三峡库区巫山段双差层析成像  

The Double-Difference Tomography of Wushan Section in the Three Gorges Reservoir Area

作　　者：孙国栋 李翠平 董蕾 唐茂云 SUN Guodong;LI Cuiping;DONG Lei;TANG Maoyun(Chongqing Earthquake Agency,339 Honghuang Road,Chongqing 401147,China;College of Earth Sciences,Chengdu University of Technology,1 Dongsan Road,Chengdu 610059,China)

机构地区：[1]重庆市地震局,重庆市401147 [2]成都理工大学地球科学学院,成都市610059

出　　处：《大地测量与地球动力学》2025年第4期397-402,共6页Journal of Geodesy and Geodynamics

基　　金：重庆市地震局地震科技创新课题(CQDZ202401)。

摘　　要：基于49个台站2008-01—2020-06期间2319次地震的走时资料,利用双差层析成像方法获得三峡库区巫山段的三维P波速度结构和地震重定位结果。结果显示,重定位后地震主要沿长江的北岸呈近EW向带状展布,距离长江水系不超过10 km。研究区存在2个明显的P波高速体,主要集中在长江和断裂交会处,一个分布在高桥断裂和周家山-牛口断裂所围限的区域,另一个分布在巫山断裂带与长江交会区域。高速体均沿着附近断裂的倾向分布,速度横剖面显示,高速区延伸至12 km深度处,巫山断裂、高桥断裂和周家山-牛口断裂为库水下渗的主要断裂通道。This article adopts the double-difference tomography method to obtain the three-dimensional P-wave velocity structure and seismic relocating results of the Wushan section in the Three Gorges reservoir,based on the travel time data of 2319 earthquakes recorded by 49 stations from January 2008 to June 2020.The results show that earthquakes are mainly concentrated on the north bank of the Yangtze river,with a nearly EW oriented strip distribution,and are not more than 10 km away from the Yangtze river system.There are two obvious P-wave high-speed bodies concentrated mainly at the intersection of the Yangtze river and the faults in the research area.One is distributed in the area trapped by the Gaoqiao fault and the Zhoujiashan-Niukou fault,and the other is distributed in the area where the Wushan fault intersects with the Yangtze river.The distribution of high-speed bodies is consistent with the dip of nearby faults.The velocity cross-section shows that the high-speed zone extends to a depth of 12 km.The Wushan fault,Gaoqiao fault,and Zhoujiashan-Niukou fault serve as the main fracture channels for reservoir water infiltration.

关 键 词：三峡库区巫山段 双差层析成像 速度结构 库水渗透 

分 类 号：P315[天文地球—地震学]