Spatiotemporal dynamics due to stick-slip friction in an elastic-membrane system.

Frictional stick-slip dynamics is studied experimentally in an elastic continuum by means of a stretched latex membrane in contact with a translating glass rod. In contrast to other laboratory-scale experiments, the characteristic stiffness length here is small compared to the size of the system but large compared to the spatial resolution of the measurements. The internal displacement field u(s,t) is measured in detail with imaging techniques, which are shown to be more sensitive than total-force measurements. The magnitudes \ensuremath{\mu} of slipping events extend over a wide range and include both small localized events and large spatially extended ones. The shape of the distribution P(\ensuremath{\mu}) depends somewhat on the measurement threshold and also varies with the parameters describing the frictional interaction, which are affected by wear. The frictional force increases with velocity and an instability is due to waves of detachment. The temporal statistics of slipping events are also discussed. The experimental results are compared qualitatively to simplified models of earthquake faults.