When faults communicate:: Viscoelastic coupling and earthquake clustering in a simple two-fault system -: art. no. 1270

[1] 3-D finite element models of a simplified northern and southern San Andreas-type fault system are presented with the goal of better understanding how great earthquakes (M greater than or equal to 7.5) on one major segment of a fault can affect the earthquake cycle on another colinear fault segment separated from the first by an asesimically creeping segment. We find that the earthquake cycles of the two seismogenic fault segments become coupled as the lower crustal viscosity and/or the fault separation distance are decreased. Further, models with a 10%-30% difference in relative fault breaking strengths exhibit a bi-modal distribution of repeat times for each fault, resulting in earthquakes that appear clustered in time.