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A thermally conductive Martian core and implications for its dynamo cessation
  • +2
  • Wen-Pin Hsieh,
  • Frédéric Deschamps,
  • Yi-Chi Tsao,
  • Takashi Yoshino,
  • Jung-Fu Lin
Wen-Pin Hsieh
Department of Geosciences, National Taiwan University, Institute of Earth Sciences, Academia Sinica

Corresponding Author:[email protected]

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Frédéric Deschamps
Institute of Earth Sciences, Academia Sinica
Yi-Chi Tsao
Institute of Earth Sciences, Academia Sinica
Takashi Yoshino
Institute for Planetary Materials, Okayama University
Jung-Fu Lin
Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin


Mars experienced a dynamo process that generated a global magnetic field ~4.3–3.6 Ga. The cessation of this dynamo strongly impacted Mars’ history and is expected to be linked to thermochemical evolution of Mars’ iron-rich liquid core, which is strongly influenced by its thermal conductivity. Here we directly measured thermal conductivities of solid iron-sulfur alloys to pressures relevant to the Martian core and temperatures to 1023 K. Our results show that a Martian core with 16 wt% sulfur has a thermal conductivity of ~19 to 32 W m-1 K-1 from its top to the center, much higher than previously inferred from electrical resistivity measurements. Our modelled thermal conductivity profile throughout the Martian deep-mantle and core indicates a ~4 to 6-fold discontinuity across the core-mantle-boundary. The core’s efficient cooling resulting from the depth-dependent, high conductivity diminishes thermal convection and forms thermal stratification, significantly contributing to cessation of Martian dynamo.
21 Dec 2023Submitted to ESS Open Archive
27 Dec 2023Published in ESS Open Archive