Davies, C, Pozzo, M, Gubbins, D et al. (1 more author) (2015) Constraints from material properties on the dynamics and evolution of Earth's core. Nature Geoscience, 8. 678 - 685. ISSN 1752-0894
Abstract
The Earth's magnetic field is powered by energy supplied by the slow cooling and freezing of the liquid iron core. Efforts to determine the thermal and chemical history of the core have been hindered by poor knowledge of the properties of liquid iron alloys at the extreme pressures and temperatures that exist in the core. This obstacle is now being overcome by high-pressure experiments and advanced mineral physics computations. Using these approaches, updated transport properties for Fe-Si-O mixtures have been determined at core conditions, including electrical and thermal conductivities that are higher than previous estimates by a factor of two to three. Models of core evolution with these high conductivities suggest that the core is cooling much faster than previously thought. This implies that the solid inner core formed relatively recently (around half a billion years ago), and that early core temperatures were high enough to cause partial melting of the lowermost mantle. Estimates of core-mantle boundary heat flow suggest that the uppermost core is thermally stratified at the present day.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 Macmillan Publishers Limited. All rights reserved. This is an author produced version of a paper published in Nature Geoscience. Uploaded in accordance with the publisher's self-archiving policy. |
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) |
Funding Information: | Funder Grant number NERC NE/L011328/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 23 Sep 2015 12:30 |
Last Modified: | 16 Nov 2016 08:13 |
Published Version: | http://dx.doi.org/10.1038/ngeo2492 |
Status: | Published |
Publisher: | Nature Publishing Group |
Identification Number: | 10.1038/ngeo2492 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:90194 |