My principal area of interest is the study of microseismicity. Large earthquakes are rare occurrences. However, regions of high seismic hazard which eventually rupture in large earthquakes often produce great numbers of small earthquakes on a nearly continuous basis. Most of these microearthquakes are much too small to be felt, but are easily recorded by modern seismic instruments. If one can accommodate disadvantages associated with lack of source control, microearthquakes have some very desirable properties as tools to probe the Earth.
Seismology is the most fruitful method of probing the structure of the deep Earth.
Another area of study that I have been involved in for many years is volcanic seismology. MEVO, funded by the National Science Foundation Office of Polar Programs, performs geophysical and geochemical research on the active Erebus Volcano from McMurdo Station , Antarctica. Magma-related signals are very common on many active volcanoes, but can be hard to locate because their signals tend to be very emergent. The effect of the magma body is very noticeable in many local earthquake seismograms through the presence of reflected phases from its top surface. The automated monitoring of highly seismic regions of the Earth is also important for monitoring compliance with the proposed Comprehensive Test Ban Treaty for nuclear nonproliferation.