{
    "tag": 14545,
    "title": "Acoustic backscatter intensity from multibeam echosounder data collected offshore of Morro Bay, California",
    "pubdate": "20220403",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/P9HEZNRO",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/DataReleases\/CMGDS_DR_tool\/DR_P9HEZNRO\/Backscatter_OffshoreMorroBay_metadata.faq.html",
    "format": null,
    "email": null,
    "descript": "This part of USGS Data Series 781 (Golden, 2019) presents 2-m-resolution acoustic backscatter data for the Offshore of Morro Bay, California, map area. Backscatter data were collected by Fugro Pelagos in 2008 using a combination of 400-kHz Reson 7125, 240-kHz Reson 8101, and 100-kHz Reson 8111 multibeam echosounder systems. The data were post-processed by the California State University Monterey Bay Seafloor Mapping Lab and the University of California Santa Cruz Center for Integrated Spatial Research. The acoustic backscatter data are available as a georeferenced TIFF image. Within the final 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).",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Kvitek, Rikk G.",
            "role": "Author"
        },
        {
            "name": "Cole, Aaron D.",
            "role": "Author"
        },
        {
            "name": "Cochrane, Guy R.",
            "role": "Author"
        },
        {
            "name": "Sherrier, Meghan",
            "role": "Author"
        },
        {
            "name": "Roca-Lezra, Alia",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "474",
            "name": "geospatial datasets",
            "scope": "Collections of related digital information that are geographically referenced."
        },
        {
            "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": "2036",
            "name": "multibeam sonar",
            "scope": "Acoustic technique for determining depths or creating backscatter imagery in a wide swath of seafloor or lakebed centered below the instrument platform."
        },
        {
            "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": 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": 23,
            "code": "23",
            "name": "Substrate",
            "scope": "Represents the character and composition of the surface and near surface of the sea floor in subtidal or intertidal areas, as defined in the Substrate Component of CMECS or in similar classification systems. Distributions are records of substrate characteristics based on visual or photographic inspection or on analysis of samples and cores, and they also include interpretive maps classifying areas on the basis of combinations of observations, hydrodynamic models, or geological models. Assessments include evaluations of present ecological or economic values of substrate distributions, drivers of substrate change, and functions of substrates. Predictions are the results of models or projections of future substrate distributions, values, or ecological impacts, including predicted substrate changes due to natural and human forces including erosion, accretion, sea-level change, extraction, trawling, or other factors; and they are the results of scenario-based models of substrate changes on ecological or economic values under different management strategies or other human alterations."
        },
        {
            "thcode": 61,
            "code": "400",
            "name": "field observation",
            "scope": "scientific investigation of physical or biological features and processes in a natural setting."
        },
        {
            "thcode": 61,
            "code": "173",
            "name": "seabed",
            "scope": "the floor of a sea or ocean."
        }
    ],
    "place_term": [],
    "image": [],
    "fan": []
}