The dynamics of regional seismicity data

Attempts to understand the physics of earthquakes over the past decade generally have focused on applying methods and theories developed based upon phase transitions, materials science, and percolation theory to a variety of numerical simulations of extended fault networks. These analyses attempt to model and explain many of the important features of the fault system, such as the scaling properties of the system, the variety of periodic, quasi-periodic and nonperiodic behaviors, and the space-time clustering of events. These results strongly support the view that seismic activity is highly correlated across many space and time scales within large volumes of the earth's crust. Techniques which focus on the analysis of seismic data, such as accelerated seismic moment release (AMR), repeating earthquakes, or precursory quiescience, generally are localized on the eventual source region, presupposing some knowledge of the earthquake source, without viewing it as a large-scale interacting complex system. Here we describe the analysis of the California fault system and seismicity data over time using a phase dynamics approach, and apply this to the statistics of this driven, near mean-field system. In particular, we show that the actual California fault system is ergodic in space and time, for the period in question.