph no. C7 (see fig. 3A for location). Mixed 

rounded to subrounded boulders and rugose rock outcrop with sand and 

scattered shells (water depth, 19 m). Abiotic complexity is high, biotic 

complexity is absent, and biocover is low. Biocover includes encrusting 

sponges (spo). Distance between lasers (green dots) is 15 cm.

6 Cam18_Tape22 Image 1555 -20m 15 cm

Figure 3G. Digital still photograph no. C6 (see fig. 3A for location). Rugose rock 

outcrop (water depth, 20 m). Abiotic complexity is high, biotic complexity is 

absent, and biocover is high. Biocover includes strawberry anemones (sta), sea 

urchin (su), encrusting coralline algae (ca), cup corals (cc), nudibranch (n), and 

young-of-the-year rockfish (rfY). Distance between lasers (green dots) is 15 cm.

ca

sta

rfY

su

cc

n

5 15 cm Cam18_Tape22 Image 1525 -22m

Figure 3F. Digital still photograph no. C5 (see fig. 3A for location). Interface 

between rugose rock outcrop with shell hash and sand in intervening channel 

(water depth, 22 m). Abiotic complexity is moderate, biotic complexity is 

absent, and biocover is low. Distance between lasers (green dots) is 15 cm.

4 Cam18_Tape22 Image 1523 -23m 15 cm

sta

spo3D

Figure 3E. Digital still photograph no. C4 (see fig. 3A for location). Rugose rock 

outcrop (water depth, 23 m). Abiotic complexity is moderate, biotic complexity is 

absent, and biocover is high. Biocover includes strawberry anemones (sta), 

encrusting sponges (spo), and 3-dimensional sponges (spo3D). Distance 

between lasers (red dots are just out of view in this image but are visible in 

previous video frame) is 15 cm.

spo

3 Cam18_Tape22 Image 1494 -24m 15 cm

Figure 3D. Digital still photograph no. C3 (see fig. 3A for location). 

Unconsolidated, fine- to medium-grained sand with oscillatory ripples in 

confused pattern and varying amounts of scattered shells (water depth, 24 m). 

Abiotic complexity is low, biotic complexity is absent, and biocover is low. 

Distance between lasers (red dots) is 15 cm. 

2 15 cm Cam18_Tape22 Image 1458 -25m

Figure 3C. Digital still photograph no. C2 (see fig. 3A for location). Interface 

between rock and fine- to medium-grained sand with sharp-crested, 

oscillatory ripples (water depth, 25 m). Abiotic complexity is low, biotic 

complexity is absent, and biocover is high. Biocover includes bat star (bas) and 

algae (a). Distance between lasers (red dots) is 15 cm.

a

bas

1 Cam18_Tape22 Image 1444 -26m 15 cm

Figure 3B. Digital still photograph no. C1 (see fig. 3A for location). 

Unconsolidated, fine- to medium-grained sand with sharp-crested, oscillatory 

ripples and varying amounts of scattered shells (water depth, 26 m). Abiotic 

complexity is low, biotic complexity is absent, and biocover is low. Distance 

between lasers (red dots) is 15 cm.

^_

^_

^_

^_

^_

^_

^_

^_

B8 B7

B6

B5

B4

B3

B2

B1

Box B Figure 2A. Detailed view of seafloor character mapped 

west of city of Half Moon Bay, approximately 4.5 km 

offshore (see Box B, on map, for location), showing 

locations of periodic real-time video observations (dots) 

and digital still photographs (stars; see figs. 2B through 

2I) from camera line CAM16, cruise F–3–07–NC.

8 Cam16_Tape21 Image 1692 -31m 15 cm

Figure 2I. Digital still photograph no. B8 (see fig. 2A for location). 

Mixed rounded to subrounded boulders and rugose rock outcrop 

(water depth, 31 m). Abiotic complexity is high, biotic complexity 

is absent, and biocover is high. Biocover includes bat stars (bas), 

cup corals (cc), and tubeworms (tw). Distance between lasers 

(green dots) is 15 cm. 

7 Cam16_Tape21 Image 1664 -30m 15 cm

cc

n

sa

beg

Figure 2H. Digital still photograph no. B7 (see fig. 2A for 

location). Interface between rock and sand with shell hash 

(water depth, 30 m). Abiotic complexity is high, biotic 

complexity is absent, and biocover is moderate. Biocover 

includes cup corals (cc), nudibranch (n), blackeye goby (beg), 

and sea anemone (sa). Distance between lasers (red dots are 

just out of view in this image but are visible in previous video 

frame) is 15 cm.

6 Cam16_Tape21 Image 1636 -33m 15 cm

Figure 2G. Digital still photograph no. B6 (see fig. 2A for location). 

Unconsolidated, fine- to medium-grained sand with sharp-crested, 

oscillatory ripples (water depth, 33 m). Abiotic complexity is low, 

biotic complexity is absent, and biocover is low. Distance between 

lasers (pairs of red and green dots) is 15 cm.

5 Cam16_Tape20 Image 1620 -33m 15 cm

cc

bs

tw

Figure 2F. Digital still photograph no. B5 (see fig. 2A for 

location). Interface between mixed boulders with cobbles and 

sand with shell hash (water depth, 33 m). Abiotic complexity is 

moderate, biotic complexity is absent, and biocover is high. 

Biocover includes cup corals (cc), brittle star arms (bs), and 

tubeworms (tw). Distance between lasers (green dots) is 15 

cm.

4 Cam16_Tape20 Image 1606 -34m 15 cm

Figure 2E. Digital still photograph no. B4 (see fig. 2A for location). 

Mixed rounded to subrounded boulders and cobbles overlying 

rock (water depth, 34 m). Abiotic complexity is moderate to high, 

biotic complexity is absent, and biocover is high. Biocover 

includes bat star (bas), cup corals (cc), and encrusting sponges 

(spo). Distance between lasers (green dots) is 15 cm.

cc

spo

bas

3 Cam16_Tape20 Image 1598 -35 m 15 cm

cc

Figure 2D. Digital still photograph no. B3 (see fig. 2A for 

location). Mixed boulders and cobbles with sand and scattered 

shells (water depth, 35 m). Abiotic complexity is low, biotic 

complexity is absent, and biocover is moderate. Biocover 

includes cup corals (cc), brittle star arms (bs), and encrusting 

sponge (spo). Distance between lasers (green dots) is 15 cm.

bs

spo

sp

bra

2 Cam16_Tape20 Image 1526 -38m 15 cm

Figure 2C. Digital still photograph no. B2 (see fig. 2A for location). 

Unconsolidated, fine- to medium-grained sand with 

sharp-crested, oscillatory ripples in confused pattern (water 

depth, 38 m). Abiotic complexity is low, biotic complexity is 

absent, and biocover is low. Biocover includes sea pen (sp), 

octopus (o), and brachiopod (bra). Distance between lasers (red 

dots) is 15 cm.

cc

tw

bas

o

cc

1 Cam16_Tape20 Image 1491 -37m 15 cm

Figure 2B. Digital still photograph no. B1 (see fig. 2A for location). 

Mixed boulders and cobbles with sand and scattered shells 

(water depth, 37 m). Abiotic complexity is moderate, biotic 

complexity is absent, and biocover is moderate. Biocover 

includes cup corals (cc) and tubeworm (tw). Distance between 

lasers (green dots) is 15 cm.

tw

^_

^_

^_

^_ A4

A3

A2

A1

Box A

Figure 1E. Digital still photograph no. A4 (see fig. 1A for location). Unconsolidated, 

fine- to medium-grained sand with sharp-crested oscillatory ripples (water depth, 

48 m). Abiotic complexity is low, biotic complexity is absent, and biocover is low. 

Distance between lasers (red dots) is 15 cm.

4 Cam22_Tape25 Image 1493 -48 15 cm 3 Cam22_Tape25 Image 1482 -49m 15 cm

Figure 1D. Digital still photograph no. A3 (see fig. 1A for location). 

Unconsolidated, fine- to medium-grained sand with oscillatory ripples (water 

depth, 49 m). Abiotic complexity is low, biotic complexity is absent, and 

biocover is low. Distance between lasers (red dots) is 15 cm.

2 15 cm Cam22_Tape25 Image 1478 -49m

Figure 1C. Digital still photograph no. A2 (see fig. 1A for location). 

Unconsolidated, medium- to coarse-grained sand with oscillatory ripples 

(water depth, 49 m). Abiotic complexity is low, biotic complexity is absent, and 

biocover is low. Distance between lasers (red dots) is 15 cm. 

1 Cam22_Tape25 Image 1474 -48m 15 cm

Figure 1B. Digital still photograph no. A1 (see fig. 1A for location). 

Unconsolidated, medium- to coarse-grained sand with oscillatory ripples 

(water depth, 48 m). Abiotic complexity is low, biotic complexity is absent, and 

biocover is low. Distance between lasers (red dots) is 15 cm.

Figure 1A. Detailed view of seafloor character mapped west of Pillar Point, approximately 5 km 

offshore (see Box A, on map, for location), showing locations of periodic real-time video 

observations (dots) and digital still photographs (stars; see figs. 1B through 1E) from camera 

line CAM22, cruise F–3–07–NC.

ONE MILE = 0.869 NAUTICAL MILES

1 0.5 0 1 KILOMETER

7000 3500 0 7000 FEET

2 1 0 2 MILES

14°

SCALE 1:50 000

APPROXIMATE MEAN

DECLINATION, 2014

MAGNETIC 

 NORTH

TRUE NORTH

Seafloor-character map simplified from map on sheet 

5, this report. Video observations recorded and digital 

still photographs taken in 2007-2008. Sample localities 

from usSEABED (Reid and others, 2006)

GIS database and digital cartography by Nadine E. 

Golden and Eleyne L. Phillips

Manuscript approved for publication October 2, 2014

Onshore elevation data collected by Photoscience in 2005 for 

U.S. Geological Survey and County of San Mateo. Offshore 

shaded-relief bathymetry from map on sheet 2, this report. 

California's State Waters limit from NOAA Office of Coast 

Survey

Universal Transverse Mercator projection, Zone 10N

NOT INTENDED FOR NAVIGATIONAL USE

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Pillar

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D

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A

122°25'

122°25'

122°30'

122°30'

122°35'

122°35'

37°30' 37°30'

37°25' 37°25'

Open-File Report 2014–1214

Sheet 6 of 10

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey