Statistical Seismic Analysis by b-Value and Occurrence Time of the Latest Earthquakes in Italy

Abstract

The study reported in this paper concerns the temporal variation in the b-value of the Gutenberg–Richter frequency–magnitude law, applied to the earthquakes that struck Italy from 2009 to 2016 in the geographical areas of L’Aquila, the Emilia Region, and Amatrice–Norcia. Generally, the b-value varies from one region to another dependent on earthquake incidences. Higher values of this parameter are correlated to the occurrence of low-magnitude events spread over a wide geographical area. Conversely, a lower b-value may lead to the prediction of a major earthquake localized along a fault. In addition, it is observed that each seismic event has a different “occurrence time”, which is a key point in the statistical study of earthquakes. In particular, its results are absolutely different for each specific event, and may vary from years to months or even just a few hours. Hence, both short- and long-term precursor phenomena have to be examined. Accordingly, the b-value analysis has to be performed by choosing the best time windows to study the foreshock and aftershock activities.

Unveiling Temporal Cyclicities in Seismic b-Values and Major Earthquake Events in Japan by Local Singularity Analysis and Wavelet Methods

“…Subsequently, we conducted local singularity analysis [10] to calculate the local singularity indices for both earthquake frequency and b-values. To quantify the fractal nature of earthquake frequency and b-values, we investigate how the total number of data points, denoted as µ(ε), within a sampling box B(ε) of radius ε grows according to a power-law:…”

“…Previous research suggests that the b-value can serve as a significant indicator of stress levels within a region [2][3][4][5], with its variations providing vital information about crustal stress accumulation and release [6,7]. Studies employing the b-value method on past seismic events indicate that temporal changes in the b-value can be considered precursors to major earthquake activity [8][9][10][11][12][13].…”