HR: 0800h
AN: C21B-1086    [Abstracts]
TI: Rising Seas and Ice Sheet Destabilization; Timing and Patterns of the Antarctic Peninsula Ice Sheet Retreat following the Last Glacial Maximum (LGM)
AU: * Heroy, D C
EM: heroy@rice.edu
AF: Rice University, 6100 Main St, Houston, TX 77005 United States
AU: Anderson, J B
EM: johna@rice.edu
AF: Rice University, 6100 Main St, Houston, TX 77005 United States
AB: We present marine sedimentologic and radiocarbon data for the timing of retreat of the largely marine-based Antarctic Peninsula Ice Sheet since the Last Glacial Maximum (LGM). Our findings indicate minimum estimates of deglaciation between 17,500 to 9,000 calibrated years before present (cal yr BP), roughly in phase with the Northern Hemisphere. This retreat occurred progressively from the outer to the inner continental shelf, as well as from the north to the south. Retreat initiated by 17,500 to 14,000 cal yr BP from the outer shelf, significantly earlier than predicted by numeric models. A significant step in the data occurs at 14,000 cal yr BP and possibly at 11,000 cal yr BP, coincidental to rapidly rising sea level (melt water pulses 1a and 1b). This supports the hypothesis that rapidly rising sea level is associated with marine ice sheet destabilization. This study highlights problems with radiocarbon dating acid insoluble organic (AIO) matter in glaciomarine sediments as well as the need for more accurate dating techniques.
DE: 0726 Ice sheets
DE: 1621 Cryospheric change (0776)
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
DE: 4901 Abrupt/rapid climate change (1605)
SC: Cryosphere [C]
MN: Fall Meeting 2005