Heat and mass transfer across thermal and chemical boundary layers within the mantle play a dominant role in the evolution of the terrestrial planets. Although the interior of planets is not accessible for direct observation, there are still seismological, mineral physics, geodetic, and geochemical data that provide constraints on mantle dynamics. Relating these observations to geodynamic processes is critical for advancing our understanding of the Earth's evolution.
This project will use laboratory experiments to characterize the spatial and temporal evolution of compositional heterogeneity in the mantle. The focus will be on fine-scale structures produced by entrainment and stirring. An experimental approach will be used because it is well suited for thermo-chemical convection. The overall goals of the experiments are to 1) elucidate the coupling of heat transfer and flow in a compositionally heterogeneous mantle, 2) characterize entrainment processes and quantify entrainment rates, 3) characterize the spatial and temporal evolution of compositional heterogeneity, 4) understand the initiation and extinction of thermo-chemical plumes. A second project will focus the interaction between thermo-chemical convection and flow associated with plate motions.The results of these studies will provide a basis for interpreting and drawing conclusions from indirect observations, in particular seismology and geochemistry.
This project will provide a training opportunity for a graduate student, and an introduction to research for undergraduates. Outreach beyond the group involved directly in the research will be through classes at UC Berkeley, scientific conferences and refereed publications. This project should lead to new interdisciplinary collaborations between the engineering and geodynamics communities.
