Pre-earthquake electromagnetic emissions with critical and tricritical behavior before the recent Durr\"es (Albania) (Mw=6.4, 26-11-2019) and Chania (Greece) (Mw=6.1, 27-11-2019) earthquakes

TL;DR

This study analyzes electromagnetic emissions before two significant earthquakes, revealing critical and tricritical behaviors that could improve understanding of earthquake preparation processes.

Contribution

It provides evidence of critical and tricritical electromagnetic fluctuations prior to earthquakes, using the method of critical fluctuations to analyze pre-seismic signals.

Findings

Electromagnetic emissions showed critical fluctuations before both earthquakes.

Chania earthquake emissions departed from criticality via symmetry breaking.

Durr"es earthquake emissions departed from criticality via tricritical crossover.

Abstract

In this brief report we present evidence for the dynamics of the earthquake (EQ) preparation processes that led to two strong events (Mw>6) that took place in Durr\"es (Albania) and Chania (West-Crete, Greece) on 26 and 27-11-2019, respectively. Specifically, MHz fracto-electromagnetic emissions (EME) recorded by our telemetric stations presented critical fluctuations prior to each one of these EQs. Subsequently, the EME possibly related to each one of these EQs evolved differently towards the occurrence of the EQ event: the ones possibly related to Chania EQ departed from critical state according to the symmetry breaking phenomenon, while the ones possibly related to Durr\"es EQ departed from critical state according to the tricritical crossover phenomenon. The analysis was performed by means of the method of critical fluctuations (MCF).