Edward M. Sweeney 2004 Vector Woods Hole, MA U.S. Geological Survey http://pubs.usgs.gov/of/2004/1082/arcgis/shape/contours/10mContour.zip Edward M. Sweeney William W. Danforth Herman A. Karl Thomas F. O'Brien William C. Schwab 2004 Open-File Report 2004-1082 U.S. Geological Survey, Woods Hole Science Center, Woods Hole, MA U.S. Geological Survey http://pubs.usgs.gov/of/2004/1082 In 1989, the U.S. Geological Survey (USGS) began a major geologic and oceanographic investigation of the Gulf of the Farallones continental shelf system, designed to evaluate and monitor human impacts on the marine environment (Karl and others, 2002). The study region is located off the central California coast, adjacent to San Francisco Bay and encompasses the Gulf of the Farallones National Marine Sanctuary. Geologic mapping of this area included the use of various remote sensing and sampling techniques such as sub-bottom profiling, sidescan-sonar and bathymetric mapping, gravity core and grab sampling, and photography. These data were used to define the surficial sediment distribution, underlying structure and sea floor morphology of the study area. The primary focus of this report is to present a georeferenced, digital sidescan-sonar mosaic of the study region. The sidescan-sonar data were acquired with the AMS-120 (120kHz) sidescan-sonar system during USGS cruise F9-89-NC. The dataset covers approximately 1000 kmē of the continental shelf between Point Reyes, California and Half Moon Bay, California, extending west to the continental shelf break near the Farallon Islands. The sidescan-sonar mosaic displays a heterogenous sea-floor environment, containing outcropping rock, ripples, dunes, lineations and depressions, as well as flat, featureless sea floor (Karl and others, 2002). These data, along with sub-bottom interpretation and ground truth data define the geologic framework of the region. The sidescan-sonar mosaic can be used with supplemental remote sensing and sampling data as a base for future research, helping to define the local current regime and predominant sediment transport directions and forcing conditions within the Gulf of Farallones. The 10m contour ESRI vector shapefile serves as continental shelf bathymetric reference information for GIS mapping and the viewing of the Gulf of the Farallones sidescan-sonar data set. 2001 publication date Complete None planned -123.432658 -122.642339 38.182490 37.366379 General USGS U.S. Geological Survey bathymetry Geographic Information Systems CMGP Coastal and Marine Geology Program GIS Geographic Information Systems field activity identifier F9-89-NC field activity serial number 89020 Woods Hole Science Center contours vector shapefile 10 meter General Farallones Gulf of the Farallones California U.S. West Coast U.S. Central Pacific Coast North America Pacific Ocean United States Half Moon Bay Point Reyes Farallon Islands Bodega Bay San Francisco None Public domain data from the U.S. government is freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of this dataset. Edward M. Sweeney U.S. Geological Survey Research Assistant mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 USA (508) 548-8700 x2307 (508) 457-2310 esweeney@usgs.gov Microsoft Windows 2000 Version 5.1 (Build 2600) Service Pack 1; ESRI ArcCatalog 8.3.0.800 These data were generated from an ESRI grid of the NGCD Coastal Relief Model. The accuracy of these data are inherited from the Coastal Relief Model. Soundings for each volume of the Coastal Relief model series are compiled from hydrographic surveys conducted by the National Ocean Service (NOS) and from various academic institutions. The surveys were carried out using a variety of sounding methods including SeaBeam 16-beam, 12-kHz swath mapping system (6000- >3000m operating water depths), General Instruments 17-beam, 36-kHz Hydrochart II swath mapping system (5-150m operating water depths), single-beam echosounder (e.g., 3.5 kHz narrow 2 degree beam), and lead-line sounding method. These latter surveys date as far back as the late 1800's. A wide range of navigation methods are also associated with the surveys. Visual navigation is based on three-point sextant fixes, theodolite intersections, and celestial fixes. Electronic navigation involves short to long range positioning systems that run the gamut from Loran-C (0.25 - 5 nm accuracy) to differential GPS (1 m accuracy). Despite the varying sounding and navigation techniques upon which they are based, all of the NOS soundings used in constructing the Coastal Relief Model meet rigorous standards for accuracy. The same standards are employed by the International Hydrographic Office and have remained relatively consistent since the 1800's. The vertical accuracy of the soundings The horizontal accuracy of the soundings is generally 30 m, but it can vary from as fine as 15 m in ports and estuaries to as coarse as 75 m in the offshore areas. Differential GPS has improved this level of accuracy considerably for the most recent survey data. Land elevations within the gridded dataset come from the United States Geological Survey/ National Image Mapping Agency (USGS/NIMA) 1:250,000 or 1 degree DEMs of the states. A description of the USGS/NIMA DEMs and how they were derived can be accessed on the World Wide Web at http://edcwww.cr.usgs.gov/glis/hyper/guide/1_dgr_dem. Our focus, however, is on the bathymetric soundings that are used in constructing the offshore regions of the grids. Soundings for each volume of the Coastal Relief model series are compiled from hydrographic surveys conducted by the National Ocean Service (NOS) and from various academic institutions. The surveys were carried out using a variety of sounding methods including SeaBeam 16-beam, 12-kHz swath mapping system (6000- >3000m operating water depths), General Instruments 17-beam, 36-kHz Hydrochart II swath mapping system (5-150m operating water depths), single-beam echosounder (e.g., 3.5 kHz narrow 2 degree beam), and lead-line sounding method. These latter surveys date as far back as the late 1800's. A wide range of navigation methods are also associated with the surveys. Visual navigation is based on three-point sextant fixes, theodolite intersections, and celestial fixes. Electronic navigation involves short to long range positioning systems that run the gamut from Loran-C (0.25 - 5 nm accuracy) to differential GPS (1 m accuracy). Despite the varying sounding and navigation techniques upon which they are based, all of the NOS soundings used in constructing the Coastal Relief Model meet rigorous standards for accuracy. The same standards are employed by the International Hydrographic Office and have remained relatively consistent since the 1800's. The vertical accuracy of the soundings is 0.3 m in 0 - 20 m of water, 1.0 m in 20 - 100 m of water, and 1% of the water depth in 100 m of water. The horizontal accuracy of the soundings is within a radius of 1.5 mm of the sounding location at the scale at which the soundings are recorded. NOS surveys are plotted at map scales that range from 1/10,000 for harbors and channels to 1/50,000 for open ocean surveys, with 1/20,000 being the most commonly used scale. The horizontal accuracy of the soundings is generally 30 m, but it can vary from as fine as 15 m in ports and estuaries to as coarse as 75 m in the offshore areas. Differential GPS has improved this level of accuracy considerably for the most recent survey data. While the NOS soundings collected since 1965 have been recorded digitally, those collected prior to this time were recorded manually and then used to make hand-drawn bathymetric maps. Approximately 1,550 of these hand-drawn bathymetric maps have been digitized and assimilated into the NOS Hydrographic Database and, subsequently, were used in constructing the many volumes of the gridded dataset. These data are complete (see: http://www.ngdc.noaa.gov/mgg/coastal/model.html) National Geophysical Data Center (NGDC) 2001 CD-ROM 2001 publication date NGDC Coastal Relief Model The ESRI Grid generated from the NGDC Coastal Relief Model was used to generate the 10 meter bathymetric contours. Contour intervals were created using the Spatial Analysis extension of the ESRI ArcMap program. For visual effectiveness, contours were created between the depths of -40 meters and -200 meters. 2004 Edward M. Sweeney U.S. Geological Survey Research Assistant mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 USA (508) 548-8700 x2307 (508) 457-2310 esweeney@usgs.gov Vector String 44 0.000089992 0.000089992 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.257224 10mContour ESRI Shapefile attribute table ESRI FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. ID Internal identification value. ESRI Identification number generated internally. CONTOUR Contour interval NGDC Coastal Relief Model -200 -10 meters Nancy Soderberg U.S. Geological Survey Data Librarian mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 USA (508) 548-8700 x2275 (580)457-2313 nsoderberg@usgs.gov 10 meter contours (ESRI Shapefile) Although this data set and its lineage have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data or its related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related items. Users must assume responsibility for the proper use of these data. The data should not be used at resolutions for which they are not intended. The data have not been reviewed for conformity with U.S. Geological Survey editorial standards, or the North American Strigraphic code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government. 10mcontours.shp ArcGIS 8.3 10 meter contours - vectors 0.219 none 20040407 Edward M. Sweeney U.S. Geological Survey mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 USA (508) 548-8700 x2307 (508) 457-2310 esweeney@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time ESRI Metadata Profile http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile 200407231024250020040723