Sudden drop of fractal dimension of electromagnetic emissions recorded prior to significant earthquake

TL;DR

This study investigates electromagnetic emissions before earthquakes, finding that a sudden drop in fractal dimension and entropy can serve as indicators of imminent catastrophic failure.

Contribution

It demonstrates that electromagnetic emissions prior to earthquakes exhibit sudden fractal dimension drops, similar to damage evolution in other systems, suggesting potential as earthquake precursors.

Findings

Electromagnetic emissions show a sudden fractal dimension drop before earthquakes.

The results align with theoretical expectations of approaching critical failure.

Electromagnetic analysis can indicate imminent seismic events.

Abstract

The variation of fractal dimension and entropy during a damage evolution process, especially approaching critical failure, has been recently investigated. A sudden drop of fractal dimension has been proposed as a quantitative indicator of damage localization or a likely precursor of an impending catastrophic failure. In this contribution, electromagnetic emissions recorded prior to significant earthquake are analysed to investigate whether they also present such sudden fractal dimension and entropy drops as the main catastrophic event is approaching. The pre-earthquake electromagnetic time series analysis results reveal a good agreement to the theoretically expected ones indicating that the critical fracture is approaching.