Frictional state evolution laws and the non-linear nucleation of dynamic shear rupture

We assess if a characteristic length for a non-linear interfacial slip instability follows from theoretical descriptions of sliding friction. We examine friction laws and their coupling with the elasticity of bodies in contact and show that such a length does not always exist. We consider a range of descriptions for frictional strength and show that the area needed to support a slip instability is negligibly small for laws that are more faithful to experimental data. This questions whether a minimum earthquake size exists and shows that the nucleation phase of dynamic rupture contains discriminatory information on the nature of frictional strength evolution.

Automated summary

We investigate the existence of a characteristic length for non-linear interfacial slip instability based on theoretical descriptions of sliding friction. By examining friction laws and their relationship with contact body elasticity, we find that such a length may not always be present. Our analysis of various descriptions of frictional strength reveals that the area required to support slip instability is negligible for laws that align more closely with experimental data. This challenges the notion of a minimum earthquake size and suggests that the nucleation phase of dynamic rupture contains valuable information on the evolution of frictional strength.