摘要
利用D-InSAR技术处理Sentinel-1卫星升降轨数据,提取2022年泸定M W6.7地震同震形变场,并联合GNSS和强震动数据反演同震断层几何和滑动分布。结果表明,发震断层走向为164.3°、倾角为73.7°、滑动角为-3.2°,以左旋走滑为主,兼具少量正断层和逆冲运动,并破裂至地表;断层滑动主要分布在0~18 km深度范围,最大滑动量为1.67 m,位于7 km深度处。利用震间GNSS速度场估计泸定地震前磨西断裂闭锁深度为17.8 km,与同震滑动空间分布较为一致,断层长期构造滑动速率为10.8 mm/a。磨西断裂自1786年来积累的地震矩为9.52×1019 Nm,本次泸定地震释放的能量仅占积累地震矩的12.3%,因此磨西断裂的地震风险性依旧很高。安宁河断裂北段处于应力加载状态,未来发震风险性值得关注。
We utilize Sentinel-1 data to obtain the coseismic deformation of the 2022 Luding M W6.7 earthquake.Then.we invert the fault geometry parameters and slip model with the InSAR,GNSS,and strong motion data as constraints.The optimal fault strike,dip,and rake angles are 164.3°,73.7°,and-3.2°.The fault ruptures to the surface,and fault motion is dominated by the left-lateral strike-slip and with a slight dip-slip.The fault slip is concentrated on the depths of 0-18 km,and the peak slip reaches 1.67 m at a depth of 7 km.We further estimate the fault kinematic parameter based on the screw dislocation model by the interseismic GNSS velocities.The fault locking depth is 17.8 km and the long-term slip rate is 10.8 mm/a.The estimated seismic moment accumulation of the Moxi segment is 9.52×1019 Nm since 1786.However,the 2022 Luding earthquake only released 12.3%of the seismic moment accumulation,indicating that the Moxi fault has a high earthquake potential.The Coulomb failure stress in the northern of the Anninghe faut is positive,which suggests the high seismic risk of the Anninghe fault.
作者
徐浪
陈强
吴远昆
杨莹辉
赵晶晶
XU Lang;CHEN Qiang;WU Yuankun;YANG Yinghui;ZHAO Jingjing(Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,999 Xi’an Road,Chengdu 611756,China;Zhejiang Huadong Mapping and Engineering Safety Technology Co Ltd,22 Chaowang Road,Hangzhou 310014,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,1 Dongsan Road,Chengdu 610059,China)
出处
《大地测量与地球动力学》
CSCD
北大核心
2024年第5期473-478,共6页
Journal of Geodesy and Geodynamics
基金
地质灾害防治与地质环境保护国家重点实验室自主研究课题(SKLGP2021Z016)。
关键词
泸定地震
联合反演
滑动模型
库仑应力
地震风险性
Luding earthquake
joint inversion
slip model
Coulomb failure stress
seismic risk
