气候变化领域集成服务门户(CCPortal): Fluids Triggered the 2021 Mw 6.1 Yangbi Earthquake at an Unmapped Fault: Implications for the Tectonics at the Northern End of the Red River Fault

CCPortal

DOI	10.1785/0220210227
	Fluids Triggered the 2021 Mw 6.1 Yangbi Earthquake at an Unmapped Fault: Implications for the Tectonics at the Northern End of the Red River Fault
	Sun, Quan; Guo, Zhen; Pei, Shunping; Fu, Yuanyuan, V; Chen, Yongshun John
通讯作者	Guo, Z (通讯作者)
发表日期	2022
ISSN	0895-0695
EISSN	1938-2057
起始页码	666
结束页码	679
卷号	93 期号:2A
英文摘要	On 21 May 2021 a magnitude Mw 6.1 earthquake occurred in Yangbi region, Yunan, China, which was widely felt and caused heavy casualties. Imaging of the source region was conducted using our improved double-difference tomography method on the huge data set recorded by 107 temporary stations of ChinArray-I and 62 permanent stations. Pronounced structural heterogeneities across the rupture source region are discovered and locations of the hypocenters of the Yangbi earthquake sequence are significantly improved as the output of the inversion. The relocated Yangbi earthquake sequence is distributed at an unmapped fault that is almost parallel and adjacent ( similar to 15 km distance) to the Tongdian-Weishan fault (TWF) at the northern end of the Red River fault zone. Our high-resolution 3D velocity models show significant high-velocity and low-VP/ VS ratios in the upper crust of the rupture zone, suggesting the existence of an asperity for the event. More importantly, low-VS and high-VP/ VS anomalies below 10 km depth are imaged underlying the source region, indicating the existence of fluids and potential melts at those depths. Upward migration of the fluids and potential melts into the rupture zone could have weakened the locked asperity and triggered the occurrence of the Yangbi earthquake. The triggering effect by upflow fluids could explain why the Yangbi earthquake did not occur at the adjacent TWF where a high-stress accumulation was expected. We speculate that the fluids and potential melts in the mid-to-lower crust might have originated either from crustal channel flow from the southeast Tibet or from local upwelling related to subduction of the Indian slab to the west.
关键词	YUNNAN PROVINCE HEAT-FLOW CHINA TOMOGRAPHY EVOLUTION STRENGTH SEQUENCE M(S)6.4 GEOLOGY TIBET
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000762027700004
来源期刊	SEISMOLOGICAL RESEARCH LETTERS
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/260655
推荐引用方式 GB/T 7714	Sun, Quan,Guo, Zhen,Pei, Shunping,et al. Fluids Triggered the 2021 Mw 6.1 Yangbi Earthquake at an Unmapped Fault: Implications for the Tectonics at the Northern End of the Red River Fault[J]. 中国科学院青藏高原研究所,2022,93(2A).
APA	Sun, Quan,Guo, Zhen,Pei, Shunping,Fu, Yuanyuan, V,&Chen, Yongshun John.(2022).Fluids Triggered the 2021 Mw 6.1 Yangbi Earthquake at an Unmapped Fault: Implications for the Tectonics at the Northern End of the Red River Fault.SEISMOLOGICAL RESEARCH LETTERS,93(2A).
MLA	Sun, Quan,et al."Fluids Triggered the 2021 Mw 6.1 Yangbi Earthquake at an Unmapped Fault: Implications for the Tectonics at the Northern End of the Red River Fault".SEISMOLOGICAL RESEARCH LETTERS 93.2A(2022).