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  1. Title: 2-Meter Bathymetric Hillshade Grid: Northern Section of North Monterey Bay, California, 2009

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    Summary: This raster dataset is a 2-meter shaded surface relief (hillshade) grid containing multibeam bathymetry data for the northern section of North Monterey Bay, California collected from a USGS Western Coastal & Marine Geology survey of the Monterey Bay area from Año Nuevo to Moss Landing. These data were acquired between August 13- September 3, 2009 (field activity S-7-09-MB), from Point Año Nuevo south to Table Rock, as well as a block west of Soquel Canyon; and between October 12 - December 16, 2009 (field activity S-10-09-MB), surveying between Table Rock and Moss Landing. Habitat analyses and final products derived from multibeam bathymetry data were handled by the Seafloor Mapping Lab at CSUMB. This layer was created as part of the California Seafloor Mapping Project. Marine data offered here represent the efforts of a comprehensive state waters mapping program for California launched by the California State Coastal Conservancy, Ocean Protection Council, Department of Fish and Game, and the NOAA National Marine Sanctuary Program. The ultimate goal is the creation of a high-resolution 1:24,000 scale geologic and habitat base map series covering all of California's 14,500 km2 state waters out to the 3 mile limit, and support of the state's Marine Life Protection Act Initiative (MLPA) goal to create a statewide network of Marine Protected Areas (MPAs). This statewide project requires, involves and leverages expertise from industry, resource management agencies and academia. The tiered mapping campaign involves the use of state-of-the-art sonar, LIDAR (aerial laser) and video seafloor mapping technologies; computer aided classification and visualization; expert geologic and habitat interpretations codified into strip maps spanning California's land/sea boundary; and the creation of an online, publicly accessible data repository for the dissemination of all mapping products. USGS Western Coastal and Marine Geology Program and Seafloor Mapping Lab. (2010). 2-Meter Bathymetric Hillshade Grid: Northern Section of North Monterey Bay, California, 2009. Seafloor Mapping Lab Available at: http://purl.stanford.edu/hc479mg3639 Raw sonar data were processed with SEA Swath Processor (version 3.05.18.04) before being cleaned and prepared for CARIS with sxpegn (build 151) by David Finlayson (USGS). Data were then imported to CARIS HIPS and SIPS (version 7.0.1.0 Service Pack 1). Within CARIS, field sheets were created to tile the data into smaller work areas, and survey lines were trimmed to optimize overlap, water column noise was removed, and data were gridded to 2m resolution using a swath angle BASE surface. Data were then exported from CARIS as ascii XYZ files and imported to ARCGIS where they were combined into a single grid. data were then exported as a single continuous ASCII grid. Bathymetry products are presented according to standard California State Mapping Project specifications, including depth-dependent resolutions of 2m for data from the 0-85m depth range, 5m for 80-250m depth range, and 10m for depths of 230-1500m. A comprehensive 5m data set was produced for the total survey coverage only if per block data exceeded 85m depth and 5m resolution products were included. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  2. Title: 2-Meter Bathymetric Slope Grid: Northern Section of North Monterey Bay, California, 2009

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    Summary: This raster dataset is a 2-meter slope grid containing multibeam bathymetry data for the northern section of North Monterey Bay, California collected from a USGS Western Coastal & Marine Geology survey of the Monterey Bay area from Año Nuevo to Moss Landing. These data were acquired between August 13- September 3, 2009 (field activity S-7-09-MB), from Point Año Nuevo south to Table Rock, as well as a block west of Soquel Canyon; and between October 12 - December 16, 2009 (field activity S-10-09-MB), surveying between Table Rock and Moss Landing. Habitat analyses and final products derived from multibeam bathymetry data were handled by the Seafloor Mapping Lab at CSUMB. This layer was created as part of the California Seafloor Mapping Project. Marine data offered here represent the efforts of a comprehensive state waters mapping program for California launched by the California State Coastal Conservancy, Ocean Protection Council, Department of Fish and Game, and the NOAA National Marine Sanctuary Program. The ultimate goal is the creation of a high-resolution 1:24,000 scale geologic and habitat base map series covering all of California's 14,500 km2 state waters out to the 3 mile limit, and support of the state's Marine Life Protection Act Initiative (MLPA) goal to create a statewide network of Marine Protected Areas (MPAs). This statewide project requires, involves and leverages expertise from industry, resource management agencies and academia. The tiered mapping campaign involves the use of state-of-the-art sonar, LIDAR (aerial laser) and video seafloor mapping technologies; computer aided classification and visualization; expert geologic and habitat interpretations codified into strip maps spanning California's land/sea boundary; and the creation of an online, publicly accessible data repository for the dissemination of all mapping products. USGS Western Coastal and Marine Geology Program and Seafloor Mapping Lab (2010). 2-Meter Bathymetric Slope Grid: Northern Section of North Monterey Bay, California, 2009. Seafloor Mapping Lab Available at: http://purl.stanford.edu/hb808tn6384 Raw sonar data were processed with SEA Swath Processor (version 3.05.18.04) before being cleaned and prepared for CARIS with sxpegn (build 151) by David Finlayson (USGS). Data were then imported to CARIS HIPS and SIPS (version 7.0.1.0 Service Pack 1). Within CARIS, field sheets were created to tile the data into smaller work areas, and survey lines were trimmed to optimize overlap, water column noise was removed, and data were gridded to 2m resolution using a swath angle BASE surface. Data were then exported from CARIS as ascii XYZ files and imported to ARCGIS where they were combined into a single grid. data were then exported as a single continuous ASCII grid. Bathymetry products are presented according to standard California State Mapping Project specifications, including depth-dependent resolutions of 2m for data from the 0-85m depth range, 5m for 80-250m depth range, and 10m for depths of 230-1500m. A comprehensive 5m data set was produced for the total survey coverage only if per block data exceeded 85m depth and 5m resolution products were included. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  3. Title: 2-Meter Bathymetric Digital Elevation Model: Southern Section of North Monterey Bay, California, 2009

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    Summary: This raster dataset is a 2-meter digital elevation model containing multibeam bathymetry data for the southern section of North Monterey Bay, California collected from a USGS Western Coastal & Marine Geology survey of the Monterey Bay area from Año Nuevo to Moss Landing. These data were acquired between August 13- September 3, 2009 (field activity S-7-09-MB), from Point Año Nuevo south to Table Rock, as well as a block west of Soquel Canyon; and between October 12 - December 16, 2009 (field activity S-10-09-MB), surveying between Table Rock and Moss Landing. Habitat analyses and final products derived from multibeam bathymetry data were handled by the Seafloor Mapping Lab at CSUMB. This layer was created as part of the California Seafloor Mapping Project. Marine data offered here represent the efforts of a comprehensive state waters mapping program for California launched by the California State Coastal Conservancy, Ocean Protection Council, Department of Fish and Game, and the NOAA National Marine Sanctuary Program. The ultimate goal is the creation of a high-resolution 1:24,000 scale geologic and habitat base map series covering all of California's 14,500 km2 state waters out to the 3 mile limit, and support of the state's Marine Life Protection Act Initiative (MLPA) goal to create a statewide network of Marine Protected Areas (MPAs). This statewide project requires, involves and leverages expertise from industry, resource management agencies and academia. The tiered mapping campaign involves the use of state-of-the-art sonar, LIDAR (aerial laser) and video seafloor mapping technologies; computer aided classification and visualization; expert geologic and habitat interpretations codified into strip maps spanning California's land/sea boundary; and the creation of an online, publicly accessible data repository for the dissemination of all mapping products. USGS Western Coastal and Marine Geology Program and Seafloor Mapping Lab. (2010). 2-Meter Bathymetric Digital Elevation Model: Southern Section of North Monterey Bay, California, 2009. Seafloor Mapping Lab Available at: http://purl.stanford.edu/qg355tf9327 Raw sonar data were processed with SEA Swath Processor (version 3.05.18.04) before being cleaned and prepared for CARIS with sxpegn (build 151) by David Finlayson (USGS). Data were then imported to CARIS HIPS and SIPS (version 7.0.1.0 Service Pack 1). Within CARIS, field sheets were created to tile the data into smaller work areas, and survey lines were trimmed to optimize overlap, water column noise was removed, and data were gridded to 2m resolution using a swath angle BASE surface. Data were then exported from CARIS as ascii XYZ files and imported to ARCGIS where they were combined into a single grid. data were then exported as a single continuous ASCII grid. Bathymetry products are presented according to standard California State Mapping Project specifications, including depth-dependent resolutions of 2m for data from the 0-85m depth range, 5m for 80-250m depth range, and 10m for depths of 230-1500m. A comprehensive 5m data set was produced for the total survey coverage only if per block data exceeded 85m depth and 5m resolution products were included. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  4. Title: 2-Meter Bathymetric Digital Elevation Model: Northern Section of North Monterey Bay, California, 2009

    Contributors:

    Summary: This raster dataset is a 2-meter digital elevation model containing multibeam bathymetry data for the northern section of North Monterey Bay, California collected from a USGS Western Coastal & Marine Geology survey of the Monterey Bay area from Año Nuevo to Moss Landing. These data were acquired between August 13- September 3, 2009 (field activity S-7-09-MB), from Point Año Nuevo south to Table Rock, as well as a block west of Soquel Canyon; and between October 12 - December 16, 2009 (field activity S-10-09-MB), surveying between Table Rock and Moss Landing. Habitat analyses and final products derived from multibeam bathymetry data were handled by the Seafloor Mapping Lab at CSUMB. This layer was created as part of the California Seafloor Mapping Project. Marine data offered here represent the efforts of a comprehensive state waters mapping program for California launched by the California State Coastal Conservancy, Ocean Protection Council, Department of Fish and Game, and the NOAA National Marine Sanctuary Program. The ultimate goal is the creation of a high-resolution 1:24,000 scale geologic and habitat base map series covering all of California's 14,500 km2 state waters out to the 3 mile limit, and support of the state's Marine Life Protection Act Initiative (MLPA) goal to create a statewide network of Marine Protected Areas (MPAs). This statewide project requires, involves and leverages expertise from industry, resource management agencies and academia. The tiered mapping campaign involves the use of state-of-the-art sonar, LIDAR (aerial laser) and video seafloor mapping technologies; computer aided classification and visualization; expert geologic and habitat interpretations codified into strip maps spanning California's land/sea boundary; and the creation of an online, publicly accessible data repository for the dissemination of all mapping products. USGS Western Coastal and Marine Geology Program and Seafloor Mapping Lab. (2010). 2-Meter Bathymetric Digital Elevation Model: Northern Section of North Monterey Bay, California, 2009. Seafloor Mapping Lab Available at: http://purl.stanford.edu/wk271cs5148 Raw sonar data were processed with SEA Swath Processor (version 3.05.18.04) before being cleaned and prepared for CARIS with sxpegn (build 151) by David Finlayson (USGS). Data were then imported to CARIS HIPS and SIPS (version 7.0.1.0 Service Pack 1). Within CARIS, field sheets were created to tile the data into smaller work areas, and survey lines were trimmed to optimize overlap, water column noise was removed, and data were gridded to 2m resolution using a swath angle BASE surface. Data were then exported from CARIS as ascii XYZ files and imported to ARCGIS where they were combined into a single grid. data were then exported as a single continuous ASCII grid. Bathymetry products are presented according to standard California State Mapping Project specifications, including depth-dependent resolutions of 2m for data from the 0-85m depth range, 5m for 80-250m depth range, and 10m for depths of 230-1500m. A comprehensive 5m data set was produced for the total survey coverage only if per block data exceeded 85m depth and 5m resolution products were included. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  5. Title: Bathymetric Digital Elevation Model (200 meters): California Coast, 2002

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    Summary: This raster dataset is a mosaic resampled to 200 meter horizontal resolution for areas of sparse data occurrence. Vertical units are fathoms (integer). The tiled 25 meter base DEMs are intermediate products used to generate the 25-200 meter zonal DEMs. These 25, 50, 100 and 200 meter "zones" were defined by plotting the source data on paper, visually identifying and hand drafting zone boundaries based on data density, then capturing the boundaries in digital format. The tiled 5-200 meter zonal DEMs are simply the coast-wide zonal DEMs (or individual 5 meter zonal DEMs) clipped to a 7500 meter buffered tile extent and stored in the tile directory. This makes it easy to find DEMs of all available resolutions for a single tile. Tile directories store only those resolutions that cover the tile. A single coast-wide Digital Elevation Model (DEM) was envisioned as the product of the California Department of Fish and Game bathymetry development project, but it quickly became evident that the source data necessitated multiple datasets, including: 1) Coast-wide 25, 50, 100 and 200 meter zonal DEMs; 2) 5 meter zonal DEMs for localities supported by high-density source data; 3) Tiled 5, 25, 50, 100 and 200 meter zonal DEMs; and 4) Tiled 25 meter base DEMs. The grid is a resampled compilation of these datasets (available upon request). The bathymetry development project covered most of the 200 nautical mile Exclusive Economic Zone (EEZ) off the coast of California. The actual extent of data is slightly beyond this zone in some areas to account for the 100 km. tiles used to process source data (some tiles extend beyond the EEZ boundary by as much as almost a tile width, or less than 100 km.). To the east, the coverage includes many major inlets along the coast. The tiles also extend north and south of California by less than one tile height. These data are not suitable for navigation purposes. California Department of Fish and Wildlife, 2003. Bathymetric Digital Elevation Model (200 meters): California Coast, 2002. Marine Region GIS Lab. Available at: http://purl.stanford.edu/ns150wp8904. --BEGIN ORIGINAL METADATA - THIS INFORMATION MAY NOT BE CURRENT-- California Department of Fish and Game BATHYMETRY PROJECT Second Edition This document provides an overall description of the California Department of Fish and Game (DFG) bathymetry development project, including source datasets, processes used, and resulting products. The bathymetry data are not suitable for navigation. DFG makes no warranty as to the suitability of the bathymetry data, and any project-related datasets, for any purpose. In addition to this readme file, other documentation files (text, XML, etc.) may accompany datasets related to this project. ACKNOWLEDGEMENTS The bathymetry processing methods and documentation were originally developed by the State of California Stephen P. Teale Data Center, GIS Solutions Group (Teale) under DFG direction. Key Teale staff involved in the project included Andy Richardson and Virginia Wong-Coppin. REVISIONS A second edition of the bathymetry data was completed by DFG in August 2002. The second edition data were processed using ARC/INFO GIS software in a Windows 2000 operating system environment and included the following enhancements: - Correction or exclusion of over 1700 miscoded and suspicious Hydrographic Surveys used in the bathymetry development process. - Replacement of older U.S. Geological Survey 7.5-minute terrestrial elevation data with the newer/higher-quality National Elevation Dataset (NED) for use in nearshore bathymetry interpolation. - Minor adjustments to some of the ARC/INFO software ARC Macro Language (AML) scripts and resolution zone boundaries used to process the bathymetry data. GEOGRAPHIC AREA Bathymetry was developed to cover most of the 200 nautical mile Exclusive Economic Zone (EEZ) off the coast of California. The actual extent of data is slightly beyond this zone in some areas to account for the 100 kilometer tiles used to process source data (some tiles extend beyond the EEZ boundary by as much as almost a tile width, or less than 100 KM). To the east, the coverage includes many major inlets along the coast. The tiles also extend north and south of California by less than 1 tile height. VITAL STATISTICS Data Format: ESRI grid (DEMs) Horizontal Datum: NAD27 (spheroid: Clarke 1866) Projection: Albers conic equal area Units: Meters Z-Units (depth values): Decimeters (land coded as zero) 1st Std. Parallel: 34 00 00 (34.0 degrees N) 2nd Std. Parallel: 40 30 00 (40.5 degrees N) Longitude of Origin: -120 00 00 (120.0 degrees W) Latitude of Origin: 00 00 00 (0.0 degrees) False Easting: 0 False Northing: -4000000 RESULTING PRODUCTS Initially a single coastwide Digital Elevation Model (DEM) was evisioned to be the product resulting from this project. Upon commencing the project it became evident that due to the nature of the source data multiple datasets were appropriate. These include: 1. Coastwide 25, 50, 100, and 200 meter zonal DEMs 2. 5 meter zonal DEMs for localities supported by high-density source data 3. Tiled 5, 25, 50, 100, and 200 meter zonal DEMs 4. Tiled 25 meter base DEMs The coastwide 25-200 meter zonal DEMs are based on the fact that there is a wide variation in the density of the source data. Where data were dense, a 25 meter zonal DEM was generated. Where data were sparse, a 200 meter zonal DEM was generated. The 50 and 100 meter zonal DEMs represent intermediate densities. Though "coastwide", data in these DEMs do not overlap, however together they cover the entire study area. These 25, 50, 100, and 200 meter "zones" were defined by plotting the source data on paper, visually identifying and hand drafting zone boundaries based on data density, then capturing the boundaries in digital format. The 5 meter zonal DEMs correspond to areas where source data are particularly dense. These areas were identified by visually scanning the source data on-screen, and "heads up" digitizing the boundaries. These DEMs differ from the 25-200 meter zonal DEMs in that they were processed using different tolerances and that they were not merged into a single coastwide zonal DEM (due to resolution / storage constraints). These DEMs are available named by geographic localities or as tiled data. The tiled 5-200 meter zonal DEMs are simply the coastwide zonal DEMs (or individual 5 meter zonal DEMs) clipped to a 7500 meter buffered tile extent and stored in the tile directory. This makes it easy for a user to find DEMs of all available resolutions for a single tile. Tile directories store only those resolutions that cover the tile. The tiled 25 meter base DEMs are intermediate products used to generate the 25-200 meter zonal DEMs. These have proven useful as a source for generating contours and depth range polygons. They are also useful for visualizing and analyzing small geographic areas, though the user must understand that the source data do not necessarily support 25 meter resolution. These DEMs are tile-wide in extent, and are available clipped to the tile boundary (dembase) and buffered 7500 meters beyond the tile (dembaseb). An available georeferenced map image (bathy_map.jpg with bathy_map.jgw world file) shows spatial distribution, tile numbers, and resolution zones of the DEM data. SOURCE DATA Four sources of depth/elevation data were used to create the bathymetric DEMs: 1. Hydrographic Survey Data version 4.0, National Ocean Service (NOS), National Oceanic and Atmospheric Administration, U.S. Department of Commerce. Dataset name = hydsura (ESRI coverage format). 2. U.S. Geological Survey bathymetric contours for the California EEZ - 100m contours from 200m to maximum depth. Dataset name = eezbata (ESRI coverage format). 3. 30 meter terrestrial DEM based on the National Elevation Dataset (NED), U.S. Geological Survey, U.S. Department of the Interior. Dataset name = dema (ESRI grid format). 4. 1:24,000-scale State of California Coastline, State Lands Commission, State of California. Dataset name = rawclipa (ESRI coverage format). The NOS Hydrographic Surveys were the primary nearshore depth data used to create the bathymetric DEMs. These data represent multiple historical ship transects and were imported to ARC/INFO as a set of over 6 million points. Sampling density is quite variable, as close as a few meters in inland bays and as far apart as hundreds or thousands of meters away from the coast. The Hydrographic Surveys were processed as-is and not filtered to model a particular range of dates. The U.S. Geological Survey bathymetric contours were provided by the U. S. Geological Survey Coastal and Marine Geology Team. The original dataset known as "eezbatcall" was reprojected by DFG to the California (Teale) Albers projection. The coverage provided contours from 200 meters to maximum depth for the California EEZ area. The contours were digitized from various small-scale (approximately 1:1,000,000) U.S. Geological Survey maps. The 30 meter terrestrial DEM was used to allow continuous gridding along the coast. Though there is no land area included in the resulting products, the bathymetry gridding process requires sampling data beyond the edge of the resulting grid to smoothly interpolate depth/elevation along the edge. The NED terrestrial DEM data were distributed by the U.S. Geological Survey then processed and re-distributed by Teale. The 1:24,000 coastline was used to define land and water areas and as source depth points of "0". This results in a well-defined coastline in the bathymetric DEMs. The original State Lands Commission coastline coverage was modified by Teale for project purposes. PROCESSING DATA In addition to the source depth/elevation data, a number of datasets were used to control processing. These include: 1. TILE100KM 2. RES_ZONES 3. RAWCLIPA 4. M5_ZONES TILE100KM is a set of 100 kilometer square (10,000 square kilometers) tiles used to split the entire EEZ into 75 managable processing areas. Many of the resulting datasets are also stored by these tiles. RES_ZONES are zones corresponding to the density of source data that were used to determine the resolution of the resulting zonal DEMs (5, 25, 50, 100, and 200 meters). RAWCLIPA contains a set of polygons that define which areas are water and which areas are land. This dataset serves two functions in the gridding process. Coastlines are extracted, converted to a set of points with a depth value of "0", merged with the Hydrographic Surveys, U.S. Geological Survey bathymetric contours, terrestrial DEMs, and gridded. When gridding is complete, land polygons are pulled from this dataset and used to blank out the resulting DEM. M5_ZONES are areas where the Hydrographic Surveys support 5 meter gridding. The final products include a single 5 meter zonal DEM for each polygon in this dataset. PROCESSING METHODOLOGY The primary engine behind the gridding process is the ARC/INFO TOPOGRID tool. TOPOGRID uses an iterative finite difference interpolation technique that is essentially a discretized thin plate spline technology. It is based upon the ANUDEM program developed my Michael Hutchinson. The online help for TOPOGRID contains the following references: Hutchinson, M.F. 1988. Calculation of hydrologically sound digital elevation models. Third International Symposium on Spatial Data Handling, Sydney. Columbus, Ohio: International Geographic Union. Hutchinson, M.F. 1989. A new procedure for gridding elevation and stream line data with automatic removal of spurious pits. Journal of Hydrology: 106, 211-232. Hutchinson, M.F. and Dowling, T.I. 1991. A continental hydrological assessment of a new grid-based digital elevation model of Australia. Hydrological Processes 5: 45-58. Hutchinson, M.F. 1993. Development of a continent-wide DEM with applications to terrain and climate analysis. In: M.F. Goodchild et al (eds), Environmental Modeling with GIS. New York, Oxford University Press: 392-399. Wahba, G. 1990. Spline models for Observational data. CBMS-NSF Regional Conference Series in Applied Mathematics, Philadelphia: Soc. Ind. Appl. Maths. The following TOPOGRID parameters were used to create the 25-200 meter DEMs: DATATYPE SPOT ENFORCE OFF ITERATIONS 30 TOLERANCES 2.5 1.5 10 XYZLIMITS %LIMITS% (%LIMITS% = bounding box of buffered tile) The following TOPOGRID parameters were used to create the 5 meter DEMs: BOUNDARY XXZONE (XXZONE is the 5 meter zone polygon) DATATYPE SPOT ENFORCE OFF ITERATIONS 30 TOLERANCES 2.5 1.5 2.5 XYZLIMITS %LIMITS% (%LIMITS% is 50 meters beyond the 5 meter zone polygon bounding box) The processing logic applied to each of the 75 tiles to create the 25-200 meter DEMs was: - Receive the tile number to process - Create a results directory corresponding to the tile number - Extract the tile from TILE100KM - Buffer the tile 10 KM - Using the buffered tile, clip out: - RES_ZONES - RAWCLIPA (land water polygons) - Hydrographic Surveys - Coastlines (from RAWCLIPA) - Convert to points - Terrestrial DEM (if tile covers land area) - Convert to points - U. S. Geological Survey bathymetric contours (if tile covers 200 meter zone) - Merge all point coverages - Run TOPOGRID to create 25 meter DEM covering buffered tile area - Blank out land areas - Clip to 7500 meters beyond tile boundary; store in tile directory - Clip to tile boundary; store in tile directory - For each resolution zone covered by the tile: - Clip out area from buffered DEM - Resample to appropriate resolution for zone (using bilinear interpolation) - Blank out land areas - Store in tile directory The process used to create the 5 meter DEMs is: - For each polygon in M5_ZONES: - Create a coverage containing a single rectangle polygon 50 meters (10 5 meter cells) larger than the zone polygon - Using the rectangle, clip out: - RAWCLIPA (land water polygons) - Hydrographic Surveys - Coastlines (from RAWCLIPA) - Convert to points - Terrestrial DEM (if tile covers land area) - Convert to points - Merge the resulting point coverages - Run TOPOGRID to create 5 meter DEM covering the rectangle - Blank out land areas - Clip to extent of the zone polygon After the original tiled 25 meter base DEMs were created by Teale, shaded reliefs were generated and visually inspected. Miscoded points that resulted in spurious pits or spikes were identified and coded as such. After all errors were corrected for a tile, the DEMs for the tile were re-created and re-inspected. DIRECTORY STRUCTURE The following outline illustrates the directory structure used to process the bathymetry data. When fully populated, the TILEx directories are quite large (several gigabytes). - BATHYMETRY - AMLS (ARC/INFO AML data processing scripts) - DATA (source and processing data) - PROCESS (bathymetry processed here) - RESULTS (contains various results directories) - METER5 (5 meter zonal DEMs, named by localities) - OTHER (empty) - STATE (25, 50, 100, 200 meter coastwide zonal DEMs) - TILES (contains tile1-tile75 directories) - TILEx (contains tiled and base DEMs) - DEMBASE (25 meter base DEM clipped to tile) - DEMBASEB (25 meter base DEM buffered 7500 meters beyond tile) - DEM5 (5 meter zonal DEM buffered 7500 meters beyond tile) - DEM25 (25 meter zonal DEM buffered 7500 meters beyond tile) - DEM50 (50 meter zonal DEM buffered 7500 meters beyond tile) - DEM100 (100 meter zonal DEM buffered 7500 meters beyond tile) - DEM200 (200 meter zonal DEM buffered 7500 meters beyond tile) DATA QUALITY ASSESSMENT The following are subjective comments regarding the data. Because the bathymetry data were generated from a variety of sources at varying scales, overall accuracy is difficult to assess. The data have not been thoroughly reviewed. Depth values should be corroborated with other sources. Some "artifacts" are present in the data, and may be especially noticeable along resolution zone and tile boundaries where differing data sources may not have provided a smooth interpolation transition. Additional errors may be present. Source Hydrographic Survey data originated from many historical surveys and thus do not necessarily represent current hydrologic conditions. For accuracy assessments of Hydrographic Survey data, please reference the documentation for that product. DEM depth values are of particular questionable quality in the following areas. Other problem areas may exist. - Nearshore areas north of Mack Pt. (southern Oregon). Source terrestrial elevation data was missing for this area but depth values were still interpolated to the shoreline. - Nearshore, Gulf of the Farallones area, south of Stormy Stack and north of Muir Beach out to about -25 meters depth. Source depth data was missing for this area but depth values were still interpolated to the shoreline. - Nearshore areas south of the California border out to -200 meters depth. Source depth and terrestrial elevation data were missing for this area but depth values were still interpolated to the shoreline. - Any depth values outside of the gridding resolution zones. Cross-reference the "tile100km" and "res_zones" coverages used in data processing to determine areas within tiled DEMs that are outside the resolution zones. The georeferenced map image (bathy_map.jpg with bathy_map.jgw world file) can also be used for this purpose. - San Diego Bay. Source data were missing for portions of the bay but depth values were still interpolated. ACCESS LIMITATIONS None. Acknowledgement of the Bathymetry Project in products derived from the data is appreciated. DATA CONTACT Will Patterson California Department of Fish and Game Information Technology Branch GIS Service Center Sacramento, CA Voice: (916) 323-1484 Fax: (916) 323-1431 Email: wpatters@dfg.ca.gov Readme Version 2002.08.23 --END ORIGINAL METADATA-- This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  6. Title: Bathymetry Hillshade: Offshore of Refugio Beach, California, 2015

    Contributors:

    Summary: This layer is a georeferenced raster image containing shaded relief (hillshade) data for the offshore area of Refugio Beach, California. The bathymetry and shaded-relief maps the area were generated from bathymetry data collected 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. The offshore region was mapped by the USGS in 2008, using a 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. 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. A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes. Dartnell, P., Phillips, E.L., Finlayson, D.P. (2015). Bathymetry Hillshade: Offshore of Refugio Beach, California, 2015. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/sd434vw6164. Information for the related USGS Pacific Coastal and Marine Science Center data collection field activity, S-8-08-SC online at http://walrus.wr.usgs.gov/infobank/s/s808sc/html/s-8-08-sc.meta.html. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  7. Title: Folds: Offshore of Refugio Beach, California, 2012

    Contributors:

    Summary: This line shapefile contains geologic folds for the offshore area of Refugio Beach, California. This map area lies within the Western Transverse Ranges province, north of the southern California Borderland (Fisher and others, 2009). This province has undergone significant north-south compression since the Miocene, and recent global positioning system (GPS) data suggest north-south shortening of about 6 mm/yr (Larson and Webb, 1992). The active west-trending Pitas Point Fault (broad zone including back faults), Red Mountain Fault, and Rincon Creek Fault are some of the structures on which this shortening occurs (e.g., Jackson and Yeats, 1982; Sorlien and others, 2000; Fisher and others, 2009). This fault system, in aggregate, extends for about 100 km through the Ventura and Santa Barbara basins and represents an important earthquake hazard (e.g., Fisher and others, 2009). A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Conrad, J.E., Ritchie, A.C., Johnson, S.Y. (2015). Folds: Offshore of Refugio Beach, California, 2012. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/tp111fr3266. Map political location: Santa Barbara County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see sheet 2, SIM 3319 for more information). References Cited: Fisher, M.A., Sorlien, C.C., and Sliter, R.W., 2009, Potential earthquake faults offshore southern California from the eastern Santa Barbara channel to Dana Point, in Lee, H.J., and Normark, W.R., eds., 2009, Earth science in the urban ocean: The Southern California Continental Borderland: Geological Society of America Special Paper 454, p. 271-290. Jackson, P.A., and Yeats, R.S., 1982, Sructural evolution of Carpinteria basin, western Tranverse Ranges, California: American Association of Petroleum Geologists Bulletin, v. 66, p. 805-829. Larson, K.M., and Webb, F.H., 1992, Deformation in the Santa Barbara Channel from GPS measurements 1987-1991: Geophysical News Letters, v. 19, p. 1491-1494. Sorlien, C.C., Gratier, J.P., Luyendyk, B.P., Hornafius, J.S., and Hopps, T.E., 2000, Map restoration of folded and faulted late Cenozoic strata across the Oak Ridge fault, onshore and offshore Ventura basin, California: Geological Society of America Bulletin, v. 112, p. 1080-1090. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  8. Title: Backscatter A (8101): Drakes Bay and Vicinity, California, 2010

    Contributors:

    Summary: This layer is a georeferenced raster image containing acoustic-backscatter data for Drakes Bay and the surrounding vicinity in California. The map of the area was generated from data collected by California State University, Monterey Bay (CSUMB), and by Fugro Pelagos. Mapping was completed between 2007 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 468-kHz SEA SWATHPlus interferometric system. These mapping missions combined to collect backscatter data (sheet 3) from about the 10-m isobath to beyond the 3-nautical-mile limit of Californiaís State Waters. Backscatter is a remote sensing activity by which electromagnetic energy is reflected back towards its source by terrain or particles. Within the acoustic-backscatter imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones). This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Dartnell, P. and Kvitek, R.G. (2014). Backscatter A (8101): Drakes Bay and Vicinity, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/bh565zz1424. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  9. Title: Seafloor Character: Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This layer is a georeferenced raster image containing seafloor character data for the offshore area of Tomales Point, California. A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. This information is not intended for navigational purposes. Erdey, M.D. and Cochrane, G.R. (2014). Seafloor Character: Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/bj788gx9955. Information for USGS Coastal and Marine Geology related activities are online at <http://walrus.wr.usgs.gov/infobank/l/l908nc/html/l-9-08-nc.meta.html> This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  10. Title: Backscatter D: Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This layer is a georeferenced raster image containing acoustic-backscatter data for the offshore area of Tomales Point, California. The acoustic-backscatter map of the area was generated from data collected by California State University, Monterey Bay (CSUMB), Fugro Pelagos and by the U.S. Geological Survey (USGS). Mapping was completed between 2004 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHPlus phase-differencing sidescan sonars. These mapping missions combined to collect backscatter data from about the 10-m isobath to beyond the 3-nautical-mile limit of California's State Waters. Within the acoustic-backscatter imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones). A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Dartnell, P., Erdey, M.D., Kvitek, R.G., and Bretz, C.K. (2014). Backscatter D: Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/bj819cr5980. None This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  11. Title: Contours: Offshore of Refugio Beach, California, 2015

    Contributors:

    Summary: This line shapefile contains bathymetric contours at 10 and 50 meter intervals for the offshore area of Refugio Beach, California. A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Ritchie, A.C., Dartnell, P., Kvitek, R.G., Johnson, S.Y. (2015). Contours: Offshore of Refugio Beach, California, 2015. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/cj457gj7638. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  12. Title: Bathymetry: Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This layer is a georeferenced raster image containing bathymetric data for the offshore area of Tomales Point, California. The bathymetric and shaded relief maps of the area were generated from data collected by California State University, Monterey Bay (CSUMB) , Fugro Pelagos and by the U.S. Geological Survey (USGS). Mapping was completed between 2004 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHPlus phase-differencing sidescan sonars. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of California's State Waters. NOTE: the horizontal datum of the bathymetry data (NAD83) differs from the horizontal datum of other layers in this data series (WGS84). Some bathymetry grids within this map 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). A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes. Dartnell, P., Kvitek, R.G., and Bretz, C.K. (2014). Bathymetry: Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/sp951ck0438. None This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  13. Title: Backscatter C (Swath): Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This layer is a georeferenced raster image containing acoustic-backscatter data for the offshore area of Tomales Point, California. The acoustic-backscatter map of the area was generated from data collected by California State University, Monterey Bay (CSUMB), Fugro Pelagos and by the U.S. Geological Survey (USGS). Mapping was completed between 2004 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHPlus phase-differencing sidescan sonars. These mapping missions combined to collect backscatter data from about the 10-m isobath to beyond the 3-nautical-mile limit of California's State Waters. Within the acoustic-backscatter imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones). A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Dartnell, P., Erdey, M.D., Kvitek, R.G., and Bretz, C.K. (2014). Backscatter C (Swath): Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/sn970qh2871. None This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  14. Title: Contours (10m): Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This line shapefile contains bathymetric contours at 10 meter intervals for the offshore area of Tomales Point, California. This layer was generated from bathymetry data collected by Fugro Pelagos and California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB) and by the U.S. Geological Survey. Mapping was completed between 2004 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHPlus phase-differencing sidescan sonars. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of Californiaís State Waters. Bathymetric contours at 10-m intervals were generated from a modified 2-m bathymetric surface. The original surface was smoothed using the Focal Mean tool in ArcGIS and a circular neighborhood with a radius of 20 to 30 meters (depending on the area). The contours were generated from this smoothed surface using the ArcGIS Spatial Analyst Contour tool. The most continuous contour segments were preserved while smaller segments and isolated island polygons were excluded from the final output. The contours were then clipped to the boundary of the map area. A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. Part of the marine habitat mapping data for the California North Central Coast Mapping Project (NCCMP), this coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Dartnell, P., Kvitek, R.G., and Bretz, C.K. (2014). Contours (10m): Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/rt793kd9427. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  15. Title: Bathymetry: Offshore of Refugio Beach, California, 2015

    Contributors:

    Summary: This layer is a georeferenced raster image containing bathymetric data for the offshore area of Refugio Beach, California. The bathymetric map of the area was generated from data collected by the U.S. Geological Survey (USGS). for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise. The offshore region was mapped by the USGS in 2008, using a 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. 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. A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes. Dartnell, P., Phillips, E.L., Finlayson, D.P. (2015). Bathymetry: Offshore of Refugio Beach, California, 2015. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/fv477rc3507. Information for the related USGS Pacific Coastal and Marine Science Center data collection field activity, S-8-08-SC online at http://walrus.wr.usgs.gov/infobank/s/s808sc/html/s-8-08-sc.meta.html. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  16. Title: Folds: Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This line shapefile depicts geologic folds within the offshore area of Tomales Point, California. The Point Reyes Peninsula is bounded to the south and west in the offshore by the north- and east-dipping Point Reyes Thrust Fault (McCulloch, 1987; Heck and others, 1990), which lies about 20 km west of Tomales Point. Granitic basement rocks are offset about 1.4 km on this thrust fault offshore of Point Reyes (McCulloch, 1987), and this uplift combined with west-side-up offset on the San Andreas Fault (Grove and Niemi, 2005) resulted in uplift of the Point Reyes Peninsula, including Tomales Point and the adjacent continental shelf. Grove and others (2010) reported uplift rates of as much as 1 mm/yr for the south flank of the Point Reyes Peninsula based on marine terraces, but reported no datable terrace surfaces that could constrain uplift for the flight of 4-5 terraces exposed farther north along Tomales Point. Folds were primarily mapped by interpretation of seismic reflection profile data (see field activity S-15-10-NC). The seismic reflection profiles were collected between 2007 and 2010. A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Hartwell, S.R., Johnson, S.Y., and Manson, M.W. (2014). Folds: Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/jf036dx3445. Map political location: San Mateo County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see Bathymetry Hillshade--Offshore of Tomales Point, California, DS 781, for more information). . References Cited Grove, K., and Niemi, T.M., 2005, Late Quaternary deformation and slip rates in the northern San Andreas fault zone at Olema Valley, Marin County, California: Tectonophysics, v. 401, p. 231-250. Grove, K, Sklar, L.S., Scherer, A.M., Lee, G., and Davis, J., 2010, Accelerating and spatially-varying crustal uplift and its geomorphic expression, San Andreas fault zone north of San Francisco, California: Tectonophysics, v. 495, p. 256-268. Heck, R.G., Edwards, E.B., Kronen, J.D., Jr., and Willingham, C.R., 1990, Petroleum potential of the offshore outer Santa Cruz and Bodega basins, California, in Garrison, R.E., Greene, H.G., Hicks, K.R., Weber, G.E., and Wright, T.L., eds. Geology and tectonics of the central California coastal region, San Francisco to Monterey: Pacific Section, American Association of Petroleum Geologists Bulletin GB67, p. 143-164. McCulloch, D.S., 1987, Regional geology and hydrocarbon potential of offshore central California, in Scholl, D.W., Grantz, A., and Vedder, J.G., eds., Geology and Resource Potential of the Continental Margin of Western North America and Adjacent Oceans Beaufort Sea to Baja California: Houston, Texas, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series, v. 6., p. 353-401. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  17. Title: Faults: Offshore of Refugio Beach, California, 2012

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    Summary: This line shapefile contains fault lines within the offshore area of Refugio Beach, California. This map area lies within the Western Transverse Ranges province, north of the southern California Borderland (Fisher and others, 2009). This province has undergone significant north-south compression since the Miocene, and recent global positioning system (GPS) data suggest north-south shortening of about 6 mm/yr (Larson and Webb, 1992). The active west-trending Pitas Point Fault (broad zone including back faults), Red Mountain Fault, and Rincon Creek Fault are some of the structures on which this shortening occurs (e.g., Jackson and Yeats, 1982; Sorlien and others, 2000; Fisher and others, 2009). This fault system, in aggregate, extends for about 100 km through the Ventura and Santa Barbara basins and represents an important earthquake hazard (e.g., Fisher and others, 2009). A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Conrad, J.E., Ritchie, A.C., Johnson, S.Y. (2015). Faults: Offshore of Refugio Beach, California, 2012. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/yg931nr6687. Map political location: Santa Barbara County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see sheet 2, SIM 3319, for more information). References Cited: Fisher, M.A., Sorlien, C.C., and Sliter, R.W., 2009, Potential earthquake faults offshore southern California from the eastern Santa Barbara channel to Dana Point, in Lee, H.J., and Normark, W.R., eds., 2009, Earth science in the urban ocean: The Southern California Continental Borderland: Geological Society of America Special Paper 454, p. 271-290. Jackson, P.A., and Yeats, R.S., 1982, Sructural evolution of Carpinteria basin, western Tranverse Ranges, California: American Association of Petroleum Geologists Bulletin, v. 66, p. 805-829. Larson, K.M., and Webb, F.H., 1992, Deformation in the Santa Barbara Channel from GPS measurements 1987-1991: Geophysical News Letters, v. 19, p. 1491-1494. Sorlien, C.C., Gratier, J.P., Luyendyk, B.P., Hornafius, J.S., and Hopps, T.E., 2000, Map restoration of folded and faulted late Cenozoic strata across the Oak Ridge fault, onshore and offshore Ventura basin, California: Geological Society of America Bulletin, v. 112, p. 1080-1090. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  18. Title: Geology: Offshore of Refugio Beach, California, 2012

    Contributors:

    Summary: This polygon shapefile contains geological features for the offshore area of Refugio Beach, California. The offshore Refugio Beach map area largely consists of a gently offshore-dipping (<1 degree) shelf (10 to ~ 90 m) underlain by sediments derived primarily from relatively small coastal watersheds draining the Santa Ynez Mountains. Nearshore and shelf deposits are primarily sand (Qms) at depths less than about 45 m and more fine-grained sediment - very fine sand, silt and clay (Qmsf), at depths greater than about 45 m. The boundary between Qms and Qmsf is based on observations and extrapolation from sediment sampling (for example, Reid and others, 2006) and camera groundtruthing. The Qms-Qmsf boundary is transitional and approximate, expected to shift based on seasonal to annual to decadal scale cycles in wave climate, sediment supply, and sediment transport. Fine-grained deposits similar to Qmsf also occur below the shelfbreak on the upper slope at water depths greater than 90 m, where they are broken out as a separate unit (Qmsl) based on their location and geomorphology. More coarse-grained deposits recognized on the basis of high backscatter and in some cases moderate seafloor relief have two modes of occurrence. In the relative nearshore (10 to 30 m water depth), coarse-grained strata (Qmsc) underlie laterally coalescing and discontinuous bars at the mouths of steep coastal watersheds. Coarser-grained sediments also form several distinct lobes (Qmscl) in water depths of 25 to 70 m, about 600 to 3,000 m offshore. The lobes range in size from ~100,000 m2 to ~1.5 km2 and are mapped on the basis of high backscatter and subtle positive seafloor relief. These coarse-grained strata were clearly derived from fluvial point sources in the adjacent, steep Santa Ynez Mountains. Bedrock exposures in the nearshore west of El Capitan are assigned to the Miocene Monterey Formation based on proximity to coastal outcrops mapped by Dibblee (1981a, b). Much of the outer shelf (water depths greater than 70 m) is also underlain by undifferentiated Tertiary bedrock (Tbu). Based on the regional cross sections constrained by deep seismic-reflection data and borehole logs (Heck, 1998; Tennyson and Kropp, 1998; Forman and Redin, 2005; Redin, 2005) and high-resolution seismic-reflection data coupled with proprietary oil industry dartcore data (Ashley, 1977), these outer-shelf outcrops consist of the Miocene Sisquoc Formation and the Pliocene Repetto and Pico Formations. These rocks have been uplifted in a large, warped, regional south-dipping homocline that formed above the blind, north-dipping North Channel fault. The fault tip is inferred at about 1.5 sec TWT (~2 km) about 6 to 7 km offshore, beneath the slope and just outside California's State Waters. Bedrock that underlies some parts of the shelf is overlain by a thin (< 1 m?) sediment veneer, recognized based on high backscatter, flat relief, continuity with moderate to high relief bedrock outcrops, and (in some cases) high-resolution, seismic-reflection data (Qms/Qtbu. Qms/Tbu, Qms/Tm). These sediment layers are likely ephemeral - they may or may not be present based on storms, seasonal/annual patterns of sediment movement, or longer-term climate cycles. This area has a long history of petroleum production (Barnum, 1998), and grouped to solitary pockmarks (Qmp) caused by gas seeps are common features in the offshore Refugio map area. Shell discovered the Molino gas field in 1962, 4 km offshore in the southwest part of the map area. Production, by onshore directional drilling of an anticlinal trap, has been underway since the 1960's (Galloway, 1998). A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Conrad, J.E., Ritchie, A.C., Johnson, S.Y. (2015). Geology: Offshore of Refugio Beach, California, 2012. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/pp901rg4093. Map political location: Santa Barbara County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see sheet 2, SIM 3319 for more information). ). References cited: Ashley, R.J., Berry, R.W., and Fischer, P.J., 1977, Offshore geology and sediment distribution of the El Capitan-Gaviota continental shelf, northern Santa Barbara Channel, California: Journal of Sedimentary Petrology, v. 47, no, 1, p. 199-208. Barnum, H.P., 1998, Redevelopment of the western portion of the Rincon offshore oil field, Ventura, California, in Kunitomi, D.S., Hopps, T.E., and Galloway, J.M., eds., Structure and petroleum geology, Santa Barbara Channel, California: American Association of Petroleum Geologists, p. 201â215. Dibblee, T.W., Jr., 1981a, Geologic map of the Tajiquas Quadrangle, California: U.S. Geological Survey Open-File Report 81-371, 1:24,000. Dibblee, T.W., Jr., 1981b, Geologic map of the Gaviota Quadrangle, California: U.S. Geological Survey Open-File Report 81-374, 1:24,000. Dibblee, T.W., Jr., 1981c, Geologic map of the Santa Ynez Quadrangle, California: U.S. Geological Survey Open-File Report 81-371, 1:24,000. Dibblee, T.W., Jr., 1981d, Geologic map of the Solvang Quadrangle, California: U.S. Geological Survey Open-File Report 81-372, 1:24,000. Forman, J., and Redin, T., 2005, Santa Barbara Channel structure and correlation sections, Correlation Section no 37, Arroyo Hondo, Gaviota Quadrangle, Santa Ynez Mts. To North West Santa Rosa Island: American Association of Petroleum Geologists, Pacific Section, Publication CS 37, 1 sheet. Galloway, J.M., 1998, Chronology of petroleum exploration and development in the Santa Barbara channel area, offshore southern California, in Kunitomi, D.S., Hopps, T.E., and Galloway, J.M., eds., Structure and petroleum geology, Santa Barbara Channel, California: American Association of Petroleum Geologists, Pacific Section and Coast Geological Society, Miscellaneous Publication 46, p. 1â12, 1 sheet. Heck, R.G., 1998, Santa Barbara Channel Regional Formline Map, Top Monterey Formation, in Kunitomi, D.S., Hopps, T.E., and Galloway, J.M., 1998, Structure and Petroleum Geology, Santa Barbara Channel, California: American Association of Petroleum Geologists, Pacific Section, Miscellaneous Publication 46, Plate 1. Minor, S.A., Kellogg, K.S., Stanley, R.G., Gurrola, L.D., Keller, E.A., and Brandt, T.R., 2009, Geologic map of the Santa Barbara coastal plain area, Santa Barbara County, California: U.S. Geological Survey Scientific Investigations Map 3001, scale 1:25,000. Redin, T., 2005, Santa Barbara Channel structure and correlation sections, Correlation Section no 36, N-S structure and correlation section, western Santa Ynez Mountains across the Santa Barbara channel to Santa Rosa Island: American Association of Petroleum Geologists, Pacific Section, Publication CS 35, 1 sheet. 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, http://pubs.usgs.gov/ds/2006/182/. Tennyson, M.E., and Kropp, A.P., 1998, Regional cross section across Santa Barbara channel from northwestern Santa Rosa Island to Canada de Molina, in Kunitomi, D.S., Hopps, T.E., and Galloway, J.M., eds., in Structure and petroleum geology, Santa Barbara Channel, California: American Association of Petroleum Geologists, Pacific Section and Coast Geological Society, Miscellaneous Publication 46, 1 plate. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  19. Title: Backscatter: Offshore of Refugio Beach, California, 2015

    Contributors:

    Summary: This layer is a georeferenced raster image containing acoustic-backscatter data for the offshore area of Refugio Beach, California. The acoustic-backscatter map of the area was generated from data collected by the U.S. Geological Survey (USGS). The USGS mapped this region in the summer 2008 using a 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. These data were later re-processed in 2012. Within the acoustic-backscatter imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and sediment type. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones). A map that show these data are published in Scientific Investigations Map 3319, "California State Waters Map Series--Offshore of Refugio Beach, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Dartnell, P., Phillips, E.L., Finlayson, D.P. (2015). Backscatter: Offshore of Refugio Beach, California, 2015. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/pb804hy8483. Information for the related USGS Pacific Coastal and Marine Science Center data collection field activities, S-8-08-SC online at http://walrus.wr.usgs.gov/infobank/s/s808sc/html/s-8-08-sc.meta.html. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  20. Title: Backscatter A (8101): Offshore of Tomales Point, California, 2010

    Contributors:

    Summary: This layer is a georeferenced raster image containing acoustic-backscatter data for the offshore area of Tomales Point, California. The acoustic-backscatter map of the area was generated from data collected by California State University, Monterey Bay (CSUMB), Fugro Pelagos and by the U.S. Geological Survey (USGS). Mapping was completed between 2004 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHPlus phase-differencing sidescan sonars. These mapping missions combined to collect backscatter data from about the 10-m isobath to beyond the 3-nautical-mile limit of California's State Waters. Within the acoustic-backscatter imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones). A map that shows these data is published in Open-File Report 2015-1088, "California State Waters Map Series--Offshore of Tomales Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Dartnell, P., Erdey, M.D., Kvitek, R.G., and Bretz, C.K. (2014). Backscatter A (8101): Offshore of Tomales Point, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/tb879rs4686. None This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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