气候变化领域集成服务门户(CCPortal): Constraints on the Depth, Thickness, and Strength of the G Discontinuity in the Central Pacific From S Receiver Functions

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DOI	10.1029/2019JB019256
	Constraints on the Depth, Thickness, and Strength of the G Discontinuity in the Central Pacific From S Receiver Functions
	Mark H.F.; Collins J.A.; Lizarralde D.; Hirth G.; Gaherty J.B.; Evans R.L.; Behn M.D.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	The relative motion of the lithosphere with respect to the asthenosphere implies the existence of a boundary zone that accommodates shear between the rigid plates and flowing mantle. This shear zone is typically referred to as the lithosphere-asthenosphere boundary (LAB). The width of this zone and the mechanisms accommodating shear across it have important implications for coupling between mantle convection and surface plate motion. Seismic observations have provided evidence for several physical mechanisms that might help enable relative plate motion, but how these mechanisms each contribute to the overall accommodation of shear remains unclear. Here we present receiver function constraints on the discontinuity structure of the oceanic upper mantle at the NoMelt site in the central Pacific, where local constraints on shear velocity, anisotropy, conductivity, and attenuation down to ∼300 km depth provide a comprehensive picture of upper mantle structure. We image a seismic discontinuity with a Vsv decrease of 4.5% or more over a 0–20 km thick gradient layer centered at a depth of ∼65 km. We associate this feature with the Gutenberg discontinuity (G), and interpret our observation of G as resulting from strain localization across a dehydration boundary based on the good agreement between the discontinuity depth and that of the dry solidus. Transitions in Vsv, azimuthal anisotropy, conductivity, and attenuation observed at roughly similar depths suggest that the G discontinuity represents a region of localized strain within a broader zone accommodating shear between the lithosphere and asthenosphere. © 2021. American Geophysical Union. All Rights Reserved.
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/187236
作者单位	Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States; Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Geological Sciences Department, Brown University, Providence, RI, United States; School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, United States; Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, United States
推荐引用方式 GB/T 7714	Mark H.F.,Collins J.A.,Lizarralde D.,et al. Constraints on the Depth, Thickness, and Strength of the G Discontinuity in the Central Pacific From S Receiver Functions[J],2021,126(4).
APA	Mark H.F..,Collins J.A..,Lizarralde D..,Hirth G..,Gaherty J.B..,...&Behn M.D..(2021).Constraints on the Depth, Thickness, and Strength of the G Discontinuity in the Central Pacific From S Receiver Functions.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Mark H.F.,et al."Constraints on the Depth, Thickness, and Strength of the G Discontinuity in the Central Pacific From S Receiver Functions".Journal of Geophysical Research: Solid Earth 126.4(2021).