Effects of temperature- and pressure-dependent viscosity and internal heating on mantle convection.

A mathematical model is considered for Rayleigh–Bénard convection of mantle where the viscosity depends strongly on both temperature and pressure defined in an Arrhenius form. The model is solved numerically for extremely large viscosity variations across a unit aspect ratio cell using a modified cut-off viscosity law, and steady solutions are obtained. The aim is to investigate the convection pattern with internal heating at a very high viscosity variation in the presence of high Rayleigh number. The study also investigates the relation between temperature dependent parameter and pressure dependent parameter in a basally heated convection cell. The numerical simulation is performed using the finite element method based PDE solver and the results are presented through figures, tables and graphs. [ABSTRACT FROM AUTHOR]