{
    "tag": 15621,
    "title": "In situ seafloor images from the lower Columbia River, Washington and Oregon, 2021",
    "pubdate": "20230808",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/10.5066\/P92U1KPY",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/DataReleases\/CMGDS_DR_tool\/DR_P92U1KPY\/dgs_images_metadata.faq.html",
    "format": null,
    "email": null,
    "descript": "In situ seafloor images were acquired at four sites (SKM, SLG, LDB, WLW) in the lower Columbia River, Washington and Oregon, with an underwater camera system between June 5 and June 8, 2021. Between 248 and 427 digital images of the sediment surface were collected at each site with an underwater camera system that was repeatedly lowered to the seabed along a series of 1 km-long transects oriented along the main navigation channel and spaced about 60 m apart. The camera consisted of a FLIR Blackfly BFS-PGE-50S5 camera and 50 mm lens in a waterproof housing that resulted in a field of view of approximately 17 mm and a resolution of 0.00657 mm per pixel when the housing window was flush with the sediment surface. The imagery is provided in .tif format and compressed into .zip archives for each site. Images used for calibration of the automated processing algorithm to determine sediment grain size distributions were different than those used to validate the technique and were provided in separate .zip archives.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Hatcher, Gerald A.",
            "role": "Author"
        },
        {
            "name": "Stevens, Andrew W.",
            "role": "Author"
        },
        {
            "name": "Dal Ferro, Peter",
            "role": "Author"
        },
        {
            "name": "Dartnell, Peter",
            "role": "Author"
        },
        {
            "name": "Warrick, Jonathan A.",
            "role": "Author"
        },
        {
            "name": "Cohn, Nicholas",
            "role": "Author"
        },
        {
            "name": "Moritz, Hans R.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "493",
            "name": "grain-size analysis",
            "scope": "Method of studying soils, sediments, sands, or rock by determining the size, distribution, and proportion of selected particles."
        },
        {
            "thcode": 2,
            "code": "816",
            "name": "ocean processes",
            "scope": "Recurrent natural changes that are physical, biological, or chemical, actively affecting the seas and oceans."
        },
        {
            "thcode": 2,
            "code": "1034",
            "name": "sediment transport",
            "scope": "Transport of solid particles of unconsolidated rock and mineral fragments, chemical precipitates, or biological materials."
        },
        {
            "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": "417",
            "name": "Global Positioning System (GPS) observations",
            "scope": "the use of satellite signals from the Global Positioning System to determine the precise location of a terrestrial receiver."
        },
        {
            "thcode": 61,
            "code": "220",
            "name": "sediment",
            "scope": "unconsolidated weathering products that have been eroded, transported, and deposited in another location."
        }
    ],
    "place_term": [],
    "image": [],
    "fan": [
        "2021-621-FA"
    ]
}