气候变化领域集成服务门户(CCPortal): Lateral Variations of Shear-Wave Velocity in the D″ Layer Beneath the Indian-Eurasian Plate Collision Zone

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DOI	10.1029/2019GL086856
	Lateral Variations of Shear-Wave Velocity in the D″ Layer Beneath the Indian-Eurasian Plate Collision Zone
	Li G.; Bai L.; Ritsema J.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:6
英文摘要	Seismic tomography has demonstrated that the shear-wave velocity is relatively high over a 3,000-km wide region in the lowermost mantle beneath southern and eastern Asia. This seismic anomaly demarcates the current position of slab remnants that may have subducted in the Cretaceous. To further characterize the seismic structure at smaller scales, we measure 929 residual travel time differences (δt) between the phases ScS and S using recordings of eight earthquakes beneath the Indian Ocean at stations from the Chinese Digital Seismic Network. We interpret variations of δt up to 10 s as due to horizontal shear-velocity variations in D″ beneath northern India, Nepal, and southwestern China. The shear velocity can vary by as much as 7% over distances shorter than 300 km. Our observations provide additional observational evidence that compositional heterogeneity and possibly melt contribute to the seismic structure of the lower mantle characterized by long-term subduction and mantle downwelling. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Acoustic wave velocity; Deuterium; Earthquakes; Plates (structural components); Shear waves; Wave propagation; Collision zone; Compositional heterogeneity; Lateral variations; long-term subduction; Seismic structure; Seismic tomography; Shear wave velocity; Wave forms; Shear flow; collision; Cretaceous; Eurasian plate; Indian plate; lower mantle; S-wave; seismic tomography; subduction zone; wave velocity; waveform analysis; Asia; India; Indian Ocean; Nepal
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170563
作者单位	Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, China; Institute of Earthquake Forecasting, China Earthquake Administration, Beijing, China; Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States
推荐引用方式 GB/T 7714	Li G.,Bai L.,Ritsema J.. Lateral Variations of Shear-Wave Velocity in the D″ Layer Beneath the Indian-Eurasian Plate Collision Zone[J],2020,47(6).
APA	Li G.,Bai L.,&Ritsema J..(2020).Lateral Variations of Shear-Wave Velocity in the D″ Layer Beneath the Indian-Eurasian Plate Collision Zone.Geophysical Research Letters,47(6).
MLA	Li G.,et al."Lateral Variations of Shear-Wave Velocity in the D″ Layer Beneath the Indian-Eurasian Plate Collision Zone".Geophysical Research Letters 47.6(2020).