 Hi there! I am a postdoctoral researcher in infrasound sensor development and seismology at IGPP/SIO, Univ. of California, San Diego. I work with the Gravity Lab, Laboratory of Atmospheric Acoustics, and Peter Shearer. I finished my B.S. in geophysics in June 1998 at the Univ. of Delaware, where I investigated the crustal structure of the Brisol Bay basin, SE Bering Sea, with Dr. Sue McGeary. I finished my Ph.D. in solid-earth geophysics in January 2004 at Stanford University under the auspices of Simon Klemperer and Götz Bokelmann. As a Bachelor's and Master's student, I used seismic reflection/refraction, potential fields, and deformation modeling techniques to test hypotheses for the origin of the Bristol Bay basin, a back arc basin in the southeast Bering sea north of the Alaska Peninsula. For my Doctorate, I mapped the geometry and magnitude of seismic anisotropy around three mantle hotspots with observations of teleseismic shear-wave splitting, and showed that such data could be explained by the interaction between a mantle upwelling and a moving plate. Our results show how splitting measurements can provide useful data with which to test geodynamic models for hotspot/lithosphere interaction where lithospheric anisotropy is not strong. I also characterized mantle anisotropy beneath the East African Plateau, and showed that the expected fast direction of anisotropy was surprisingly not parallel to the Late Tertiary extension direction, but is most likely due to fossilized lithospheric anisotropy and asthenospheric anisotropy due to relative plate motion. The title of my thesis is "Exploring Problems in Tectonics and Geodynamics with Seismology". More recently, I became interested in rapidly determining the rupture geometry of very large earthquakes. This work with Peter Shearer led me from trying to locate very early aftershocks with teleseismic P waves to directly imaging the rupture itself via back projection of the teleseismic P wavetrain. We imaged the Sumatra Mw 8.6 2005 earthquake, and showed it was a bi-lateral rupture with a rupture velocity around 3.1 km/s. We also imaged the 300-400 km long Denali and Kokoxili (Kunlun) strike slip earthquakes, and showed that their ruptures had similar propagation characteristics: both transitioned from subRayleigh-wave rupture velocity to a velocity near the local P-wave velocity (~5.6 km/s). I also have become fascinated by infrasound and fiber optic sensor technology. I recently worked on array procesing methodologies with Mark Zumberge and Michael Hedlin for determining the "direction of arrival" of signals recorded by several line sensors, specifically applied to infrasound (atmospheric acoustic waves with f < ~18 Hz). My work mostly continues in the development of the OFIS sensor, but is beginning to branch into other aspects of infrasound such as source location, global event detection, and seismic-acoustic coupling.In a nutshell, geophysics excites me, especially when one can use a variety of techniques to investigate a particular problem or test a hypothesis. I don't lean too much on just data or modeling, but prefer integrating both approaches, with a dash of field work for extra flavor. Thanks for dropping by! |
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