First-Order Phase Transition in a Model for Earthquakes

Abstract

A simple mechanical model for earthquake dynamics with a generic velocity-dependent friction is investigated. It is shown that in the limit of slow driving the system undergoes a discontinuous (first-order) transition from stick-slip behavior to creep motion as the friction parameter is varied. This result is robust in that it does not rely on any particular choice of the friction law. The implications of these findings for the Burridge-Knopoff spring-block model for earthquakes is also discussed. In particular, it is argued that such models do not display critical behavior.