Effects of continental configuration on mantle heat loss

Abstract

Two-dimensional (2D) and three-dimensional (3D) simulations are used to explore the effects of continental distribution on mantle convection. In both 2D and 3D, at total surface areas < 50%, internal temperature is weakly sensitive to continental configuration. Mantle heat flux values show mild variations with changing configuration. In 3D, at total continental area > 50%, the dependence of mantle heat loss on continental configuration becomes stronger. Mantle temperature continues to increase with total continental area but now varies by 5%-7% with changing configurations. When distributed, continents can cause flow patterns to become locked. This leads to significant variations in mantle temperature below continental and oceanic regions. This differs from the expectation that supercontinents would preferentially lead to large lateral variations in mantle temperatures and suggests that insulation-induced thermal anomalies could exist below continents today if they have remained fixed relative to mantle flow (e.g., Africa). Show more