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Pozzo, M, Davies, C, Gubbins, D et al. (1 more author) (2014) Thermal and electrical conductivity of solid iron and iron-silicon mixtures at Earth's core conditions. Earth and Planetary Science Letters, 393. 159 - 164. ISSN 0012-821X
Abstract
We report on the thermal and electrical conductivities of solid iron and iron–silicon mixtures (Fe0.92Si0.08 and Fe0.93Si0.07), representative of the composition of the Earth's solid inner core at the relevant pressure–temperature conditions, obtained from density functional theory calculations with the Kubo–Greenwood formulation. We find thermal conductivities View the MathML source, and electrical conductivities View the MathML source at the top of the inner core (centre of the Earth). These values are respectively about 45–56% and 18–25% higher than the corresponding conductivities in the liquid outer core. The higher conductivities are due to the solid structure and to the lower concentration of light impurities. These values are much higher than those in use for previous inner core studies, k by a factor of four and σ by a factor of three. The high thermal conductivity means that heat leaks out by conduction almost as quickly as the inner core forms, making thermal convection unlikely. The high electrical conductivity increases the magnetic decay time of the inner core by a factor of more than three, lengthening the magnetic diffusion time to 10 kyr and making it more likely that the inner core stabilises the geodynamo and reduces the frequency of reversals.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2014 Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/). |
Keywords: | inner core; conductivity; geodynamo; core convection; first principles; mineral physics |
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: | 19 Oct 2015 11:34 |
Last Modified: | 26 Feb 2019 10:26 |
Published Version: | http://dx.doi.org/10.1016/j.epsl.2014.02.047 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.epsl.2014.02.047 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:88053 |
Available Versions of this Item
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Thermal and electrical conductivity of solid iron and iron-silicon mixtures at Earth's core conditions. (deposited 14 Jul 2015 09:08)
- Thermal and electrical conductivity of solid iron and iron-silicon mixtures at Earth's core conditions. (deposited 19 Oct 2015 11:34) [Currently Displayed]