Earthquake relocation using a 3D velocity model and implications on seismogenic faults in the Beijing-Tianjin-Hebei region  

作　　者：Jinxin Hou Yunpeng Zhang Liwei Wang Zhirong Zhao 

机构地区：[1]School of Safety Engineering and Emergency Management,Shijiazhuang Tiedao University,Shijiazhuang,050043,China [2]Division of Leading-Edge Geophysical Technology,Institute of Geophysics,China Earthquake Administration,Beijing,10081,China [3]Guangdong Earthquake Agency,Guangzhou,510070,China [4]Shuohuang Railway Development Co.,Ltd.,Suning,062350,China

出　　处：《Earthquake Research Advances》2024年第2期55-64,共10页地震研究进展（英文）

基　　金：supported by the Natural Science Foundation of China(U2034207);the Natural Science Foundation of Hebei Province(E2021210099);the Technical Development Project of Shuohuang Railway Development Co.,Ltd.(GJNY-20-230).

摘　　要：To enhance the understanding of the geometry and characteristics of seismogenic faults in the Beijing-Tianjin-Hebei region,we relocated 14805 out of 16063 earthquakes(113°E-120°E,36°N-43°N)that occurred between January 2008 and December 2020 using the double-difference tomography method.Based on the spatial variation in seismicity after relocation,the Beijing-Tianjin-Hebei region can be divided into three seismic zones:Xingtai-Wen'an,Zhangbei-Ninghexi,and Tangshan.(1)The Xingtai-Wen'an Seismic Zone has a northeastsouthwest strike.The depth profile of earthquakes perpendicular to the strike reveals three northeast-striking,southeast-dipping,high-angle deep faults(>10 km depth),including one below the shallow(<10 km depth)listric,northwest-dipping Xinghe fault in the Xingtai region.Two additional deep faults in the Wen'an region are suggested to be associated with the 2006 M 5.1 Wen'an Earthquake and the 1967 M 6.3 Dacheng earthquake;(2)The Zhangbei-Ninghexi Seismic Zone is oriented north-northwest.Multiple northeast-striking faults(10-20 km depth),inferred from the earthquake-intensive zones,exist beneath the shallow(<10 km depth)Xiandian Fault,Xiaotangshan Fault,Huailai-Zhuolu Basin North Fault,Yangyuan Basin Fault and Yanggao Basin North Fault;(3)In the Tangshan Seismic Zone,earthquakes are mainly concentrated near the northeast-striking Tangshan-Guye Fault,Lulong Fault,and northwest-striking Luanxian-Laoting Fault.An inferred north-south-oriented blind fault is present to the north of the Tangshan-Guye Fault.The 1976 M 7.8 Tangshan earthquake occurred at the junction of a shallow northwest-dipping fault and a deep southeast-dipping fault.This study emphasizes that earthquakes in the region are primarily associated with deep blind faults.Some deep blind faults have different geometries compared to shallow faults,suggesting a complex fault system in the region.Overall,this research provides valuable insights into the seismogenic faults in the Beijing–Tianjin–Hebei region.Further studies and monitoring of

关 键 词：BEIJING-TIANJIN-HEBEI Double difference tomography Earthquake location Seismogenic faults 

分 类 号：P315.7[天文地球—地震学]