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Although Antarctica remains one of the least-studied regions of the Earth, this is changing due to the application of increasingly sophisticated technologies and coordinated research programs. The Institute for Geophysics is home to one such coordinated effort, the Support Office for Aerogeophysical Research (SOAR), created by the NSF Office of Polar Programs in 1994 to execute all NSF-sponsored airborne geophysical research in Antarctica. Aerogeophysical surveying is a rapid and cost-effective method of researching vast areas of the ice sheet without the risk of sending a ground-based field party into the survey area. During the Antarctic field season, SOAR operates a ski-equipped DeHavilland Twin Otter aircraft fitted with instruments to collect laser altimetry, magnetic, gravity, and surface elevation measurements. SOAR provides raw and processed data collected from the aircraft to NSF-approved investigators. |
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UTIG scientists use data collected by SOAR to investigate the structure and dynamics of the West Antarctic Ice Sheet (WAIS). The WAIS is particularly vulnerable to warming trends because large sections of it, like the unstable Ross ice shelf, are not grounded on continental rocks but extend over the ocean. These "marine" ice sheets are characterized by rapidly moving streams of ice which penetrate and drain a slowly moving ice reservoir. Were the entire WAIS to melt or to become supported entirely by the ocean, global sea levels would rise four meters over a period of 200 years or less.
Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding the stability of the WAIS and to test models of ice sheet behavior. UTIG scientists have accrued mounting evidence that the fast-moving ice streams glide on a lubricating layer of water-saturated sediment and that their behavior may be controlled by the geology of the underlying West Antarctic rift system. This system's easily eroded fault-bound basins provide the sediment for the slurry; overlying ice provides the water, melted by elevated heat flux associated with lithospheric extension. Using gravity and ice-penetrating radar measurements, the SOAR team has also detected volcanic activity beneath the ice surface for the first time.
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Because of their airborne geophysical expertise in Antarctica, UTIG scientists have become involved in the planning of an unmanned space mission to Europa, one of Jupiter's largest moons. Europa is thought to have an ocean that may possibly host exotic life under its icy surface. The orbiting spacecraft that is scheduled to be sent to Europa in 2003 will be equipped with a suite of geophysical instruments, including ice-penetrating radar. |
