Tectonic Deformation and Fault Activity of Active Blocks in
Longmenshan and Surrounding Area after Wenchuan Earthquake
1 Key Laboratory of Earthquake Geodesy, Institute of Seismology, CEA, 40 Hongshance Road, Wuhan 430071, China
2 Wuhan Base of Institute of Crustal Dynamics, CEA, 40 Hongshance Road, Wuhan 430071, China
Abstract:Based on GPS velocity field data from 1999 to 2013, we calculate the train rate field and the Euler rotation vector of main blocks in Longmenshan and the surrounding area. Using these results as constraints, we calculate the slip rate and locking depth of the main active faults with the Rngchn program based on the Okada model, and then discuss regional tectonic deformation and strain distribution in the research area. Finally, we analyze the effect of the Wenchuan earthquake on the above process. The research shows that: most active blocks, such as east Bayan Har, northwest Sichuan and middle Yunnan, are moving to the southeast with a clockwise rotation at the same time. Due to the crustal strain absorption and adjustment of thrust belts such as the Longmenshan fault, the regional crustal deformation decreases gradually from the west to the east. The Wenchuan earthquake not only accelerated the motion of Bayan Har and northwest Sichuan block, but also enhanced the strike-slip and thrust movement of the Anninghe-Zemuhe-Xiaojiang fault and the Lijiang-Xiaojinhe fault.
XIONG Wei,TAN Kai,QIAO Xuejun et al. Tectonic Deformation and Fault Activity of Active Blocks in
Longmenshan and Surrounding Area after Wenchuan Earthquake[J]. jgg, 2015, 35(5): 758-763.