Determining Seismic Fault Plane Using Static Coulomb Stress Triggering Criterion

The focal mechanism solution has two nodal planes, one of which is the fault plane of the earthquake and is difficult to be determined using seismic waveform data. Study on seismic static stress triggering shows that main-shock has relatively obvious trigger effect on its subsequent aftershocks. The spatial distribution of aftershocks provides effective information for the fault plane determination. In this study, the Wenchuan earthquake sequence and Yushu earthquake sequence are used as examples to investigate the possibility of determining the fault plane from the two nodal planes of the focal mechanism through maximum stress triggering criterion of the aftershock. The study of two cases shows that, the fault plane determined using above the method is consistent with the aftershock distribution, surface observation. This study may provide a way for the rapid determination of earthquake fault plane.