InSAR数据约束下2016年和2022年青海门源地震震源参数及其滑动分布  

Source Parameters and Slip Distributions of the 2016 and 2022 Menyuan,Qinghai Earthquakes Constrained by InSAR Observations

作　　者：李振洪 韩炳权[1,2] 刘振江 张苗苗 余琛[1,2,4] 陈博[1,2] 刘海辉 杜静 张双成[1,2,3] 朱武 张勤 彭建兵[1,3] LI Zhenhong;HAN Bingquan;LIU Zhenjiang;ZHANG Miaomiao;YU Chen;CHEN Bo;LIU Haihui;DU Jing;ZHANG Shuangcheng;ZHU Wu;ZHANG Qin;PENG Jianbing(College of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China;Big Data Center for Geosciences and Satellites(BDCGS),Chang'an University,Xi'an 710054,China;Key Laboratory of Western China's Mineral Resource and Geological Engineering,Ministry of Education,Xi'an 710054,China;School of Engineering,Newcastle University,Newcastle upon Tyne,NE17RU,UK)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054 [2]长安大学地学与卫星大数据研究中心,陕西西安710054 [3]西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [4]英国纽卡斯尔大学工程学院,英国纽卡斯尔NE17RU

出　　处：《武汉大学学报（信息科学版）》2022年第6期887-897,共11页Geomatics and Information Science of Wuhan University

基　　金：国家重点研发计划(2020YFC1512000);陕西省科技创新团队项目(2021TD-51);欧洲空间局-科技部国家遥感中心龙计划5项目(59339)。

摘　　要：中国青海省门源县于2016年和2022年分别发生了Mw 5.9和Mw 6.7地震,相距不足40 km。利用欧洲空间局Sentinel-1A升降轨雷达影像,采用合成孔径雷达干涉测量(interferometric synthetic aperture radar,InSAR)技术分别获取两次地震的同震地表形变场,进而利用弹性半空间的位错模型确定上述事件的震源参数,基于分布式滑动模型反演确定两次地震断层面上的滑动分布,并探讨2016年门源地震对2022年门源地震的发震影响及触发机制。结果表明,2016年门源地震为逆冲型地震,并未破裂到地表,升、降轨同震形变场沿视线向的最大形变量分别为6.7 cm和7.0 cm,断层的最大滑动量为0.53 m,主要集中在地下4~12 km区域滑动。2022年门源地震同震形变场沿NWW-SEE向破裂,降轨影像最大视线向地表形变量为78 cm,断层的最大滑动值达到3.5 m,处于地下4 km左右,断层滑动分布模型揭示此次地震为左旋走滑型地震;结合冷龙岭断裂的运动性质和几何特征,可初步判定发震断层主要为冷龙岭断裂的西段、且极有可能破裂到了其西北端西侧的托莱山断裂。静态库仑应力触发关系显示,2016年门源地震对2022年门源地震的发生有一定的促进作用。Objectives:Two earthquakes with a distance less than 40 km occurred in Menyuan,Qinghai Province,China,including Mw 5.9 earthquake on 26th January 2016 and Mw 6.7 earthquake on 8th January 2022.Methods:The interferometric synthetic aperture radar(InSAR)technique was utilized to process Sentinel-1A radar images from both ascending and descending tracks to retrieve high resolution coseismic surface displacement maps for these two Menyuan earthquakes.The coseismic surface displacements were then inverted to determine the fault geometry parameters and the non-uniform fault slip distributions with a dislocation model in an elastic half-space.Results:The results show that the 2016 Menyuan earthquake was a reverse event on a buried fault with a maximum surface displacement of 6.7 cm and 7.0 cm on the ascending and descending tracks,respectively.The maximum slip on the fault plane reached 0.53 m and concentrated at depths of 4-12 km.The 2022 Menyuan earthquake ruptured along the NWW-SEE strike with a maximum surface displacement of 78 cm in the satellite radar line of sight and a maximum fault slip of 3.5 m occurred at a depth of approximately 4 km.Conclusions:Considering the tectonic settings around the Lenglongling fault zone,the 2022 Menyuan earthquake is likely to occure in the western segment of the left-lateral Lenglongling fault,with its western end extending westward to the Tuolaishan fault.By calculating the coulomb failure stress changes(CFS),it is inferred that the 2016 Menyuan earthquake generated considerable positive CFS which might have triggered the 2022 Menyuan earthquake.

关 键 词：2016年门源地震 2022年门源地震 合成孔径雷达干涉测量 同震地表形变 地震断层滑动 地震触发关系 

分 类 号：P227[天文地球—大地测量学与测量工程] P315[天文地球—测绘科学与技术]