Temporal and spatial correlations in a visco-elastic model of   heterogeneous faults
  We study the temporal and spatial correlations in a one-dimensional model of a heterogeneous fault zone, in the presence of visco-elastic effects. As a function of dynamical weakening and of dissipation, the system exhibits three different "phases" : one in which there are no time correlations between the events, a second, in which there are ``Omori's law'' type temporal correlations, and a third, runaway phase with quasiperiodic system size events. 
Bora Orcal and Ayse Erzan (Istanbul Technical University, Turkey and   Gursey Institute, Istanbul, Turkey)