王家庆, 单新建, 张国宏, 吕健, 申星. 2017年九寨沟MS7.0地震InSAR同震形变场与断层滑动分布反演[J]. 华北地震科学, 2018, 36(2): 1-7. DOI: 10.3969/j.issn.1003-1375.2018.02.001
引用本文: 王家庆, 单新建, 张国宏, 吕健, 申星. 2017年九寨沟MS7.0地震InSAR同震形变场与断层滑动分布反演[J]. 华北地震科学, 2018, 36(2): 1-7. DOI: 10.3969/j.issn.1003-1375.2018.02.001
WANG Jia-qing, SHAN Xin-jian, ZHANG Guo-hong, LYU Jian, SHEN Xing. Fault Slip Distribution Inversion and Co-seismic Deformation of the 2017 Jiuzhaigou MS7.0 Earthquake Based on InSAR[J]. North China Earthquake Sciences, 2018, 36(2): 1-7. DOI: 10.3969/j.issn.1003-1375.2018.02.001
Citation: WANG Jia-qing, SHAN Xin-jian, ZHANG Guo-hong, LYU Jian, SHEN Xing. Fault Slip Distribution Inversion and Co-seismic Deformation of the 2017 Jiuzhaigou MS7.0 Earthquake Based on InSAR[J]. North China Earthquake Sciences, 2018, 36(2): 1-7. DOI: 10.3969/j.issn.1003-1375.2018.02.001

2017年九寨沟MS7.0地震InSAR同震形变场与断层滑动分布反演

Fault Slip Distribution Inversion and Co-seismic Deformation of the 2017 Jiuzhaigou MS7.0 Earthquake Based on InSAR

  • 摘要: 联合升、降轨Sentinel-1A卫星的差分干涉数据反演2017年8月8日四川九寨沟MS7.0地震的断层滑动分布。首先对SAR复数干涉像对进行"二通"差分干涉处理,获取了覆盖震区的多视向InSAR同震形变场;然后利用四叉树和均匀采样法分别进行近、远场数据降采样,在此基础上,利用弹性半空间矩形位错模型,反演发震断层的几何参数和最优滑动分布。结果显示:①InSAR干涉条纹呈蝶状分布,最大LOS向沉降和抬升形变量分别为-20.3 cm、11.3 cm;②发震断层以左旋走滑为主兼有少量正断运动,断层走向为154°,倾角为82°;③断层滑动分布集中在2~15 km深度,平均滑动角为-22°,最大滑移量约为0.68 m,位于沿断层面深约9 km处,地震释放的能量约为9.6×1018 N·m (MW6.6),与测震学的研究结果基本一致。

     

    Abstract: An MS7.0 earthquake struck Jiuzhaigou, Sichuan province on 8 August 2017. This work obtained two LOS co-seismic measurements by carrying out the "Two-pass" differential interferometry on two tracks (1 ascending and 1 descending) of ERS sentinel-1A images firstly; Then the co-seismic displacements located in near and far field were subsampled with Quad-tree sampling and uniform sampling methods, respectively. The fault slip distributions were built based on the rectangular dislocation model in an elastic half space from the subsampled measurements. The results show that:① the both inteferograms display a similar butterfly shape caused by Jiuzhaigou earthquake, with the max amplitude of -20.3 cm and 11.3 cm, respectively. ② The seismogenic fault is dominated by left-lateral strike with little normal faulting, with strike of 154° and dip of 82°. ③ The fault slip is mainly happened in the depth between 2 km and 15 km, with maximum slip of 0.68 m located at 9km depth, and the average rake of -22°. The moments released by the earthquake is about 9.6×1018 Nm (MW6.6), which is almost consistent with the seismology research.

     

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