Unfolding the procedure of characterizing recorded ultra low frequency, kHZ and MHz electromagetic anomalies prior to the L'Aquila earthquake as pre-seismic ones. Part I

TL;DR

This paper proposes a multidisciplinary procedure to identify and analyze electromagnetic anomalies at ultra low, kHz, and MHz frequencies as potential precursors to earthquakes, specifically applied to the 2009 L'Aquila event.

Contribution

It introduces a novel method for classifying EM anomalies as pre-seismic by linking multi-frequency electromagnetic signals with earthquake preparation stages.

Findings

Electromagnetic anomalies were recorded prior to the L'Aquila earthquake.

A procedure for identifying pre-seismic EM anomalies was proposed.

The analysis suggests a link between EM anomalies and earthquake preparation processes.

Abstract

Ultra low frequency, kHz and MHz electromagnetic anomalies were recorded prior to the L'Aquila catastrophic earthquake that occurred on April 6, 2009. The main aims of this contribution are: (i) To suggest a procedure for the designation of detected EM anomalies as seismogenic ones. We do not expect to be possible to provide a succinct and solid definition of a pre-seismic EM emission. Instead, we attempt, through a multidisciplinary analysis, to provide elements of a definition. (ii) To link the detected MHz and kHz EM anomalies with equivalent last stages of the L'Aquila earthquake preparation process. (iii) To put forward physically meaningful arguments to support a way of quantifying the time to global failure and the identification of distinguishing features beyond which the evolution towards global failure becomes irreversible. The whole effort is unfolded in two consecutive parts. We clarify we try to specify not only whether or not a single EM anomaly is pre-seismic in itself, but mainly whether a combination of kHz, MHz, and ULF EM anomalies can be characterized as pre-seismic one.