Shock and shock-ramp compression of iron-rich (Mg,Fe)O at Earth's core conditions

ORAL

Abstract

Where Earth’s iron core and silicate mantle meet is a region of the Earth’s interior that is still poorly understood. Seismological results suggest the presence of ultra-low velocity zones (ULVZ’s) sitting directly atop the core. One possible explanation for these features is that they are regions of highly iron-enriched ferropericlase (Mg,Fe)O (Wicks et al. 2010), however the thermodynamic properties at near-core conditions are poorly constrained. Here we present the results of combined ab-initio calculations and shock measurements of (Mg,Fe)O containing 25 and 50 mol% Fe. The results are being used to design shock-ramp experiments on the Z machine at Sandia National Laboratories.

Wicks, J. K., Jackson, J. M., & Sturhahn, W. (2010) Very low sound velocities in iron‐rich (Mg, Fe) O: Implications for the core‐mantle boundary region. Geophysical Research Letters, 37(15).

*Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy National Nuclear Security Administration under contract DE-NA0003525.This work was supported by the US Department of Energy — National Nuclear Security Administration through the Chicago / DOE Alliance Center.

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Presenters

  • Hannah Bausch

    • Northwestern University

Authors

  • Hannah Bausch

    • Northwestern University

  • Joshua P Townsend

    • Sandia National Laboratories
    • Sandia National Laboratories, Albuquerque NM 87185, USA

  • Steven D Jacobsen

    • Northwestern University

  • Alisha N Clark

    • University of Colorado, Boulder
    • University of Colorado Boulder

  • Sakun Duwal

    • Sandia National Laboratories

  • Chad A McCoy

    • Sandia National Laboratories

  • Jean-Paul Davis

    • Sandia National Laboratories