Event Detail Information
Physics Colloquium: "Granular material under shear in relation to geophysical problems"
Due to comminution over geologic time, fault blocks shearing past one another in the earth develop granular material in their core. We hypothesize that the granular physics of this material, known as ‘fault gouge’ influences much of the physics of slip. In this presentation I will describe observations and simulation of granular materials under laboratory shear conditions, including acoustic emission, shear failure and dilation. I will discuss the primary indicators leading to failure observed in the gouge and relate these to earthquake processes. The dynamic wave experiments support widespread observations in the earth of ‘dynamic earthquake triggering’, a process whereby seismic waves from one earthquake trigger earthquakes nearby and far from the triggering source.