The earth still trembles at the Flegrei campsand fear makes itself felt among the inhabitants. The seismic swarm started on Saturday 15 February shows no sign of subsiding, with hundreds of shocks that continue to shake the area. The strongest, of magnitude 3.1 and 3.0, they were recorded just this nightbetween 18 and 19 February, with an epicenter between Pisciarelli and the Solfataraat a depth of about 2 kilometers.
The incessant succession of shocks, felt distinctly by the population of Pozzuoli, Bacoli, fourth and in the western neighborhoods of Naples, generated an atmosphere of apprehension and uncertainty. Many residents, frightened by the possibility of more intense events, preferred to spend the night out of their homes. Dozens of people poured on the Pozzuoli promenade, finding refuge in their cars or branded made available by Civil Protection at the Palatrincone of Monteruscello.
Despite the situation of discomfort, The schools of Pozzuoliclosed as a precaution in recent days, they reopened todaytrying to restore a sense of normality.
The seismic swarm in place is linked to the phenomenon of bradyseismcharacteristic of the Phlegrean area. Bradisism is a slow vertical movement of the soil, caused by pressure variations in the subsoil. In recent decades, the Phlegraean camps have crossed several stages of bradisism, with periods of lifting and lowering of the soil. The current lifting phase began in 2005.
The INGV (National Institute of Geophysics and Volcanology) is constantly monitoring the evolution of the situation. “In the last week, the Campi Flegrei area was affected by hundreds of earthquakes, related to the lifting of the soil,” he explains Carlo Doglionipresident of the Ingv. “It is obviously observed that the more the lifting speed increases, the more the number of earthquakes increases.”
Doglioni reassures, however, that “the lifting is currently quite slow, about one centimeter per month. A year and a half ago it was 4 cm per month, while in the period 1982-84 the 9 cm per month were reached. Before the eruption of 1538, soil lifting was even 14 meters. From 2005 to today, the soil has risen by about 4 meters “.
The President of the Ingv explains that Seismicity is linked to the structure of the volcano.
Magma introduces itself in depth and creates a sort of piston that pushes upwards, inhering the earth’s crust and generating earthquakes. These are mostly minor earthquakes, the maximum recorded has been around magnitude 4, even if prudentially we assume that up to 5 could go.
Doglioni makes a comparison with the 1982-84 bradisismic crisis.
The seismicity of that period was very intense, but then vanished. What is different from this sequence is that, although there is less earthquakes, these are more diluted over time, there is no concentration of events like then.
Regarding the volcanic activity of the Campi Flegrei, Doglioni explains: “The Flegrei fields are an area that emits 5,000 tons of CO2 alone per day. In recent years there has been a continuous and constant increase in gas emissions, but also in the past there have been moments of climb and then of descent. This does not necessarily mean that we are going towards an imminent eruption. “
The president of the Ingv underlines the importance of monitoring: “At the moment there is no evidence of a skill of magma towards the surface, But nature sometimes surprises us. For this we are trying to ‘listen’ to the volcano as much as possible, monitoring all geochemical, geodesic and gravimetric parametersto understand if there are indicators of an imminent risk “.
Doglioni concludes: “Each volcano has its own history and behaves in a different way. The Flegrei fields are an active volcano, but at the moment there are no elements that make one think of an imminent eruption. It is important to remember that in May of last year there was a shock of magnitude 4, therefore the current seismic swarm can be considered a recovery that can lead to something more important “.
It is essential that the population comply with the information provided by the official bodies and follow the security indications. The INGV makes available on its website updates in real time on the seismic and volcanic situation of the Flegrei Campi.
