On the recent seismic activity at Ioannina (Greece): Pre-earthquake electromagnetic emissions with critical and tricritical behavior

TL;DR

This study analyzes electromagnetic emissions before the Ioannina earthquake, revealing a transition from critical to tricritical behavior indicative of earthquake preparation processes, using the method of critical fluctuations.

Contribution

It demonstrates the presence of critical and tricritical electromagnetic emissions prior to an earthquake, highlighting a potential precursor detection method.

Findings

EME exhibited critical behavior five days before the quake

A transition to tricritical behavior was observed closer to the event

Spontaneous symmetry breaking distinguished critical from tricritical states

Abstract

In this short paper we report that the dynamics of the earthquake (EQ) preparation processes, as embedded in the observed fracture-induced electromagnetic emissions (EME), were characterized by critical and then tricritical behavior a few days before the occurrence of the recent Ioannina (Greece) earthquake [($39.79^o N, 20.69^o E$), 15 October 2016, $M_L=5.3$]. Specifically, an excerpt of the MHz EME recorded by our remote telemetric station near the city of Ioannina five days before the EQ was found to possess critical characteristics, followed by an excerpt possessing tricritical characteristics. The analysis was performed by means of the method of critical fluctuations (MCF). Interestingly, spontaneous symmetry breaking was identified between critical and tricritical behavior.