Nature of fault rupture under the influence of the dynamic interaction between rupture process and sedimentary layers

Abstract

Large and long-period velocity pulses observed in the parallel direction at near-fault stations are important in earthquake engineering. A previous study has indicated that the existence of the ground surface and sedimentary layers affects fault rupture. This study conducts dynamic rupture simulations and discusses the dynamic interaction between fault rupture and seismic wave field induced by the sedimentary layer. The dynamic model of fault rupture is implemented using the finite element method to consider the interaction. Longer τh (pulse width) and shorter τr (rise time) of the near-surface slip rates are observed when the sedimentary layer exists, and τr is related to the travel time of reflected waves at the interface between the sedimentary layer and the basement.