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Physics Colloquium: "Granular material under shear in relation to geophysical problems"

Event Type
Seminar/Symposium
Topic
physics
Sponsor
Physics Department
Location
141 Loomis
Date
Feb 18, 2015   4:00 pm  
Speaker
Paul Johnson, Los Alamos National Laboratory
Cost
None
Originating Calendar
Physics - Colloquium

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.

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