HR: 0800h
AN: H51A-1098    [Abstracts]
TI: Sediment Proxies of Quaternary Glacial Dynamics in the Gulf of Alaska Region
AU: * Jaeger, J M
EM: jaeger@geology.ufl.edu
AF: University of Floirda, P.O. Box 112120, Gainesville, FL 32611-1120 United States
AU: Vienne, W
EM: wvienn1@ufl.edu
AF: University of Floirda, P.O. Box 112120, Gainesville, FL 32611-1120 United States
AU: Hildick, A
EM: alrock8@ufl.edu
AF: University of Floirda, P.O. Box 112120, Gainesville, FL 32611-1120 United States
AU: Stoner, J
EM: jstoner@coas.oregonstate.edu
AF: Oregon State University, 104 COAS Adminstration Building, Corvallis, OR 97331-5503 United States
AB: Southeastern Alaska is one setting where the depositional products of the interplay between tectonics and climate are recorded at exceptionally high temporal resolution. An important advantage of Alaska over other margins is proximity of the highest coastal mountain range on earth next to an energetic ocean with essentially no intervening basins to trap sediment. Climatic signals are therefore quickly recorded in offshore areas with little modification resulting from long transport in rivers or temporary storage in intervening sedimentary basins. Recent studies of glacial mass balances in southern Alaska reveal rapid loss in the past decade, which is ascribed to global climate change trends. However, it is not possible to place these recent changes in a larger context of regional climate change because the terrestrial record of Holocene glacial dynamics is incomplete. A recent field campaign has been initiated in the Gulf of Alaska region to examine the Late Quaternary to Modern record of glacial dynamics. We will present results of sedimentary studies on the continental margin that highlight chronological and provenance approaches used to document the dynamics of specific glacial basins in the region at decadal resolution. Specifically, a combination of environmental magnetism, U-Th-K activities, and sediment physical property measurements reveal that glacial source regions can be differentiated in marine sediments. Also, Little Ice Age glacial dynamics appear to have strongly varied over decadal time scales in conjunction with regional temperature indices. These advance-retreat cycles are manifested on the continental shelf as decadal -long pulses of sediment discharge from coastal mountains followed by equally long periods of terrestrial sediment storage and corresponding low marine sediment accumulation rates.
DE: 4215 Climate and interannual variability (3309)
DE: 4558 Sediment transport
DE: 3022 Marine sediments--processes and transport
DE: 1827 Glaciology (1863)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting