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Bathymetry layer
The Bathymetry layer represents the depth to the ocean floor over an area
generally covering the continental shelf, and sometimes beyond.
The resolution of the data in the application is 15 seconds by 15 seconds, which translates
to a quarter of a nautical mile (1,519 ft or 463 m) vertically. Horizontally, it depends
on the latitude. At the lowest latitude (south Florida), it would be 1,382 ft (421 m), and the highest
latitude (near the Canadian border), it would be about 1,002 ft (305 m).
The depth is stored in whole meters and is translated into feet if desired. This
obviously affects the vertical resolution, especially for very shallow areas.
The California version has an old isobath-based version which will be replaced
with the much more complete raster version in the next update.
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| Off the coast of Washington and Oregon |
Depth detail |
Options
Color
There are three color options:
- Linear is the most obvious: deeper is darker
- Log is used for better visualizing small depth differences in shallow waters
- False uses false colors to reveal details that are otherwise difficult to see
Terrain shading
Artificially renders highlights and shadows as if light was coming from the northwest.
Show isobaths
This is an experimental feature which draws rough isobaths at the specified intervals.
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Origin
National Oceanic and Atmospheric Administration
National Geophysical Data Center (NGDC)
Divins, D.L., and D. Metzger, NGDC Coastal Relief Model
Description of data source
This Coastal Relief Gridded database provides the first comprehensive view of the US Coastal Zone;
one that extends from the coastal state boundaries to as far offshore as the NOS hydrographic data will
support a continuous view of the seafloor. In many cases, this seaward limit reaches out to, and in places even beyond the continental slope.
Bathymetric data sources include the US National Ocean Service Hydrographic Database,
the US Geological Survey (USGS), Monterey Bay Aquarium Research Institute (MBARI), US Army Corps of Engineers LIDAR (SHOALS),
and various other academic institutions. Volumes 3 through 5 also use bathymetric contours from the International Bathymetric Chart of
the Caribbean Sea and the Gulf of Mexico project as input to the gridding process.
The gridded database contains data for the entire coastal zone of the conterminous US, including Hawaii and Puerto Rico.
Gridded data for the Great Lakes, and integrated grids of these and additional U.S. Coastal areas, including Alaska are also available at other resolutions.
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