XClose

UCL Earth Sciences

Home
Menu

Giles Ostermeijer

“Evolution and significance of fault damage structures on plate boundary faults.”

PhD project title:

Evolution and significance of fault damage structures on plate boundary faults: the southern San Andreas fault system.


Giles Ostermeijer
Project description:

The damage zone surrounding active faults is of key importance in controlling the mechanics of faulting and the earthquake process. Because damaged rocks have very different physical properties than surrounding intact rock, damage zones directly affect the nucleation and propagation of ruptures during earthquakes, and the radiation of seismic energy. The importance of the damage zone in the faulting and earthquake process is widely recognized, but our understanding of the evolution of damage zones, their characteristic properties, and how they feed back into the seismic cycle, are remarkably poorly known.

The project involves field investigations of seismically active fault strands of the San Andreas Fault System (California, USA and Baja California, Mexico), combined with laboratory experiments of natural fault damage samples, in order to ascertain how this damage affects the physical and transport properties of fault rocks within the seismic cycle, and possibly the size of potential earthquakes. Characterising the extent, distribution, and density of the damage zone should allow for calculations of kinematic energy requirements for its formation, potentially improving estimations of the earthquake energy budget.