Mound, JE orcid.org/0000-0002-1243-6915 and Davies, CJ orcid.org/0000-0002-1074-3815 (2020) Scaling Laws for Regional Stratification at the top of Earth’s Core. Geophysical Research Letters, 47 (16). e2020GL087. ISSN 0094-8276
Abstract
Seismic and geomagnetic observations have been used to argue both for and against a global stratified layer at the top of Earth's outer core. Recently, we used numerical models of turbulent thermal convection to show that imposed lateral variations in core‐mantle boundary (CMB) heat flow can give rise to regional lenses of stratified fluid at the top of the core while the bulk of the core remains actively convecting. Here, we develop theoretical scaling laws to extrapolate the properties of regional stratified lenses measured in simulations to the conditions of Earth's core. We estimate that regional stratified lenses in Earth's core have thicknesses of up to a few hundred kilometres and Brunt‐Väisälä frequencies of hours, consistent with independent observational constraints. The location, thickness, and strength of the stratified regions would change over geological time scales in response to the slowly evolving CMB heat flux heterogeneity imposed by mantle convection.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | ©2020. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | core stratification; Earth's outer core; fluid dynamics ‐ scaling laws; geodynamics |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Jul 2020 15:48 |
Last Modified: | 25 Jun 2023 22:21 |
Status: | Published |
Publisher: | American Geophysical Union |
Identification Number: | 10.1029/2020GL087715 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:163430 |