???2004??Ms6.7??2005??Ms6.5?????InSAR????α????

???????Envisat??????????????2004??7??12???2005??4??8?????????Ms6.7??Ms6.5?????InSAR????α??????????????ε????????????20 km??20 km??Χ???EW?????????Σ??????η???19.0 cm??30.5 cm???????????????????????????ε???????????????????????,????λ??83.71??E,30.70??N,??Mw6.1,83.72??,E30.52??N????Mw6.2??????????????? 1 m??1.4 m?????ε??????????NW?????3?????????????NS?????????-????????????λ

ANALYSIS OF DEFORMATION OF ZHONGBA TIBET 2004 Ms6.7 AND 2005 Ms6.5 EARTHQUAKES AS CONSTRAINED BY InSAR MEASUREMENTS

The Envisat images from ESA were used to derive the coseismic deformation interferograms caused by the Zhongba Ms6.7 earthquake on July12,2004 and Ms6.5 earthquake on April 8,2005 occurred in Tibet. The results indicate that two earthquakes caused the deformation in an area of 20 km with a maximum LOS change about 19.0 cm and 30.5 cm recpectively. Adopting isotropic elastic half space dislocation model, we estimate that the two earthquakes epicenter locate at E83.71°,N30.70° with a seismic moment tensor Mw6.1 and E83.72°，N30.52° with a seismic moment tensor Mw6.2, dominated by normal fault fracture with maximum slip 1 m and 1.4 m, located at the intersection of NW Brahmaputra fault zone and the near side NS Palongcuo-Cangmucuo fault zone