Global correlation of lower mantle structure and past subduction

Initiation of the Andean orogeny by lower mantle subduction

Seismic Evidence for Subduction-Transported Water in the Lower Mantle

We use seismic attenuation tomography to identify a region at the top of the lower mantle that displays very high attenuation consistent with an elevated water content. Tomography inversions with >80,000 differential travel-time and attenuation measurements yield 3D whole-mantle models of shear velocity (VS) and shear quality factor (Q ). The global attenuation pattern is dominated by the locat...

Structure and dynamics of Earth's lower mantle.

Processes within the lowest several hundred kilometers of Earth's rocky mantle play a critical role in the evolution of the planet. Understanding Earth's lower mantle requires putting recent seismic and mineral physics discoveries into a self-consistent, geodynamically feasible context. Two nearly antipodal large low-shear-velocity provinces in the deep mantle likely represent chemically distin...

Correlation of Earth’s magnetic field with lower mantle thermal and seismic structure

Variations in the Earth’s lower mantle appear to influence the geodynamo operating in the liquid core. We present a solution to the full dynamo equations with lateral variations in heat flux on the outer boundary defined by the shear wave velocity of the lowermost mantle. The magnetic field is almost stationary and locked to the boundary, with 4 symmetrical concentrations of flux sited beneath ...

Subduction to the lower mantle – a comparison between geodynamic and tomographic models

It is generally believed that subduction of lithospheric slabs is a major contribution to thermal heterogeneity in Earth’s entire mantle and provides a main driving force for mantle flow. Mantle structure can, on the one hand, be inferred from plate tectonic models of subduction history and geodynamic models of mantle flow. On the other hand, seismic tomography models provide important informat...