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Airborne Geophysics
Program History: UTIG's aerogeophysical program began in 1991 with a project to develop the first integrated airborne platform to simultaneously address problems in glaciology and subglacial geology. This initial research grant (with the unwieldy acronym CASERTZ) targeted understanding the influence of underlying geology on the location and evolution of West Antarctic ice streams. Following the success of that initial 50,000 line-kilometer survey, UTIG was asked by the National Science Foundation to operate a facility (the Support Office for Aerogeophysical Research; SOAR) for conducting all U.S. aerogeophysics in Antarctica. In successive field campaigns from 1994 until 2002, SOAR acquired and reduced 210,000 line kilometers of aerogeophysical data from 425 research flights. These flights supported 10 research projects with 20 investigators at 14 U.S. institutions. Approximately 130,000 line kilometers of these data were collected for research projects carried out by UTIG scientists in both East and West Antarctica.
Instrumentation:
For its aerogeophysical work in Antarctica, UTIG researchers use a ski-equipped,
DeHavilland Twin Otter aircraft fitted with the world's most powerful
ice-penetrating radar (see our profile over subglacial Lake Vostok below). Other
instruments simultaneously collect laser altimetry, gravity, and magnetic
data. This integrated geophysical instrumentation package is ideally suited
for glaciology and sub-ice geologic problems on sub-continental scales.
Current Research: Concerns about the potential impacts of global environmental change are a principal motivation for glaciological research in West Antarctica. From satellite remote sensing observations, we know that the Amundsen Sea Embayment is the only major ice drainage basin in Antarctica that is presently out of balance and contributing to global sea-level rise. In some locations, it is thinning at rates of more than 10 meters per year. In collaboration with researchers at the British Antarctic Survey, UTIG researchers Holt and Blankenship have been funded by NSF to conduct an 800x800x1100 kilometer survey of the entire Amundsen Sea Embayment (labeled AGASEA on the coverage map) of the West Antarctic ice sheet during 2004-2005. UTIG's aerogeophysics group is also currently funded to develop new techniques for radar sounding, and testing these during further airborne and ground-based radar surveys in East and West Antarctica. These new techniques are used to investigate the development of water systems beneath the terrestrial ice sheets and will be applicable to studies of the Martian ice caps and of Jupiter's icy moon, Europa. Future Plans: UTIG researchers are developing plans to migrate their instrumentation and techniques to other aircraft and platforms for different applications. One application is to execute large area surveys in East Antarctica using long-range U.S. Navy aircraft. Another application under study is the use of aerogeophysics to understand the link between mountain uplift and glacier processes in Alaska and to help solve hydrologic problems in Texas. Relevance: Global climate change and it's consequences are an important topic of scientific research and societal concern. The ice in polar regions plays a crucial role on mediating and controlling global climate. Because of the remoteness and scale of Antarctica, the role of the ice sheet in the global climate system can only be properly understood through coordinated research programs such as those conducted by scientists at UTIG. Education and Training: The Antarctic research program at UTIG has provided valuable research opportunities for many graduate and undergraduate students as well as high school students who carry out summer internships at the Institute each year as part of the Science and Engineering Apprenticeship Program administered by the Applied Research Laboratory at The University of Texas at Austin. |
