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Dynamics of planetary mantles: the effect of realistic viscosity

Academic lead
Andrew Walker (Earth and Environment)
Chris Davies (Earth and Environment), Steve Tobias (Mathematics)
Project themes
Geophysical and Astrophysical Flows

Convection in rocky or icy planetary mantles controls the evolution of the terrestrial planets and many of the moons in the solar system. This convection is intimately linked to planetary habitability: it determines whether surface material participates in the global-scale dynamics (as on Earth) or remains isolated (as on Venus) and also determines the viability of magnetic field generation in the liquid core. Using state of the art high performance computing these parameters can now be reached in numerical models (as shown in the figure). The rich and complex dynamics exhibited by the terrestrial planets arise from the physical properties of the Earth materials that form their mantles. In particular the non-linear viscosity is enormously sensitive to small changes in temperature, pressure and composition, but the influence of complex viscosity on the nature of mantle convection is still poorly understood. Starting from a 2D Cartesian case, and working towards a spherical shell, you will utilise numerical simulations and theoretical analysis to quantify the influence of non-linear viscosity on the transport of heat, mass and momentum in planetary mantles. Theoretical insights derived from these numerical studies will allow you to construct new parameterised models of the thermal evolution of planetary mantles spanning the 4.5 billion years of solar system history.