气候变化领域集成服务门户(CCPortal): Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy

CCPortal

DOI	10.1016/j.epsl.2020.116317
	Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy
	Hoggard M.J.; Parnell-Turner R.; White N.
发表日期	2020
ISSN	0012821X
卷号	542
英文摘要	Mantle convection is the principal mechanism by which heat is transferred from the deep Earth to the surface. Cold subducting slabs sink into the mantle and steadily warm, whilst upwelling plumes carry heat to the base of lithospheric plates where it can subsequently escape by conduction. Accurate estimation of the total heat carried by these plumes is important for understanding geodynamic processes and Earth's thermal budget. Existing estimates, based upon swell geometries and velocities of overriding plates, yield a global heat flux of ∼2 TW and indicate that plumes play only a minor role in heat transfer. Here, we revisit the Icelandic and Hawaiian plumes to show that their individual flux estimates are likely to be incorrect due to the assumption that buoyancy is mainly produced within the lithosphere and therefore translates at plate velocities. We develop an alternative methodology that depends upon swell volume, is independent of plate velocities, and allows both for decay of buoyancy through time and for differential motion between asthenospheric buoyancy and the overlying plate. Reanalysis of the Icelandic and Hawaiian swells yields buoyancy fluxes of 4.0±0.5 Mg s−1 and 2.9±0.6 Mg s−1, respectively. Both swells are used to calibrate a buoyancy decay timescale of ∼45 Myr for the new volumetric approach, which enables buoyancy fluxes to be estimated for a global inventory of 53 swells. Estimates from magmatic hotspots yield a cumulative lower bound on global plume flux of 2 TW, which increases to 6 TW if amagmatic swells are also included and if all buoyancy is assumed to be thermal in origin. Our results suggest that upwelling plumes play a significant role in the transfer of heat into the uppermost mantle. © 2020 Elsevier B.V.
关键词	bathymetric swell buoyancy flux dynamic topography heat flow mantle plume thermal budget
英文关键词	Budget control; Buoyancy; Heat flux; Plates (structural components); Structural geology; Accurate estimation; Cold subducting slabs; Geodynamic process; Global inventories; Mantle convection; Uppermost mantle; Upwelling plume; Volumetric approach; Heat transfer; geodynamics; heat flux; heat transfer; hot spot; mantle plume; mantle upwelling; upper mantle; Calluna vulgaris
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202652
作者单位	Department of Earth & Planetary Sciences, Harvard University, United States; Lamont-Doherty Earth Observatory, Columbia University, United States; Scripps Institution of Oceanography, University of California San Diego, United States; Bullard Laboratories, University of Cambridge, United Kingdom
推荐引用方式 GB/T 7714	Hoggard M.J.,Parnell-Turner R.,White N.. Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy[J],2020,542.
APA	Hoggard M.J.,Parnell-Turner R.,&White N..(2020).Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy.Earth and Planetary Science Letters,542.
MLA	Hoggard M.J.,et al."Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy".Earth and Planetary Science Letters 542(2020).