My interests are in the physics of volcanoes; the processes that cause the changes that we measure and phenomena we see. This includes the mechanisms of magma transport, volcanic structure and magma storage, and during eruptions the transport of ash in the atmosphere. I use numerical methods, including artificial intelligence, to model data, and Bayesian methods to constrain the models with data.
I have been a Geophysicist with the Cascades Volcano Observatory since 1996. My major accomplishments are as follows:
- Constructed a model for shallow water flow, modeled floods throughout western US
- Showed that a 2d shallow water model effectively modeled two millennial floods on the Verde River, Arizona, effectively verifying the three-dimensional variation of stage to give unique discharge of nearly 3200 cubic meters per second. This discharge was verified by flow through a dam immediately downstream.
- Constructed a dambreak model for the Pakistan Army to mitigate the Haittian landslide dam that had just buried 2 entire villages. Modeling determined how much to downcut the landslide to preserve infrastructure downstream. The cut was made and the resulting flow matched the prediction of my model. For this work Dan O'Connell and I received recognition from the Pakistan Army.
- Constructed a shallow flow model for debris flows and avalanches to model USGS flume data.
- Co-construction of Ash3d, an ash transport program, along with Hans Schwaiger (USGS) and Larry Mastin (USGS). Used Bayesian methods to refine forecasts of ash clouds.
- Used gravity and seismic data to quantify gravitational component, verify existing volcano-tectonic features, and illustrate the deep structure cradling magma and mush in the volcano.
- NRC postdoctoral Fellow 1979
- Submersible work with US Navy, 1986-1989
- Geophysicist, adjunct, Oceanography Dept, University of Washington, 1986-1999
- Visiting Scientist, Meteorological Office, Exeter, England, 2016
Groundwater Flow and Subsidence, 1980-1982
Volcano Deformation and Geophysics, 1981-1986
Established magnetization and cooling rate of Mount Saint Helens growing dome.
Seafloor Volcanism, Deformation, and Thermal History, 1986-1992
Member of team that discovered SeaCliff hydrothermal field within Escanabah Trough.
Corrected the thermal structure of oceanic lithosphere to account for phase changes during cooling.
Deformation Chief, Hawaiian Volcano Observatory, 1992 - 1996
Established GPS/GNSS network on south flank of Kilauea volcano.
Measured large, episodic monthly changes in rate of south flank movement on Kilauea volcano.
Established that the south flank of Kilauea volcano had a landslide structure.
WORKSHOPS and REVIEW PANELS
Workshop that formed the RIDGE consortium of academia and government to study the ocean floor, 1988
Institute of Volcanic Studies, University of Washington, Seattle, WA, 1990-1992
Rosenstiel School of Marine and Atmospheric Science Workshop, SAR Interferometry and Surface Change Detection, 1994
USGS NEHRP Review panel for Pacific Northwest, 1994, 1995, 2002
USGS Multidisciplinary Workshop to assess “A unified approach toward probabilistic risk assessment for earthquakes, floods, landslides, and volcanoes” within the USGS, Golden, CO, November 16-17, 1999. Funded by the USGS Urban Hazards Initiative.
USGS Working Group to assess research directions to improve methods to solve advection-diffusion equations, Denver, CO, August 1999
Member International Committee to organize and plan mathematical workshops on granular flow.
GEOPRISMS working group funded for active and passive Mount St. Helens seismic experiments.
RIDGE Panel to plan and assemble a proposal to Congress to establish RIDGE Program, 1988
USGS Research Evaluation Panel, Volcano Hazards Team, 1995
1st Federal Interagency Hydrologic Modeling Conference Panel, “Formulation and use of flood models within and outside the Federal government”, Las Vegas, NV, April 1998
Seismo-tectonic program, US Bureau of Reclamation, Denver, CO, 1996-2012
Ferguson rockslide, Merced River Canyon, US Forest Service, 2005-2012
Avalanche and debris flow program, Ecole Polytechnique Federale de Lausanne, Switzerland, 2005-2012
Hattian landslide dambreak, General Tahir Hayat, Pakistan Army, Pakistan, 2005-2009
Education and Certifications
PhD, Geophysics, Stanford University 1979
MS, Geophysics, Stanford University, 1977
BS, Geology, CSU Hayward, 1974
BA, Physics, CSU Hayward, 1973
Affiliations and Memberships*
Member, American Geophysical Union
Member, Geological Society of America
Past memberships in Society of Industrial and Applied Mathematics, Seismological Society of America
Honors and Awards
Special Service Award, US Geological Survey, for work on granular flows
Abstracts and Presentations
1992 keynote speaker Penrose Conference on “Water-Volcano Interaction”, Warm Springs, OR
1999 keynote speaker UNAVCO Volcano Geodesy Workshop, International NAVSTAR Consortium, Jackson Hole, WY
2003 keynote speaker Isaac Newton Institute for Mathematical Sciences Workshop, Bristol, England
2012 keynote speaker IUGG, International Congress for Theoretical and Applied Mechanics, Beijing, China
2018 keynote speaker Denver Geophysical Society, Denver, Colorado
Science and Products
Science and Products
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government