Inferring faulting model using InSAR deformation differencing vector: application to the 2014 Napa earthquake.

InSAR observation is widely used for mapping the coseismic deformation and estimating the earthquake source model. However, atmospheric delay noise reduces the accuracy of the mapped coseismic surface deformation, which results in the significant uncertainty of the InSAR-derived faulting model. Therefore, it is significant to mitigate the negative effect of atmospheric noise and improve the InSAR data inversion performance of earthquake source modeling. In this study, a new method of fault slip inversion is proposed, in which InSAR deformation differencing vector (IDV) is utilized as an independent constraint on source modeling instead of the original InSAR observation. According to the experimental result obtained from the simulated InSAR data, the proposed method significantly mitigates the negative effect of atmospheric noise, and the slip residual is reduced by up to ~ 65% when compared to the estimate based on the original InSAR observation. Then, the proposed method is applied to investigate the coseismic faulting of the 2014 Napa, California earthquake. It is found that the surface deformation predicted by the IDV-derived faulting model is more consistent with the GPS observation than the result obtained through the original InSAR-derived faulting model, and that the accuracy is improved by ~ 28%. [ABSTRACT FROM AUTHOR]