Correlated earthquakes in a self-organized model

TL;DR

This paper introduces a simple fault model that reproduces key statistical features of earthquakes, such as power-law distributions and aftershock laws, highlighting the role of fluctuating stress domains in seismic activity.

Contribution

It presents a novel self-organized model capturing scale-invariance and clustering in earthquakes, challenging the traditional view of criticality with fluctuating coherence domains.

Findings

Power-law distributions in event sizes and distances

Aftershock rates follow a generalized Omori law

Correlation length is a fraction of system size

Abstract

Motivated by the fact that empirical time series of earthquakes exhibit long-range correlations in space and time and the Gutenberg-Richter distribution of magnitudes, we propose a simple fault model that can account for these types of scale-invariance. It is an avalanching process that displays power-laws in the event sizes, in the epicenter distances as well as in the waiting-time distributions, and also aftershock rates obeying a generalized Omori law. We thus confirm that there is a relation between temporal and spatial clustering of the activity in this kind of models. The fluctuating boundaries of possible slipping areas show that the size of the largest possible earthquake is not always maximal, and the average correlation length is a fraction of the system size. This suggests that there is a concrete alternative to the extreme interpretation of self-organized criticality as a process in which every small event can cascade to an arbitrary large one: the new picture includes fluctuating domains of coherent stress field as part of the global self-organization. Moreover, this picture can be more easily compared with other scenarios discussing fluctuating correlations lengths in seismicity.