Advances in experiments and numerical simulations on the effects of stress perturbations on fault slip

Laboratory experiments and numerical simulations on rock friction perturbations, an important means for understanding the mechanism and influencing factors of stress-triggered earthquakes, are of great significance for studying earthquake mechanisms and earthquake hazard analysis. We reviews the experiments and numerical simulations on the effects of stress perturbations on fault slip, and the results show that stress perturbations can change fault stress and trigger earthquakes. The Coulomb failure criterion can shed light on some questions about stress-triggering earthquakes but cannot explain the time dependence of earthquake triggering nor be used to investigate the effect of heterogeneous stress perturbations. The amplitude and period are important factors affecting the correlation between stress perturbation and fault instability. The effect of the perturbation period on fault instability is still controversial, and the effect of the high-frequency perturbation on earthquakes may be underestimated. Normal and shear stress perturbation can trigger fault instability, but their effects on fault slip differ. It is necessary to distinguish whether the stress perturbation is dominated by shear or normal stress change when it triggers fault instability. Fault tectonic stress plays a decisive effect on the mode of fault instability and earthquake magnitude. Acoustic emission activity can reflect the changes in fault stress and the progression of fault nucleation, and identify the meta-instability stage and precursor of fault instability, providing a reference for earthquake prediction.