An earthquake cluster occurred in the Shanxi reservoir, located around Wenzhou city in Zhejiang Province. From February 4 to February 11, 2006, 9 earthquakes with M_L≥4.0 occurred, and the greatest magnitude was M_L4...An earthquake cluster occurred in the Shanxi reservoir, located around Wenzhou city in Zhejiang Province. From February 4 to February 11, 2006, 9 earthquakes with M_L≥4.0 occurred, and the greatest magnitude was M_L4.6. The correlations of earthquake occurrence time with reservoir level changes and tides are discussed, and the possible factors that induced the reservoir earthquakes and the trend of seismic activity are analyzed based on the characteristics of earthquake occurrence time. Finally, we suggest that it is necessary to slow down the speed of storing water and to maintain a level below the highest historical level to avoid greater earthquakes in the reservoir.展开更多
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 structu...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.展开更多
基金This research was funded by the Joint Earthquake ScienceFoundation,China (104103)
文摘An earthquake cluster occurred in the Shanxi reservoir, located around Wenzhou city in Zhejiang Province. From February 4 to February 11, 2006, 9 earthquakes with M_L≥4.0 occurred, and the greatest magnitude was M_L4.6. The correlations of earthquake occurrence time with reservoir level changes and tides are discussed, and the possible factors that induced the reservoir earthquakes and the trend of seismic activity are analyzed based on the characteristics of earthquake occurrence time. Finally, we suggest that it is necessary to slow down the speed of storing water and to maintain a level below the highest historical level to avoid greater earthquakes in the reservoir.
基金supported by the National Key Technology R&D Program(2008BAC38B03-01-05)the Earthquake Scientific Research Project(200708020),China
文摘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.
