{
    "tag": 13330,
    "title": "Shotpoint navigation (100 shot interval) for CHIRP seismic data collected during USGS cruise GYRE 99002 (L1_5SP100G.SHP)",
    "pubdate": "2005",
    "sername": null,
    "series_name": null,
    "issue": "2005-1071",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/whcmsc\/open_file_report\/ofr2005-1071\/l1_5sp100gmeta.faq.html",
    "format": null,
    "email": null,
    "descript": "This GIS overlay is a component of the U.S. Geological Survey, Woods Hole Science Center's, Gulf of Mexico GIS database.  The Gulf of Mexico GIS database is intended to organize and display USGS held data and provide on-line (WWW) access to the data and\/or metadata.  A two week cruise aboard the R\/V GYRE focused on mapping surficial sedimentary processes and their connection to the subsurface geology.  The study area was on the upper continental slope in the northwestern Gulf of Mexico; an area of active hydrocarbon exploration. Active salt movement, hydrocarbon movement up faults, the presence of gas hydrates associated with biogenic and thermogenic methane, and overpressured sand deposits all present hazards to oil exploration in this area.  This study used sidescan sonar and high-resolution chirp subbottom profiling techniques to map the surficial and shallow subsurface expression of these processes in two areas roughly 15 by 25 km in size.  High-resolution multi-channel seismic-reflection data were collected simultaneously with the sidescan imagery to provide a link to the deeper subsurface. Additional multi-channel and Huntec seismic data were collected along regional lines between the detailed study areas to tie these studies to other areas of known hydrates and to wells where shallow overpressured sands have been drilled.  The detailed studies attempted to map entire geological systems in this upper slope environment to provide a broader perspective than can be seen from studying a single lease block.  One study area focused on two adjacent salt withdrawal basins to assess the processes that are shaping the flanks of the basins, the processes affecting sedimentation in the basin floors, and to compare the deeper structures and surficial processes between the basins.  The second study area focused on three salt domes, the processes associated with them, and how they affect the shallow subsurface stratigraphy. Initial observations suggest that most of the surface and shallow subsurface geohazards are associated with the flanks of salt structures. Here active salt movement generates faults along which hydrocarbons can escape to the seafloor, and tectonic oversteepenning generates slope failures.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Foster, David S.",
            "role": "Author"
        },
        {
            "name": "Twichell, David C.",
            "role": "Author"
        },
        {
            "name": "Cross, VeeAnn A.",
            "role": "Author"
        },
        {
            "name": "Paskevich, Valerie F.",
            "role": "Author"
        },
        {
            "name": "Hutchinson, Deborah R.",
            "role": "Author"
        },
        {
            "name": "Winters, W. J.",
            "role": "Author"
        },
        {
            "name": "Hart, Patrick E.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "474",
            "name": "geospatial datasets",
            "scope": "Collections of related digital information that are geographically referenced."
        },
        {
            "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": "2078",
            "name": "navigational data",
            "scope": "Geospatial data indicating the locations of instruments, vessels, aircraft, or other vehicles used to collect scientific observations.  These data include horizontal coordinates in sequence, and may include time or vertical position."
        },
        {
            "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": "013",
            "name": "location",
            "scope": "Positional information and services, for example addresses, geodetic networks, geodetic control points, postal zones and services, place names, geographic names"
        },
        {
            "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"
        }
    ],
    "place_term": [],
    "image": [
        {
            "name": "https:\/\/pubs.usgs.gov\/of\/2005\/1071\/data\/seismic\/1999\/chirp\/nav\/l1_5sp100g.gif",
            "description": "Overview image showing the extent and coverage of the data layer."
        }
    ],
    "fan": []
}