On the origin and evolution of electrical signals during frictional stick slip in sheared granular material

Electromagnetic signals have been reported in association with geophysical phenomena including earthquakes, landslides, and volcanic events. Mechanisms that suggested to explain seismoelectrical signals include triboelectricity, piezoelectricity, streaming potentials, and the migration of electron holes, yet the origin of such phenomena remains poorly understood. We present results from laboratory experiments regarding the relationship between...