Finite difference tomography of the crustal velocity structure in Tengchong, Yunnan province

doi:10.6038/cjg20130411

	Finite difference tomography of the crustal velocity structure in Tengchong, Yunnan province
	Cao Ling-Min 1; Xu Yi 2; Wu Shi-Guo 1
刊名	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
	2013-04-01
卷号	56 期号:4 页码:1159-1167
关键词	P wave tomography Magmatism Longling earthquakes Tengchong volcanic area
ISSN号	0001-5733
DOI	10.6038/cjg20130411
文献子类	Article
英文摘要	This paper applies the finite difference tomography method to invert for the P-wave velocity structure in the Tengchong area using earthquake data from a temporary network and other permanent stations, and analyzes the magmatic activity of the Tengchong volcanoes and the deep tectonic genesis of Longling M7.3/M7.4 earthquakes. The results show the mean velocity in the crust with clear heterogeneity is a little lower. The lower velocities in the shallow layers are caused by unconsolidated basin deposits, Cenozoic volcanic deposits, fluid fractures and hot springs. The high-velocity zone at 5 similar to 15 km depth probably represents the cooled and solidified magmatic intrusions or the less volatile ultramafic remnants. The low-velocity structure in the deep indicates the molten or semi-molten magma. It is probable that the magmatic activity beneath the volcanoes and heat flow intrusions in the deep crust of Longling earthquake zone are from the same magmatic hearth area, which is the main area of the present magmatic activities. A strong lateral heterogeneity is observed in Longling earthquake zone. The east of the Nujiang fault belt and the west of the Long ling fault belt have the characters of high-velocity with the high strength of rock, which are the main bearing body of stress accumulation. However, the low-velocity anomaly between the two faults extends to lower crust, probably caused by magmatic intrusions in the deep crust. The magmatic activity in this area is controlled clearly by the Long ling fault and the Nujiang fault. The Long ling M7.3 and M7.4 earthquakes occurred near the velocity boundary beneath the faults. The main reasons of the strong earthquakes in the Long ling area contain the heterogeneity of stress accumulation caused by the lateral variation of the crustal medium strength, the deep magmatic aggregation and dynamic effects.
WOS关键词	SIMULTANEOUS INVERSION ; SEISMIC TOMOGRAPHY ; TIBETAN PLATEAU ; WESTERN YUNNAN ; VOLCANIC FIELD ; TRAVEL-TIMES ; BENEATH ; CHINA ; EARTHQUAKE ; REGION
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000318456900011
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/86604]
专题	中国科学院地质与地球物理研究所
通讯作者	Cao Ling-Min
作者单位	1.Chinese Acad Sci, Inst Oceanol, Marine Geol & Environm Key Lab, Qingdao 266071, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resource Res, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Cao Ling-Min,Xu Yi,Wu Shi-Guo. Finite difference tomography of the crustal velocity structure in Tengchong, Yunnan province[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2013,56(4):1159-1167.
APA	Cao Ling-Min,Xu Yi,&Wu Shi-Guo.(2013).Finite difference tomography of the crustal velocity structure in Tengchong, Yunnan province.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,56(4),1159-1167.
MLA	Cao Ling-Min,et al."Finite difference tomography of the crustal velocity structure in Tengchong, Yunnan province".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 56.4(2013):1159-1167.