EAR-PF: Dynamics and melting of the upper mantle: Relating the length scales of compositional heterogeneity in the crust and mantle

Bianco Todd A, Honolulu HI

Investigators

Abstract

Dr. Todd A. Bianco has been granted an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at Brown University. Using computer simulations of mantle dynamics, rock melting and melt transport, this project will test how different size distributions in mantle heterogeneity affect crust composition. Further, the project will address how realistic processes of melt migration amplify or dampen the signature of mantle composition and mantle dynamics in crust composition. The computer simulations will solve conservation of mass, momentum, and energy in a three dimensional space with properties that capture the rheologic, temperature, and density variations in the upper mantle. In addition, the simulation will include discrete domains of compositional heterogeneity of varying sizes. Predictions from computational simulations will be compared to observations of crust composition at a variety of tectonic settings such as a mid-ocean ridge, and anomalously thick seafloor. Mantle convection controls much of the evolution of earth, and therefore is an essential piece to understanding observations of the current state of the earth. The size and distribution of compositional heterogeneity in the mantle gives a picture of the state of mantle convection over time. Therefore, by quantifying the relationship between observed compositional variation in the crust with inferred variation in the mantle, this project will, in a broader sense, improve our understanding of how the earth has evolved. In addition the PI will provide undergraduate research opportunities at Brown University, the host institution for the project, as well as research experience to local teachers through Brown University's NSF-funded GK-12 program.