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/sim/3281/

Suggested Citation: Kvitek, R.G., Dartnell, P., Phillips, E.L., and Cochrane, G.R., 2013, Shaded-relief bathymetry, Offshore of Santa 

Barbara map area, California, sheet 2 in Johnson, S.Y., Dartnell, P., Cochrane, G.R., Golden, N.E., Phillips, E.L., Ritchie, A.C., Greene, 

H.G., Krigsman, L.M., Kvitek, R.G., Dieter, B.E., Endris, C.A., Seitz, G.G., Sliter, R.W., Erdey, M.D., Gutierrez, C.I., Wong, F.L., Yoklavich, 

M.M., Draut, A.E., Hart, P.E., and Conrad, J.E. (S.Y. Johnson and S.A. Cochran, eds.), California State Waters Map Series—Offshore of 

Santa Barbara, California: U.S. Geological Survey Scientific Investigations Map 3281, pamphlet 45 p., 11 sheets, scale 1:24,000, 

http://dx.doi.org/10.3133/sim3281.

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3281

US Army Corps

of Engineers

Figure 1. Map showing areas of multibeam-echosounder and bathymetric-sidescan surveys (pink shading), 

bathymetric- and topographic-lidar surveys (orange diagonal lines), and publicly available interferometric 

synthetic aperture radar (ifSAR) topography (yellow shading). Also shown are data-collecting agencies 

(CSUMB, California State University, Monterey Bay, Seafloor Mapping Lab; USACE, U.S. Army Corps of 

Engineers; USGS, U.S. Geological Survey) and dates of surveys if known.

Santa Barbara

USGS, 2006

USGS, 

 2005 USGS, 2006

CSUMB, 2007

119°45' 119°40'

34°25'

34°20'

USACE, 2009

20

DISCUSSION 

This shaded-relief bathymetry map of the Offshore of Santa Barbara map area in southern California was 

generated from bathymetry data collected by California State University, Monterey Bay (CSUMB), by the 

U.S. Geological Survey (USGS), and by Fugro Pelagos for the U.S. Army Corps of Engineers (USACE) Joint 

Lidar Bathymetry Technical Center of Expertise (fig. 1). Most of the offshore area was mapped by CSUMB in 

the summer of 2007, using a 244-kHz Reson 8101 multibeam echosounder. Smaller areas in the far-east 

nearshore, as well as further offshore to the west and in the southeast outer shelf area, were mapped by the 

USGS in 2005 and 2006, using a combination of 468-kHz (2005) and 117-kHz (2006) SEA (AP) Ltd. 

SWATHplus-M phase-differencing sidescan sonars. The nearshore bathymetry and coastal topography were 

mapped for USACE by Fugro Pelagos in 2009, using the SHOALS-1000T bathymetric-lidar and Leica ALS60 

topographic-lidar systems. These mapping missions combined to collect bathymetry from the 0-m isobath to 

beyond the 3-nautical-mile limit of California’s State Waters.

During the CSUMB mapping mission, an Applanix position and motion compensation system (POS/MV) 

was used to accurately position the vessel during data collection, and it also accounted for vessel motion such 

as heave, pitch, and roll (position accuracy, ±2 m; pitch, roll, and heading accuracy, ±0.02°; heave accuracy, 

±5%, or 5 cm). NavCom 2050 GPS receiver (CNAV) data were used to account for tidal-cycle fluctuations, 

and sound-velocity profiles were collected with an Applied Microsystems (AM) SVPlus sound velocimeter. 

Soundings were corrected for vessel motion using the Applanix POS/MV data, for variations in water-column 

sound velocity using the AM SVPlus data, and for variations in water height (tides) using vertical-position 

data from the CNAV receiver. 

During the USGS mapping missions, differential GPS (DGPS) data were combined with measurements 

of vessel motion (heave, pitch, and roll) in a CodaOctopus F180 attitude-and-position system to produce a 

high-precision vessel-attitude packet. This packet was transmitted to the acquisition software in real time and 

combined with instantaneous sound-velocity measurements at the transducer head before each ping. The 

returned samples were projected to the seafloor using a ray-tracing algorithm that works with previously 

measured sound-velocity profiles. Statistical filters were applied to the raw samples that discriminate the 

seafloor returns (soundings) from unintended targets in the water column. Finally, the soundings were 

converted into 2-m-resolution bathymetric-surface-model grids.

During the Fugro Pelagos mapping mission that was completed as part of the National Coastal Mapping 

Program of USACE, the Leica ALS60 topographic-lidar and the SHOALS-1000T bathymetric-lidar systems 

were mounted on an aircraft that flew survey lines at an altitude of 300 to 400 m (bathymetry) and 300 to 

1,200 m (topography), at speeds of between 135 and 185 knots. The ALS60 system collected data at a maximum pulse rate of 200 kHz, and the SHOALS system collected data at 1 kHz. Information on aircraft position, 

velocity, and acceleration were collected using the Novatel and POS A/V 410 systems (SHOALS) and the 

onboard GPS/IMU system (ALS60). Aircraft-position data were processed using POSPac software, and the 

results were combined with the lidar data to produce 3-D positions for each lidar shot. Various commercial and 

proprietary software packages were used to clean the data, to convert all valid data from ellipsoid to orthometric heights, and to export the data as a series of topography and bathymetry ASCII files. 

Soundings from the different mapping missions were converted into individual 2-m-resolution 

bathymetric-surface-model grids. The individual bathymetric-surface models were then merged into one 

overall bathymetric-surface model and clipped to the boundary of the map area. An illumination having an 

azimuth of 300° and from 45° above the horizon was then applied to the bathymetric surface to create the 

shaded-relief imagery. Bathymetric contours were generated from a modified 10-m-resolution bathymetric 

surface where a smooth arithmetic mean convolution function that assigns a weight of one-ninth to each cell in 

a 3-pixel by 3-pixel matrix was applied iteratively to the surface ten times.

The onshore-area image was generated by applying the same illumination (azimuth of 300° and from 45° 

above the horizon) to the coastal airborne topographic-lidar data, as well as to publicly available, 3-m-resolution, 

interferometric synthetic aperture radar (ifSAR) data, available from National Oceanic and Atmospheric 

Administration (NOAA) Coastal Service Center’s Digital Coast, at http://csc-s-maps-q.csc.noaa.gov/

dataviewer/viewer.html (last accessed April 5, 2011).

EXPLANATION

Amount of illumination

Illuminated (facing false sun)

In shadow (facing away from false sun)

Direction of illumination from false sun—Position of false sun is at 300° azimuth, 45° above 

horizon [arrow included in explanation for illustration purposes only; not shown on map]

 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

Bathymetric contour (in meters)—Derived from modified 10-m-resolution bathymetry grid. 

Contour interval: 10 m

CALIF.

0 4 8 Nautical Miles

Kilometers 0 5 10

120° 119°40' 119°20' 119°

34°

34°20'

MAP LOCATION

Ventura

Santa Barbara

Anacapa

Island

Santa Cruz Island Santa Rosa Island

Santa Barbara Channel

Limit of California’s

State Waters

Area of

Map

1

California State University, Monterey Bay, Seafloor Mapping Lab;

2

U.S. Geological Survey

Shaded-Relief Bathymetry, Offshore of Santa Barbara Map Area, California

By

Rikk G. Kvitek,1 Peter Dartnell,2 Eleyne L. Phillips,2 and Guy R. Cochrane2

2013 

ONE MILE = 0.869 NAUTICAL MILES

BATHYMETRIC CONTOUR INTERVAL 10 METERS

1 .5 0 1 KILOMETER

1000 0 1000 2000 3000 4000 5000 6000 7000 FEET

1 1/2 0 1 MILE

SCALE 1:24 000

APPROXIMATE MEAN

DECLINATION, 2013

MAGNETIC NORTH

12 / ° 1 2

TRUE NORTH

Shaded-relief bathymetry by Peter Dartnell, 2012 (data collected by U.S. Geological 

Survey in 2005 and 2006, by California State University, Monterey Bay, Seafloor 

Mapping Lab in 2007, and by U.S. Army Corps of Engineers in 2009). Bathymetric 

contours by Andrew C. Ritchie, 2011

GIS database and digital cartography by Nadine E. Golden and Eleyne L. Phillips

Edited by Taryn A. Lindquist

Manuscript approved for publication December 12, 2013

Onshore elevation data from NOAA Coastal Services Center (data collected by 

EarthData International in 2002-2003) and from U.S. Army Corps of Engineers 

(data collected by Fugro Pelagos in 2009). California's State Waters limit from 

NOAA Office of Coast Survey

Universal Transverse Mercator projection, Zone 11N

NOT INTENDED FOR NAVIGATIONAL USE

20

10

40

30

60

50

80

70

50

60

50

Santa Barbara

119°45' 119°40'

34°25'

34°20'

34°25'

34°20'

119°45' 119°40'

Scientific Investigations Map 3281

Sheet 2 of 11

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey