Much of past research has focused on the attenuation of seismic waves in artificial samples, corresponding to near surface partially saturated rocks, and deeper in-situ rocks of the Western United States. The latter was subsequently coupled with other observables to infer the temperature and composition of the upper mantle. Additional work on the passive end of seismology has involved using receiver functions to image the upper mantle beneath Cook Strait, New Zealand.
   My current research involves the other end of seismology, the earthquake source. I am currently working at the US Geological Survey in Golden studying time-dependent earthquake probabilities and their incorporation into seismic hazard maps. This work makes use of finite element calculations of crustal deformation resulting from regional earthquakes to estimate the stress transferred to nearby faults and the subsequent changes in rupture probability. I have also been involved in advancing the way estimates of earthquake recurrence are implemented.