Simultaneous Inversion of Earthquake Relocation and Velocity Structure in the Shanxi-reservoir,Wenzhou  

作　　者：Zhong Yuyun Zhang Zhenfeng Kan Baoxiang 

机构地区：[1]Earthquake Administration of Zhejiang Province, Hangzhou 310013, China

出　　处：《Earthquake Research in China》2011年第4期468-476,共9页中国地震研究（英文版）

基　　金：supported by the National Key Technology R&D Program(2008BAC38B03-01-05);the Earthquake Scientific Research Project(200708020),China

摘　　要：Using the data of P-wave network and Zhejiang and travel time recorded at the Shanxi-reservoir seismological Fujian local networks, we implemented a simultaneous inversion of earthquake relocation and velocity structure and determined the new locations of earthquakes in the Shanxi-reservoir. The results show that： （1） the overall epicenter distribution is NW directed, and the Shanxi reservoir induced seismicity has a close relationship to the Shuangxi-Jiaoxiyang fault; （2） the focal depth of the Shanxi reservoir induced seismicity is 5.4km in average, less than the average focal depth in the South China earthquake zone; （3） the focal depth is shallower on the reservoir shore and deeper in the reservoir inundation area. At the beginning of the reservoir induced seismicity, the focal depth increased gradually. This may be due to the gradual penetration of water into a larger depth that induced deeper earthquakes; and （4） there is a low P-wave velocity anomaly in the study area, located at the intersection of multiple faults in the reservoir inundation area. The Shanxi reservoir induced seismicity mostly occurred in this lowvelocity anomaly zone. This may be related to water penetration.Using the data of P-wave travel time recorded at the Shanxi-reservoir seismological network and Zhejiang and Fujian local networks, we implemented a simultaneous inversion of earthquake relocation and velocity structure and determined the new locations of earthquakes in the Shanxi-reservoir. The results show that: (1) the overall epicenter distribution is NW directed, and the Shanxi reservoir induced seismicity has a close relationship to the Shuangxi-Jiaoxiyang fault; (2) the focal depth of the Shanxi reservoir induced seismicity is 5.4km in average, less than the average focal depth in the South China earthquake zone; (3) the focal depth is shallower on the reservoir shore and deeper in the reservoir inundation area. At the beginning of the reservoir induced seismicity, the focal depth increased gradually. This may be due to the gradual penetration of water into a larger depth that induced deeper earthquakes; and (4) there is a low P-wave velocity anomaly in the study area, located at the intersection of multiple faults in the reservoir inundation area. The Shanxi reservoir induced seismicity mostly occurred in this low-velocity anomaly zone. This may be related to water penetration.

关 键 词：Shanxi reservoir Velocity structure Simultaneous inversion Earthquake location 

分 类 号：P315.9[天文地球—地震学] P315.61[天文地球—固体地球物理学]