Quasiperiodic events in an earthquake model
  We introduce a modification of the OFC earthquake model [Phys. Rev. Lett. 68, 1244 (1992)] in order to improve resemblance with the Burridge and Knopoff mechanical model and with possible laboratory experiments. A constant force continually drives the system, and thresholds are distributed randomly following a narrow distribution. We find quasiperiodic behavior in the avalanche time series with a period proportional to the degree of dissipation of the system. Periodicity is not as robust as criticality when the threshold force distribution widens; and foreshocks and aftershocks are connected to the observed periodicity. 
O. Ramos, E. Altshuler, K. J. Maloy