The NGDC Seafloor Sediment Grain Size Database

The NGDC (now NCEI) Seafloor Sediment Grain Size Database contains particle size data for over 17,000 seafloor samples worldwide. The file was begun by NGDC in 1976 in response to a need by the Outer Continental Shelf Environmental Assessment Program (OCSEAP) for a detailed, digital file of textural analyses. Data are from OCSEAP studies, academic institutions, environmental baseline studies conducted under contract to the Bureau of Land Management under the Outer Continental Shelf (OCS) Program, and from laboratory reports generated by the U.S. Naval Oceanographic Office. Data include collecting institution, ship, cruise, sample id, latitude/longitude, date of collection, water depth, sampling device, method of analysis, sample weight, sampled interval, raw weight percentages of sediment, within a given phi range. Some samples also have percentages of total gravel, sand, silt, clay, and statistical measurements such as mean, median, skewness, kurtosis, and standard deviation of grain size.