Rivix.com: NOAA/NOS EEZ Bathymetry

NOAA/NOS EEZ Bathymetry

Description

The US Exclusive Economic Zone (EEZ) is a zone that surrounds all US possessions and trust territories to a distance of 200 nautical miles from the coastline. Sovereign rights to all natural resources in this zone were unilaterally declared by Presidential Order on March 10, 1983. The combined area of this zone is equal to two-thirds of all US lands prior to the declaration.

Gridded bathymetric data for the EEZ was released by the National Ocean Service (NOS) of NOAA in 1991. The source data was collected using multibeam swath sounding techniques. The gridded data is available in two forms: a UTM (Universal Transverse Mercator) grid and a Geographic grid. Each grid spans one-half degree of latitude and one degree of longitude, except for grids in Alaska which span 1.5 degrees of longitude. The UTM grids have a grid spacing of 250 meters and contain about 230 rows and a latitude-dependent number of columns. They are stored in ASCII files that have the extension ".DAT", with geocoding information in a separate ASCII file that has the extension ".PRU". The Geographic grids have a grid spacing of 15 arcseconds (approximately 465 meters near the equator) and always have 121 rows and 241 columns. They are stored in ASCII files that have the extension ".GRD", with geocoding information in a separate ASCII file that has the extension ".PRG". Data values are negative integers that represent depths in meters. Missing data is flagged with a value of 0. The horizontal datum is North American Datum 1983 (GRS 80 ellipsoid).

Data Source

Word Data Center for Marine Geology and Geophysics (WDC MGG) of the National Geophysical Data Center (NGDC) of the National Oceanic and Atmospheric Administration (NOAA)

Data Availability

This data can be purchased online and is available on various media. It is included on NGDC's Global Relief CD-ROM. It is unclear whether complete coverage of the EEZ is available.

Web Site

Main Page: http://www.ngdc.noaa.gov/mgg/bathymetry/multibeam/multibeam_products.html

Notes

The US Geological Survey has been charged with surveying this region, and in 1984 launched a project called EEZ-SCAN to study it with a long-range sidescan sonar system called GLORIA (Geological Long-Range Inclined Asdic). For more information on this project see: http://walrus.wr.usgs.gov/gloria.