Geodesy, tectonics, earthquake/volcanic hazards, earthquake physics, and anthropogenic change. I use geodetic data to measure the sudden or long-term motion of the earth's surface and to understand the tectonic, volcanic, and human-created processes that cause this motion. Data from GPS / GNSS observing stations fixed to the ground can measure this motion at high precision and are one of my primary monitoring tools for this work. My other tool is satellite radar (InSAR), which enables us to map accumulated ground motion over time, and in some cases can detect millimeter-scale changes in surface elevation. These data enable us to construct better models of the underlying physical processes at work and help us to provide key information about Earth hazards to communities at risk. This work involves new advances in InSAR processing, collection of GPS data in the field (current projects include locations across Southeast Asia), and develop new numerical modeling techniques. See my personal website for more.