An automaton approach for modelling the physics of interacting earthquake faults

An automaton approach is employed to model strain evolution within a 2D system of earthquake faults. A large number of linear faults with a fractal distribution of lengths, are inserted within a large region consisting of a regular grid of cells. Failure strengths along faults are fractally distributed, modelling variations in material strength. Tectonic loading is simulated by periodically incrementing the strain of all cells by a constant amount. When the strain of a fault cell exceeds its failure strength, a rupture is initiated which travels along the fault, potentially rupturing multiple fault cells. Subsequent to the dynamic rupture, the strain in the region surrounding the fault is altered, simulating static strain changes due to the earthquake. A nearest neighbour strain relaxation rule ensures the medium behaves similarly to an elastic medium on longer timescales. Preliminary results suggest that in some cases, this model displays accelerating seismic energy release in the lead-up to large ruptures. This appears to be associated with some form of strain correlation evolution, as proposed in the Critical Point Hypothesis of earthquakes. The distribution of earthquake faults appears to play an important role, governing the type of macroscopic dynamical behaviour of the system.