Interpreting Earth's Largest Internal Seismic Anomalies: Deep Thermochemical Piles

The Earths lowermost mantle has strong large scale heterogeneity in elastic properties, with reduced seismic velocities present in broad regions underlying many hotspots. Global tomographic models indicate that two nearly antipodal large low shear velocity provinces (LLSVPs) exist at the base of the mantle, one beneath Africa-Southern Atlantic-Indian Ocean, and one beneath the south-central Pacific. This talk will present a mineralogical interpretation of these LLSVPs consistent with geodynamic scenarios and mineral elasticity.