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The fate of water within Earth and super-Earths and implications for plate tectonics

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the deve...

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Detalles Bibliográficos
Autores principales: Tikoo, Sonia M., Elkins-Tanton, Linda T.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394257/
https://www.ncbi.nlm.nih.gov/pubmed/28416729
http://dx.doi.org/10.1098/rsta.2015.0394
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author Tikoo, Sonia M.
Elkins-Tanton, Linda T.
author_facet Tikoo, Sonia M.
Elkins-Tanton, Linda T.
author_sort Tikoo, Sonia M.
collection PubMed
description The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subduction. The following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? The giant impacts of late accretion created magma lakes and oceans, which degassed during solidification to produce a heavy atmosphere. However, some water would have remained in the mantle, trapped within crystallographic defects in nominally anhydrous minerals. In this paper, we present models demonstrating that processes associated with magma ocean solidification and overturn may segregate sufficient quantities of water within the upper mantle to induce partial melting and produce a damp asthenosphere, thereby facilitating plate tectonics and, in turn, the habitability of Earth-like extrasolar planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’.
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spelling pubmed-53942572017-04-24 The fate of water within Earth and super-Earths and implications for plate tectonics Tikoo, Sonia M. Elkins-Tanton, Linda T. Philos Trans A Math Phys Eng Sci Articles The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subduction. The following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? The giant impacts of late accretion created magma lakes and oceans, which degassed during solidification to produce a heavy atmosphere. However, some water would have remained in the mantle, trapped within crystallographic defects in nominally anhydrous minerals. In this paper, we present models demonstrating that processes associated with magma ocean solidification and overturn may segregate sufficient quantities of water within the upper mantle to induce partial melting and produce a damp asthenosphere, thereby facilitating plate tectonics and, in turn, the habitability of Earth-like extrasolar planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’. The Royal Society Publishing 2017-05-28 2017-04-17 /pmc/articles/PMC5394257/ /pubmed/28416729 http://dx.doi.org/10.1098/rsta.2015.0394 Text en © 2017 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Articles
Tikoo, Sonia M.
Elkins-Tanton, Linda T.
The fate of water within Earth and super-Earths and implications for plate tectonics
title The fate of water within Earth and super-Earths and implications for plate tectonics
title_full The fate of water within Earth and super-Earths and implications for plate tectonics
title_fullStr The fate of water within Earth and super-Earths and implications for plate tectonics
title_full_unstemmed The fate of water within Earth and super-Earths and implications for plate tectonics
title_short The fate of water within Earth and super-Earths and implications for plate tectonics
title_sort fate of water within earth and super-earths and implications for plate tectonics
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394257/
https://www.ncbi.nlm.nih.gov/pubmed/28416729
http://dx.doi.org/10.1098/rsta.2015.0394
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