Physicochemical Interpretation of Time-dependent Healing of Frictional Strength

A Quantitative Analysis with Absolute Rate Theory

Abstract

A quantitative interpretation was made on the observational parameters in an equation of time-dependent healing of frictional strength of faults. The interpretation is based on a physical model that explains the time-dependent growth curve of frictional strength as an increase of the real contact area of the fault surface due to asperity creep driven by the stress normal to the contacts. The creep is assumed to be rate-limited by some stress-assisted thermally activated process. The model thus predicts temperature and normal contact-stress dependences of the observational parameters of the time-dependent healing of frictional strength. The predictions are more or less consistent with available experimental data, which include different healing mechanisms associated with different types of elementary contact deformation mechanism, such as stress corrosion and pressure solution.