Measuring Elevation Changes on the Greenland Ice Sheet
Visualizations by
Cindy Starr
Released on March 25, 2014
Since the late 1970's, NASA has been monitoring changes in the Greenland Ice Sheet. Recent analysis of seven years of surface elevation readings from NASA's ICESat satellite and four years of laser and and ice-penetrating radar data from NASA's airborne mission Operation IceBridge shows us how the surface elevation of the ice sheet has changed.
The colors shown on the surface of the ice sheet represent the accumulated change in elevation since 2003. The light yellow over the central region of the ice sheet indicates a slight thickening due to snow. This accumulation, along with the weight of the ice sheet, pushes ice toward the coast. Thinning near coastal regions, shown in green, blue and purple, has increased over time and now extends into the interior of the ice sheet where the bedrock topography permits. As a result, there has been an average loss of 300 cubic kilometers of ice per year between 2003 and 2012.
This animation portrays the changes occurring in the surface elevation of the ice sheet since 2003 in three drainage regions: the southeast, the northeast and the Jakobshavn regions. In each region, the time advances to show the accumulated change in elevation from 2003 through 2012.
The ice sheet is cut away to reveal how the bedrock topography beneath the ice sheet affects the movement of glacial ice in each region. The bedrock topography is colored by elevation with areas below sea level shown in brown and areas above sea level shown in green. Yellow indicates regions at sea level.
The bedrock topography affects the movement of the ice sheet. Blue/white velocity flows indicate the direction and speed of the ice over time. Slower moving ice is shown as shorter blue flow lines while faster moving ice is shown as longer white flow lines.
IceBridge Education and Outreach: George Hale (Telophase Corporation)
Spacecraft Models courtesy of Chris Meaney (Honeywell Technology Solutions)
Aircraft Model courtesy of Scott Hanger (NASA)
Glacier footage provided courtesy of James Balog, Extreme Ice Survey earthvisiontrust.org and www.extremeicesurvey.org
Elevation change over Greenland provided courtesy of Beata Csatho, University at Buffalo
Greenland ice sheet velocity data provided courtesy of Eric Rignot (NASA/JPL)
Greenland bed elevation provided courtesy of Bamber, et al., A new bed elevation dataset for Greenland, The Cryosphere, 7, 499-510, doi:10.5194/tc-7-499-2013, 2013.
Greenland Mapping Project (GIMP) Digital Elevation Model provided courtesy of the BPRC Glacier Dynamics Research Group, Ohio State University
The Blue Marble data is courtesy of Reto Stockli (NASA/GSFC).
Please give credit for this item to: NASA's Goddard Space Flight Center Scientific Visualization Studio
Short URL to share this page: https://svs.gsfc.nasa.gov/4022
Assembled from satellite radar interferometry data acquired during the International Polar Year (2008-2009). The satellites are Envisat Advanced Synthetic-Aperture Radar (ASAR), Advanced Land Observation System's (ALOS) Phase-Array L-band SAR (PALSAR), RADARSAT-1 SAR
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0