Co-seismic,Inter-seismic And Post-seismic Deformation Based On High-precision Image Coregistration

Interferometric Synthetic Aperture Radar(InSAR)technology is a space-to-Earth observation technology that has developed rapidly in the past two decades.It combines Synthetic Aperture Radar(SAR)imaging technology and interferometry technology.It has the advantages of wide observation range,short revisit period,high measurement accuracy,and all-day and all-weather monitoring.Therefore,it has important application value in surface deformation monitoring and digital elevation reconstruction research,and provides favorable conditions for the study of inter-seismic deformation and co-seismic deformation of complex and diverse geological tectonic movements.Based on the Sentinel-1 remote sensing image,this thesis conducts theoretical research and application experiments on SAR image registration.First of all,in the study of seismic tectonic motion,differential interferometric synthetic aperture radar(D-InSAR),offset tracking(OT)technology and burst-overlap interferometry(BOI)technique obtains reliable coseismic deformation information.Secondly,based on the elastic half-space homogeneous dislocation model,combined with multi-source deformation fields,the slip distribution of the Maduo earthquake occurred in the Guoluo Tibetan Autonomous Prefecture of Qinghai Province was studied.In terms of studying the inter-seismic activity of faults,through the time series inversion of the along-track deformation field obtained by burst-overlap interferometry(BOI),the annual average slip of the Chaman fault located in the Chaman fault system in the Himalayas was obtained respectively.The annual average slip rate of the faults located in the southern part of the Dead Sea fault zone will provide effective data sample support for future research on the Chaman fault and the Dead Sea fault.The main research work of this thesis is as follows:(1)The coseismic deformation field along the radar line-of-sight of the Qinghai Maduo earthquake was obtained by using differential interferometry of synthetic aperture radar(D-InSAR);Then,the 3D deformation field of the earthquake is inverted with the 2D offset of the lifting rail;the offset of the earthquake along the track is obtained by using the Burst-Overlap interferometry method.(2)Using the Okada elastic half-space homogeneous medium dislocation model,the deformation fields obtained by D-InSAR,OT,and BOI are used to jointly invert the fault geometry parameters and slip distribution of the Maduo earthquake.The results show that the Qinghai Maduo earthquake caused a left-lateral rupture fault with a length of about 190kilometers in northeastern Tibet,and the fault bifurcates into two scissor-shaped fault chains on the east side.The maximum displacement of the surface deformation field of the fault along the radar line of sight is 1321mm,the fault strike is about 284°,the dip angle is about84.6°,and the focal depth is 17km.The maximum slip is 5783.5mm,and the moment magnitude is₇.473.(3)In view of the fault activity of the Dead Sea fault zone,this thesis uses the TOPS IW model image data of Sentinel 1 with a time span from October 2014 to November 2021 for deformation analysis.By using BOI to extract the azimuthal deformation field of the burst overlapping area of each interferogram;then using the time series technique to obtain the average annual deformation rate of the southern part of the Dead Sea fault;finally,using the elastic dislocation model to invert the deformation profile perpendicular to the Dead Sea fault,The deformation rate in the southern part of the Dead Sea fault zone is obtained to be?5 mm/a,which is consistent with the GPS observation and verifies the reliability of the time series BOI results.(4)Aiming at the fault activity of the Chaman fault zone in the Himalayas,this thesis is based on the C-band image data of Sentinel 1 from October 2014 to August 2021.First,the BOI is used to obtain the azimuth offset of the burst overlapping area of each interferogram;secondly,the time series inversion of the BOI azimuth offset is used to successfully obtain the deformation rate map of the Charman fault.The results show that the deformation rate of the Chaman fault in the middle of the Chaman fault zone is about 8.9 mm/a,the rate of the Ghazaband fault is about 16.3 mm/a,the rate of the Hoshab fault is about 125.0 mm/a.The Chaman fault in Afghanistan has a lower slip rate,possibly due to the slip rate of the left-lateral shear being incorporated into the Gardez fault above the northern segment of the Chaman fault and the Ghazaband fault south of its southern segment.The high slip rate of the Hoshab fault in Pakistan is due to the large Mw7.7 earthquake that occurred in Balochistan in 2013,and the post-earthquake deformation analysis is mainly carried out in this area.