Central Italy Electromagnetic Network

CIEN is a non-governmental and nonprofit organization created to investigate the nature of earthquakes from electrodynamic phenomena as for example earthquake lights.

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Motivations

Earthquake lights have been reported over the centuries both before and while the ground is shaking. A large number of reports were collected in Italy where many scientists in the XVIII and XIX centuries experimented strong earthquakes. M. Baratta carried out investigations on electric and magnetic phenomena observed during the main quakes in May 1891, where there were listed more than one hundred cases.

Just seconds before (see Fidani, 2010) the 2009 L'Aquila, Italy, earthquake,

people saw four-inch (ten-centimeter) flames of light flickering above a stone

street. Diffused light was reported hours before the mainshock appearing as

reddish light, with shades ranging from orange to violet. Witnesses described

diffused halos which were uniform in the sky having a dull rose-colored

luminosity. Yellow- and rose-colored luminous vapors were observed

immediately before and after the mainshock. The vapor was generally

reported to be low-lying, just a few meters above the ground or covering half

of the profile of the mountains. Luminous clouds with orange, red, pink, and

purple-stained outlines were observed, they were also lit far from the position

of the Moon. Both small and large flashes were observed lasting from a

fraction of the second and a few seconds, principally white, but also red and

in few cases shades of blue. Electrical discharges were reported around and

at the time of the mainshock. They were described occurring without

thunderstorms, with thin clouds through which it was possible to see the light

of the stars or without clouds. Such discharges were less luminous than lightning bolts, as they did not illuminate the landscape in the neighborhoods, and they were either white, green, or a shade ranging from red to violet. Fire columns were observed during or around the time of the mainshock. Their colors ranged from orange to red, and in one case, the vertical column was associated with electrical discharges. Fireballs were observed several months before the mainshock on 6 April. As with foreshock activity which started to increase in October 2008, reports of fireballs started in the summer of 2008 and increased in number till the end of March 2009. Luminous phenomena as those reported in the video above were observed in every part of the world and are

common in the rift environments.

A questionnaire was also prepared to collect testimonies regarding biological and

other non-common phenomena from Abruzzo residents after the strong quake of

April 6, 2009. One thousand and three hundred phenomena were reported, 551 of

which were biological phenomena (see Fidani, 2013). A photo is shown on the right

where dead fishes on the surface of Lake Scanno, L’Aquila, Italy, appeared on

October 10, 2008. At least 278 of such phenomena occurred before the mainshock

and other strong events of the seismic sequence. Many of the domestic animals

were reported to have a remarkable capacity at anticipating the stronger shocks,

even up to hours before. Earthworms and ants were reported to behave strangely

several days before the quakes. These results are in agreement with past

observations regarding anomalous animal behavior around strong seismic events,

where shifts of precursor times towards smaller values regarding observations of

larger animals (Rikitake, 2003) were confirmed. Most animal reports concerned

domestic animal observations, and their early observation times lasted from a few

seconds up to a few hours, where the shift of precursor time towards smaller

values regarding observations of larger animals was evidenced. The hypothesis was suggested (Tributsch, 1978) that the physiological effects were essentially caused by an increase of the air ion concentration resulting in reactions such as the serotonin irritation syndrome.

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History

The first experiments were carried out in 2003 on a mobile station built

with an old FIAT 500, see the photos on the right. However, continuous

long-term EM monitoring is necessary for obtaining reliable results

regarding correlations with seismic activity. Therefore, a simple and

economical recording system for both electric oscillations and magnetic

pulses was realized on stable places which is currently operative at the

six stations of Central Italy, where the relevant probability of strong

seismic events was calculated in recent studies.

CIEN that has been operating for more than thirteen years initially it

started to record the electric component in 2006 with the first station at

San Procolo, Fermo, reached a maximum of 16 stations in 2015 – 2017; 

see a map of past stations distribution on the right. After, the station 

number was reduced and updated with new instruments. Initially

equipped with electric detectors in 2006, CIEN stations started to record

magnetic fields in 2012 at the Chieti Station, then it was extended to 

Città di Castello, Avigliano Umbro, Perugia, Narni, Norcia, Gubbio,

L'Aquila, and Fermo utilizing the existing station for electric monitoring.

Presently, there are six CIEN stations working with a magnetic sensor; 

Chieti, Perugia, Norcia, Gubbio, L'Aquila, and Fermo.

Three periods of major seismic swarms have occurred throughout three

different regions of Central Italy over the last decade: the April 6 L'Aquila 

earthquake in 2009, M = 6.3, the May 20 (M = 6.0) and 28 (M = 5.8) 

Modena earthquakes in 2012 and the Amatrice – Norcia – Capitignano 

sequence which occurred August 24 and October 30, 2016, as well as

January 18, 2017, (M = 6.0, 6.5 and 5.7) respectively.

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Stations

CIEN stations are made up of two principal parts: sensors and the recording system. Outdoor sensors are composed of electrode wires with electronics that prepare the signals. These must be positioned outdoors as they are responsible for picking up EM signals in the atmosphere.

A loop magnetometer constitutes the indoor sensor, as it must be protected by atmospheric

mechanical and electromagnetic disturbances. The recording system consists of a standard PC

audio card with the necessary software to carry out a real-time analysis and store data. The

recording system is positioned indoors so as to protect it from the weather. The power supply

for the sensor electronics is incorporated into the PC, while the indoor and outdoor parts are

connected by a multiple signal/power-supply shielded wire.

All antennae have two long thin wires, from l = 10 m to l = 20 m in length and from s = 0.5 mm

to s = 1 mm of thickness, which are perpendicular to each other and horizontally fixed at about

h = 8–10 m off the ground. All the station electrodes have one wire positioned approximately

toward the N-S and the other wire toward the E-W. The wires are covered by an insulating

sheath as well as the supports that keep them off the ground. Moreover, all conductive parts of

the system are also covered by an insulating sheath to protect against direct contact with

atmospheric charge, while the mass supply is connected to the ground. The electronics include

two amplifiers having high impedance, high gain, and wideband (DC to 100 kHz). Finally, protection limits excessive induced electrical potentials on the electrodes, thereby preventing damage to the electronics. The magnetic detector consists of an electrically shielded loop oriented along the Appennine Chain, NNW – SSE. After several years of experimentation, the Chieti Station software was concentrated on 1 Hz – 450 Hz band and it was reproduced in other CIEN stations with different types of low-frequency

wideband amplifiers. Different loop typologies were also tested concerning big loop and squares on-air

as well as small coils with iron and mu-metal cores.

Sensors are connected to a PC at each station which supplies power to the electronics and samples the

signals by way of sound cards. The signals are registered in stereo mode for both direction antennas

with a 16 bit A/D conversion, permitting a dynamical range of about 96 dB. This is necessary, as weak

signals start at −100 dB, while meteorological perturbations can increase the signal amplitudes up until

−20 dB. Spectrum Laboratory free software is used to fix the recording parameters and to analyze the

signals utilizing Fast Fourier Transform. Data is stored in Hard Disks and DVDs for further analysis

allowing for further comparison of the measurements (see Fidani, 2011).

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Findings

1) A systematic regional survey of the population was carried out after the L'Aquila earthquake in 2009, M = 6.3,

using questionnaires. The statements made by witnesses were collected by visiting the 179 camps set up by the

Italian Civil Protection service, as well as in meeting places such as schools, malls, hospitals, coffee shops, social

clubs, public and private institutions such as the police, firemen, and forest rangers. A collection of testimonies

about luminous phenomena and animal behavior observed in and around L’Aquila before and after the earthquake

on April 6, and also around other seismic events confirmed previous reports. Red Sky on the right (see Fidani, 2010).

                                                                                                           2) Oscillations in electric field intensity of the order of micro Volts, lasting

                                                                                                           from minutes to several hours, and a frequency range between 20 Hz and

                                                                                                           300 Hz, were detected. Their intensities increased around strong seismic

                                                                                                           activity in being of the same kind and size for the 2009 L’Aquila, 2012

                                                                                                           Emilia, and 2016 Norcia earthquakes. Unlike L’Aquila in 2009, when strong

                                                                                                           oscillations started several months before and ended several months after

                                                                                                           the mainshock (see picture on the right) in the case of the Emilia and 

                                                                                                           Norcia seismic events strong oscillations started to occur about a few

weeks before mainshocks and lasted some weeks after the mainshocks (see Fidani and Martinelli, 2015).

3) Magnetic pulses having time lengths around 0.1 sec were observed around the times of the major seismic

events in Central Italy. The magnetic data analysis at Chieti Station, performed through two independent

methods, shows that six days before the earthquake of Norcia, one day before the Castelsantangelo sul Nera

and Capitignano earthquakes, a large number of pulses were recorded with amplitudes mostly in the range of

2 to 80 nT; see the graph on the right. Similar observations were made days before the M = 6.3 L'Aquila and

M = 6.0 Emilia mainshocks occurred in April 2009 and May 2012 respectively (see Orsini and Fidani, 2018).

                                                                                                4) By using more than 16 years of NOAA satellite particle data, a statistically

                                                                                                significant correlation between extended perturbations of electron counting rates

                                                                                                and large earthquakes was observed. The precipitating low L-shell electrons

                                                                                                phenomena occurred 2–3 h before mainshocks. This result supports the                                                                                                                hypothesis that there exists a link between ionospheric and surface seismic

                                                                                                activities when earthquake depths are less than 200 km. Based on the drift

                                                                                                period, and hypothesizing an interaction region above the epicenter of Sumatra

                                                                                                and The Philippine regions, the times of earthquake–ionosphere interactions

                                                                                                occurred 4–10 h before the earthquake times (see Fidani, 2015).