Map of Antarctic bedrock elevation now available in Atlas of the Cryosphere

Release Date: January 9, 2009

The following map of Antarctica's bedrock elevation (the elevation of the solid land beneath the ice sheet) is now available in the Atlas of the Cryosphere (

The BEDMAP project compiled the available ice thickness measurements over Antarctica to produce a topographic model of the bed of the Antarctic ice sheet. This map is compiled at 5 km resolution from ground-based and airborne surveys collected over the period 1951-1999, primarily from radar and seismic sounding as well as gravimetric measurements. Elevations are reported relative to the OSU91A geoid.

Below are images of both the Antarctic and Greenland (Bamber et al. 2001) bedrock elevation maps available through the Atlas of the Cryosphere. The color scale of the latter has been slightly modified to allow for easier qualitative comparison between the two ice sheets. Note that shades of orange are above average sea level while those in shades of gray are below average sea level.

Bedrock elevation of the Antarctic (left) and Greenland (right) ice sheets. Click on either image to view the map in the Atlas of the Cryosphere Web interface (this will open in a new page).

In addition to accessing the Antarctic BEDMAP data set through the Atlas of the Cryosphere Web interface, it is also available remotely in a variety of formats and map projections through Open Geospatial Consortium (OGC) protocols, as in the following examples:

We welcome your feedback on this project. If you have questions, comments or suggestions, please contact NSIDC User Services at +1.303.492.6199,, or via our online contact form. The development of this map server application was supported by NASA's Earth Observing System (EOS) Program under contract NAS5-03099 and was developed using MapServer, an Open Source development environment for building spatially-enabled internet applications. The Atlas of the Cryosphere was developed by John Maurer. Future updates will continue to be announced on this RSS feed.