Numerical simulation of the stress field in California: implications for the stress perturbation by Big Bend and Garlock Fault (original) (raw)

2D finite element modelling is used to analyze the state of stress in and around the San Andreas Fault System (SAFS) taking the whole area of California. In this study we focus on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology. The purpose of the present study is to simulate the regional stress field and also to find the stress perturbation due to Big Bend and Garlock Fault. Although in nature there is lateral and vertical variation in rheology, our highly simplified domain properties have simulated results comparable with the observed data. Our imposed boundary condition (fixed North American plate, Pacific plate motion along N34W vector up to northern terminus of the San Andreas faults and N50E vector motion for the subducting Gorda plate) simulated the present day regional Hmax orientation and velocity vector. Simulated results show local effect on the stress field and displacement vector by the Big Bend and is further enhanced by the Garlock Fault, which may have significant impact on fault slip, stress, and hence deformation in the surrounding region.