HR: 0830h
AN: T51F-0223    [PDF]
TI: Structure and Seismicity of West Antarctica
AU: * Winberry, J
EM: winberry@essc.psu.edu
AF: Department of Geosciences Pennsylvania State University, 441 Deike Building, University Park, Pa 16802 United States
AU: Anandakrishnan, S
EM: sak@essc.psu.edu
AF: Department of Geosciences Pennsylvania State University, 441 Deike Building, University Park, Pa 16802 United States
AB: A large part of the West Antarctic Ice Sheet (WAIS) is situated on the West Antarctic rift system. The base of the ice sheet is currently below sea level, which has lead some researchers to suggest that its size, volume, and flow characteristics are particularly sensitive to climate change. Much of the ice is transported from the interiors to the coast via fast-flowing glaciers and ice streams whose flow dynamics are strongly controlled by conditions at the bed. Variations in basal temperature, water content, and the distribution and lithology of sedimentary basins and crystalline basement contribute to the complexity of flow environments observed in the Antarctic. Mapping those parameters will contribute to an improved ability to model the ice sheet accurately. We report on the mapping of sedimentary layers beneath the Antarctic using broadband seismic techniques and their association with flow of the ice sheet. We also report on the first documentation of seismicity in the region. The data presented indicate that the ice sheet does not suppress seismicity as has been previously proposed. However, the observed earthquake pattern suggests the West Antarctic rift system is no longer actively extending.
DE: 7205 Continental crust (1242)
DE: 7230 Seismicity and seismotectonics
DE: 8107 Continental neotectonics
DE: 9310 Antarctica
SC: Tectonophysics [T]
MN: 2003 Fall Meeting