Launched January 12, 2003, NASA's Ice, Cloud, and land Elevation Satellite, or ICESat, is designed to measure the mass balance of Earth's ice sheets (balance between processes that add ice to the ice sheets versus processes that remove ice), the height of clouds and aerosols, and the topography of the land. A primary goal of the mission is to help scientists determine whether the ice sheets of Earth's poles are growing or shrinking, and to better understand how changes in the atmosphere and climate affect the polar ice caps and global sea level. The colors on the map above represent ICESat's measurements of Antarctica's topography, using data collected from October 3 through November 8, 2004. Red shows the highest elevations (up to 4,000 meters above sea level). Yellow, green, and turquoise show progressively lower elevations (green is 2,000 meters above sea level). Dark blue shows sea level. Using ICESat data, scientists recently confirmed that there is accelerated movement of glaciers on the West Antarctic ice sheet and the Antarctic Peninsula (located at about 10 o'clock) following the breakup of the floating ice shelf onto which the glaciers flowed. At the American Geophysical Union (AGU) Conference in San Francisco, on December 13, 2004, scientists from NASA's Goddard Space Flight Center reported that part of the West Antarctic ice sheet is growing thinner as a result of this glacial flow into the Bellingshausen Sea. Any significant flow of glacial ice off Antarctica will contribute to rising sea level. (For more details, please see www.nasa.gov/vision/earth/lookingatearth/icesat_light.html NASA's ICESat Satellite Sees Changing World Affecting Many .)
