HR: 14:40h
AN: T33D-05    [Abstracts]
TI: The results of coupled climate/tectonic numerical and analytical models of margin development during episodes of climate change
AU: * Tomkin, J H
EM: tomkin@geol.lsu.edu
AF: Louisiana State University, Dept. Geology and Geophysics, Baton Rouge, LA 70803 United States
AU: Brandon, M T
AF: Yale University, Dept. Geology and Geophysics, New Haven, CT 06511 United States
AB: Current theory suggests that rock uplift in active orogens is coupled to surface processes, which are in turn coupled to climate. This idea is both analytically and numerically tested. A critical wedge based analytical model is compared with a geodynamic model that couples a thermo-mechanical model of crustal shortening with a landscape evolution model that includes glacial evolution. The analytical model predicts that at an active orogen and in a cooling climate, the "glacial buzzsaw hypothesis" produces an instantaneous increase in the rate of erosion, and that this increase can lead to a doubling in both rates of erosion and uplift. The numerical results reproduce the large increase in rock uplift and erosion, but also indicate that there is a significant delay in the coupled system. This delay is of the order of hundreds of thousands of years. The numerical model also suggests that the "glacial buzzsaw hypothesis" is inconsistent with current theories of glacial erosion in coupled orogenic systems.
DE: 8105 Continental margins and sedimentary basins
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
DE: 1827 Glaciology (1863)
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting