This proposal is for the data analysis phase of ground.based radar studies conducted by the U.S. Geological Survey and St. Olaf College in 1987.89 in the Siple Coast region of the West Antarctic Ice Sheet. The drainage of this ice sheet is in large part controlled by fast ice stream flow in this area which recently has shown dramatic change. In 1987.88 digitized radar waveforms were recorded in high density profiles at 5 transmitter frequencies on ice stream B. A similar program was conducted on ice stream C in 1988.89 in which over 400 Km of profiles were recorded, including both shear marginal zones and a longitudinal area coinciding with the Ohio State University strain grid. Preliminary analysis of these data has shown that they contain detailed information about internal layering, buried crevasses, and conditions at the bed . information which can aid in understanding the nature of fast ice stream dynamics and flow history in this area. This proposal covers a two year period October 1, 1989 . October 1, 1991, the first year coinciding with the data analysis phase of a number of geophysical studies conducted by other groups working on ice streams B and C. The focus of the research will be on the processing and analysis of radar data acquired in the past two field seasons and using this information in conjunction with the data obtained by other investigators to answer a number of questions about ice stream dynamics.
