Stability of a melt/solid interface with reference to a plume channel

The structure of free-convection flow in a plume channel formed as a result of melting above a local heat source placed on the basement of a solid mass is experimentally investigated. The channel shape and the flow pattern in it are functions of the relative power Ka = N/N ₁, where N is the plume source power and N ₁ is the heat removed to the surrounding mass. When the heat is withdrawn from the plume channel by heat conduction, the channel represents a system of convective cells on whose boundaries there are channel constrictions. The temperature fields and the cell flow patterns are investigated. For mantle plumes, such as the Hawaiian, Iceland, and Bouvet plumes and extended igneous provinces, the basement diameter and the values of the criterion Ka are determined.