Small-world structure of earthquake network

TL;DR

This paper reveals that earthquake networks exhibit small-world and scale-free properties, with high clustering and short path lengths, highlighting the complex nature of seismic activity.

Contribution

It demonstrates that earthquake networks have small-world and scale-free features, providing new insights into seismicity as a complex network phenomenon.

Findings

Connectivity distribution follows a power law.

Characteristic path length is between 2 and 3.

Clustering coefficient is significantly higher than random networks.

Abstract

Discoveries of the scale-free and small-world features are reported on a network constructed from the seismic data. It is shown that the connectivity distribution decays as a power law, and the value of the degrees of separation, i.e., the characteristic path length or the diameter, between two earthquakes (as the vertices) chosen at random takes a small value between 2 and 3. The clustering coefficient is also calculated and is found to be about 10 times larger than that in the case of the completely random network. These features highlight a novel aspect of seismicity as a complex phenomenon.