Midcrustal low-velocity layer beneath the central Himalaya and southern Tibet revealed by ambient noise array tomography

doi:10.1029/2009GC002458

	Midcrustal low-velocity layer beneath the central Himalaya and southern Tibet revealed by ambient noise array tomography
	Guo, Zhi 1; Gao, Xing 1; Yao, Huajian 2; Li, Juan 3; Wang, Weimin
刊名	GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
	2009-05-28
卷号	10
关键词	Himalaya southern Tibet ambient noise tomography lower-velocity layer midcrustal structure
ISSN号	1525-2027
DOI	10.1029/2009GC002458
文献子类	Article
英文摘要	Ambient noise tomography has been becoming an important tool to image the shallow lithospheric structure of the Earth. Using 2 months of ambient noise data from 20 stations of the Himalayan Nepal Tibet Seismic Experiment, we investigate the upper and middle crustal structure in the central Himalaya and southern Tibet. About 120 interstation Rayleigh wave empirical Green's functions with sufficient signal-to-noise ratio are obtained and used for group velocity dispersion analysis in the period range 6-25 s using frequency-time analysis technique. The obtained dispersion data are then used to construct 2-D group velocity maps. At the short periods from 9 to 15 s, the distribution of Rayleigh wave velocities delineates several distinct low-and high-velocity zones separated mainly by geological boundaries. The high group velocity zone is located mainly around regions with plutonic rocks, and the low group velocity zone is located around regions with sedimentary or metasedimentary rocks. Finally, we invert for the shear velocity structure in the upper and middle crust along a N-S trending cross section at the longitude 86.5 degrees E. We observe a clear low-velocity layer in the middle crust (about 10-25 km depth) distributed on both sides of the Indus Yarlung Suture zone. The existence of this midcrustal low-velocity zone suggests a mechanically weaker middle crust beneath the central Himalaya and southern Tibet, which might decouple the upper crustal deformation from that of the lower crust in the Tibetan-Himalayan orogenic processes.
WOS关键词	SURFACE-WAVE TOMOGRAPHY ; SEISMIC NOISE ; INDIAN SUBCONTINENT ; 2-STATION ANALYSIS ; CRUSTAL STRUCTURE ; KANGMAR DOME ; SUTURE ZONE ; SE TIBET ; MANTLE ; PLATEAU
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000266517100001
资助机构	National Science Foundation of China(40874033 ; National Science Foundation of China(40874033 ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; 40674073) ; 40674073) ; National Science Foundation of China(40874033 ; National Science Foundation of China(40874033 ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; 40674073) ; 40674073) ; National Science Foundation of China(40874033 ; National Science Foundation of China(40874033 ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; 40674073) ; 40674073) ; National Science Foundation of China(40874033 ; National Science Foundation of China(40874033 ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; 40674073) ; 40674073)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/71068]
专题	中国科学院地质与地球物理研究所
通讯作者	Guo, Zhi
作者单位	1.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100085, Peoples R China 2.MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA 3.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Guo, Zhi,Gao, Xing,Yao, Huajian,et al. Midcrustal low-velocity layer beneath the central Himalaya and southern Tibet revealed by ambient noise array tomography[J]. GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS,2009,10.
APA	Guo, Zhi,Gao, Xing,Yao, Huajian,Li, Juan,&Wang, Weimin.(2009).Midcrustal low-velocity layer beneath the central Himalaya and southern Tibet revealed by ambient noise array tomography.GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS,10.
MLA	Guo, Zhi,et al."Midcrustal low-velocity layer beneath the central Himalaya and southern Tibet revealed by ambient noise array tomography".GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 10(2009).