2023年甘肃积石山M_(S)6.2地震:一次逆冲为主的浅源强震  

The 2023 Jishishan M_(s)6.2 Earthquake in Gansu Province,China:A Shallow Strong Earthquake with Thrust-dominated Components

作　　者：杨彦明 苏淑娟[3] YANG Yan-ming;SU Shu-juan(State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Earthquake Agency of Inner Mongolia Autonomous Region,Hohhot 010010,China;State Key Labortaory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Beijing 100083,China)

机构地区：[1]中国地震局地质研究所地震动力学国家重点实验室,北京100029 [2]内蒙古自治区地震局,内蒙古呼和浩特010010 [3]中国矿业大学(北京)煤炭精细勘探与智能开发全国重点实验室,北京100083

出　　处：《地震》2024年第1期167-174,共8页Earthquake

基　　金：中国地震局地震预测开放基金项目(XH23077D);内蒙古自治区自然科学基金项目(2023MS04012);内蒙古自治区人才开发基金项目(内人社办函[2023]182号);山东省地震局一般科研项目(YB2313)。

摘　　要：基于区域数字地震台网波形数据,在三维空间内利用波形拟合反演方法获得2023年12月18日甘肃积石山M_(S)6.2地震最佳震源机制解,结果表明:节面Ⅰ走向305°,倾角56°,滑动角61°;节面Ⅱ为走向169°,倾角43°,滑动角125°;矩震级M_(W)6.02。最佳拟合的空间精细位置为102.377°E,35.968°N,深度9 km。结果显示,地震破裂沿NW方向扩展。初步推断此次地震的发震断层面为节面Ⅱ,发震断层是拉脊山北缘断裂(积石山东缘断裂),是一次逆冲为主,兼少量走滑分量的浅源强震事件。The focal mechanism solution of the Jishishan M_(s)6.2 Earthquake on 18 Decem-ber 2023 in Gansu Province was made an inversion by the waveform fitting method in three-dimensional space using the observed waveform from the Regional Seismic Networks in China.The results show that the moment magnitude is M_(w)6.02,the strike/dip/slip of the first nodal plane are 305°/56°/61°and those of the second nodal plane are 169°/43°/125°.The best fine spatial position of the waveform fitting is 102.377°E,35.968°N,with depth of 9 km.The results show that main rupture extends along NW direction.It is in-ferred preliminary that the nodal plane Ⅱ is Fault-Plane,and seismogenic fault is the northern margin fault of the Lajishan mountains(eastern margin fault of the Jishishan mountain).Additionally,the event is a shallow strong earthquake induced by thrust-dom-inated faulting mechanism with little strike-slip component.

关 键 词：2023年积石山M_(S)6.2地震 震源机制解 质心深度 逆冲断层 拉脊山北缘断裂 

分 类 号：P315.7[天文地球—地震学]