Models of convection-driven tectonic plates: a comparison of methods and results

Recent numerical studies of convection in the Earth's mantle have included various features of plate tectonics. A number of different methods for modelling ‘plate-like’ behaviour have been used. The differences in the methods of modelling plates may assume or predict significantly different plate deformation. We describe three methods of modelling plates through: material properties, force balance, and a thin power-law sheet approximation. We compare the results obtained using each method on a series of simple calculations. From these results we are able to develop scaling relations between the different parametrizations. While each method produces different degrees of deformation within the surface plate, the surface heat flux and average plate velocity agree to within a few per cent. The main results are not dependent upon the plate modelling method and therefore are representative of the physical system we set out to model.