Locating the Small 1999 Frenchman Flat, Nevada Earthquake with InSAR Stacking

Due to high interferometric coherence in the Nevada region,Interferometric Synthetic Aperture Radar(InSAR)phase stacking is capable of mapping coseismic signals from the 27 January 1999,M w 4.8 Frenchman Flat earthquake.This is one of the smallest earthquakes yet studied using InSAR with line-of-sight displacements as small as~1.5 cm.Modelling the event as dislocation in an elastic half space suggests that the fault centroid was located at(115.96°W,36.81°N)with a precision of 0.2~0.3 km(1σ)at a depth of 3.4±0.2 km.Despite the dense local seismic network in southern Nevada,differences as large as 2~5 km were observed between our InSAR earthquake location and those estimated from seismic data.The InSAR-derived magnitude appeared to be greater than that from seismic data,which is consistent with other studies,and believed to be due to the relatively long time interval of InSAR data.