InSAR observations constrained coseismic slip distribution and Coulomb stress variation of Mw 6.7 Menyuan earthquake in 2022

doi:10.13474/j.cnki.11-2246.2023.0197

Abstract

Abstract: In this paper, the line-of-sight (LOS) co-seismic deformation field of the Mw 6.7 Menyuan earthquake in Qinghai province on January 8, 2022 is obtained by using synthetic aperture radar differential interferometry (DInSAR) technology based on the Sentinel-1A satellite ascending and descending data. The non-negative least squares principle is used to retrieve the geometric parameters and co-seismic slip distribution of seismogenic faults. Finally, the Coulomb stress variation is calculated based on the fault slip distribution parameters and Coulomb fracture criterion. The results show that the Menyuan earthquake caused significant surface deformation, the coseismic deformation area is about 33 km×22 km, and the maximum LOS shape variables of ascending and descending data are -60 and 85 cm, respectively. Co-seismic sliding model display, the Menyuan earthquake is a left-lateral strike-slip event with a little thrust, and caused a co-seismic rupture about 36 km long (24 km for the main fault and 12 km for the branch fault) on the surface. The main rupture area is concentrated in 0～15 km depth, and the maximum slip of the main fault is 2.94 m, corresponding to 1.5 km depth.The maximum slip of the branch fault is 1.43 m, corresponding to 4.5 km depth. The seismic moment releases by inversion is 1.37×10¹⁹ N·m, which is equivalent to a Mw 6.73 earthquake. Based on the results of field investigation and fault inversion, it is preliminarily determined that the co-seismogenic fault is the west end of Lenglongling fault and ruptures to the east end of Tuoleshan fault. The results of coseismic Coulomb stress variation and aftershock distribution show that the Coulomb stress at the east end of Lenglongling fault and the west end of Tuoleshan fault are obviously under loading condition, and the risk of strong earthquakes in the future is high.

Key words: Menyuan earthquake, co-seismic deformation, DInSAR, sliding distribution, Coulomb stress variation

CLC Number:

P237

WANG Xin, LI Shuiping, KANG Jing. InSAR observations constrained coseismic slip distribution and Coulomb stress variation of Mw 6.7 Menyuan earthquake in 2022[J]. Bulletin of Surveying and Mapping, 2023, 0(7): 32-38.

References

[1] 李振洪,韩炳权,刘振江,等. 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[J]. 武汉大学学报(信息科学版),2022,47(6):887-897.
[2] 颜丙囤,季灵运,蒋锋云,等. InSAR数据约束的2022年1月8日青海门源MS6.9地震发震构造研究[J]. 地震工程学报,2022,44(2):450-457.
[3] LI Yongsheng,JIANG Wenliang,LI Yujiang,et al. Coseismic rupture model and tectonic implications of the January 7 2022,Menyuan Mw 6.6 earthquake constraints from InSAR observations and field investigation[J]. Remote Sensing,2022,14(9):2111.
[4] GAUDEMER Y,TAPPONNIER P,MEYER B,et al. Partitioning of crustal slip between linked,active faults in the eastern Qilian Shan,and evidence for a major seismic gap,the ‘Tianzhu gap’,on the western Haiyuan fault,Gansu (China)[J]. Geophysical Journal International,1995,120(3):599-645.
[5] 刘国祥,陈强,罗小军. InSAR原理与应用[M]. 北京:科学出版社,2019.
[6] WANG Qi,QIAO Xuejun,LAN Qigui,et al. Rupture of deep faults in the 2008 Wenchuan earthquake and uplift of the Longmen Shan[J]. Nature Geoscience,2011,4(9):634-640.
[7] 郭鹏. 北祁连山冷龙岭断裂大震复发行为与危险性研究[D]. 北京:中国地震局地质研究所,2019.
[8] 姜文亮,李永生,田云锋,等. 冷龙岭地区2016年青海门源6.4级地震发震构造特征[J]. 地震地质,2017,39(3):536-549.
[9] 梁宽,何仲太,姜文亮,等. 2022年1月8日青海门源Ms 6.9地震的同震地表破裂特征[J]. 地震地质,2022,44(1):256-278.
[10] HUANG Z,ZHOU Y,QIAO X,et al. Kinematics of the 1000 km Haiyuan fault system in northeastern Tibet from high-resolution Sentinel-1 InSAR velocities:fault architecture,slip rates,and partitioning[J]. Earth and Planetary Science Letters,2022,583:117450.
[11] 贺巍. 阿尔金断裂带库仑应力演化与强震间相互影响研究[D].西安:西北大学,2019.
[12] GOLDSTEIN R M,WERNER C L. Radar interferogram filtering for geophysical applications[J]. Geophysical Research Letters,1998,25(21):4035-4038.
[13] EINEDER M,HUBIG M,MILCKE B. Unwrapping large interferograms using the minimum cost flow algorithm[C]//Proceedings of 1998 IEEE International Geoscience and Remote Sensing. Seattle:IEEE,1998:83-87.
[14] 潘家伟,李海兵,CHEVALIER M L,等. 2022年青海门源Mw 6.9地震地表破裂带及发震构造研究[J]. 地质学报,2022,96(1):215-231.
[15] JONSSON S. Fault slip distribution of the 1999 Mw 7.1 hector mine,California,earthquake,estimated from satellite radar and GPS measurements[J]. Bulletin of the Seismological Society of America,2002,92(4):1377-1389.
[16] 刘泽民,张广伟,梁姗姗,等. 2022年青海门源Ms 6.9地震余震的空间迁移特征[J]. 地震工程学报,2022,44(2):475-487.
[17] LI Shuiping,TAO Tingye,CHEN Yunguo,et al. Geodetic observation and modeling of the coseismic and postseismic deformations associated with the 2020 Mw 6.5 Monte Cristo earthquake[J]. Earth and Space Science,2021,8(6):e2021EA001696.
[18] 李水平,陈刚,何平,等. 2015年尼泊尔地震同震滑动及震后余滑的三角位错模型反演[J]. 武汉大学学报(信息科学版),2019,44(12):1787-1796.