Geological faults ihave granular textures on many scales, from microscopic grains to macroscopic rocks. We seek to understand the extent to which granular interactions (interparticle, frictional slip) account for the range of geological observations & the inferred dynamic fault histories.
We conduct laboratory experiments using birefringent (photoelastic) particles in a simulated strike-slip fault. This movie of a laboratory fault experiment shows events in which the abrupt localization of the shear strain to the center of apparatus corresponds to little change in the force chain geometry away from the "fault." Bright particles are experiencing greater force than dark particles.
[This movie] shows an annular fault, and is representative of the pronounced stick-slip behavior we observe in the lab.
Ted Brzinski, postdoc