Dynamics of planetary mantles: the effect of realistic viscosity

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 since the physical properties that characterise mantle material, and in particular the non-linear viscosity, are enormously sensitive to small changes in temperature, pressure and composition. However, the influence of complex viscosity on the nature of mantle convection is still poorly understood. This project 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.