Numerical Simulation of the stress field in California

FE modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) system.In this study we mainly focus on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology.Stress perturbation due to major fault, its geometry and major branches are analyzed. Series of calculations were performed with the parametrical variations of domain properties and were applied for the strong/weak SAF. All the simulated results are finally utilized for the implication of present day plate kinematics. The imposed boundary condition have simulated the present day regional Hmax orientation and displacement vector.Our simulated results in the weak fault in relatively strong crust conditions has more or less reproduced comparable and theoretically correct results, allowed us to favor Weak fault in relatively strong crust. Depthwise variation of the fault type reveal that as the depth increases, the fault types are generally normal and at shallow depth more strike slip and thrust faults are formed. In conclusion that SAF may terminate as a normal fault at the depth.

Autorentext

MATRIKA PRASAD KOIRALA: M.Sc.Engineering Geological Techniques, Geology 2001, Tribhuvan University, Nepal; M.Sc. Numerical Simulation, 2008 from University of the Ryukyus, Okinawa, Japan. DAIGORO HAYASHI: Ph.D. Hokkaido University, 1977, Japan Professor at University of the Ryukyus, Okinawa, Japan.