Earthquake cycling simulations by a Curved Grid Finite Difference Method

Rate- and state-dependent friction law (RSF), derived from laboratory studies, is very useful in explaining the earthquake mechanism, especially for modeling a complete earthquake cycle including preseismic, coseismic and postseismic processes. Semi-analytical methods such as the boundary integral equation method have been adopted in previous studies to model an earthquake process following the RSF, but it is difficult to handle the problem with heterogeneous medium using the semi-analytical methods. In recent years, pure numerical methods such as finite difference method or finite element method have been developed to solve the dynamic rupture process following the RSF, which are flexible to handle with heterogeneous medium. Thus, we implement the Curve-Grid Finite Difference Method (CG-FDM) proposed by Zhang and Chen (2006) to calculate the earthquake cycling process including quasi-static and dynamic rupture processes controlled by the RSF. CG-FDM not only has the simplicity and efficiency in algorithm, but also can deal with complex fault geometries, which is suitable for calculating earthquake rupture processes of actual faults. With this method, we simulate and discuss the effects of rupture parameters, fault geometry and heterogeneous media during earthquake cycling processes. This work gives us a better understanding of seismic source physics for actual earthquakes.