Fault surface morphology as an indicator for earthquake nucleation potential

Abstract Laboratory measurements can determine the potential for geologic materials to generate unstable (seismic) slip, but a direct relation between sliding behavior in laboratory and physical characteristics observable field is lacking, especially phyllosilicate-rich gouges that are widely observed natural faults. We integrated friction experiments with surface topography microscopy demonstrated quantitative correlation frictional slip fault morphology of centimeter-scale samples. Our results show striated, smooth surfaces were formed exhibited stable sliding, whereas potentially was associated rougher, isotropic surfaces. interpret stability linked via evolution asperity contacts on localized If roughness obeys fractal relationship over large range length scales, then we infer morphological could indicate earthquake nucleation