Entropic Analysis of Geographical Subzones for the Maule Mw8.8 (2010) Earthquake

Three entropic functions are used to characterize the seismic activity prior and after the major Mw8.8 earthquake of Maule (Chile) dated on 27 February 2010. Shannon entropy, mutability, and Tsallis entropy are calculated globally on the seisms extracted from the catalog of the National Center of Seismology (Chile). Calculations are done both globally on the whole data and also dynamically on windows of different number of seisms after filtering data with a Gutenberg–Richter analysis. The data are time series based on two observables: seism magnitudes and inter-event intervals. It is found that the two entropies and mutability give similar descriptions on the different regimes present between 2005 and 2022. However, mutability can be calculated in a direct and straightforward way. It is also found that the results for inter-event intervals produce more contrast between periods than the corresponding ones for magnitudes. The region spanning six degrees in latitude is split in five overlapping subzones of two degrees each. This allows us to find the way the rupture takes place: from south to north, for about 400 km.