Third M.I.T. Conference on Computational Fluid and Solid Mechanics June 14–17, 2005  

Three-dimensional numerical simulations of thermo-chemical multiphase convection in the Earth's mantle

Takashi Nakagawaa,*, Paul J. Tackleyb
aDepartment of Earth and Planetary Sciences, University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-0033, Japan bDepartment of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, 595 Charles Young Drive E, Los Angeles, CA 90405 USA

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ABSTRACT
Three-dimensional numerical simulations of thermo-chemical mantle convection that include melting-induced compositional differentiation, self-consistent plate-like behavior, and composition-dependent solid-solid phase changes (including the newly-discovered post-perovskite transition) are used to model the 4.5 billion year evolution of the Earth, and are successful in matching many of the major observational constraints. These simulations are at high Rayleigh number (107 ) and large viscosity contrast (varying by six orders of magnitude with temperature and two orders of magnitude with depth), and can match many characteristics of Earth's mantle from a compositionally-homogeneous initial condition, with all chemical heterogeneity generated by melting-induced differentiation. Such simulations achieve greater realism than previously possible and facilitate an improved understanding of the dynamics of the Earth and planetary interiors.

Keywords:  Mantle convection; 3D numerical simulations; Melt-induced differentiation

* Corresponding author. Tel.: + 81 (3) 5841 8332; Fax: + 81 (3) 5841 8791; E-mail: takashi@eps.s.u-tokyo.ac.jp