GNGTS 2018 - 37° Convegno Nazionale

342 GNGTS 2018 S essione 2.1 where d is the distance between collect plate and polarity plate in cm. The instrument revealed to be very sensible to humidity. Beyond 90% in humidity the ion counter had many problems to detect air ions and seldom failed to record long series of data. This problem was very common for air ion measurements and new technical solutions are required (Sheldon et al. 2018). For this motif, a long time series of air ion data was collected exclusively during the last summer when humidity values maintained under 95% also during the night, see Figure 3 for a two weeks time period. Aknowledgements. The Author would like to thank Sheldon Warden and Tom Blair for sharing some solutions for air ion adaptation to high humidity values. References Cinti F.R., Faenza L., Marzocchi W., Montone P.; 2004: Probability map of the next M ³ 5.5 earthquakes in Italy. Geochemistry Geophysics Geosystems, Volume 5, Number 11, 1-15. Fidani C.; 2005: Ipotesi sulle anomalie elettromagnetiche associate ai terremoti. Libreria Universitaria Benedetti L’Aquila, L’Aquila, Italy, 300pp. Fidani C.; 2010: The EQLs of the L’Aquila earthquake, April 6, 2009, NHESS, vol. 10, p. 967-978. Fidani C.; 2011: The Central Italy Electromagnetic Network and the 2009 L’Aquila earthquake: observed electric activity. Geoscience, 1, 3-25. Fidani C. and Marcelli D.; 2017: Ten Years of the Central Italy Electromagnetic Network (CIEN) Continuous Monitoring, Open Journal of Earthquake Research, 6, 73-88. Tennakone K.; 2011: Stable spherically symmetric static charge separated configurations in the atmosphere: Implications on ball lightning and earthquake lights. J. Electrostat., 69, 638-640. Warden S., Blair T. and Kappler K.; 2018: Long-term air ion monitoring applied to earthquake forecasting, EMSEV 2018, September 17 – 21, 230-233. A GROUND DISTRIBUTED ELECTRIC CURRENT TO MODEL MAGNETIC PULSES RECORDED BY CIEN DURING STRONG SEISMIC ACTIVITY C. Fidani 1,2 , M. Orsini 1 1 Central Italy Electromagnetic Network, Fermo, Italy 2 “A. Bina” Seismic Observatory, Perugia, Italy Magnetic recordings were made at several Central Italy Electromagnetic Network (CIEN) stations during past five years. They were made by induction coils of a diameter of about 80 – 100 cm, with the objective of detecting the magnetic component of electric oscillations already revealed during strong seismic activity. The recordings confirmed the absence of magnetic radiation correspondent to electric field oscillation measurements and this result was described according to the charged cloud model (Fidani and Marcelli, 2017). CIEN stations where magnetic field detectors were installed are: Chieti, Città di Castello, Avigliano Umbro, Norcia, Narni and Perugia. Only the first three were active during the strong seismic swarm in Central Italy in 2016. Even if the magnetic component of the electric field oscillations did not appear, a large number of intense magnetic pulses were detected at the Chieti Station before main shocks occurred in 2016 and 2017. Magnetic pulses had a time length of 0.1 sec and were concentrated around the time of the Norcia and the Capitignano seismic events. Specifically, daily pulse numbers increased suddenly on October 26, when two strong earthquakes, Mw = 5.4 and Mw = 5.9, struck Central Italy about 100 km from the Chieti Station, see Fig. 1. Pulse rates increased about four hours before the quakes (Orsini and Fidani, 2017). The number of magnetic pulses was equal to 30 on October 26, 45 on October 27, around 90 on October 28, returning to 30 on October 29 and increased to 60 on October 30,