Scale-dependence in Earthquake Processes and Seismogenic Structures

We provide a positive answer to the question whether large earthquakes can be separated from small ones using various observations on the earthquake processes and seismogenic structures. For California, the boundary of separation is at M 5. This conclusion leads to the possibility of deterministic modeling of earthquake occurrence for prediction. We recognize, however, that the system of earthquake occurrence involves nonlinear physics with many degrees of freedom. We suggest that the geometrical barriers and asperities may be a good starting point for the modeling. We also discuss the implication of our finding on the numerical simulation of earthquake rupture propagation, and conclude that the model fault zone must be made thicker for a more realistic simulation of major earthquakes.