Steady Solution for Thermal Convection within the Earth's Mantle

Abstract

A linear stability problem for the mantle of the earth is considered. Upper and lower mantle convection currents are assumed to reflect a rapid change in the viscosity at transition zone. The theory of mantle convection proposed by TOZER is adopted as a basis for the present investigation. For appropriate values of physical parameters it is found that the mantle should be in a convective state. Using the minimum temperature assumption, the internal temperature distribution in the presence of mantle convection current is considered.The temperature at the bottom of the upper mantle convection cell is about 1450-1650°K regardless of conduction transfer and the thickness of the convecting zone. The temperature gradient within the upper mantle convecting zone differs very little from the adiabatic gradient. The temperature at the core-mantle boundary is about 2100-3800°K.