Introduzione alle luci sismiche
di Massimo Silvestri
The aim of the paper is to present and describe a particular geophysical phenomenon that sometimes occurs in coincidence with earthquakes, that of seismic lights.
Noted since ancient times as a precursory sign of an earthquake, over the last two centuries the subject of seismic lights has aroused great controversy between those considering them to be real lights and directly linked to the earthquake, and those instead believing them to be fantasies imagined by the terrified victims of the earthquake.
Only in the last thirty years, after the emergence of concrete evidence such as the photos taken during the earthquakes registered at Matsushiro in Japan between 1965 and 1967, has the scientific community started to conduct studies (on which this paper is based) in an attempt to understand this rare natural phenomenon. The intention of the article is to introduce readers to the existence of this interesting geophysical phenomenon, reviewing and analysing the various optical phenomena observed, like lightning, flashes, light rays, luminous mist and whirlpools of light, terminating with incredible luminescent globes that in both appearance and behaviour recall globe lightning.
A selection of past and recent cases reported in Europe, Asia and the Americas will be presented. An attempt will be made to take stock of the current position of research, presenting a panorama of the various theories proposed to clarify this enigma. In addition an account will be given of the analyses made at the beginning of the 20th century by Ignazio Galli, the first person in Italy to study these strange phenomena, leading him to publish in 1910 one of the earliest catalogues, listing 148 cases of earthquakes in which various types of light phenomena had been noted.
© Copyright: Massimo Silvestri - CISU-UDN
Quale espressione dell'attività intellettuale dell'autore, questo materiale è protetto dalle leggi internazionali sul diritto d'autore. Tutti i diritti riservati. Nessuna riproduzione, copia o trasmissione di questo materiale può essere eseguita senza il permesso scritto dell'autore. Nessun paragrafo e nessuna tabella di questo articolo possono essere riprodtti, copiati o trasmessi, se non con il permesso scritto dell'autore. Chiunque utilizzi in qualsiasi modo non autorizzato questo materiale è perseguibile a norma delle vigenti leggi penali e civili.
For the Photographs:
© Copyright Steinbrugge Collection, Earthquake Engineering Research Center, University of California, Berkeley.