Fault Slip Rate Based Kinematic Model for Southern California

We present a kinematic model of Southern California determined by prescribing geometry and geologic slip rates on active faults and modeling deformation in a linear elastic half-space. Faults creep below seismogenic depths of 13 +/- 3 km and are locked above. Velocity and strain rate are calculated throughout the model using the results of Okada (1992). We compare our results with geodetic rates to address two objectives. 1. Where and why do modeled and geodetic rates disagree. 2. What effects do laterally variable crustal elastic properties (e.g., an elastically weak L.A. sedimentary basin embedded in crystalline crust) have on modeled velocities. We use seismic velocity to determine elastic properties, which predict the L.A. Basin and Imperial Valley area to be elastically weaker by approximately a factor of two. Modeled and geodetic rates are generally consistent, though we find significant differences in areas where laterally varying elastic properties are known to be important.