The paper, Fault weakening and earthquake instability by powder lubrication, explores the role of fault gouge in the weakening -- and strengthening -- of faults during the course of an earthquake. According to the research, depending on the stage of the earthquake, fault gouge may either increase or decrease friction between the plates.
|a, b, Blocks of Sierra White granite after experiment 652. LB, lower block; UB, upper block; SR, sliding ring; EG, gouge ejected. Note adhered gouge coating on the sliding ring (a) and heaps of ejected gouge on the lower block (b). c, Close-up view of a sliding surface showing adhered gouge and gouge layer. d, SEM image with melted-like area in which glass ‘glues’ fine angular grains (test 556). e, Atomic force microscope image of gouge grains of test 670 on glass plate; note the submicrometre grains and agglomerated grains in the lower left corner.|
Their research can be found in full for free online here.