HR: 15:25h
AN: C13A-08    [Abstracts]
TI: Will continued thinning of Pine Island Glacier, Antarctica lead to rapid grounding line retreat?
AU: * Vaughan, D G
EM: d.vaughan@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Corr, H F
EM: hfjc@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Holt, J W
EM: jack@ig.utexas.edu
AF: Institute of Geophysics, University of Texas at Austin, Austin, TX 78759 United States
AB: The measured thinning of glaciers in West Antarctica has reopened the debate concerning the stability of this marine ice sheet, and its likely contribution to sea level rise. Prognostic modelling of the evolution of these glaciers over the coming decades and centuries has, however has been impeded by a paucity of data indicating ice thickness and bed topography. The collection in 2004/05 by a US/UK collaboration, of over 100,000 km of airborne geophysical data across West Antarctica, including a high-resolution ice-penetrating radar survey of the downstream portion of Pine Island Glacier has provided a new basis on which to make such predictions. We present new basal topographic and ice thickness grids of Pine Island Glacier derived from the new data, together with assessments of basal roughness. Using these, we predict the satbility of the grounding line over decades and centuries, in response to continued thinning at the present rate and with the accelerated thinning as basal restraint is reduced by grounding line retreat. We identify areas of reverse bed slope that could promote periods of rapid grounding line retreat and basal topographic highs that could cause retreat to pause, or even halt long enough for equilibrium to be re-established.
DE: 0726 Ice sheets
DE: 0730 Ice streams
DE: 1621 Cryospheric change (0776)
DE: 1641 Sea level change (1222, 1225, 4556)
SC: Cryosphere [C]
MN: Fall Meeting 2005