Previous laboratory studies suggested that smoother faults tend to exhibit unstable slip by comparing prefabricated roughness. However, the change in the natural fault roughness is driven by slip. Therefore, this paper aims at the effects of the slip-driven roughness change on the fault stability by conducting multiple “loading-unloading-reloading” experiments on a granodiorite simulated fault. The experimental results showed that stick-slip occurs during the loading on the original rough bare fault, which becomes smooth with the removal of the primordial gouges after unloading and then exhibits stable slip during reloading.  The spectra of the fault surface profiles indicated that the change in the fault stability may depend on the change in the contact asperity shape during slip.

roughness,fault stability