InSAR Monitoring Seismic Coseismic Deformation And Fault Dislocation Inversion

As an important technique of geodesy,InSAR has been developing rapidly for the recent decades,it is widely used in geological disaster monitoring and warning aspects,since it is a space-to-ground large area continuous observation technology,InSAR has a great advantage over the monitoring of seismic activity.The earthquakes are one of the most destructive natural disasters.In this paper,we use the D-InSAR technique to get the ground coseismic deformation of the earthquake,we combine the dislocation theory with the observation results of insar to invert the dislocation of the seismogenic fault.The following research work is carried out on the two earthquakes in Tajikistan and Aktaw in western China in recent years:?1?Murghob earthquake coseismic deformation and fault slip distribution inversion based on the Sentinel-1A data.We collected the Sentinel-1A satellite data covering the earthquake area,used the D-InSAR technique to get the line of sight of the rising and falling rails in the coseismic deformation field of the Tajikistan Mw2.7 Murghob earthquake in the year of 2015,the result of deformation field show that the surface is dominated by horizontal strike-slip motion,the deformation field is distributed in the NE-SW direction as a whole,the maximum LOS variables of the rising and falling orbits are-75cm and 52cm.Based on the viscoelastic hierarchical dislocation model,combined with previous research results and the geological data as well as the InSAR observation results of the seismic area,we established the seismogenic fault model.At the meantime,the fault slip distribution and source parameters of the earthquake were obtained by using the data of the rising and falling orbit deformation field as constraints.As can be seen from the result,the fault is divided into three segments,all mainly motioned as the left-lateral strike-slip motion,the average trend is 219 degrees,the fault inclination of F1 in the north segment is 85 degrees,the fault inclination of F2 in the middle segment is 80 degrees,the fault inclination of F3 in the south segment is 89 degrees,the maximum slip momentum is 3.9 meters,it is 13.75 kilometers underground.The inversion seismic moment is M₀=9.405×10¹99 Nm,itapproximately comes to the moment magnitude of M_w7.28.?2?Aktao earthquake coseismic deformation and fault slip distribution inversion based on the Sentinel-1A/B data.We collected the Sentinel-1A/B satellite data of the rising and falling orbit,used the D-InSAR technique to get the line of sight of the rising and falling rails in the coseismic deformation field in the LOS direction of the XinJiang M_w6.4 Aktao earthquake in the year of2016,the deformation field is distributed near the east and the west,the surface is dominated by horizontal strike-slip motion,the maximum LOS variables of the rising and falling orbits are 14cm and-21cm,Based on the viscoelastic hierarchical dislocation model,combined with the former conditions and the aftershock distribution results,we established a single fault model and a double fault model for the inversion experiments.Obtained the slip distribution model of the fault.As we can see from the result,the inversion results of the double fault model fit the ground insar deformation with smaller residual,therefore,the double fault model is more consistent with the actual fault rupture.The average trend of the two faults is 105.5degrees,the optimum dip angle of the fault in the east of the epicenter is 75 degrees,the optimum dip angle of the fault in the west of the epicenter is 55 degrees,the maximum slip is located 13.26 kilometers below the fault in the west of the epicenter,it is up to 0.73 meter.The inversion seismic total moment is M₀=1.4496×10¹⁹Nm,it approximately comes to the moment magnitude of M_w6.4.The earthquake was triggered by the muji fault under the Gonger Mountain tension system of the Pamir tectonic junction.In recent years,there have been many moderate and strong earthquakes in the Pamir structure,there will still be the possibility of earthquakes in this area in the future.