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DOI	10.1016/j.epsl.2020.116570
	The strength of the Iceland plume: A geodynamical scaling approach
	Ribe N.M.; Tackley P.J.; Sanan P.
发表日期	2020
ISSN	0012821X
卷号	551
英文摘要	An important measure of the strength of a mantle plume is its buoyancy flux B, defined as the integral over a horizontal plane of the product of the vertical velocity and the density deficit within the plume. In the case of the Iceland plume, which currently rises directly beneath the mid-Atlantic ridge, published estimates of B cover a range of a factor of 37. To reconcile these diverse estimates, we study a simple fluid mechanical model of a ridge-centered plume in which plume fluid with spreadability σ (buoyancy over viscosity) is supplied at a volumetric rate Q from a plume conduit located directly beneath a ridge with a half spreading rate U. The plume fluid spreads laterally to form a thin pool beneath a lithosphere whose thickness increases as the square root of age. Application of scaling and dimensional analysis to this model leads to a general scaling law for the ‘waist width’ Ww, the length of the plume-induced elevation anomaly along the ridge. The law has the form Ww/W0=f2(Πb,Πs), where W0=(σQ4/U5)1/6 is the fundamental length scale for plume-ridge interaction, Πb=(σQ/U2)1/3 is of the order of the aspect ratio (width/thickness) of the plume pool, Πs=(κ2σ/U3)1/4 measures the effect on the pool of the sloping base of the lithosphere (κ is the thermal diffusivity), and f2 is an unknown function. We determine f2 using a suite of 32 numerical solutions of a three-dimensional thermomechanical model implemented in the code StagYY (Tackley, 2008). To apply our scaling law to Iceland, we invert it to estimate the buoyancy flux B required to produce a waist width Ww=2300±300 km. After correction for the effect of ridge migration, we find B=2.3±0.6 Mg s−1. This is comparable within uncertainty to the buoyancy flux B=3.0±0.8 Mg s−1 of the Hawaiian plume estimated using a 3-D dynamical model by Ribe and Christensen (1999). © 2020 Elsevier B.V.
关键词	Iceland lubrication theory mantle plumes plume-ridge interaction
英文关键词	Aspect ratio; Buoyancy; Lakes; Dimensional analysis; Dynamical model; Mid Atlantic Ridge; Numerical solution; Ridge migration; Thermomechanical model; Vertical velocity; Volumetric rates; Uncertainty analysis; buoyancy; geodynamics; lithospheric structure; mantle plume; thermomechanics; Atlantic Ocean; Iceland; Mid-Atlantic Ridge
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/202855
作者单位	Laboratoire FAST, CNRS, Université Paris-Saclay, Bâtiment 530, Campus Universitaire, Orsay, F-91400, France; Institute of Geophysics, Department of Earth Sciences, ETH Zurich, Sonneggstrasse 5, Zürich, 8092, Switzerland
推荐引用方式 GB/T 7714	Ribe N.M.,Tackley P.J.,Sanan P.. The strength of the Iceland plume: A geodynamical scaling approach[J],2020,551.
APA	Ribe N.M.,Tackley P.J.,&Sanan P..(2020).The strength of the Iceland plume: A geodynamical scaling approach.Earth and Planetary Science Letters,551.
MLA	Ribe N.M.,et al."The strength of the Iceland plume: A geodynamical scaling approach".Earth and Planetary Science Letters 551(2020).