Abstract:In this paper, we use InSAR data from the Sentinel-1A satellite to invert the focal mechanism solutions of the MS7.4 earthquake,which occurred in Tajikistan on 7 December 2015. First,two-pass interferometry technique is utilized to obtain the coseismic deformation of the region, covering the whole epicenter of the Tajikistan earthquake. Second, we utilize the distributed slip model inversion method to obtain a more precise distribution of fault slip by means of down-sampling the original observation data. The results indicates that inversion results are consistent with the observation data. In addition, the inversion results show that the seismogenic fault is dominated by sinistral strike-slip movement. The maximum slip of the earthquake fault is 4.42 m, and the coseismic seismic moment is about 73.71×1018 Nm (MW7.19), which is consistent with the seismic research results available from USGS, GCMT, IPGP after this event. It also shows that this earthquake is a normal and inevitable rupture event in the significant tectonic setting with left-lateral strike-slip motion.
LI Ning,ZHAO Qiang,SUN He. InSAR Observation Results of the 2015 Tajikistan MS7.4 Earthquake and Its Tectonic Significance[J]. jgg, 2018, 38(1): 43-47.