Broad distribution of stick-slip events in Slowly Sheared Granular Media: Table-top production of a Gutenberg-Richter-like distribution

¹ Department of Physics, University of Michigan - Ann Arbor, MI 48109, USA
² Department of Statistics, University of Tennessee - Knoxville, TN 37996, USA
³ Department of Physics, Colorado State University - Fort Collins, CO 80523, USA
⁴ Frontier Research System, The Institute of Physical and Chemical Research (RIKEN) Saitama 351-0198, Japan

Received: 15 February 2006
Accepted: 13 April 2006

Abstract

We monitor the stick-slip displacements of a very slowly driven moveable perforated top plate which interacts via shearing with a packing of identical glass beads confined in a tray. When driven at a constant stress rate, the distributions of large event displacements and energies triggered by the stick-slip instabilities exhibit power law responses reminiscent of the Gutenberg-Richter law for earthquakes. Small events are quasi-size independent, signaling crossover from single-bead transport to collective behavior.