GNGTS 2017 - 36° Convegno Nazionale

314 GNGTS 2017 S essione 2.1 (3) This means that, if a correlation exists between earthquakes and electron bursts, and the right time difference is considered between earthquake and electron burst events, the probability of a strong earthquake is increased by a term proportional to the correlation. References Anagnostopoulos, G. C., Vassiliadis, E. and Pulinets, S.; 2012: Characteristics of flux-time profiles, temporal evolution, and spatial distribution of radiation-belt electron precipitation bursts in the upper ionosphere before great and giant earthquakes. Annales of Geophysics, 55, 21–36. Billingsley, P.; 1995: Probability and Measure (3rd ed.). New York: John Wiley and Sons. Fidani C.; 2015: Particle precipitation prior to large earthquakes of both the Sumatra and Philippine Regions: a statistical analysis, Journal of Asian Earth Science, 114, 384-392. Fidani C.; 2016: Further developments on correlations between strong earthquakes and NOAA el ectron bursts from space, 35th GNGTS, Lecce, 286-289. Electricity perturbations observed around the October 30, 2016 Norcia earthquake, M = 6.5 C. Fidani 1,2,3 1 Central Italy Electromagnetic Network, Fermo, Italy 2 GEA Observatory, Foligno, Italy 3 SARA Electronic instruments, Perugia, Italy The Central Italy Electromagnetic Network aims to verify associations between electrodynamicsandseimicity,bymeansofwidebandelectromagneticdetectorsthatcontinuously monitor the electric components of the electromagnetic field, ranging from a few of Hz to tens of kHz. The network has been operating in central Italy for more than ten years. The recorded signals and their power spectrum contents have been analysed in real time. Time/frequency data have been saved for further analysis. The spectral contents have evidenced very distinct power spectrum signatures in ELF band, that increased in intensity when strong seismic activity occured near the stations: at the time of the Castelsantangelo sul Nera-Norcia (M = 5.4, M = 5.9, M = 6.5) earthquakes in 2016 when ten stations were operative, at the time of the Emilia (M = 6) earthquakes in 2012 when nine stations were operative (Fidani and Martinelli, 2015), and at the time of the L’Aquila (M = 6.3) earthquakes in 2009 when only two stations were operative (Fidani, 2011). Eecordings from the Chieti Station of the electrode E-W, between August - November 2016, are shown in Fig. 1. Green bars quantify the maximum daily intensity of ELF oscillations in one electrode, showing increasing electric oscillations from the beginning of October Fig. 1 - The distribution of daily maximum amplitude, in green, of ELF oscillations recorded by the E-W electrode. The vertical red arrows indicate stronger shocks occurring in 2016, vertical turquoise bands indicate periods when data were lost at the Chieti Station.