2015年7月3日在西昆仑推覆构造带前缘发生了M_W6. 4新疆皮山地震,是近40a以来该区域发生的最大的一次中强地震。文中利用近场大地测量数据,包括4个高精度GPS点和一景高空间分辨率ALOS-2 In SAR干涉数据,联合IRIS/USGS提供的25个远震台网...2015年7月3日在西昆仑推覆构造带前缘发生了M_W6. 4新疆皮山地震,是近40a以来该区域发生的最大的一次中强地震。文中利用近场大地测量数据,包括4个高精度GPS点和一景高空间分辨率ALOS-2 In SAR干涉数据,联合IRIS/USGS提供的25个远震台网P波数据,基于有限断层理论,采取多参数非线性模拟退火算法反演了此次地震的同震破裂模型。联合反演的断层滑移模型显示皮山地震的主破裂区深度集中于9～16km,最大滑移量为95cm,释放的矩能量相当于M_W6. 42,且沿断层走向N302°W单侧破裂,与余震分布吻合。通过与单一数据源反演结果进行对比分析,文中采用的多源数据可以同时约束地震矩能量和断层破裂分布,有效解决了远震台网波形数据模型空间分辨率低(尤其对中强地震而言)和近场大地测量数据在地震矩评估方面不够精确的问题。展开更多
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 struct...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.展开更多
文摘2015年7月3日在西昆仑推覆构造带前缘发生了M_W6. 4新疆皮山地震,是近40a以来该区域发生的最大的一次中强地震。文中利用近场大地测量数据,包括4个高精度GPS点和一景高空间分辨率ALOS-2 In SAR干涉数据,联合IRIS/USGS提供的25个远震台网P波数据,基于有限断层理论,采取多参数非线性模拟退火算法反演了此次地震的同震破裂模型。联合反演的断层滑移模型显示皮山地震的主破裂区深度集中于9～16km,最大滑移量为95cm,释放的矩能量相当于M_W6. 42,且沿断层走向N302°W单侧破裂,与余震分布吻合。通过与单一数据源反演结果进行对比分析,文中采用的多源数据可以同时约束地震矩能量和断层破裂分布,有效解决了远震台网波形数据模型空间分辨率低(尤其对中强地震而言)和近场大地测量数据在地震矩评估方面不够精确的问题。
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 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.
