HR: 12:10h
AN: C22A-08    [Abstracts]
TI: The Co-evolution of continental ice cover and permafrost extent over the last glacial-interglacial cycle in North America
AU: * Tarasov, L
EM: lev@atmosp.physics.utoronto.ca
AF: Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7 Canada
AB: The University of Toronto glacial systems model (UofT GSM) has been employed to simulate both the evolution of the North American ice sheet and the evolution of the spatial and depth extents of permafrost over the most recent glacial-interglacial cycle in North America.The model is initialized during the Eemian interglacial and has been calibrated using a Bayesian methodology against multiple observational data sets. These data sets include (1) a very large number of radio-carbon dated RSL time series from sites on the Laurentide platform, (2) a sequence of measurements of the time dependence of the surface gravitational acceleration based upon absolute gravity measurments, (3) VLBI measurements of the rate of vertical crustal motion. The UofT GSM is coupled to a detailed model of the thermal evolution of the sub-surface and to a basal processes module that includes the influence the deformation of soft sediment and heat flow into the base of the ice sheet from the Earth's interior. Climate forcing through the ice age cycle has been approximated by employing the summit, Greeland ice core records of del-18O as a means to interpolate between a modern NCEP/NCAR reanalysis climatolgy and an LGM climatology derived from an ensemble of results from the international Paleoclimae Modelling Intercomparison Project.Results and shown to reconcile a number of sub-surface thermal constraints.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0429 Climate dynamics (1620)
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 0475 Permafrost, cryosphere, and high-latitude processes (0702, 0716)
SC: Cryosphere [C]
MN: Fall Meeting 2005