  The Burridge-Knopoff model of earthquake faults with viscous friction is
equivalent to a van der Pol-FitzHugh-Nagumo model for excitable media with
elastic coupling. The lubricated creep-slip friction law we use in the
Burridge-Knopoff model describes the frictional sliding dynamics of a range of
real materials. Low-dimensional structures including synchronized oscillations
and propagating fronts are dominant, in agreement with the results of
laboratory friction experiments. Here we explore the dynamics of fronts in
elastic excitable media.
