Effects of heterogeneous gouge segments on the slip behavior of experimental faults at dm scale

Abstract Frictional heterogeneity within fault zones is one of the factors proposed to explain the spectrum of slow, intermediate, and fast slip behaviors exhibited by faults in nature. Numerical modeling shows how even a simplified model setup incorporating sliding on a velocity-weakening (VW) patch surrounded by velocity-strengthening (VS) material can reproduce a rich variety of slip behaviors resembling nature. However, experimental investigations of sliding on heterogeneous faults are few. In this study, the slip behavior of three, 347 mm long × 50 mm wide, heterogeneous experimental faults, constructed using diagonally sawcut PMMA forcing blocks, was investigated at low normal stresses (