Enhanced ULF radiation observed by DEMETER two months around the strong 2010 Haiti earthquake

TL;DR

This study analyzes ULF electromagnetic wave energy variations recorded by DEMETER satellite around the 2010 Haiti earthquake, revealing significant energy increases prior to and after the event, suggesting potential earthquake precursors.

Contribution

We developed a novel two-stage method combining filtering and Singular Spectrum Analysis to detect ULF energy variations related to seismic activity.

Findings

Significant energy increase 30 days before earthquake

Energy changes observed 25 days after earthquake linked to aftershocks

Differences in night and day satellite passes, but similar energy change rates

Abstract

In this paper we study the energy of ULF electromagnetic waves that have been recorded by the satellite DEMETER, during its passing over Haiti before and after a destructive earthquake. This earthquake occurred on 12/1/2010, at geographic Latitude 18.46o and Longitude 287.47o, with Magnitude 7.0 R. Specifically, we are focusing on the variations of energy of Ez-electric field component concerning a time period of 100 days before and 50 days after the strong earthquake. In order to study these variations, we developed a novel method that can be divided in two stages: first we filter the signal keeping only the very low frequencies and afterwards we eliminate its trend using techniques of Singular Spectrum Analysis, combined with a third-degree polynomial filter. As it is shown, a significant increase in energy is observed for the time interval of 30 days before the strong earthquake. This result clearly indicates that the change in the energy of ULF electromagnetic waves could be related to strong precursory earthquake phenomena. Moreover, changes in energy were also observed 25 days after the strong earthquake associated with strong aftershock activity. Finally, we present results concerning the comparison in changes in Energy during night and day passes of the satellite over Haiti, which showed differences in the mean energy values, but similar results as far as the rate of energy change is concerned.