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DOI	10.6038/cjg20170607
	Temporal and spatial variation of b-value before and after Wenchuan earthquake and its tectonic implication
	Liu Yan-Bing; Pei Shun-Ping
通讯作者	Pei, SP (通讯作者)
发表日期	2017
ISSN	0001-5733
起始页码	2104
结束页码	2112
卷号	60 期号:6
英文摘要	Seismic b-value shows close relationship with stress, with high stress corresponding to low b-values. Research on temporal and spatial variation of b-value in Longmenshan area will provide useful information to understand stress evolution of Wenchuan earthquake. In this paper, we relocated the earthquakes in Longmen Shan region before and after the Wenchuan earthquake (M(S)8. 0) by both joint inversion of hypocenter location and velocity structure and the double difference earthquake location method, and then calculated temporal variation of the b-value in entire region and its spatial distribution in different time periods before and after Wenchuan earthquake. The results show: (1) The b-values show a significant boundary at depth of similar to 15 km, above which the b-value is much higher than that blow 15 km. This boundary indicates the division between brittle and ductile layers in the upper crust. (2) Temporal variation of average b-value shows clear decrease after the Wenchuan Earthquake, and then gradually increases till Lushan earthquake, however decreases again after the Lushan Earthquake. This variation trend represents not only the co-seismic change but also healing process of the Longmenshan fault. (3) Spatial variation of b-value shows increase (i.e. decreased stress) in Wenchuan rupture zone after Lushan earthquake that reveals possible ductile deformation in the gap between the Lushan and the Wenchuan earthquake and the Lushan earthquake promoted the healing of the rupture zone of the Wenchuan earthquake. (4) The significant low b-value anomaly in the Pengguan complex rock area near Yingxiu before Wenchuan earthquake suggests high differential stress in this region and therefore maximum dislocation occurred here after the Wenchuan Earthquake.
关键词	LONGMENSHAN TOMOGRAPHY RELOCATION SEQUENCE CHINA
英文关键词	Wenchuan Earthquake; Lushan Earthquake; b-value; Differential stress; Brittle and ductile behavior
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000403744600007
来源期刊	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
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/258901
推荐引用方式 GB/T 7714	Liu Yan-Bing,Pei Shun-Ping. Temporal and spatial variation of b-value before and after Wenchuan earthquake and its tectonic implication[J]. 中国科学院青藏高原研究所,2017,60(6).
APA	Liu Yan-Bing,&Pei Shun-Ping.(2017).Temporal and spatial variation of b-value before and after Wenchuan earthquake and its tectonic implication.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,60(6).
MLA	Liu Yan-Bing,et al."Temporal and spatial variation of b-value before and after Wenchuan earthquake and its tectonic implication".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 60.6(2017).