Enhanced ULF electromagnetic activity detected by DEMETER above seismogenic regions

TL;DR

This study analyzes four years of ULF electromagnetic data from DEMETER, finding increased ULF activity above seismogenic regions, supporting its potential as an earthquake precursor.

Contribution

It demonstrates a clear correlation between ULF electromagnetic energy increases and high seismic activity regions using SSA analysis.

Findings

Significant ULF energy increase above active seismic regions

Supports ULF EM activity as an earthquake precursor

Confirms previous evidence of ionospheric anomalies before earthquakes

Abstract

In this paper we present results of a comparison between ultra low frequency (ULF) electromagnetic (EM) radiation, recorded by an electric field instrument (ICE) onboard the satellite DEMETER in the topside ionosphere, and the seismicity of regions with high and lower seiismic activity. In particular we evaluated the energy variations of the ULF Ez-electric field component during a period of four years (2006-2009), in order to examine check the possible relation of ULF EM radiation with seismogenic regions located in central America, Indonesia, Eastern Mediterranean Basin and Greece. As a tool of evaluating the ULF Ez energy variations we used Singular Spectrum Analysis (SSA) techniques. The results of our analysis clearly show a significant increase of the ULF EM energy emmited from regions of highest seismic activity at the tectonic plates boundaries. We interpret these results as suggesting that the highest ULF EM energy detected in the topside ionosphere is originated from seismic processes within Earth's crust. We understand the results of the present study as confirming previous evidence that the ULF EM anomalous wave activity in the ionosphere can be considered a useful earthquake precursory signal