联合InSAR和地震波数据反演甘肃积石山Ms 6.2地震震源时空破裂过程  

Joint Inversion of InSAR and Seismic Data for the Kinematic Rupture Process of the 2023 Ms 6.2 Jishishan(Gansu,China)Earthquake

作　　者：方楠 孙凯 黄传超 柏承元 陈志丹 谢磊 杨知 徐英辉 解鸿斌 冯光财[1] 李志伟[1] 许文斌[1] FANG Nan;SUN Kai;HUANG Chuanchao;BAI Chengyuan;CHEN Zhidan;XIE Lei;YANG Zhi;XU Yinghui;XIE Hongbin;FENG Guangcai;LI Zhiwei;XU Wenbin(School of Geoscience and Info‑Physics,Central South University,Changsha 410083,China;Department of Geology,Lomonosov Moscow State University,Moscow 119991,Russia;China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]莫斯科国立大学地质系,俄罗斯莫斯科119991 [3]中国电力科学研究院有限公司,北京100192

出　　处：《武汉大学学报(信息科学版)》2025年第2期333-343,共11页Geomatics and Information Science of Wuhan University

基　　金：国家重点研发计划课题(2022YFB3903602);国家自然科学基金项目(42388102,42174023,42304037);中南大学前沿交叉研究项目(2023QYJC006);湖南省自然科学基金重点项目(2024JJ3031);中南大学研究生自主探索创新项目(2021zzts0249);湖南省研究生科研创新项目(CX20210104)。

摘　　要：2023-12-18,甘肃省临夏回族自治州积石山县发生了Ms 6.2地震,该地震发生在祁连山内部的次级断裂拉脊山断裂上,该断裂活动强度较低、发震频率不高,本次地震为人们重新认识祁连山内部这一特殊构造提供了机会。利用Sentinel-1A卫星的升、降轨数据获得了本次地震的同震地表形变,采用贝叶斯反演方法确定了发震断层的几何参数,联合地震波数据反演了该地震的动态滑动分布。本次地震的发震断层朝北东倾,倾角为32.2°,走向为~325.2°,滑动角为~112°,发震断层呈现逆冲兼具右旋走滑分量的运动性质。结合邻区主要活动断裂的断层几何和运动学特征,认为本次积石山地震发生在拉脊山南缘北东倾的断层上。本次积石山地震所在的拉脊山断裂东段可能是青海南山断裂、拉脊山断裂西段和西秦岭断裂的阶区转换构造,该阶区的左行右阶型挤压作用为本次逆冲型地震事件的驱动机制。Objectives:On December 18,2023,an Ms 6.2 earthquake occurred in Jishishan County,Gansu Province,China.This event occurred on the Lajishan fault,a secondary fault with low activity and infrequent seismicity in the Qilian Mountains,which event provides an opportunity to study this special structure within the Qilian Mountains.Methods:We derived the coseismic deformation field using both ascending and descending Sentinel-1A data,applied the Bayesian inversion method to determine the source parameters of the seismogenic fault,and combined seismic wave records with interferometric synthetic aperture radar data to model the dynamic slip distribution of this event.Results:The event has a northwest-dipping fault with a dip of 32.2°,a strike of 325.2°and a rake of 112°,indicating that this earthquake is a thrust event with a dextral slip component.Conclusions:By analyzing the fault geometry and kinematic characteristics of the primary active faults in the surrounding region,we found that the Jishishan earthquake occurred on the southern edge of the Laji Mountain.This study concludes that the Jishishan earthquake occurred on a northeast-dipping fault at the southern margin of the Laji Mountains.It also suggests that the eastern section of the Laji Mountain fault,where the Jishishan earthquake occurred,may be a step-over structure between the Qinghai Nanshan fault,the western section of the Laji Mountain fault,and the west Qinling fault.Additionally,it proposes that the left-running,right-step-type extrusion of the step-over zone is the driving mechanism of this retrograde seismic event.

关 键 词：青藏高原东北缘 积石山Ms 6.2地震 联合反演 转换构造 INSAR 时空破裂过程 

分 类 号：P315[天文地球—地震学]