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DOI	10.1016/j.tecto.2020.228663
	Rupture models and viscoelastic stress changes of three Mw similar to 6.3 earthquakes along the southern front of the Qilian Mountains, northeastern Tibetan plateau
	Zhu, Xiaojie; He, Jiankun; Wang, Weimin; Wang, Xun; Xiao, Jie
通讯作者	He, JK (通讯作者)
发表日期	2020
ISSN	0040-1951
EISSN	1879-3266
卷号	796
英文摘要	Around the southern front of the Qilian Mountains, three Mw 6.3 strong earthquakes have occurred since 2003. The distances between the epicenters of these events range from 18 to 46 km. By collecting available datasets, including broadband waveforms, coseismic surface geodetic measurements and active fault mapping results, we invert rupture models for these strong earthquakes with a finite fault model approach in elastic half space. Constrained by these detailed rupture models, we then build a three-dimensional finite element model to calculate Coulomb stress change due to the coseismic displacement and postseismic viscoelastic relaxation. Combined with an effective friction coefficient of 0.2-0.8 and variable rheological characteristics, numerical results show that following the 2003 event, the Coulomb stress change along the 2008 rupture segment was positive with magnitudes between 1.8 x 10(3) Pa and 2.2 x 10(3) Pa. Among the stresses, the postseismic viscoelastic relaxation contributed 10.7% similar to 23.3%. Just prior to the occurrence of the 2009 earthquake, the total changes of the Coulomb stress around its hypocenter reached 2.71 x 10(4) similar to- 3.72 x 10(4) Pa, to which the 2003 event and the 2008 event contributed approximately 7 x 10(2) similar to 1.5 x 10(3) Pa (2.58% similar to 4.03%) and 2.64 x 10(4) - 3.57 x 10(4) Pa (95.97% similar to 97.42%), respectively. We believe that other postseismic behaviors, including afterslip and poroelastic rebound, could also yield extra changes in the Coulomb stress, which probably further enhance the triggering effect among the sequential earthquakes. The numerical results also show that the increased stress around the hypocenters of latter two events was mainly determined by the positive shear stress. After the three strong earthquakes, the Coulomb stress on some active faults increased and is still increasing, suggesting that great attention should be paid to the potential earthquake hazards in this region.
关键词	1999 HECTOR-MINE QAIDAM BASIN SLIP RATES CONTINENTAL COLLISION TRANSIENT VISCOSITY VELOCITY-FIELD STRIKE-SLIP FAULT DEFORMATION EVOLUTION
英文关键词	Rupture model; Coulomb stress; Viscoelastic deformation; Strong earthquake; Qilian Mountains
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000595808000010
来源期刊	TECTONOPHYSICS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259735
推荐引用方式 GB/T 7714	Zhu, Xiaojie,He, Jiankun,Wang, Weimin,et al. Rupture models and viscoelastic stress changes of three Mw similar to 6.3 earthquakes along the southern front of the Qilian Mountains, northeastern Tibetan plateau[J]. 中国科学院青藏高原研究所,2020,796.
APA	Zhu, Xiaojie,He, Jiankun,Wang, Weimin,Wang, Xun,&Xiao, Jie.(2020).Rupture models and viscoelastic stress changes of three Mw similar to 6.3 earthquakes along the southern front of the Qilian Mountains, northeastern Tibetan plateau.TECTONOPHYSICS,796.
MLA	Zhu, Xiaojie,et al."Rupture models and viscoelastic stress changes of three Mw similar to 6.3 earthquakes along the southern front of the Qilian Mountains, northeastern Tibetan plateau".TECTONOPHYSICS 796(2020).