Scaling laws in earthquake occurrence: Disorder, viscosity, and finite size effects in Olami-Feder-Christensen models

TL;DR

This paper investigates earthquake scaling laws using an extended Olami-Feder-Christensen model, incorporating heterogeneity, viscoelasticity, and finite-size effects to better match observed seismic data.

Contribution

It introduces modifications to the OFC model to account for heterogeneity and viscoelasticity, explaining multiple observed scaling regimes and crossover phenomena.

Findings

Reproduces multiple scaling regimes observed in seismic data

Identifies the role of geometry and bulk dynamics in crossover behavior

Shows finite-size effects influence earthquake scaling laws

Abstract

The relation between seismic moment and fractured area is crucial to earthquake hazard analysis. Experimental catalogs show multiple scaling behaviors, with some controversy concerning the exponent value in the large earthquake regime. Here, we show that the original Olami, Feder, and Christensen model does not capture experimental findings. Taking into account heterogeneous friction, the visco elastic nature of faults together with finite-size effects, we are able to reproduce the different scaling regimes of field observations. We provide an explanation for the origin of the two crossovers between scaling regimes, which are shown to be controlled both by the geometry and the bulk dynamics.