气候变化领域集成服务门户(CCPortal): The Viscosity of the Top Third of the Lower Mantle Estimated Using GPS, GRACE, and Relative Sea Level Measurements of Glacial Isostatic Adjustment

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DOI	10.1029/2020JB021537
	The Viscosity of the Top Third of the Lower Mantle Estimated Using GPS, GRACE, and Relative Sea Level Measurements of Glacial Isostatic Adjustment
	Argus D.F.; Peltier W.R.; Blewitt G.; Kreemer C.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	We distinguish between two models of solid Earth's viscoelastic response to unloading of the Laurentide ice sheet over the past 26,000 years. The upper mantle viscosity in both models is 0.5 × 1021 Pa s. The viscosity of the top 500 km of the lower mantle (670–1,170 km) in model L17 is 13 × 1021 Pa s, eight times larger than the value of 1.6 × 1021 Pa s in ICE-6G_D (VM5a). In ICE-6G_D (VM5a), viscous relaxation of solid Earth was rapid 8,000 years ago and is slow today, with present-day uplift at the Laurentide ice center being 12 mm/yr. In L17, solid Earth relaxed more slowly 8,000 years ago but is faster today, with present uplift of the ice center occurring at 20 mm/yr. The significant difference is not due to different ice histories given that total ice loss in L17 is just 12% less than in ICE-6G_D. We determine a comprehensive set of GPS uplift rates for North America that is more accurate than in prior studies due to (1) more sites and a longer data time history, (2) removal of elastic loading produced by increase in Great Lakes water, and (3) technical advances in GPS positioning that have significantly reduced the dispersion in position estimates. We find uplift at the ice center to be about 12 mm/yr, supporting the low value of the viscosity of the top 500 km of the lower mantle in ICE-6G_D (VM5a), but ruling out the high value in L17. © 2021. Journal of Geophysical Research: Solid Earth.
英文关键词	glacial isostatic adjustment; GPS; GRACE; mantle 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/187098
作者单位	Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States; Department of Physics, University of Toronto, Toronto, ON, Canada; Nevada Geodetic Laboratory, Nevada Bureau of Mines and Geology, University of Nevada, Reno, NV, United States
推荐引用方式 GB/T 7714	Argus D.F.,Peltier W.R.,Blewitt G.,et al. The Viscosity of the Top Third of the Lower Mantle Estimated Using GPS, GRACE, and Relative Sea Level Measurements of Glacial Isostatic Adjustment[J],2021,126(5).
APA	Argus D.F.,Peltier W.R.,Blewitt G.,&Kreemer C..(2021).The Viscosity of the Top Third of the Lower Mantle Estimated Using GPS, GRACE, and Relative Sea Level Measurements of Glacial Isostatic Adjustment.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Argus D.F.,et al."The Viscosity of the Top Third of the Lower Mantle Estimated Using GPS, GRACE, and Relative Sea Level Measurements of Glacial Isostatic Adjustment".Journal of Geophysical Research: Solid Earth 126.5(2021).