S. W. French

TL;DR: The use of a whole-mantle seismic imaging technique is described that reveals the presence of broad, quasi-vertical conduits beneath many prominent hotspots, and it is shown that the imaged conduits are robustly broader than classical thermal plume tails, suggesting that they are long-lived, and may have a thermochemical origin.

TL;DR: In this paper, a hybrid waveform-inversion approach was employed to combine the accuracy and generality of the spectral finite element method (SEM) for forward modeling of the global wavefield, with non-linear asymptotic coupling theory for efficient inverse modelling.

TL;DR: In this article, the authors used 93 permanent seismic stations to image upper mantle velocity discontinuities across the contiguous United States and portions of southeast Canada and northwest Mexico, using frequency-domain deconvolution and migrated with 1D models that account for variations in crustal structure and mantle velocities between stations.

TL;DR: A global tomographic model of the upper mantle and transition zone that is sensitive to changes in seismic velocity and anisotropy is constructed and suggests the presence of a dynamic interplay between plate-driven flow in the low-velocity zone and active influx of low-rigidity material from deep mantle sources deflected horizontally beneath the moving top boundary layer.

TL;DR: Using scattering of teleseismic shear waves beneath rifted zones and adjacent areas in Southern California, this work resolves the lithosphere-asthenosphere boundary and lithospheric thickness variations to directly constrain this deformation.