HR: 09:00h
AN: PP41F-05    [Abstracts]
TI: Holocene sediment accumulation rates in fjords and bays of Chilean Patagonia and the Antarctic Peninsula
AU: * Wellner, J S
EM: jwellner@uh.edu
AF: University of Houston, S&R1, Rm 312, 4800 Calhoun Rd., Houston, TX 77204,
AU: Anderson, J B
EM: johna@rice.edu
AF: Rice University, MS-126, 6100 Main St., Houston, TX 77005,
AU: Milliken, K
EM: milliken@rice.edu
AF: Rice University, MS-126, 6100 Main St., Houston, TX 77005,
AU: Fernandez, R
EM: r.f@rice.edu
AF: Rice University, MS-126, 6100 Main St., Houston, TX 77005,
AU: Michalchuk, B
EM: bm1@rice.edu
AF: Rice University, MS-126, 6100 Main St., Houston, TX 77005,
AU: Boyd, B
EM: boydoboyd7@gmail.com
AF: Rice University, MS-126, 6100 Main St., Houston, TX 77005,
AB: Beginning in 2005 and ending in May of 2007, we completed a series of four research cruises in the fjords and bays of Chilean Patagonia and the Antarctic Peninsula aimed, in part, at determining the style and rate of Holocene sediment accumulation in a range of glacial settings. Our original hypothesis stated that rates of glacial erosion are a function of sliding speed, and are therefore expected to diminish sharply as basal temperatures drop below the melting point. To test this hypothesis, we measured sediment accumulation in tidewater glacier fjords ranging from fast-moving temperate glaciers in Patagonia to slower moving polar glaciers on the Antarctic Peninsula. Four fjords were surveyed in Patagonia ranging from San Rafael fjord in the Northern Patagonia ice field to Marinelli fjord in Tierra del Fuego. The cruises to the Antarctic Peninsula included two SHALDRIL legs during which drill cores recovered 108 m and 80 m of Holocene sediment in Maxwell Bay, South Shetland Islands, and the Firth of Tay in the northwestern Weddell Sea, respectively. An additional nine fjords across the northern peninsula were surveyed with kasten and jumbo piston cores. To date, we have completed nearly 100 radiocarbon dates from fossil carbonate material, both shells and foraminifera, extracted from the sediment cores obtained in these fjords. Our initial results highlight the complexity of the controls on sediment yields and the extreme variability in sediment accumulation amongst fjords. While climate may be the first order control on glacier erosion rates and sediment transport to bays and fjords, several other factors must significantly influence these processes and may mask the broader signal. Our ongoing work with this newly acquired comprehensive dataset is examining additional controls including drainage basin size, precipitation gradient, altitude of the glaciers, and glacial substrate.
DE: 3022 Marine sediments: processes and transport
DE: 3036 Ocean drilling
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
DE: 4926 Glacial
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting