The secret to mimicking natural faults? Plexiglass and Teflon

When a fault ruptures in nature, some sections of the fault slip suddenly and seismically, weakening as velocity increases. Other regions creep slowly and strengthen with increasing velocity. The relative locations of these sections affect the size and nature of seismic activity along the fault. In one common configuration, a velocity-weakening section is surrounded by a velocity-strengthening section, which stops the spread of ruptures.