气候变化领域集成服务门户(CCPortal): Constraints on Mantle Viscosity From Intermediate-Wavelength Geoid Anomalies in Mantle Convection Models With Plate Motion History

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DOI	10.1029/2020JB021561
	Constraints on Mantle Viscosity From Intermediate-Wavelength Geoid Anomalies in Mantle Convection Models With Plate Motion History
	Mao W.; Zhong S.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	The Earth's long- and intermediate-wavelength geoid anomalies are surface expressions of mantle convection and are sensitive to mantle viscosity. While previous studies of the geoid provide important constraints on the mantle radial viscosity variations, the mantle buoyancy in these studies, as derived from either seismic tomography or slab density models, may suffer significant uncertainties. In this study, we formulate 3-D spherical mantle convection models with plate motion history since the Cretaceous that generate dynamically self-consistent mantle thermal and buoyancy structures, and for the first time, use the dynamically generated slab structures and the observed geoid to place important constraints on the mantle viscosity. We found that non-uniform weak plate margins and strong plate interiors are critical in reproducing the observed geoid and surface plate motion, especially the net lithosphere rotation (i.e., degree-1 toroidal plate motion). In the best-fit model, which leads to correlation of 0.61 between the modeled and observed geoid at degrees 4–12, the lower mantle viscosity is ∼1.3–2.5 × 1022 Pa⋅s and is ∼30 and ∼600–1,000 times higher than that in the transition zone and asthenosphere, respectively. Slab structures and the geoid are also strongly affected by slab strength, and the observations prefer moderately strong slabs that are ∼10–100 times stronger than the ambient mantle. Finally, a thin weak layer below the 670-km phase change on a regional scale only in subduction zones produces stagnant slabs in the mantle transition zone as effectively as a weak layer on a global scale. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	dynamic topography; geoid; mantle convection; plate motion; viscosity
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/187209
作者单位	Department of Physics, University of Colorado, Boulder, CO, United States
推荐引用方式 GB/T 7714	Mao W.,Zhong S.. Constraints on Mantle Viscosity From Intermediate-Wavelength Geoid Anomalies in Mantle Convection Models With Plate Motion History[J],2021,126(4).
APA	Mao W.,&Zhong S..(2021).Constraints on Mantle Viscosity From Intermediate-Wavelength Geoid Anomalies in Mantle Convection Models With Plate Motion History.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Mao W.,et al."Constraints on Mantle Viscosity From Intermediate-Wavelength Geoid Anomalies in Mantle Convection Models With Plate Motion History".Journal of Geophysical Research: Solid Earth 126.4(2021).