Finite-frequency tomography and waveform modeling of the South Atlantic mantle

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This body-wave tomography aims to image the entire cluster of hotspots in the South and Central Atlantic, at all mantle depths. The goal is to extract a maximum of information from observed broadband seismograms. Exploiting all available regional data sets, it will be embedded in a global finite-frequency P- and PP-wave inversion. As a central component and technical novelty, we will develop the tomography of core-diffracted P-waves, by means of sensitivity kernels from full-waveform modeling. This wave type grazes the core and therefore samples the deepest part of the mantle extensively. Hence we hope for better information on the “footing” of mantle plumes and the internal structure of the vast African anomaly. The South and Central Atlantic is the prime target for diffracted P-wave tomography, since it is the only region with both decent sampling and an accumulation of presumed mantle plumes. The tomographic models will be verified with full 3D waveform modeling, which we will push to the highest observed frequencies using our considerable supercomputing resources. Their interpretation -- in terms of heat fluxes and mantle heating regime -- will be quantitatively tied to numerical mantle circulation simulations and mineralogical modeling.