TThe upper 10-40 km of Earth is cold and brittle. Most deformation in that region is therefore brittle, which in the long timescale occurs by the slip and growth of faults and on the short timescale occurs by earthquakes. Brittle tectonics thus is a single dynamical system that involves both the mechanics of faulting and of earthquakes. My research involves the study of this system in its entirety, employing laboratory experimentation on rock fracture and friction, observational and field study of earthquakes and faults, and theory. The work is physics based and is not regional. Earthquakes and faults selected for special study are global in extent and are selected based on criteria relevant to their likelihood of revealing new aspects of their mechanics. Recent fault studies have been in Ethiopia, Malawi, Iceland, California and New York.
- Head, Center for Nonlinear Earth Systems