气候变化领域集成服务门户(CCPortal): Characteristics of stress field and crustal kinematics of the southern region of Sichuan-Yunnan block, southern Tibet Plateau

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DOI	10.1016/j.quaint.2022.10.011
	Characteristics of stress field and crustal kinematics of the southern region of Sichuan-Yunnan block, southern Tibet Plateau
	Wu, Weiwei; Long, Feng; Liang, Mingjian; Su, Jinrong; Chen, Xuefen
发表日期	2023
ISSN	1040-6182
EISSN	1873-4553
起始页码	70
结束页码	79
卷号	656
英文摘要	The Red River fault is a massive tectonic shear zone of the Sichuan-Yunnan block, southern Tibet Plateau. The target area of this study is the Red River fault's middle-northern section and adjacent areas. Considering the spatial difference of tectonic structures and the inhomogeneity of focal mechanism solutions, we divided the target area into three structural units: the northern extension area, the middle strike-slip movement area, and the west complex rupture area. The study is carried out on the basis of zoning. Using the CAP method to invert the focal mechanism of moderate earthquakes and the principal compressive and tensile stress. Restoring the seismic source spectrum of small and medium earthquakes, then inversion the stress drops in three sub-units based on Brune model using digital waveform records. Our study suggests that: (1) Many high-stress drop earthquakes occurred in the transitional areas from the Weixi-Qiaohou fault to the Red River fault and from the Chuxiong fault to the Qujiang fault, also occurred in the Changning-Baoshan-Yongping area, revealing a large accumulation of local tectonic stress. (2) Some events with Delta sigma >= 20 MPa have occurred in the prominent low-speed anomaly area, indicating that a passive deformation crossed the Red River fault and extended to the west. Yangbi MS 6.4 earthquake (2021) occurred in a strongly locked area with high potential earthquake risk. (3) In the north of the study region, the movement of the Sichuan-Yunnan block to SE-SSE orientation was governed by the dextral strike-slip movement of the NW strike fault; in the middle region, the SE-orientated movement of the block relative to the South China block was governed by the sinistral slip movement of the SN-strike faults; and in the west region, the tectonic stress was governed by clockwise rotation of the block and the sinistral slip movement of the NE strike faults. We suggest that strike slip and rotation of the Red River fault's middle section may drive and aggravate passive movement in the north section, resulting in locally geophysical field responses. Therefore, the potential risk of a large earthquake in the middle-northern section of the Red River fault should be monitored.
关键词	Red river fault Deformation mechanism Focal parameters Crustal dynamics Stress field
英文关键词	RED-RIVER FAULT; MODERATE EARTHQUAKES; SOUTHEASTERN MARGIN; SOURCE PARAMETERS; FOCAL MECHANISMS; CHINA; PROVINCE; MOTION; BORDER; MODEL
WOS研究方向	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:000983071000001
来源期刊	QUATERNARY INTERNATIONAL
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283287
作者单位	China Earthquake Administration; Sichuan Earthquake Agency, CEA; China Earthquake Administration
推荐引用方式 GB/T 7714	Wu, Weiwei,Long, Feng,Liang, Mingjian,et al. Characteristics of stress field and crustal kinematics of the southern region of Sichuan-Yunnan block, southern Tibet Plateau[J],2023,656.
APA	Wu, Weiwei,Long, Feng,Liang, Mingjian,Su, Jinrong,&Chen, Xuefen.(2023).Characteristics of stress field and crustal kinematics of the southern region of Sichuan-Yunnan block, southern Tibet Plateau.QUATERNARY INTERNATIONAL,656.
MLA	Wu, Weiwei,et al."Characteristics of stress field and crustal kinematics of the southern region of Sichuan-Yunnan block, southern Tibet Plateau".QUATERNARY INTERNATIONAL 656(2023).