HR: 1340h
AN: G53A-0865    [Abstracts]
TI: Discrepancy Between Geodetic and Geological Fault Slip Rates and Crustal Deformation: Insights From Geodynamic Modeling
AU: * Luo, G
EM: glk82@mizzou.edu
AF: Department of Geological Sciences, University of Missouri-Columbia, 101 Geology Building, Columbia, MO 65211
AU: Liu, M
EM: lium@missouri.edu
AF: Department of Geological Sciences, University of Missouri-Columbia, 101 Geology Building, Columbia, MO 65211
AB: Space geodesy has becoming an increasingly powerful tool for measuring crustal deformation; however, in many places the strain rates derived from geodetic data are significantly different from that based on geological evidence. This discrepancy may indicate different strain rates in the geological past, or it may simply reflect the timescale-dependent behavior of fault movement. The latter is amenable to numerical simulations. Here we present results of a numerical investigation of the short- and long-term behavior of normal, reverse, and strike-slip faults. Using 3D finite element model with viscoelasto-plastic rheology, we simulate the spatial-temporal evolution of co-seismic, post-seismic, and interseismic crustal deformation, and compare the results with long-term deformation. We explore the effects of major model parameters, including rheological contrasts between the upper and lower crust, the depth and length of seismogenic zone, and the geometry of the faults. Our results show that, because of the different timescales represented by geodetic and geological data, systematic discrepancy is expected even for idealized simple fault systems. We show that results from these simple models are helpful to reconcile discrepancies between geodetic and geological strain rates in many regions in the world.
DE: 0545 Modeling (4255)
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1242 Seismic cycle related deformations (6924, 7209, 7223, 7230)
SC: Geodesy [G]
MN: Fall Meeting 2005