論文

査読有り
2018年

Crystallization of a compositionally stratified basal magma ocean

Physics of the Earth and Planetary Interiors
  • Laneuville, Matthieu
  • ,
  • Hernlund, John
  • ,
  • Labrosse, Stephane
  • ,
  • Guttenberg, Nicholas

276
開始ページ
86
終了ページ
92
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.pepi.2017.07.007
出版者・発行元
Elsevier {BV}

Earth's similar to 3.45 billion year old magnetic field is regenerated by dynamo action in its convecting liquid metal outer core. However, convection induces an isentropic thermal gradient which, coupled with a high core thermal conductivity, results in rapid conducted heat loss. In the absence of implausibly high radioactivity or alternate sources of motion to drive the geodynamo, the Earth's early core had to be significantly hotter than the melting point of the lower mantle. While the existence of a dense convecting basal magma ocean (BMO) has been proposed to account for high early core temperatures, the requisite physical and chemical properties for a BMO remain controversial. Here we relax the assumption of a well mixed convecting BMO and instead consider a BMO that is initially gravitationally stratified owing to processes such as mixing between metals and silicates at high temperatures in the core-mantle boundary region during Earth's accretion. Using coupled models of crystallization and heat transfer through a stratified BMO, we show that very high temperatures could have been trapped inside the early core, sequestering enough heat energy to run an ancient geodynamo on cooling power alone. (C) 2017 Elsevier B.V. All rights reserved.

Web of Science ® 被引用回数 : 10

リンク情報
DOI
https://doi.org/10.1016/j.pepi.2017.07.007
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000425198900008&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.pepi.2017.07.007
  • ISSN : 0031-9201
  • eISSN : 1872-7395
  • ORCIDのPut Code : 50860054
  • Web of Science ID : WOS:000425198900008

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