Structure of the crust and lithosphere of the Cascadia subduction zone from active source seismic and potential field data; tectonics and evolution of the Mendocino triple junction region; gas hydrate distribution and dynamics beneath Hydrate Ridge on the Oregon continental margin.

Velocity structure and tectonics of western North America - Since 1986, I have been collaborating with the U.S. Geological Survey and several other universities and research institutions to acquire a network of seismic 2-D and 3-D seismic images of the the crust and upper mantle of the western north American continental margin in order to understand the plate interactions along the transform and subduction plate boundaries that control the geologic evolution and seismic hazards in this region. I have conducted seismic experiments in across the San Andreas Fault system in central California (1986) and northern California (1993, 1994, 1999); across the Cascadia subduction zone in central Oregon (1989, 1991, 1996), northern California (1993, 1994) and Washington (1995, 1998, 1999); and across the Queen Charlotte Fault in southeast Alaska and British Columbia (1994). Current efforts are focussed on northern California, where we are investigating the tectonic history of the eastern end of the Mendocino transform fault and its impact on deformation within the neighboring plates, and northwestern Washington, where we are imaging the plate interactions beneath the Olympic peninsula and Straits of Juan de Fuca (see SHIPS link below).

Gas hydrates on the Oregon continental margin - While the presence of gas hydrates on continental margins has been known for several decades, in the past few years hydrates have become a major internation research focus because of the recognition that they may play a significant role in sudden global climate change and slope stability, and may represent a major energy source for the future. I am part of a multidisciplinary group at Oregon State University and at GEOMAR (Kiel, Germany) that has identified a major gas hydrate system in the accretionary complex of the Cascadia subduction zone offshore Oregon. I have participated in several cruises to observe and sample this system (see TECFLUX link below), and will be returning next summer for a high-resolution 3-D seismic survey. This region is scheduled for drilling by the Ocean Drilling Program in 2001.

I am also involved in the Princeton Earth Physics Project, which is placing seismometers in the high schools and middle schools around the country as a tool for teaching geology, physics, and computer networking.

Seismic Hazards Investigation of Puget Sound (SHIPS)

TECFLUX

Origin and Tectonic Evolution of the Gorda Escarpment

Other Projects and General Information about OSU Geophysics