Among the data recorded by the National Seismic Network of the National Institute of Geophysics and Volcanology (INGV) there are some that cannot be traced back to natural events. In fact, it may happen that some human activities determine "seismic" signals, causing a movement that is often not perceived by the population but is detected by the stations. Among these, some signals are the result of very pleasant activities and moments of exultation. We met the Director of the INGV Vesuvius Observatory, Francesca Bianco, who spoke to us about the "seismic signals of happiness".
Where do these signals come from that are not attributable to natural activity?
There is a huge range of signal sources that derive from human-related activities, one of many being traffic, both vehicular and air, which in the event of breaking the sound barrier can generate a "seismic" signal detected by the stations. However, even the exultation linked to sporting activities and some musical events, such as concerts, can generate seismic signals... here in Naples this has happened to us on many occasions.
What was the first time you happened to find a "sign of happiness" on monitors?
It happened to me for the first time between the eighties and nineties, when Diego Armando Maradona was playing for the Napoli football team. The jumps of the Neapolitan fans, in raptures inside the stadium, produced signals of a higher amplitude than the background noise. From our seismic monitors of the time we were able to verify that a particular "seismic" signal was also generated by the support of the Napoli player Antônio de Oliveira Filho, known as Careca, famous for particularly strong shots. The chorus dedicated to him recited “Carè Carè Carè, tira la bomba, tira la bomba!” and at that point the audience jumped. This produced a movement that was promptly registered. The signals resulting from Maradona's goal celebrations were also clearly recognizable.
Once acquired, how is this data classified? What is their scientific value?
This data is not entered into our databases as it is not associated with natural events. However, they are analyzed and stored, since we have the task of understanding all the signals that reach us, what they are due to and their different waveforms. All in order to better focus on our main objective, earthquakes. A scientific acknowledgment of these events occurred after the conquest of the World Cup by the Italian national football team in 2006. A work by the seismologist Marco Mucciarelli, published in the journal Seismological Research Letters, highlighted how on the evening of 9 July 2006 the exultation for the victory of the national team against France (the match ended, on penalties, with a goal by Fabio Grosso who awarded the World Cup to Italy) caused a signal that Mucciarelli called "Football Quake". A similar event occurred in 2018, on the occasion of a Napoli match at the Turin Stadium. Napoli won against Juventus with the unforgettable goal by Kalidou Koulibaly, in the 90th minute. Also in this case, in the moment of the goal, the sensors of the Neapolitan area recorded the signal. Therefore, the Football Quake signals are not necessarily produced inside a stadium. They can also be generated by viewers who watch television at home.
What are the other “happy” activities that you often see on your monitors?
Other events of this type that generate signals recorded by our monitoring networks, and sometimes even felt by the population, are musical performances. It happened, for example, last March 14 on the occasion of the Salmo concert which was held at the PalaPartenope in Naples: we received many phone calls from people in the area (Fuorigrotta district) who reported vibrations to us. Well, behind these vibrations there was the show. The same happened many years ago, on the occasion of a legendary concert by Spandau Ballet but also when U2 and Caparezza performed. On all these occasions we have recorded these "vibrations" and they have often been perceived by citizens.
Seismogram 1 - Recording from the INGV-OV Monitoring Room of the "Champions" shout on the occasion of the Napoli-PSG match at the San Paolo on 6 November 2018
Seismogram 2 - Recording from the INGV-OV Monitoring Room on the occasion of the Vasco Rossi concert on 3 July 2015