Simulation of earthquake rupture process and strong ground motion

Computer simulation of the strong ground motion generated from the earthquake•rupture process on a shallow strike-slip fault are carried out by using a 3-D finite difference method. The faulting process is modeled using a dynamic crack model with fixed rupture velocity or with finite-stress-fracture criterion. The near-source ground motion is sensitive to the details of sliprate or slip-acceleration function. So we do not choose the kinematic modelling in which slip-rate time need to be assumed. In dynamic modelling, the slip-rate time function at each fault point is calculated by solving 3D wave equation of motion. The variability of peak ground velocity patterns, correlated with fault location and source parameters such as stress drop or rupture velocity is investigated. Our findings suggest that these patterns are strongly affected by rupture directivity and the uppermost depth of the fault, or that of the asperity. These results help better predict the strong ground motion generated from a potential fault.