气候变化领域集成服务门户(CCPortal): Weak Crust in Southeast Tibetan Plateau Revealed by Lg-Wave Attenuation Tomography: Implications for Crustal Material Escape

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DOI	10.1029/2020JB020748
	Weak Crust in Southeast Tibetan Plateau Revealed by Lg-Wave Attenuation Tomography: Implications for Crustal Material Escape
	He X.; Zhao L.-F.; Xie X.-B.; Tian X.; Yao Z.-X.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	The continuous convergence between the Indian and Eurasian plates caused massive lithospheric deformation in the Tibetan Plateau and led to excessive crustal material escaping through its southeastern margin. However, the mechanisms that accommodate the escaping materials and whether they intrude into the Indochina Peninsula are continually under debate. Seismic Lg waves mostly propagate within the crust waveguide with an amplitude decay that is sensitive to crustal material properties, such as temperature, partial melting, and fracture. Therefore, Lg attenuation can be a useful indicator of potential crustal material escape. In this study, we developed a high-resolution broadband Lg attenuation model in this region between 0.05 and 10.0 Hz, with the resolution reaching 1° in regions with dense raypath coverage. Prominent low-Q anomalies beneath the southeastern margin of the Tibetan Plateau, correlating with previously observed low velocity, high conductivity and high Poisson’s ratio, may indicate possible high temperature and/or partial melting within a relatively weak crust, and suggest a north-south interconnected corridor for gravity-driven material flow. Through our results and other geological and geophysical observations, a dynamic model is suggested here by combining shallow rigid block extrusion and deep viscous crustal flow to explain crustal material escape in the southeastern margin of the Tibetan Plateau. Additionally, neither shallow extrusion nor deep material flow enter the Indochina Peninsula based on the relatively high Q values, which indicate a stronger crust there. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	crustal material flow; dynamic mechanism; Indochina Peninsula; Lg wave attenuation; Q tomography; southeastern margin of the Tibetan Plateau
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187269
作者单位	Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China; Innovation Academy for Earth Sciences, Chinese Academy of Sciences, Beijing, China; Institute of Geophysics and Planetary Physics, University of California, Santa Cruz, Santa Cruz, CA, United States; State Key Laboratory of Lithosphere Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China
推荐引用方式 GB/T 7714	He X.,Zhao L.-F.,Xie X.-B.,et al. Weak Crust in Southeast Tibetan Plateau Revealed by Lg-Wave Attenuation Tomography: Implications for Crustal Material Escape[J],2021,126(3).
APA	He X.,Zhao L.-F.,Xie X.-B.,Tian X.,&Yao Z.-X..(2021).Weak Crust in Southeast Tibetan Plateau Revealed by Lg-Wave Attenuation Tomography: Implications for Crustal Material Escape.Journal of Geophysical Research: Solid Earth,126(3).
MLA	He X.,et al."Weak Crust in Southeast Tibetan Plateau Revealed by Lg-Wave Attenuation Tomography: Implications for Crustal Material Escape".Journal of Geophysical Research: Solid Earth 126.3(2021).