HR: 1340h
AN: G53A-0867    [Abstracts]
TI: Lithospheric Elasticity Promotes Episodic Fault Activity
AU: * Chery, j
EM: jean@dstu.univ-montp2.fr
AF: Laboratoire Dynamique de la LithosphŠre, CC 060, place E. Bataillon, CNRS-Universit‚ de Montpellier II, Montpellier, 34095 France
AU: Vernant, P
EM: vernant@mit.edu
AF: Earth, Atmospheric and Planetary Sciences Department, Massachusetts Institute of Technology, 54-617, 77 Massachusetts avenue, Cambridge, MA 02139-4307 United States
AB: Based on the agreement between geodetic and geological plate velocities, interplate fault slip rates are usually considered constant over long periods of time. However, measurements made at different time scales on intracontinental faults suggest that slip rate evolves with time. We examine the slip evolution of a fault embedded in an elastic lithosphere loaded by plate motion. We first assume that the fault friction varies due to a climatic cause. Then we show that high fault stress and low lithospheric stiffness favour large variations of slip rate. In the case where fault weakening is controlled by slip rate, we find that high loading velocity leads to a low stress, constant slip rate, while low loading velocity drives the fault slip rate to cycle between high and low values. This suggests that geodetic and paleoseismic slip rate could overpass the loading velocity but also fall to zero for some period of time.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1236 Rheology of the lithosphere and mantle (7218, 8160)
DE: 1242 Seismic cycle related deformations (6924, 7209, 7223, 7230)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
SC: Geodesy [G]
MN: Fall Meeting 2005