Surface of the Earth, 2 minute color relief images

Click on a 45 degree by 45 degree square below to zoom in,
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This image was generated from digital data bases of seafloor and land elevations on a 2-minute latitude/longitude grid (1 minute of latitude = 1 nautical mile, or 1.852 km). Assumed illumination is from the west; shading is computed as a function of the east-west slope of the surface with a nonlinear exaggeration favoring low-relief areas. A Cylindrical Equidistant projection was used for the world image, which spans 360 degrees of of longitude from 180 West eastward to 180 East; latitude coverage is from 90 degrees North to 90 degrees South. The resolution of the gridded data varies from true 2-minute for the Atlantic, Pacific, and Indian Ocean floors and all land masses to 5 minutes for the Arctic Ocean floor. Clicking on a square above brings up a 512 x 512 pixel color relief image of the 45 degree area selected, clicking on the 512 x 512 image brings up the full-resolution 1350 x 1350 pixel (roughly 3 mb) color image of the area.

Major Sources of Data:

1. The seafloor data between latitudes 64° North and 72° South are from the work of Smith and Sandwell (1997). These data were derived from satellite altimetry observations combined with carefully, quality-assured shipboard echo-sounding measurements, by Dr. Walter H.F. Smith, of the NOAA Laboratory for Satellite Altimetry and Dr. David T. Sandwell, of the Institute of Geophysics and Planetary Physics at the University of California, San Diego. Data version 8.2 is used here.
   
   For reference on generation of these data, consult:
   W.H.F. Smith and D.T. Sandwell, "Global Sea Floor Topography from Satellite Altimetry and Ship Depth Soundings," Science Magazine, vol. 277, issue 5334, 1997.
   
   
2. Seafloor data southward of 72° South are from the US Naval Oceanographic Office's (NAVOCEANO) Digital Bathymetric Data Base Variable Resolution (DBDBV), version 4.1, gridded at 5 minute spacing; some data in this region are from the older DBDB5 (these data were also used in ETOPO5). Seafloor data northward from 64° North are from the new International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 1.
   
   For reference on generation of the IBCAO data, consult:
   Jakobsson,M., N.Z. Cherkis, J. Woodward, R.Macnab, and B. Coakley. New grid of Arctic bathymetry aids scientists and mapmakers; Eos,Transactions, American Geophysical Union, v.81, no.9, p. 89,93,96.
   
   
3. Land topography is from the GLOBE Project, an internationally designed, developed, and independently peer-reviewed global digital elevation model (DEM), at a latitude-longitude grid spacing of 30 arc-seconds (30"). The GLOBE Task Team was established by the Committee on Earth Observation Satellites (CEOS). It is part of Focus I of the International Geosphere-Biosphere Programme - Data and Information System. Primary contributors to the GLOBE database are:
   
   • National Imagery and Mapping Agency (formerly Defense Mapping Agency), Fairfax, Virginia, USA
   • Geographical Survey Institute, Tsukuba, Japan
   • Australian Surveying and Land Information Group, Canberra, ACT, Australia
   • Jet Propulsion Laboratory, Pasadena, California, USA
   • University College London, UK
   • DLR-German Remote Sensing Data Center, Oberpfaffenhofen, Germany
   • NOAA National Geophysical Data Center, Boulder, Colorado, USA
   • USGS EROS Data Center, Sioux Falls, South Dakota, USA

Data Base Assembly

The five major data sources were assembled into the single ETOPO2 2-minute data base without formal edge matching or other methods that alter the data as initially posted. Higher-resolution data take precedence: data derived from GLOBE mask all other data, Smith/Sandwell data come next, followed by IBCAO, with the 5-minute data filling any gaps.

Five-minute data from DBDBV and ETOPO5 and 30-second data from GLOBE were regridded to 2 minute spacing by bicubic spline interpolation. IBCAO data were originally gridded in a polar stereographic projection; these data were interpolated along lines of constant latitude at 2 minute steps for every 2 minutes of latitude from 72° North to the pole.

Further information on the Smith and Sandwell data is available at: http://www.ngdc.noaa.gov/mgg/bathymetry/predicted/explore.HTML

For further information on the GLOBE project, consult: http://www.ngdc.noaa.gov/mgg/topo/globe.html.

Also see our products page offering data on CD-ROMs, posters, slides, and other media.

Or try our on-line viewer showing the same data set as globes from different views

NGDC can produce custom images, on request, for many of our databases. Please contact Dr. Peter W. Sloss (), NOAA/NGDC Mail Code E/GC3, 325 Broadway, Boulder, CO USA 80305, Phone 303-497-6119, fax 303-497-6513, for details.