Colloquium: Aaron Wolf

Aaron Wolf

Graduate student, Division of Geological and Planetary Sciences, Caltech

Abstract: Our understanding of the Earth's mantle depends on direct seismic observations of how waves propagate at depth, combined with our knowledge of how terrestrial rocks behave at extreme conditions. Constraining the high pressure thermal properties of terrestrial materials is one of the outstanding challenges in mineral physics and helps to inform us about the structure and evolution of the deep Earth. In this talk, I will demonstrate how I use a mixture of experimental and novel theoretical techniques to determine the high temperature properties of iron bearing magnesium silicates in solid and liquid states. I will report the results of high P & T diamond anvil cell experiments to measure the thermal properties of (Mg,Fe)SiO₃ perovskite, the dominant mineral in the Earth's mantle, and show how these measurements affect how we interpret the large coherent structures visible on the core mantle boundary beneath Africa and the Pacific. I will also present a new simplified model I have developed to understand silicate liquids at high pressures, the Coordinated HArd Sphere Model (CHASM), and demonstrate how it relates to our understanding of the evolution and crystallization of a whole mantle magma ocean in the early Earth.