HR: 14:10h
AN: H33F-03    [Abstracts]
TI: Orogen Evolution in Response to Oscillating Climate
AU: * Meade, B J
EM: meade@fas.harvard.edu
AF: Department of Earth and Planetary Science, Harvard University, 20 Oxford St., Cambridge, MA 02138
AB: Over the last several years quantitative models have been developed to predict the steady state form of mountain belts. These models define steady state in terms of mass conservation, where climate mediated erosional efflux is balanced by tectonic influx. However, paleoclimate records suggest that climate is not steady and varies over a wide range of frequencies, ω. Here we quantify orogen response to oscillating climate by building on a recently developed theory for the transient evolution of mountain belts in response to a step function change in climate. Both dimensional analysis and numerical experiments suggest that the relative change in orogen cross sectional area, δ A, is inversely proportional to the frequency of climate oscillations, δ A ~ ω^-1. This indicates that high frequency variations in climate do not significantly perturb the overall form of an orogen because the climate state changes before the orogen has time to remove, or add, enough to mass to approach a new steady state.
DE: 1815 Erosion
DE: 8175 Tectonics and landscape evolution
DE: 8177 Tectonics and climatic interactions
SC: Hydrology [H]
MN: Fall Meeting 2005