Coseismic surface deformation caused by the Wenchuan M8 earthquake from InSAR data analysis

The D-InSAR technology is used to aquired seven belts of coseismic surface deformation of Sichuan M8 earthquake of 12 May 2008 from the ALOS/PALSAR satellite data of Japan. The result covers Yinxiu, Dujiangyan, Wenchuan, Moxian, Beichuan, Pingwu and Qingchuan county, each 500 km in north-south and 70 km in east-west. The investigation indicates that the surface rupture zone caused by the earthquake coincides the Beichuan-Yingxiu fault, extending from nearby the epicenter southwest of the Yingxiu town to north of the Suhe, Qingchuan county for about 230 km. The northwest wall of the seismogenic fault has uplifted, exhibiting a dominant thrust motion. The maximum relative LOS displacement at the epicenter reaches 260 cm. A swell of LOS 120-180 cm displacements is present from Beichuan to Pingtong. Another uplifted belt of displacements 70-80 cm occurs nearby north of Suhe, Qingchuan. Around Ya´an and Mount Emeishan, and from Shehong to north of Chongqing, there is a large area of subsidence. In Chongqing and its south is seen a small uplifted area of 20-30 cm. From Qingchuan, eastward to Guangyuan and Ningqiang, uplift amplitudes are 60-70 cm. The whole area of the deformation filed is fairly large, even in the Sichuan basin occurs surface deformation of different degrees.