USGS - science for a changing world
INSTAAR Logo and Link

usSEABED: Coastal & Marine Geology Program


usSEABED Data Format and Content

usSEABED is linked to the original data through the source file:

_SRC      Source information, including authors, institution, dates of collection, area, and navigation technique.  Each source file has a linked file that provides FGDC-compliant metadata.

Textural and other basic information

Textural, statistical, geochemical, geophysical, dominant component and color information are held in three separate, but similar, data files, based on the type of data:

_EXT Numeric data extracted from lab-based investigations.
_PRS Numeric data parsed from word-based data.
_CLC Numeric data calculated from the application of models or empirical relationships using data found in the EXT and PRS files.

The three data file types have the same fields and can be combined for more extensive coverage of the seafloor. Data users should see discussions in the data publications that delineate the differences and limitations of these three files.

Component/feature and facies data

Two data files contain mined numeric values from word-based data about presence of certain compositional content (i.e., quartz, andesite, benthic foramifera, nodules, etc.) seafloor features (i.e., ripples, bioturbation, worm tubes), biota, and sediment structure. These data represent the types of data most recorded in reports (i.e., presence).

The dbSEABED program acts on, and usSEABED data files record, only data that are noted by the original researcher. That is, many other instances of 'shells', 'bioturbation', 'kelp', 'coral', or 'brittlestar' undoubtedly exist on the seabed; but, if the original researcher was not interested and did not note them, this process cannot assess them. Users of these data should be aware that only relative presence of components and features can be suggested; absence should not be assumed.

_CMP      Numeric values about the components (content and features) of the seabed. Examples include feldspar, phosphorite, bivalves, seagrass, wood, etc.
_FAC Numeric values for appropriately grouped content components. Examples include volcanic rocks, geochemical signals, corals, etc.

As with the parsed data files, the values held within the _CMP and _FAC files are the results of filters based on fuzzy set membership to chosen sets, and represent a measure of truth about the attribute, not a percentage or defined values.

An additional output file type, although unpublished, provides quality control for the data and is used extensively prior to publication to debug and test the data.

Next page

Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey
last modified 2007