The high conductivity of iron and thermal evolution of the Earth's core

Hitoshi Gomi, Kenji Ohta, Kei Hirose, Stéphane Labrosse, Razvan Caracas, Matthieu J. Verstraete, John W. Hernlund

    Research output: Contribution to journalArticlepeer-review

    198 Citations (Scopus)

    Abstract

    We measured the electrical resistivity of iron and iron-silicon alloy to 100. GPa. The resistivity of iron was also calculated to core pressures. Combined with the first geophysical model accounting for saturation resistivity of core metal, the present results show that the thermal conductivity of the outermost core is greater than 90. W/m/K. These values are significantly higher than conventional estimates, implying rapid secular core cooling, an inner core younger than 1. Ga, and ubiquitous melting of the lowermost mantle during the early Earth. An enhanced conductivity with depth suppresses convection in the deep core, such that its center may have been stably stratified prior to the onset of inner core crystallization. A present heat flow in excess of 10. TW is likely required to explain the observed dynamo characteristics.

    Original languageEnglish
    Pages (from-to)88-103
    Number of pages16
    JournalPhysics of the Earth and Planetary Interiors
    Volume224
    DOIs
    Publication statusPublished - Nov 2013

    Keywords

    • Core
    • Electrical resistivity
    • High pressure
    • Thermal conductivity
    • Thermal evolution

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Geophysics
    • Physics and Astronomy (miscellaneous)
    • Space and Planetary Science

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