Stability of rapid finite-fault inversion for the 2014 M(w)6.1 South Napa earthquake

Local seismograms are useful for rapidly reconstructing kinematic finite-fault sources, but the results often depend not only on the data coverage but also on uncertainties of parameters (e.g., hypocentral location and fault geometry) used as a priori information during the inversion. An automatic scheme was applied to offline tests for the 2014 South Napa earthquake. In the case of retrospective full-waveform inversions, a network with station spacing of 10km within the epicentral distance of 30 km is able to provide adequate stable key source parameters if the preestimated hypocenter and fault orientation are accurate of +/-5km and +/-15 degrees, respectively. In simulated real-time inversions, the magnitude reaches M(w)6.0 at 13 s, and the slip distribution matches that from the retrospective inversion at about 22-28 s after the origin time of the earthquake. These results are meaningful for estimating the lead time of a catastrophic seismic event.National Natural Science Foundation of China (NSFC) [41574035, 41541035, 41090291]; REAKT project (Towards Real-Time Earthquake Risk Reduction) of the European Seventh Framework Programme [282862]SCI(E)EIARTICLEzhygn@163.com2310263-102724