Dynamic Weakening by Acoustic Fluidization during Stick-Slip Motion.

Title Dynamic Weakening by Acoustic Fluidization during Stick -Slip Motion

Laboratory observation of acoustic fluidization in granular fault gouge and implications for dynamic weakening of earthquake faults

[1] Several lines of evidence, including remote triggering of earthquakes and modulation of seismic tremor by Earth tides, suggest that faults weakenwhen subject to shaking and dynamic stresses associatedwith the passage of seismic waves. However, the origin of such dynamic weakening is poorly understood. Here we explore the role of acoustic resonance for dynamic fault weakening using laborator...

On the question of whether lubricants fluidize in stick-slip friction.

Intermittent sliding (stick-slip motion) between solids is commonplace (e.g., squeaking hinges), even in the presence of lubricants, and is believed to occur by shear-induced fluidization of the lubricant film (slip), followed by its resolidification (stick). Using a surface force balance, we measure how the thickness of molecularly thin, model lubricant films (octamethylcyclotetrasiloxane) var...

Microscopic and macroscopic aspects of stick-slip motion in granular shear.

An annular shear cell has been used to investigate a number of factors known to influence stick-slip motion in an assembly of near monosized, spherical glass beads. In this paper, both the sample shear stress and volumetric strain were recorded, allowing new insights into the possible mechanics of stick-slip motion in a granular body. Rather than the commonly presented mechanism of sample dilat...

Experimental and Numerical Model Studies of Frictional Instability Seismic Sources

Stick-slip frictional instability is widely regarded as a viable mechanism for crustal earthquakes, particularly because of the way that it can be incorporated into the notion of earthquakes as episodic unstable slip events along preexisting zones or planes of weakness represented by faults in the Earth. In this thesis, detailed laboratory observations of stick-slip events generated on a simula...