{
    "tag": 15556,
    "title": "Digital Sidescan-Sonar Mosaic collected within the Gulf of the Farallones, National Marine Sanctuary (FARALLONES.TIF, UTM 10, WGS84)",
    "pubdate": "2004",
    "sername": null,
    "series_name": null,
    "issue": "2004-1082",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/whcmsc\/open_file_report\/ofr2004-1082\/farallones.tif.faq.html",
    "format": null,
    "email": null,
    "descript": "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 km2 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.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Sweeney, Edward M.",
            "role": "Author"
        },
        {
            "name": "Danforth, William W.",
            "role": "Author"
        },
        {
            "name": "Karl, Herman A.",
            "role": "Author"
        },
        {
            "name": "O'Brien, Thomas F.",
            "role": "Author"
        },
        {
            "name": "Schwab, William C.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "2046",
            "name": "image mosaics",
            "scope": "Composite images formed by overlapping existing images, typically arranged to achieve greater spatial coverage."
        },
        {
            "thcode": 2,
            "code": "707",
            "name": "marine geophysics",
            "scope": "Branch of earth sciences concerned with the physical processes of the oceans and continental margins.  We include here studies of large bodies of brackish and fresh water, such as lakes and rivers."
        },
        {
            "thcode": 2,
            "code": "2053",
            "name": "sea-floor acoustic reflectivity",
            "scope": "Acoustic energy received by a sonar system, providing a measure of the roughness of the sea floor."
        },
        {
            "thcode": 2,
            "code": "1025",
            "name": "sea-floor characteristics",
            "scope": "Geomorphic features and geographic, compositional, and textural variation in the materials composing the ocean floor. Includes both large-scale structures (such as seamounts and rises) and fine-scale variations in rocks and deposits on the sea floor."
        },
        {
            "thcode": 2,
            "code": "2038",
            "name": "sidescan sonar",
            "scope": "Acoustic technique for creating oblique backscatter imagery of the seafloor or lakebed."
        },
        {
            "thcode": 15,
            "code": "008",
            "name": "geoscientificInformation",
            "scope": "Information pertaining to earth sciences, for example geophysical features and processes, geology, minerals, sciences dealing with the composition, structure and origin of the earth's rocks, risks of earthquakes, volcanic activity, landslides, gravity information, soils, permafrost, hydrogeology, groundwater, erosion"
        },
        {
            "thcode": 15,
            "code": "010",
            "name": "imageryBaseMapsEarthCover",
            "scope": "Base maps, for example land\/earth cover, topographic maps, imagery, unclassified images, annotations, digital ortho imagery"
        },
        {
            "thcode": 15,
            "code": "014",
            "name": "oceans",
            "scope": "Features and characteristics of salt water bodies (excluding inland waters), for example tides, tidal waves, coastal information, reefs, maritime, outer continental shelf submerged lands, shoreline"
        },
        {
            "thcode": 23,
            "code": "3",
            "name": "Distributions",
            "scope": "Locations or patterns of a feature of interest across space and (or) time. These data can include point data, lines, polygons, and temporal data at any scale relevant to CMSP and can be produced by observation, interpolation, or modeling. Distributions can also include maps or statistics of climatology, the environmental values that are expected to be observed at the present time."
        },
        {
            "thcode": 23,
            "code": "21",
            "name": "Physical Habitats and Geomorphology",
            "scope": "Includes measures of the geologic and structural characteristics of the coast or sea floor, such as the features defined in the Geoform Component of CMECS. Distributions are detailed topographic and bathymetric maps, geolocated photographs, or sea-floor descriptions; Distributions includes maps that interpret observations to categorize areas on the basis of geoform types such as those in CMECS. Assessment types include evaluations of ecological or human use value and can include models that project environmental or economic effects of erosion, climate change, dredging, and other stressors. Predictions are the results of models or projections of future distributions, values, or ecological impacts of physical habitats, including predicted changes due to natural and human forces; they are also from scenario-based models of resource losses, gains, or impacts on ecological or economic values under different management strategies (for example, mining, removal, relocation, or the building of structures)."
        },
        {
            "thcode": 61,
            "code": "738",
            "name": "marine geophysics",
            "scope": "used for geophysical and related studies of ocean basins and margins."
        },
        {
            "thcode": 61,
            "code": "173",
            "name": "seabed",
            "scope": "the floor of a sea or ocean."
        },
        {
            "thcode": 61,
            "code": "403",
            "name": "sidescan sonar",
            "scope": "acoustic technique for producing oblique imagery of the sea floor."
        }
    ],
    "place_term": [],
    "image": [],
    "fan": []
}