My doctoral research utilized receiver functions and shear-wave splitting to characterize the structure and deformational fabric of the continental lithosphere and sub-continental asthenosphere across several regions of the North American Cordillera. Much of this work was undertaken as part of the Sierra Nevada EarthScope Project and the Batholiths Continental Dynamics Experiment.
My ongoing research spans several topics:
-Using established seismic techniques to understand the processes by which a Cordillera is reworked following subduction; particularly considering the geodynamic implications of events such as lithospheric foundering beneath the Sierra Nevada and asthenospheric flow under the Canadian Cordillera.
-Improving constraints on structure of the crust and upper mantle using methods of noise-suppression.
-Reconciling seismic observations (Vp/Vs ratio), petrologic data (modal compositions of mineral aggregates and the corresponding elastic responses), and surface geology.
-Investigating epierogenic uplift and its relation to deeply-seated seismic anomalies.
Presently
TopoScandiaDeep: Mantle Investigations of Norwegian Uplift Structures (MAGNUS)
Sierra Nevada EarthScope Project
~100 broadband stations, 2+ years, and enough array-management for a career: SNEP. After assembling a high-quality dataset of broadband waveforms sampling nearly the entire length of the Sierra Nevada Batholith, our goal is to characterize the ongoing delamination of a dense residue from beneath the Central Sierra Nevada. Additionally, we seek to place constraints on the extent of residue produced, if any, beneath the Northern Sierra Nevada. This work has been featured in the IRIS Long Range Plan for Seismology and EarthScope Science Plan for 2010-2020. Earthquake locations courtesy of Owen Hurd (formerly Arizona, now Stanford). Further information related to this figure is available upon request, as I wouldn't want to spoil the results of this publication!
Geophysical Journal International Article
Coast Mountains Batholith Seismic Transects (Batholiths Continental Dynamics Experiment)
In conjunction with Ken Dueker (Wyoming) and his students, Arizona helped deploy 46 broadband seismometers in two transects across west-central British Columbia from May 2005 to September 2006. Our goal is to evaluate the seismic character of the lithosphere beneath various accreted exotic terranes and Coast Mountains Batholith, which dominate the geology of western British Columbia. Measured shear-wave splitting shows large splits beneath much of the Central Canadian Cordillera. Splitting magnitude and orientation suggestions asthenospheric flow possibly related to the northern edge of the Juan de Fuca slab.
Formerly
Consortium for Arizona Reconnaissance Seismic Experiment (COARSE)
The Universities of Arizona and Arizona State maintained an array of 10 broadband seismometers across Southeast and Central Arizona to evaluate changes in the character of the crust and upper mantle across the Basin and Range and Colorado Plateau. The publication largely deals with the issue of isostatic support for the elevated metamorphic core complexes in the southern Basin and Range of Arizona.
Earth and Planetary Science Letters Article
Episodic Tremor and Slip and Subduction Zone Structure (ETS)
Ten years of Pacific Northwest Seismic Network broadband recordings, along with newly acquired data from a dense array which recorded from August to November 2005, are used characterize the receiver function response of the subducting slab and mantle hydrated zone during the periodic episodes of non-volcanic tremor and geodetic slip within the Juan de Fuca subduction zone. Do receiver function attributes change during ETS episodes? If so, why? Believe it or not, there was some skepticism over this idea! Further work on this is being saved for a rainy year.
South Carolina Earth Physics Project (SCEPP)
I worked on the issue of network clock accuracy on the SCEPP Seismic Network. Mostly this was an excuse to learn how to do something well in unix. It still took years to get comfortable with grep and awk but there's also this publication to show for it.
SCEPP Seismological Research Letters Article
Summer of Applied Geophysical Experience (SAGE)
SAGE runs a geophysics field research program each summer near Santa Fe, NM. Our study focused on a seismic, gravity, and geoelectric investigation in the Santo Domingo Basin between Santa Fe and Albuquerque. At the end of SAGE I processed, interpreted, and presented magnetotelluric data that helped develop a 1-D resistivity cross-section of the survey area. The Cochiti Indians used these results to evaluate water reservoir potential on their reservation.