Fig. 4

Computed result of the coupled core-mantle evolution in a parameterized mantle convection with the mantle melting parameterization (Driscoll and Bercovici 2014). Top left: temperature (mass averaged mantle temperature, upper mantle, lower mantle, and core-mantle boundary); top right: heat flow (surface heat flow, heat flow across the CMB, heat producing elements in the mantle, and heat transport due to the partial melting); bottom left: inner core growth, which has 1.6 Ga of the age of the inner core; bottom right: magnetic moments plotted for two values of the thermal conductivity at the center of the Earth’s core. When the thermal conductivity is assumed as 163 W/m/K (Gomi et al. 2013), the magnetic field generation stops between 2.3 and 3.0 billion years. Conversely, the magnetic field may be continuously generated with 125 W/m/K of thermal conductivity at the center of the Earth’s core