Interseismic fault system activity at plate boundary zones

Using elastic block theory and GPS observations, we simultaneously estimate vertical rotation of crustal blocks, kinematically consistent fault slip rates, elastic deformation, spatially variable fault coupling, and intrablock strain at plate boundary zones, without prior assumptions about the relative importance of these processes.

We are actively applying this technique to the Japan, western North American, and Himalaya-Tibet plate boundary zones.

Subduction zone earthquake cycle processes
The world’s subduction zones are responsible for the largest earthquakes ever recorded.  In addition to the activity taking place on the subduction interface, deformation in the overriding plate is also driven by subduction processes.  Using geodesy, field work, and modeling, I work to understand the interaction between the subduction zone seismic cycle and observable deformation in the forearc.

Areas of active subduction zone research include Japan, northern Chile, and Cascadia.

Seismic segmentation of plate boundary zones

Large subduction zone earthquakes rupture an area several hundred kilometers in length.  What governs the total rupture length?  What features form seismic segment boundaries?  For how long do segment boundaries act, and what evidence provides clues to the extent of longevity?

The Nazca-South American plate boundary is an ideal location to study the above questions, given its rich history of great earthquakes, and the capacity of the hyperarid Atacama Desert in northern Chile to preserve structures that document long-term segmentation of the margin.