Interoccurrence time statistics in the two-dimensional Burridge-Knopoff earthquake model

TL;DR

This study uses a 2-D spring-block earthquake model to analyze interoccurrence time statistics, demonstrating that with optimal parameters, the model reproduces real earthquake temporal patterns, including power law distributions and Poisson processes.

Contribution

The paper introduces a parameter tuning approach in the 2-D Burridge-Knopoff model to accurately replicate observed interoccurrence time distributions of real earthquakes.

Findings

Interoccurrence times follow power law and Zipf-Mandelbrot distributions.

Optimal model parameters match real earthquake statistics.

Large-magnitude events tend to follow a Poisson process.

Abstract

We have numerically investigated statistical properties of the so-called interoccurrence time or the waiting time, i.e., the time interval between successive earthquakes, based on the two-dimensional (2-D) spring-block (Burridge-Knopoff) model, selecting the velocity-weakening property as the constitutive friction law. The statistical properties of frequency distribution and the cumulative distribution of the interoccurrence time are discussed by tuning the dynamical parameters, namely, a stiffness and frictional property of a fault. We optimize these model parameters to reproduce the interoccurrence time statistics in nature; the frequency and cumulative distribution can be described by the power law and Zipf-Mandelbrot type power law, respectively. In an optimal case, the b-value of the Gutenberg-Richter law and the ratio of wave propagation velocity are in agreement with those derived from real earthquakes. As the threshold of magnitude is increased, the interoccurrence time distribution tends to follow an exponential distribution. Hence it is suggested that a temporal sequence of earthquakes, aside from small-magnitude events, is a Poisson process, which is observed in nature. We found that the interoccurrence time statistics derived from the 2-D BK (original) model can efficiently reproduce that of real earthquakes, so that the model can be recognized as a realistic one in view of interoccurrence time statistics.