Verifying the self-affine nature of regional seismicity using nonextensive Tsallis statistics

TL;DR

This paper verifies that regional seismicity exhibits self-affine properties by analyzing earthquake data with a nonextensive Tsallis statistics model, revealing consistent statistical behavior across different earthquake populations and scales.

Contribution

It demonstrates that regional seismicity and fault fracture events follow the same nonextensive statistical law, supporting the self-affine nature of earthquake processes.

Findings

Regional seismicity follows a nonextensive Gutenberg-Richter law.

Parameters q and α vary with magnitude thresholds and radius, indicating self-affinity.

Earthquake populations before and during fracture events share statistical characteristics.

Abstract

The aspect of self-affine nature of faulting and fracture is widely documented from the data analysis of both field observations and laboratory experiments. In this direction, Huang and Turcotte have stated that the statistics of regional seismicity could be merely a macroscopic reflection of the physical processes in earthquake source, namely, the activation of a single fault is a reduced self-affine image of regional seismicity. This work verifies the aforementioned proposal. More precisely we show that the population of: (i) the earthquakes that precede of a significant event and occur around its the epicentre, and (ii) the "fracto-electromagnetic earthquakes" that are emerged during the fracture of strong entities distributed along the activated single fault sustaining the system follow the same statistics, namely, the relative cumulative number of earthquakes against magnitude. The analysis is mainly performed by means of a recently introduced nonextensive model for earthquake dynamics which leads to a Gutenberg-Richter type law. We examine the variation of the parameters $q$ and $\alpha$, which are included in the nonextensive law, for different thresholds of magnitude and different radius around the epicentre. Such analysis enhances the physical background of the underlying self-affinity. The parameter $q$ describes the deviation of Tsallis entropy from the extensive Boltzmann-Gibbs entropy, and $\alpha$ is the constant of proportionality between the energy released during the fracture of a fragment and its size.