Earth is unique among the known planets in exhibiting plate tectonics as the primary means of transporting internally generated heat. Plate tectonics is responsible for Earth's unusual topography distribution, geochemical interaction between the surface and the deep interior, and the strength of the geodynamo, among other factors that make our home planet special. The timing of the origin of plate tectonics on Earth has been difficult to establish observationally, but there are hints of very early (Hadean) geochemical processes with modern plate tectonic analogues. The mechanism and timing of plate tectonic initiation have direct bearing on models of the geochemical and thermal evolution of our planet, the uniqueness of Earth as an abode for life, and our understanding terrestrial planets in general.
This project will primarily support a graduate student to carry out, under the mentoring of the PI, numerical simulations of heat transport in the pre-plate tectonic Earth in order to understand the transition to plate tectonic behavior. This period of history is dominated by volcanic heat transport, called the heat-pipe mode of planetary cooling. Numerical simulation of the flow of Earth?s mantle materials including heat transport by melting and melt segregation (volcanism) will be accomplished using a specialized code. A systematic investigation of the parameters governing convection and melting will be undertaken, and bounds on the transition to plate tectonics will be established. The implications for early Earth will be compared with published petrological and geochemical data.
