Thermal Convection in Vesta’s Core from Experimentally-Based Conductive Heat Flow Estimates
Description
Electrical resistivity measurements of Fe-5wt%Ni were made in-situ under pressures of 2-5 GPa and temperatures up to 2000 K in a cubic-anvil press. The thermal conductivity was calculated from the measured electrical resistivity data using the Wiedemann–Franz law. Comparison of these data with previous studies on pure Fe and Fe-10wt%Ni shows that a change in the Ni con-tent within the range 0-10wt% Ni has no significant effect on electrical resistivity of Fe alloys. Comparing the estimated adiabatic core heat flux of ~331 MW at the top of Vesta’s core to the range of estimated heat flux through the CMB of 1.5–78 GW, we infer that the mechanism stir-ring Vesta’s liquid outer core to generate its surface magnetic field tens of millions of years in its early history was thermal convection.