Near-field surface movement during the Wenchuan M_s8.0 earthquake measured by high-rate GPS  

作　　者：YIN HaiTao ZHANG PeiZhen GAN WeiJun WANG Min LIAO Hua LI XiaoJun LI Jie XIAO GenRu 

机构地区：[1]State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China [2]Earthquake Administration of Shandong Province, Jinan 250014, China [3]Earthquake Administration of Sichuan Province, Chengdu 610041, China [4]Institute of Engineering Mechanics, China Earthquake Administration, Beijing 100080, China

出　　处：《Chinese Science Bulletin》2010年第23期2529-2534,共6页

基　　金：supported by the National Natural Science Foundation of China (40841013)

摘　　要：Based on high-rate (1 Hz) GPS data from the Sichuan GPS Continuous Observation Network on the footwall of the Longmenshan Fault, we have characterized the near-field surface movement process during the 5.12 Wenchuan Earthquake. Results show that the maximum deformation near the fault is larger than the deformation set. Stations on the northern segment of the fault moved towards the epicenter first, and then turned toward the vertical orientation of the fault. Deformation of stations on the southern segment is smaller and recovered. The initial motion at all of the stations was downward followed by periodic up and down movements. Comparing the displacement from high-rate GPS and accelerograph data, we can see that they are consistent prior to the arrival of the principal shock, but afterwards a 10 cm difference is found, even though they are synchronized and in phase. More work is yet to be done to explain this. This is the first time that actual the real near-field surface movements of an earth- quake of M >7.0 have been determined in china. These measurements are therefore of high value for studies of surface rupture processes and the analysis of seismic wave travels paths in this region.Based on high-rate （1 Hz） GPS data from the Sichuan GPS Continuous Observation Network on the footwall of the Longmenshan Fault, we have characterized the near-field surface movement process during the 5.12 Wenchuan Earthquake. Results show that the maximum deformation near the fault is larger than the deformation set. Stations on the northern segment of the fault moved towards the epicenter first, and then turned toward the vertical orientation of the fault. Deformation of stations on the southern segment is smaller and recovered. The initial motion at all of the stations was downward followed by periodic up and down movements. Comparing the displacement from high-rate GPS and accelerograph data, we can see that they are consistent prior to the arrival of the principal shock, but afterwards a 10 cm difference is found, even though they are synchronized and in phase. More work is yet to be done to explain this. This is the first time that actual the real near-field surface movements of an earthquake of M 〉7.0 have been determined in china. These measurements are therefore of high value for studies of surface rupture processes and the analysis of seismic wave travels paths in this region.

关 键 词：GPS测量 地表运动 大地震 近场 汶川 高速率 龙门山断裂带 地表移动过程 

分 类 号：P228.4[天文地球—大地测量学与测量工程] P315.3[天文地球—测绘科学与技术]