The Dynamic Characteristics of Strain Fields and Crustal Movement before the Wenchuan Earthquake (M_S=8.0)  

作　　者：Jiang Zaisen Wu Yanqiang Fang Ying Li Peng Wang Wuxing 

机构地区：[1]Institute of Earthquake Science, CEA, Beijing 100036, China

出　　处：《Earthquake Research in China》2009年第3期257-265,共9页中国地震研究（英文版）

基　　金：sponsored by the National Key Science and Technology R&D Program (2006BAC01B02-02-02);and National Natural Science Foundation of China(40674010)

摘　　要：In this paper, we analyze the crustal movements, strain field changes and large scale dynamic characteristics of horizontal deformation before the Wenchuan earthquake （ Ms = 8.0） using GPS data obtained from the Crustal Movement Observation Network of China. The following issues are discussed. First, the strain fields of the Longmeushan fault zone located at the epicenter show slow accumulation, because of the tectonic dynamics process subjected to the eastward movement of the Bayan Har block. Second, the different movements between the Longmenshan fault and South China block are smaller than the errors of GPS observation. Third, the high value of compressive strain （2004 - 2007） is located at the epicenter, which shows that the local squeezing action is stronger than before. Fourth, the data from GPS reference stations in the Chinese Mainland show that crustal shortening is faster than before in the north-eastern direction, which is part of the background of the local tectonic dynamics increase in the Longmenshan fault zone.In this paper, we analyze the crustal movements, strain field changes and large scale dynamic characteristics of horizontal deformation before the Wenchuan earthquake (M_S=8.0) using GPS data obtained from the Crustal Movement Observation Network of China. The following issues are discussed. First, the strain fields of the Longmenshan fault zone located at the epicenter show slow accumulation, because of the tectonic dynamics process subjected to the eastward movement of the Bayan Har block. Second, the different movements between the Longmenshan fault and South China block are smaller than the errors of GPS observation. Third, the high value of compressive strain (2004～2007) is located at the epicenter, which shows that the local squeezing action is stronger than before. Fourth, the data from GPS reference stations in the Chinese Mainland show that crustal shortening is faster than before in the north-eastern direction, which is part of the background of the local tectonic dynamics increase in the Longmenshan fault zone.

关 键 词：Wenchuan earthquake （ Ms = 8.0 ） GPS Crustal movement Strain field Tectonic dynamics background 

分 类 号：P227[天文地球—大地测量学与测量工程] P315.7[天文地球—测绘科学与技术]