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The NOAA/NOS and USCGS Bottom Type database contains surficial sediment descriptions for over 200,000 seafloor samples primarily in U.S. Coastal areas. Descriptions were abstracted from unpublished data reports and Bottom Type "M" log sheets, and digitized from survey smooth sheets produced by the NOAA National Ocean Service (NOS) and its predecessor, the U.S. Coast and Geodetic Survey (USCGS).

Effective August 3, 2011 bottom sample information will be extracted from NOS field surveys and sent to NGDC in digital form for addition to this database, distribution and archive under Hydrographic Technical Directive 2011-6 (HTD 2011-6).


Marine Geology Data

The NOAA/NOS and USCGS Bottom Type Descriptions from Hydrographic Surveys

NGDC Data Set G10163

World Data Center for Geophysics & Marine Geology, Boulder


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source "digitized" = data digitized from NOS Smooth Sheets
source "survey rep" = data key entered from Descriptive Reports (DRs)
source "NMNH" = data entered by the Smithsonian Institution from NOS bottom survey sheets

Historic data include collecting survey id, sample id, latitude/longitude, original datum, and a brief description of the surficial sediment at the location.

More recent descriptions use the International Hydrographic Organization (IHO) S-57 standard "NATSUR" (nature of surface) and "NATQUA" (nature of surface qualifier) coding scheme.

Related Data: Many additional data sets available through NGDC contain seafloor sediment data that are not included in this database; some are in paper reports, other data are in diverse formats. For a more complete search of seafloor sediment data available from NGDC, please search the marine geology inventory.

Data Set Credits

Prior to August 2001, sediment samples collected during hydrographic surveys were routinely sent to the Smithsonian Institution Museum of Natural History (NMNH) for archive with accompanying "M" log forms from which bottom type and other information were coded into the NMNH sediment database. In 2001, NMNH contributed a copy of the database to NGDC to be incorporated into the Index to Marine and Lacustrine Geological Samples, and for distribution to data users needing access to the bottom type information in the files.

With support from NOS, NGDC digitized thousands of additional bottom type observations from historic NOS Hydrographic Survey smooth sheets and added them to the database.

Dan Neumann of NOS is currently supervising coding of bottom type observations from several hundred additional historic survey Descriptive Reports (DRs) for entry into the database.