The supershear effect of topography on rupture dynamics

Abstract

The Earth's free surface is a critical boundary for dynamic rupture propagation that plays an important role in influencing rupture patterns, especially the subshear-to-supershear transition. Surfaces with irregular topographies, which are prevalent in nature, may change this supershear transition mechanism. Using the curved grid finite-difference method, which can be employed to solve elastodynamic equations in curvilinear coordinates, we model spontaneous dynamic rupture on faults with irregular free surfaces. We investigate its effect on the dynamic rupture process with extensive numerical simulations. The simulated results show that the effect of topography on a rupture is dependent on the shape and epicentral distance of the topography.