Global Upper Mantle Tomography
I have spent considerable effort constructing a global shear-velocity model of the upper mantle, including azimuthal anisotropy, using unprecedentedly large seismic waveform datasets. This is accomplished using automated multimode inversions to accurately and efficiently extract maximum structural constraints from each and every waveform, to be inverted for 3D anisotropic Earth Models. Using this approach, more than one million seismograms have been successfully fit to date, and the most recent tomographic model, SL2013sv, is constructed using the best more than half a million. Such new models, which utilize more of the available data, will further investigations into the processes associated with lithosphere formation, stabilization, and erosion, through the analysis of both seismic velocity and anisotropy (radial and azimuthal).
Continental Scale Tomography
Our new model, SL2013NA, is based on the same dataset as SL2013sv, however augmented by additional global network and USArray Transportable Array data to improve resolution both within the footprint of the USArray and across the rest of the continent.
Upper Mantle and Transition Zone Structure
In addition to global surface wave techniques mentioned above, I also make use of Receiver Function techniques to investigate the structure of the Earth’s upper mantle and transition zone. Both P and S RFs yield complimentary information which can be used to learn about the composition and discontinuity structure within the Earth, as well as querying the nature and complexities of the Lithosphere-Asthenosphere Boundary, within both ancient and modern continental environments. I have applied these techniques to several array’s in north Western Canada to look at the mantle structure immediately overlying the transition zone.
Global Water Cycle
A combination of seismic, petrologic, and geochemical constraints were combined in a geodynamic modelling framework to investigate the effects of varying water (and in general volatile) content on the Earth’s whole mantle through all geologic time. A simple yet accurate geodynamic model was constructed to simulate Earth’s evolution to analyse the effects of varying water (and volatiles in general) contents within the Earth’s mantle.
Subduction zone structure and dynamics
Seismic investigation combined with numerical modeling of wave propagation to characterize the structural elements within the subduction zone and surrounding environs.