Effects of latent heat release at phase boundaries on flow in the Earth's mantle, phase boundary topography and dynamic topography at the Earth's surface

Mantle flow models that do not consider the effects of latent heat on phase boundaries typically predict dynamic surface topography too large to be compatible with observations. Here these effects were implemented in a mantle flow model and resulting changes in dynamic topography and topography of phase boundaries were computed. Inclusion of these effects was found to reduce the rms amplitude of dynamic topography by about 50-60 m, still leaving a substantial misfit from observations in most cases considered. Generally, it also leads to a slight improvement of correlation with dynamic surface and phase boundary topography constrained by observations. Results thus indicate that the model implemented here is applicable to the Earth, but that other effects need to be considered as well in order to fully explain phase boundary and dynamic surface topographies. (c) 2007 Elsevier B.V. All rights reserved.