On the night between Wednesday and Thursday in Naples and in the surrounding areas the great fear of the earthquake returned. The shock of magnitude 4.4 with an epicenter in the sea in front of Pozzuoli struck, without fortunately causing victims, the Flegrei camps and panicked the local population in panic. The damage to the buildings was however evident and many people had to pass the latest nights on the street or in any case far from their homes. The swarm then ended in about twenty -four hours, but this new strong seismic episode – quite similar to that which took place on 20 May – leads to specific reflections on bradisism. And above all it forces accurate analyzes on the real level of danger for those who live in affected areas, starting from Naples. Giuseppe De Christmasvolcanologist and research manager Ingv, tries to clarify and launches the alarm: «Two nights ago the tragedy has been touched. You can no longer think of leaving the population exposed to a very high risk ».
-Dotor de Natale what reading do we have to go to the event that happened?
«I state first of all that I answer personal and for my experience. The earthquake was of magnitude 4.4, and together with that of May 20, 2024 of equal magnitude, was the strongest ever recorded in the Flegrea area. The most powerful therefore at least from 1580, the year in which the seismicity associated with the Monte Nuovo eruption of 1538 ended. Fortunately, the other night only one person was injured in a non -serious way. But there were huge damage. The acceleration measured to the closest seismic stations has been higher than that of gravity and this level of acceleration is reached only by the strongest Apennine earthquakes. What prevents, in this area, real catastrophes is the fact that these earthquakes are of low magnitude and have accelerations with higher frequencies. In any case, these earthquakes are very superficial and very close to the buildings. Therefore they are extremely dangerous ».
-Napoli and the surrounding areas are in real danger or is it good to reassure people?
«As mentioned, the extreme danger of these earthquakes derives solely from the fact that they are extremely superficial and also practically continuous. However, their superficiality implies that they can produce, as we have seen, extreme accelerations only at a very low distance. Let’s say no more than 1-2 km. So, although in the part of Naples outside the caldera the earthquakes still feel a lot and generate fear is extremely unlikely that they can produce serious damage ».
-When concrete measures can be taken to reduce the risks for the population of the area?
«The only measure to be taken is to make sure that inhabited buildings can resist earthquakes like these and also much stronger than these. In fact, we know that earthquakes can take place in this area up to magnitude 5. That is to say at least ten times stronger than that which took place two nights ago, in terms of energy. If you cannot quickly make the carpet checks of the buildings at least in the area at maximum risk, the only alternative is to evacuate in advance, at least until the necessary checks are completed. These continuous earthquakes have growing seismicity that could last for years or decades ».
-What can we expect in the next few days?
«What we can unfortunately we can expect, in a situation of continuous lifting of the soil, is a further increase in seismicity. Moreover, since February 15, there has been a tripled lifting speed compared to the previous months. Seismicity depends on two factors. One is the level of pressure inside the system, which causes the lifting of the soil and breaks the rocks, thus also producing earthquakes. And then there is the speed of increased effort, which is also recorded as a lifting speed of the soil. Since now the lifting continues with a much higher speed than in the past months, there are both ingredients to generate even greater seismicity than this. However, we cannot know when the earthquakes will take place, with what magnitude and above all if in the short-medium period the lifting speed will change significantly or even zero. And in the latter case, seismicity would end ».
-GiMagina the worst scenario possible: that of an eruption. Can the phenomenon be expected in advance?
“In this area – there were two evacuations for a possible imminent eruption: in 1970 and 1984, without anything then occurred – an eruption cannot be foreseen with certainty. This is now a very clear assumption of recent volcanological research, and my research group has also made specific publications on this issue by suggesting the most effective measures to mitigate the risk of eruption ».
-Tre the Flegrei fields and Vesuvius are there concrete connections?
“No, there is no connection, as far as we know and also from the observations of the volcanic activity of the two systems made both in the historical era and by the reconstruction of the oldest and most recent eruptions, between the two volcanic areas”.
