Parameters for Earthquake Rupture Dynamics

Abstract

Recent progress on our understanding of earthquake rupture dynamics based on seismological observations is reviewed. One of the most important advances is the physical understanding of breakdown process that occurs at the propagating rupture front of earthquakes. The parameters such as breakdown stress drop, slip-weakening distance and fracture energy, which control the progress of dynamic rupture propagation, have now been able to be estimated. Fracture energy and hence slip-weakening distance are found to be scale dependent. To achieve such scale dependence, several different physical processes might microscopically develop, one of which dominates depending on the environmental situation at the source. Then its macroscopic behavior becomes quite simple and seems to be modeled with a single law.