Burst increases of precipitating electrons recorded by the DEMETER satellite before strong earthquakes

Abstract

Abstract. This case study developed a method for data processing over six years, from 2004 to 2010, of 70 keV-2.3 MeV electrons recorded by the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite. Short time increases in electron counting rates, having 99 % probabilities of not being Poisson fluctuations, were statistically selected using geomagnetic invariant space and called electron bursts. Temporal series were analysed confirming the seasonal variations in low energy bands of 70-450 keV. Differently from previous results, the DEME-TER results exhibited two peaks of electron bursts: one in the period June-August and one in the period DecemberFebruary annually. Specifically, six earthquake cases are presented in detail having increases in electron burst number prior to events. Moreover, electron burst precipitation occurring before each strong earthquake of the entire period over the life of the satellite with M ≥ 7.0 was verified as having a probability greater than 97 % of not being of a statistical origin. Low energetic electrons in 70-330 keV resulted occurring more frequently near seismic activity than those observed in 330 keV-2.34 MeV energy bands at the satellite altitude in the ionosphere.

Particle precipitation prior to large earthquakes of both the Sumatra and Philippine Regions: A statistical analysis

“…A criterion to select electron bursts has been applied on high energy electron flux data at 70 keV-2.34 MeV recorded by IDP on DEMETER (Zhang et al, 2013). The calculated time differences between CRs by IDP and EQs were longer than those of previously published works, and increases in energetic electron fluxes were observed a few days before EQs (Anagnostopoulos et al, 2010), accompanied by broadband kHz emissions (Anagnostopoulos et al, 2012;Zhang et al, 2012) and compared to the VLF transmitter contributions (Sidiropoulos et al, 2011;Sauvad et al, 2014).…”

Possibilities for selected space weather and atmospheric studies in JEM-EUSO project?

“…[56]), but also changes of high energy e flux is reported to be related to seismicity (e.g. [57,58] among others).…”

Recent progress in ionospheric earthquake precursor study in China: A brief review

“…Except for the ionospheric data from the ground-based ionosondes and GPS receivers, some other satellite data (such as FORMOSAT3/COSMIC and DEMETER) were also utilized to study abnormal variations before earthquakes (Zhang et al, , 2010b(Zhang et al, , 2013Liu et al, , 2011bSarkar et al, 2007;Zeren et al, 2010Zeren et al, , 2012. COSMIC data further reveal that the NmF2 significantly decreases by approximately 40%, and the hmF2 drops about 50-80 km when the GPS TEC anomalously reduces .…”

“…Zhang et al (2013) statistically analyzed the ULF electric field observed by the DEMETER satellite for 27 earthquakes in Indonesia and Chile. All of the results showed that perturbations varied from 1.5 to 16 mV/m in the upper ionosphere, and the perturbations were mainly located just over the epicenter area.…”