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

TL;DR

This study demonstrates that slowly sheared granular media produce a broad distribution of stick-slip events with power-law characteristics similar to earthquake statistics, revealing a transition from individual to collective behavior.

Contribution

It provides the first tabletop experimental evidence of Gutenberg-Richter-like distributions in granular media under slow shear conditions.

Findings

Large event displacements follow power-law distributions.

Small events are size-independent, indicating a crossover in behavior.

The system exhibits collective dynamics akin to seismic activity.

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.