HR: 0800h
AN: B31A-0202    [Abstracts]
TI: Environmental Framework for Vostok Core Samples of Lake Vostok
AU: * Bell, R E
EM: robinb@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Rte. 9W, Palisades, NY 10964 United States
AU: Studinger, M
EM: mstuding@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Rte. 9W, Palisades, NY 10964 United States
AU: Castello, J D
EM: jdcastel@syr.edu
AF: State University of New York - Environmental Science and Forestry, 1 Forestry Dr., Syracuse, NY 13210 United States
AB: We have developed an environmental framework for interpreting the results of extensive biologic studies from the Vostok core basal ice (below 3540 m) by using new flow velocities of the ice sheet over Lake Vostok during the last glacial maximum and enhanced imaging of the shoreline topography. The ice core represents a suite of samples across the lakeshore and the lake. The oldest accretion ice in the Vostok core formed $\sim$ 56,000 years ago at accretion rates of 0.45-0.72 cm/yr at the westernmost lake shoreline. Within our new environmental framework, the ice core can be classified on the basis of water depth and relative isolation from the processes active in the main lake. Review of the basal ice studies to date, and excluding from consideration likely contaminants, the diversity of microbial taxa reflects some systematic variation with both water depth and lake environment. These results support the interpretation that some of the observed microbes are neither the product of contamination nor the result of transport of windblown surface material, but rather are a partial but accurate representation of the subglacial Lake Vostok microbial community
DE: 1827 Glaciology (1863)
DE: 1615 Biogeochemical processes (4805)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting