Slow rupture of frictional interfaces

TL;DR

This paper demonstrates that slow rupture phenomena are an inherent feature of simple rate-and-state friction laws, revealing a new velocity scale and continuum of rupture states, which align with recent experimental observations.

Contribution

It introduces the concept of a minimum velocity scale in friction laws and characterizes slow rupture as a fundamental, intrinsic property of these laws, expanding understanding of rupture dynamics.

Findings

Slow rupture is a robust property of rate-and-state friction laws.

A new velocity scale $c_{min}$ determines the onset of rupture.

Rupture velocities range from $c_{min}$ to elastic wave speeds.

Abstract

The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale $c_{min}$, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from $c_{min}$ to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.