At the bottom, \b[$T(0,t)=T_1$]. Convecting <mantle> is treated as maintaining the basal <temperature> and supplying <heat> to the plate. This is a prescribed thermal boundary at fixed thickness, not a claim that the real mechanical base is an impermeable material interface.

Solution

Past exam of the physics of the Earth as a Planet course of the University of Cambridge / 2013 / Paper 1 / 1 / a / iii / Solution

 Solution (source code)