气候变化领域集成服务门户(CCPortal): Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau

CCPortal

DOI	10.1016/j.tecto.2017.08.009
	Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau
	Li, Guohui; Bai, Ling; Zhou, Yuanze; Wang, Xiaoran; Cui, Qinghui
通讯作者	Zhou, YZ (通讯作者)
发表日期	2017
ISSN	0040-1951
EISSN	1879-3266
起始页码	349
结束页码	360
卷号	721
英文摘要	P-wave triplications related to the 410 km discontinuity (the 410) were clearly observed from the vertical component seismograms of three intermediate-depth earthquakes that occurred in the Indo-Burma Subduction Zone (IBSZ) and were recorded by the Chinese Digital Seismic Network (CDSN). By matching the observed P-wave triplications with synthetics through a grid search, we obtained the best-fit models for four azimuthal profiles (I-IV from north to south) to constrain the P-wave velocity structure near the 410 beneath the southeastern margin of the Tibetan Plateau (TP). A ubiquitous low-velocity layer (LVL) resides atop the mantle transition zone (MTZ). The LVL is 25 to 40 km thick, with a P-wave velocity decrement ranging from approximately -53% to -3.6% related to the standard Earth model IASP91. An abrupt transition in the velocity decrement of the LVL was observed between profiles II and III. We postulate that the mantle structure beneath the southeastern margin of the TP is primarily controlled by the southeastern extrusion of the TP to the north combined with the eastward subduction of the Indian plate to the south, but not affected by the Emeishan mantle plume. We attribute the LVL to the partial melting induced by water and/or other volatiles released from the subducted Indian plate and the stagnant Pacific plate, but not from the upwelling or the remnants of the Emeishan mantle plume. A high-velocity anomaly ranging from approximately 1.0% to 1.5% was also detected at a depth of 542 to 600 km, providing additional evidence for the remnants of the subducted Pacific plate within the MTZ. (C) 2017 Elsevier B.V. All rights reserved.
关键词	EMEISHAN FLOOD BASALTS HYDROUS SILICATE MELT P-WAVE-FORM SEISMIC DISCONTINUITY 410-KM DISCONTINUITY WATER PHASE ATOP LAYER ASIA
英文关键词	P-wave triplication; Low-velocity layer; High-velocity anomaly; Mantle transition zone; Southeastern margin of the Tibetan Plateau
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000418309400023
来源期刊	TECTONOPHYSICS
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/258972
推荐引用方式 GB/T 7714	Li, Guohui,Bai, Ling,Zhou, Yuanze,et al. Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau[J]. 中国科学院青藏高原研究所,2017,721.
APA	Li, Guohui,Bai, Ling,Zhou, Yuanze,Wang, Xiaoran,&Cui, Qinghui.(2017).Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau.TECTONOPHYSICS,721.
MLA	Li, Guohui,et al."Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau".TECTONOPHYSICS 721(2017).