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DOI	10.6038/cjg2022Q0048
	Three-dimensional shear wave velocity structure in the eastern margin of the Tibetan Plateau based on the ambient noise
	Tan YouHeng; Yu XiangWei; Song Qian; Zhang WenBo
发表日期	2023
ISSN	0001-5733
起始页码	1050
结束页码	1069
卷号	66 期号:3
英文摘要	In this paper, we collected continuous waveform data recorded by 105 broadband seismic stations in Sichuan, Chongqing, Gansu, Qinghai and Shanxi seismic network during August 2017 to August 2018, and extracted empirical Green's functions of Rayleigh surface-wave based on the cross -correlation calculation on the long-time ambient noise data recorded by station pairs to obtain 5416 fundamental-order Rayleigh surface-wave dispersion curves with periods in the range of 5 s to 40 s. The three-dimensional shear wave velocity structure of the crust and uppermost mantle beneath the eastern margin of the Tibetan Plateau was inverted. Our results show that the velocity structure beneath the eastern margin of the Tibetan Plateau exhibits very pronouncedly lateral heterogeneity, and the characteristics of the velocity structure of underground shallow layer fit well with the main geological characteristics and block units in the study area. The low-velocity body beneath the eastern margin of the Tibetan Plateau is blocked by the rigid crust of the Sichuan basin during its eastward extension. Part of the low-velocity body penetrates the Sichuan-Yunnan block southward, forming extensively low-velocity anomalies of about 15 km in thickness at 30 km below, and the other part extends towards the north and then upwells and accumulates beneath the Tazang fault, resulting in the local Moho's subsidence. In addition, the low-velocity body under the eastern margin of the Tibetan Plateau crosses the East Kunlun fault zone into the Qaidam block in the northeast direction, and reaches the vicinity of the West Qinling fault zone. Among them, there is a large-scale low-velocity body of about 15 km in thickness at 30 km beneath the Bayan Har block, which is associated with the uplifted topography and crustal thickening on the eastern margin of the Tibetan Plateau. Furthermore, the low-velocity body narrows below the Qaidam block, and may be connected with a small low-velocity body of about 10 km in thickness at 30 km beneath Qilian block. However, the value of the low-velocity body of the Qilian block is slightly higher than that of the Bayan Har block, which may indicate that the low-velocity body of the Qilian block is in the early developmental stage of the Bayan Har block.
关键词	Eastern margin of Tibetan Plateau Ambient noise Three-dimensional shear wave velocity structure Low-velocity body in the middle-lower crust
英文关键词	MANTLE STRUCTURE; SE TIBET; CRUSTAL; DISPERSION; TOMOGRAPHY; CHINA; FLOW; DEFORMATION; EMERGENCE; INVERSION
WOS研究方向	Geochemistry & Geophysics
WOS记录号	WOS:000945003800015
来源期刊	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283845
作者单位	Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
推荐引用方式 GB/T 7714	Tan YouHeng,Yu XiangWei,Song Qian,et al. Three-dimensional shear wave velocity structure in the eastern margin of the Tibetan Plateau based on the ambient noise[J],2023,66(3).
APA	Tan YouHeng,Yu XiangWei,Song Qian,&Zhang WenBo.(2023).Three-dimensional shear wave velocity structure in the eastern margin of the Tibetan Plateau based on the ambient noise.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,66(3).
MLA	Tan YouHeng,et al."Three-dimensional shear wave velocity structure in the eastern margin of the Tibetan Plateau based on the ambient noise".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 66.3(2023).