This part of DS 781 presents data for the bathymetry map of the Offshore of Santa Barbara map area, California. The raster data file is included in "Bathymetry_OffshoreSantaBarbara.zip," which is accessible from https://pubs.usgs.gov/ds/781/OffshoreSantaBarbara/data_catalog_OffshoreSantaBarbara.html. These data accompany the pamphlet and map sheets of 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.E., 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.), 2013, California State Waters Map Series—Offshore of Santa Barbara, California: U.S. Geological Survey Scientific Investigations Map 3281, 45 p., 11 sheets, scale 1:24,000, https://doi.org/10.3133/sim3281. The bathymetry map of the Offshore of Santa Barbara map area, California, was generated from bathymetry da ...

Bathymetry data were collected by the U.S. Geological Survey in July 2008 in the northern Santa Barbara Channel in southern California. Data were collected aboard the R/V Parke Snavely, during USGS Field Activity S-9-08-SC, using a bathymetric sidescan system.

Data layer containing 10 meter bathymetric contours for the Channel Islands National Marine Sanctuary and Santa Barbara Bay. Data are derived from 1:250,000-scale National Oceanic and Atmospheric Administration (NOAA) charts and Monterey Bay Aquarium Research Institute (MBARI), Santa Barbara Bay Multibeam Data

description: This report presents bathymetry and acoustic backscatter data collected in July 2008 in the northern Santa Barbara Channel, California, using a bathymetric sidescan system. The report also presents a summary of the mapping effort as well as Federal Geographic Data Committee (FGDC) metadata. This metadata file describes the bathymetry data. For more information on the bathy surveys see http://walrus.wr.usgs.gov/infobank/s/s808sc/html/s-8-08-sc.meta.html -sf.meta.html; abstract: This report presents bathymetry and acoustic backscatter data collected in July 2008 in the northern Santa Barbara Channel, California, using a bathymetric sidescan system. The report also presents a summary of the mapping effort as well as Federal Geographic Data Committee (FGDC) metadata. This metadata file describes the bathymetry data. For more information on the bathy surveys see http://walrus.wr.usgs.gov/infobank/s/s808sc/html/s-8-08-sc.meta.html -sf.meta.html

These metadata describe bathymetry data collected during an October 2016 multibeam-echosounder survey of the northern portion of the Santa Barbara Channel, California. Data were collected and processed by the the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) with fieldwork activity number 2016-666-FA. The bathymetry data are provided as a GeoTIFF image.

description: Substrate was classified using the method of (Cochrane and Lafferty, 2002) for this study. Sea floor character derived from towed sidescan sonar data is available for the mainland coast within the study area from USGS online publications (Cochrane and others, 2003; Cochrane and others, 2005). The number of substrate classes was reduced because rugosity could not be derived for all areas due to the lack of bathymetry data for other data sets used in the study. References Cited: Cochrane, G.R., Nasby, N.M., Reid, J.A., Waltenberger, B., Lee, K.M., 2003, Nearshore Benthic Habitat GIS for the Channel Islands National Marine Sanctuary and Southern California State Fisheries Reserves Volume 1: U.S. Geological Survey Open-File Report 03-85, http://pubs.usgs.gov/of/2003/0085/. Cochrane, G.R., and Lafferty, K.D., 2002, Use of acoustic classification of sidescan sonar data for mapping benthic habitat in the Northern Channel Islands, California: Continental Shelf Research, v. 22, p. 683-690. Cochrane, G.R., Conrad, J.E., Reid, J.A., Fangman, S., Golden, N.E., 2005, The Nearshore Benthic Habitat GIS for the Channel Islands National Marine Sanctuary and Southern California State Fisheries Reserves, Volume II; Version 1.0: U.S. Geological Survey Open-File Report 2005-1170, http://pubs.usgs.gov/of/2005/1170/.; abstract: Substrate was classified using the method of (Cochrane and Lafferty, 2002) for this study. Sea floor character derived from towed sidescan sonar data is available for the mainland coast within the study area from USGS online publications (Cochrane and others, 2003; Cochrane and others, 2005). The number of substrate classes was reduced because rugosity could not be derived for all areas due to the lack of bathymetry data for other data sets used in the study. References Cited: Cochrane, G.R., Nasby, N.M., Reid, J.A., Waltenberger, B., Lee, K.M., 2003, Nearshore Benthic Habitat GIS for the Channel Islands National Marine Sanctuary and Southern California State Fisheries Reserves Volume 1: U.S. Geological Survey Open-File Report 03-85, http://pubs.usgs.gov/of/2003/0085/. Cochrane, G.R., and Lafferty, K.D., 2002, Use of acoustic classification of sidescan sonar data for mapping benthic habitat in the Northern Channel Islands, California: Continental Shelf Research, v. 22, p. 683-690. Cochrane, G.R., Conrad, J.E., Reid, J.A., Fangman, S., Golden, N.E., 2005, The Nearshore Benthic Habitat GIS for the Channel Islands National Marine Sanctuary and Southern California State Fisheries Reserves, Volume II; Version 1.0: U.S. Geological Survey Open-File Report 2005-1170, http://pubs.usgs.gov/of/2005/1170/.

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic DEMs are used to support tsunami forecasting and warning efforts at the NOAA Center for Tsunami Research, Pacific Marine Environmental Laboratory (PMEL). The DEMs are part of the tsunami forecast system SIFT (Short-term Inundation Forecasting for Tsunamis) currently being developed by PMEL for the NOAA Tsunami Warning Centers, and are used in the MOST (Method of Splitting Tsunami) model developed by PMEL to simulate tsunami generation, propagation, and inundation. Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. National Ocean Service (NOS), the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of Mean High Water (MHW) and horizontal datum of World Geodetic System 1984 (WGS84). Grid spacings for the DEMs range from 1/3 arc-second (~10 meters) to 3 arc-seconds (~90 meters).

description: This Data Release contains GIS data generated by USGS for use in a BOEM funded project to compare natural rockfish nursery habitat to habitat created by manmade structures in the eastern Santa Barbara Channel. The contours were created from published Data Elevation Models of Carignan and others (2009) and Dartnell and others (2012). Contours were generated using the ESRI Contour tool in spatial analyst. The contour interval is 10 meters. The contours were clipped to exclude areas outside the BOEM rockfish nurseries study area.; abstract: This Data Release contains GIS data generated by USGS for use in a BOEM funded project to compare natural rockfish nursery habitat to habitat created by manmade structures in the eastern Santa Barbara Channel. The contours were created from published Data Elevation Models of Carignan and others (2009) and Dartnell and others (2012). Contours were generated using the ESRI Contour tool in spatial analyst. The contour interval is 10 meters. The contours were clipped to exclude areas outside the BOEM rockfish nurseries study area.

In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within California’s State Waters. The program supports a large number of coastal-zone- and ocean-management issues, including the California Marine Life Protection Act (MLPA) (California Department of Fish and Wildlife, 2008), which requires information about the distribution of ecosystems as part of the design and proposal process for the establishment of Marine Protected Areas. A focus of CSMP is to map California’s State Waters with consistent methods at a consistent scale. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data (the undersea equivalent of satellite remote-sensing data in terrestrial mapping), acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. It is emphasized that the more interpretive habitat and geology data rely on the integration of multiple, new high-resolution datasets and that mapping at small scales would not be possible without such data. This approach and CSMP planning is based in part on recommendations of the Marine Mapping Planning Workshop (Kvitek and others, 2006), attended by coastal and marine managers and scientists from around the state. That workshop established geographic priorities for a coastal mapping project and identified the need for coverage of “lands” from the shore strand line (defined as Mean Higher High Water; MHHW) out to the 3-nautical-mile (5.6-km) limit of California’s State Waters. Unfortunately, surveying the zone from MHHW out to 10-m water depth is not consistently possible using ship-based surveying methods, owing to sea state (for example, waves, wind, or currents), kelp coverage, and shallow rock outcrops. Accordingly, some of the data presented in this series commonly do not cover the zone from the shore out to 10-m depth. This data is part of a series of online U.S. Geological Survey (USGS) publications, each of which includes several map sheets, some explanatory text, and a descriptive pamphlet. Each map sheet is published as a PDF file. Geographic information system (GIS) files that contain both ESRI ArcGIS raster grids (for example, bathymetry, seafloor character) and geotiffs (for example, shaded relief) are also included for each publication. For those who do not own the full suite of ESRI GIS and mapping software, the data can be read using ESRI ArcReader, a free viewer that is available at http://www.esri.com/software/arcgis/arcreader/index.html (last accessed September 20, 2013). The California Seafloor Mapping Program is a collaborative venture between numerous different federal and state agencies, academia, and the private sector. CSMP partners include the California Coastal Conservancy, the California Ocean Protection Council, the California Department of Fish and Wildlife, the California Geological Survey, California State University at Monterey Bay’s Seafloor Mapping Lab, Moss Landing Marine Laboratories Center for Habitat Studies, Fugro Pelagos, Pacific Gas and Electric Company, National Oceanic and Atmospheric Administration (NOAA, including National Ocean Service–Office of Coast Surveys, National Marine Sanctuaries, and National Marine Fisheries Service), U.S. Army Corps of Engineers, the Bureau of Ocean Energy Management, the National Park Service, and the U.S. Geological Survey. These web services for the Santa Barbara Channel map area includes data layers that are associated to GIS and map sheets available from the USGS CSMP web page at https://walrus.wr.usgs.gov/mapping/csmp/index.html. Each published CSMP map area includes a data catalog of geographic information system (GIS) files; map sheets that contain explanatory text; and an associated descriptive pamphlet. This web service represents the available data layers for this map area. Data was combined from different sonar surveys to generate a comprehensive high-resolution bathymetry and acoustic-backscatter coverage of the map area. These data reveal a range of physiographic including exposed bedrock outcrops, large fields of sand waves, as well as many human impacts on the seafloor. To validate geological and biological interpretations of the sonar data, the U.S. Geological Survey towed a camera sled over specific offshore locations, collecting both video and photographic imagery; these “ground-truth” surveying data are available from the CSMP Video and Photograph Portal at https://doi.org/10.5066/F7J1015K. The “seafloor character” data layer shows classifications of the seafloor on the basis of depth, slope, rugosity (ruggedness), and backscatter intensity and which is further informed by the ground-truth-survey imagery. The “potential habitats” polygons are delineated on the basis of substrate type, geomorphology, seafloor process, or other attributes that may provide a habitat for a specific species or assemblage of organisms. Representative seismic-reflection profile data from the map area is also include and provides information on the subsurface stratigraphy and structure of the map area. The distribution and thickness of young sediment (deposited over the past about 21,000 years, during the most recent sea-level rise) is interpreted on the basis of the seismic-reflection data. The geologic polygons merge onshore geologic mapping (compiled from existing maps by the California Geological Survey) and new offshore geologic mapping that is based on integration of high-resolution bathymetry and backscatter imagery seafloor-sediment and rock samplesdigital camera and video imagery, and high-resolution seismic-reflection profiles. The information provided by the map sheets, pamphlet, and data catalog has a broad range of applications. High-resolution bathymetry, acoustic backscatter, ground-truth-surveying imagery, and habitat mapping all contribute to habitat characterization and ecosystem-based management by providing essential data for delineation of marine protected areas and ecosystem restoration. Many of the maps provide high-resolution baselines that will be critical for monitoring environmental change associated with climate change, coastal development, or other forcings. High-resolution bathymetry is a critical component for modeling coastal flooding caused by storms and tsunamis, as well as inundation associated with longer term sea-level rise. Seismic-reflection and bathymetric data help characterize earthquake and tsunami sources, critical for natural-hazard assessments of coastal zones. Information on sediment distribution and thickness is essential to the understanding of local and regional sediment transport, as well as the development of regional sediment-management plans. In addition, siting of any new offshore infrastructure (for example, pipelines, cables, or renewable-energy facilities) will depend on high-resolution mapping. Finally, this mapping will both stimulate and enable new scientific research and also raise public awareness of, and education about, coastal environments and issues. Web services were created using an ArcGIS service definition file. The ArcGIS REST service and OGC WMS service include all Santa Barbara Channel map area data layers. Data layers are symbolized as shown on the associated map sheets.

This data release presents data for 5-m resolution multibeam-bathymetry data of the northern Channel Islands region, southern California. The raster data files are included in "USGS_NChannelIslands_NorthArea_Bathy_5m.zip" and "USGS_NChannelIslands_SouthArea_Bathy_5m.zip," which are accessible from http://dx.doi.org/10.5066/F7S46Q1J. In 2004 The U.S. Geological Survey, Pacific Coastal and Marine Science Center collected multibeam-bathymetry and acoustic-backscatter data in the northern Channel Islands region, southern California. The region was mapped aboard the R/V Ewing using a Kongsberg Simrad EM-1002 multibeam echosounder. These data were previously published on-line at http://pubs.usgs.gov/of/2005/1153/#metadata. In this data release the data have been reprocessed to a finer spatial resolution (5-m versus 15-m) using more modern processing techniques. Due to the large file sizes the entire survey area is provided as two ASCIIRaster files(USGS_NChannelIslands_NorthArea_Bathy_5m.zip and USGS_NChannelIslands_SouthArea_Bathy_5m.zip).

This part of DS 781 presents data for the depth-to-transition (the depth to the bedrock at the Last Glacial Maximum) map of the Santa Barbara Channel, California, region. The raster data file is included in "DepthToTransition_SantaBarbaraChannel.zip," which is accessible from https://pubs.usgs.gov/ds/781/SantaBarbaraChannel/data_catalog_SantaBarbaraChannel.html. As part of the USGS's California Seafloor Mapping Project, a 50-m-resolution grid of depth to the transgressive surface of the Last Glacial Maximum within California State Waters between Refugio Beach and the Hueneme Canyon and vicinity map area was generated from seismic-reflection data collected in 2007 and 2008 (USGS activities Z-3-07-SC and S-7-08-SC), supplemented with outcrop and geologic structure data from DS 781. The resulting sediment-thickness grid was subtracted from regional bathymetry to determine the depth to the last glacial maximum transitional surface. The resulting grid covers an area of approximately 60 ...

This data release presents data for 5-m resolution multibeam-bathymetry data of the northern Channel Islands region, southern California. The raster data files are included in "USGS_NChannelIslands_NorthArea_Bathy_5m.zip" and "USGS_NChannelIslands_SouthArea_Bathy_5m.zip," which are accessible from https://doi.org/10.5066/F7S46Q1J. In 2004 The U.S. Geological Survey, Pacific Coastal and Marine Science Center collected multibeam-bathymetry and acoustic-backscatter data in the northern Channel Islands region, southern California. The region was mapped aboard the R/V Ewing using a Kongsberg Simrad EM-1002 multibeam echosounder. These data were previously published on-line at http://pubs.usgs.gov/of/2005/1153/. In this data release the data have been reprocessed to a finer spatial resolution (5-m versus 15-m) using more modern processing techniques. Due to the large file sizes the entire survey area is provided as two ASCIIRaster files(USGS_NChannelIslands_NorthArea_Bathy_5m.zip and USGS_NChannelIslands_SouthArea_Bathy_5m.zip).

This part of DS 781 presents data for the map showing the predicted distribution of tall sea pens in the Santa Barbara Channel, California, region. The raster data file is included in "TallSeaPens_SantaBarbaraChannel.zip," which is accessible from https://pubs.usgs.gov/ds/781/SantaBarbaraChannel/data_catalog_SantaBarbaraChannel.html. Presence-absence data of benthic macro-invertebrates and associated habitat (that is, sediment type and depth) were collected using a towed camera sled in selected areas along the coast off southern California during a ground-truth observation cruise conducted by the U.S. Geological Survey and NOAA National Marine Fisheries Service for the California Seafloor Mapping Program. Benthic community structure was determined from 35 video towed-camera transects within California's State Waters 3-nautical-mile limit in the Santa Barbara Channel. These transects produced a total of 923 10-second observations from the Offshore of Refugio Beach map area (34.5 degrees N., 120.1 degrees W.) to the Hueneme Canyon and vicinity map area (34.1 degrees N., 119.2 degrees W.). Presence-absence data were collected for 29 benthic, structure-forming nonmobile taxa. Using this information, generalized linear models (GLMs) were developed to predict the probability of occurrence of five commonly observed taxa (cup corals, hydroids, short and tall sea pens, and brittle stars in the sediment) in five map areas within the Santa Barbara Channel (SBC). A sixth map area (Offshore of Carpinteria) was not modeled owing to insufficient data. The analysis demonstrates that the community structure for the five map areas can be divided into three statistically distinct groups: (1) the Hueneme Canyon and vicinity and the Offshore of Ventura map areas; (2) the Offshore of Santa Barbara and the Offshore of Coal Oil Point map areas; and (3) the Offshore of Refugio Beach map area. These three distinct groups are the main reason that the probability for each taxa can be so dramatically different within one predictive-distribution map area. The five most frequently observed benthic macro-invertebrate taxa were selected for these predictive-distribution grids. Presence-absence data for each selected invertebrate were fit to specific generalized linear models using geographic location, depth, and seafloor character as covariates. Data for the covariates were informed by the bathymetry, seafloor character, and other ground-truth data from the different map areas of the Santa Barbara Channel region that are part of the California State Waters Map Series DS 781. Observations based on depth were limited by the capability of the towed camera sled; as a result, no predictions were made below depths of 150 m (in other words, on the continental slope or in Hueneme Canyon). Cup corals and hydroids had high predicted probabilities of occurrence in areas of hard substrata, whereas short and tall sea pens were predicted to occur in parts of the SBC that had unconsolidated and mixed sediment. Our model predicted that brittle stars would occur throughout the entire SBC on various bottom types.

This part of DS 781 presents data for the map showing the predicted distribution of hydroids in the Santa Barbara Channel, California, region. The raster data file is included in "Hydroids_SantaBarbaraChannel.zip," which is accessible from https://pubs.usgs.gov/ds/781/SantaBarbaraChannel/data_catalog_SantaBarbaraChannel.html. Presence-absence data of benthic macro-invertebrates and associated habitat (that is, sediment type and depth) were collected using a towed camera sled in selected areas along the coast off southern California during a ground-truth observation cruise conducted by the U.S. Geological Survey and NOAA National Marine Fisheries Service for the California Seafloor Mapping Program. Benthic community structure was determined from 35 video towed-camera transects within California's State Waters 3-nautical-mile limit in the Santa Barbara Channel. These transects produced a total of 923 10-second observations from the Offshore of Refugio Beach map area (34.5 degrees N., 120.1 degrees W.) to the Hueneme Canyon and vicinity map area (34.1 degrees N., 119.2 degrees W.). Presence-absence data were collected for 29 benthic, structure-forming nonmobile taxa. Using this information, generalized linear models (GLMs) were developed to predict the probability of occurrence of five commonly observed taxa (cup corals, hydroids, short and tall sea pens, and brittle stars in the sediment) in five map areas within the Santa Barbara Channel (SBC). A sixth map area (Offshore of Carpinteria) was not modeled owing to insufficient data. The analysis demonstrates that the community structure for the five map areas can be divided into three statistically distinct groups: (1) the Hueneme Canyon and vicinity and the Offshore of Ventura map areas; (2) the Offshore of Santa Barbara and the Offshore of Coal Oil Point map areas; and (3) the Offshore of Refugio Beach map area. These three distinct groups are the main reason that the probability for each taxa can be so dramatically different within one predictive-distribution map area. The five most frequently observed benthic macro-invertebrate taxa were selected for these predictive-distribution grids. Presence-absence data for each selected invertebrate were fit to specific generalized linear models using geographic location, depth, and seafloor character as covariates. Data for the covariates were informed by the bathymetry, seafloor character, and other ground-truth data from the different map areas of the Santa Barbara Channel region that are part of the California State Waters Map Series DS 781. Observations based on depth were limited by the capability of the towed camera sled; as a result, no predictions were made below depths of 150 m (in other words, on the continental slope or in Hueneme Canyon). Cup corals and hydroids had high predicted probabilities of occurrence in areas of hard substrata, whereas short and tall sea pens were predicted to occur in parts of the SBC that had unconsolidated and mixed sediment. Our model predicted that brittle stars would occur throughout the entire SBC on various bottom types.

This data set was created from processed multibeam sonar data acquired with a Reson SeaBat 7125 Multibeam Sonar system on the ROV Jason II during R/V Atlantis expedition AT18-11 conducted in 2011 (Chief Scientist: Dr. David Valentine).

This part of DS 781 presents data for the map showing the predicted distribution of cup corals in the Santa Barbara Channel, California, region. The raster data file is included in "CupCorals_SantaBarbaraChannel.zip," which is accessible from https://pubs.usgs.gov/ds/781/SantaBarbaraChannel/data_catalog_SantaBarbaraChannel.html. Presence-absence data of benthic macro-invertebrates and associated habitat (that is, sediment type and depth) were collected using a towed camera sled in selected areas along the coast off southern California during a ground-truth observation cruise conducted by the U.S. Geological Survey and NOAA National Marine Fisheries Service for the California Seafloor Mapping Program. Benthic community structure was determined from 35 video towed-camera transects within California's State Waters 3-nautical-mile limit in the Santa Barbara Channel. These transects produced a total of 923 10-second observations from the Offshore of Refugio Beach map area (34.5 degrees N., 120.1 degrees W.) to the Hueneme Canyon and vicinity map area (34.1 degrees N., 119.2 degrees W.). Presence-absence data were collected for 29 benthic, structure-forming nonmobile taxa. Using this information, generalized linear models (GLMs) were developed to predict the probability of occurrence of five commonly observed taxa (cup corals, hydroids, short and tall sea pens, and brittle stars in the sediment) in five map areas within the Santa Barbara Channel (SBC). A sixth map area (Offshore of Carpinteria) was not modeled owing to insufficient data. The analysis demonstrates that the community structure for the five map areas can be divided into three statistically distinct groups: (1) the Hueneme Canyon and vicinity and the Offshore of Ventura map areas; (2) the Offshore of Santa Barbara and the Offshore of Coal Oil Point map areas; and (3) the Offshore of Refugio Beach map area. These three distinct groups are the main reason that the probability for each taxa can be so dramatically different within one predictive-distribution map area. The five most frequently observed benthic macro-invertebrate taxa were selected for these predictive-distribution grids. Presence-absence data for each selected invertebrate were fit to specific generalized linear models using geographic _location, depth, and seafloor character as covariates. Data for the covariates were informed by the bathymetry, seafloor character, and other ground-truth data from the different map areas of the Santa Barbara Channel region that are part of the California State Waters Map Series DS 781. Observations based on depth were limited by the capability of the towed camera sled; as a result, no predictions were made below depths of 150 m (in other words, on the continental slope or in Hueneme Canyon). Cup corals and hydroids had high predicted probabilities of occurrence in areas of hard substrata, whereas short and tall sea pens were predicted to occur in parts of the SBC that had unconsolidated and mixed sediment. Our model predicted that brittle stars would occur throughout the entire SBC on various bottom types.

This part of SIM 3281 presents data for the bathymetry and shaded-relief maps (see sheets 1, 2, SIM 3281) of the Offshore of Santa Barbara map area, California. The raster data file for the bathymetry map is included in "Bathymetry_OffshoreSantaBarbara.zip." The raster data file for the shaded-relief map is included in "BathymetryHS_OffshoreSantaBarbara.zip." Both are accessible from http://pubs.usgs.gov/ds/781/OffshoreSantaBarbara/data_catalog_OffshoreSantaBarbara.html. The bathymetry and shaded-relief maps of the Offshore of Santa Barbara map area, California, were generated from bathymetry data collected by California State University, Monterey Bay, Seafloor Mapping Lab (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. 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. All these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters. NOTE: The horizontal datum of this bathymetry data (NAD83) differs from the horizontal datum of other layers in this SIM (WGS84). Some bathymetry grids within this map area were projected horizontally from WGS84 to NAD83 using ESRI tools to be more consistent with the vertical reference of the North American Vertical Datum of 1988 (NAVD88).

This data release presents data for 5-m resolution acoustic-backscatter data of the northern Channel Islands region, southern California. The raster data files are included in "USGS_NChannelIslands_NorthArea_Backscatter_5m.zip" and "USGS_NChannelIslands_SouthArea_Backscatter_5m.zip," which are accessible from https://doi.org/10.5066/F7S46Q1J. In 2004 the U.S. Geological Survey, Pacific Coastal and Marine Science Center collected multibeam-bathymetry and acoustic-backscatter data in the northern Channel Islands region, southern California. The region was mapped aboard the R/V Ewing using a Kongsberg Simrad EM-1002 multibeam echosounder. These data were previously published on-line at http://pubs.usgs.gov/of/2005/1153/. In this data release the data have been reprocessed to a finer spatial resolution (5-m versus 15-m) using more modern processing techniques. Due to the large file sizes the entire survey area is provided as two ASCIIRaster files(USGS_NChannelIslands_NorthArea_Backscatter_5m.zip and USGS_NChannelIslands_SouthArea_Backscatter_5m.zip). A few survey line files in the northern region did not process and are missing from the ASCIIRaster file.

This layer is a georeferenced raster image of the depth to transition (base) map of uppermost Pleistocene and Holocene sediments in the Santa Barbara Channel in California. As part of the USGS's California State Waters Mapping Project, a 20-m grid of depth to the transgressive surface of the last glacial maximum (LGM) was generated for the areas within the 3-nautical mile limit of the channel. The depth to base of the post-LGM unit was generated by adding sediment thickness data to water depths determined by multibeam bathymetry. The resulting grid covers an area of approximately 600 sq km. The depth to the transgressive surface of the LGM ranges between 12 and 190 meters. A map that shows these data is published in Scientific Investigations Map 3225, "California State Waters Map Series--Hueneme Canyon and Vicinity, California." This layer is part of USGS Data Series 781.

Substrate was classified using the method of (Cochrane 2008) for this study multibeam sonar. Sea floor character derived from multibeam sonar data is available for the mainland coast within the study area from the California State Waters Mapping Program (Johnson and others, 2012; Johnson and others, 2013a; Johnson and others, 2013b; Johnson and others, 2013c). The number of substrate classes was reduced because rugosity could not be derived for all areas due to the lack of bathymetry data for other data sets used in the study. References Cited: Cochrane, G.R., 2008, Video-supervised classification of sonar data for mapping seafloor habitat, in Reynolds, J.R., and Greene, H.G., eds., Marine habitat mapping technology for Alaska: Fairbanks, University of Alaska, Alaska Sea Grant College Program, p. 185-194, accessed April 5, 2011, at http://doc.nprb.org/web/research/research%20pubs/615_habitat_mapping_workshop/Individual%20Chapters%20High-Res/Ch13%20Cochrane.pdf. Johnson, S.Y., Dart ...