Strong Earthquake of magnitude 4.4 of March 13 with epicenter a Bagnoliin the Flegrei camps, and felt distinctly throughout the city of Naples, has brought an understandable fright in the population, also because of the damage Which caused, like the collapse of a attic in Pozzuoli, rubble finished on cars and a wounded person. The schools in the area have remained closed and numerous checks are being carried out on the road and railway network.
Among other things, the new seismic swarm is hitting the Phlegraean area while a Increase in CO emissions2which can be dangerous above all for possible accumulations in basements and low planes. The concern of the population is therefore understandable. Many wonder if there is fear for the imminent arrival of a much more violent earthquake or even a eruption inside the caldera. We therefore try to clarify by analyzing the data of the last Bulletins issued by the Ingv (National Institute of Geophysics and Volcanology), according to which at the moment “No elements are not highlighted such as to suggest significant short -term evolutions “.
What does the last Ingv bulletin say on the Flegrei fields: the data
The latest weekly Ingv bulletin, referring to the week from 3 to 9 March, confirms the fact that from mid -February The speed of the soil has increased significantly In the Phlegraean camps due to the volcanic phenomenon of bradisism.
In particular, from the beginning of the seismic swarm of February 15-20 (which led to the most intense shock of last month, of magnitude 3.9) the ski speed reached the rather high (but still preliminary) value in the land district 30 millimeters per month. We are talking about a triple value compared to the 10 millimeters per month registered on average in the period between August 2024 and February 2025, and higher than 20 millimeters per month from April to August 2024.
However, it is not the highest value recorded since the beginning of the current bradisismic crisis in progress since 2005. In 2023for example, the ground of the earth has reached a speed of as well 40 millimeters per month. During the 1982-1984 bradisismic crisis, the soil rose by 180 centimeters in two years, with an average of over 7 centimeters per month. In short, what is happening now is not something that has never been seen in the area.
In any case, thecurrent acceleration Of the rise of soil in the Flegrei camps is a fact. And the more the soil dates back, the more the earthquakes tend to increase and intensity. It is no coincidence that a remarkable increase in the number of earthquakes is paid to this acceleration: February 2025 It has been the most seismic month of the last 40 years In the Flegrea area, with 1813 earthquakes there is magnitude greater than 0.0 (most of which warned only by the seismographs) and 9 different seismic swarms.
As confirmed also by the press conference held in the past few hours by the Vesuvian Observatory of the Ingv, the overall picture which emerges from the data collected on the Phlegraean fields (land variations, hydrothermal emissions etc.) left expectations on a Increase in seismicity in the area, even if as always in these cases It is never possible to predict when and with what intensity the next earthquake will affect. The increase in the shocks and the intensity of the earthquake of magnitude 4.4 of tonight is therefore consistent with the overall situation of the Flegrea area and therefore cannot be interpreted as a sign of the fact that something is about to happen.
And the question of gas? Lately there has been a lot of talk about the increase in carbon dioxide and sulfur dioxide in the Phlegrean area. The last bulletin shows a trend of increased co emissions2 From the Pisciarelli sulfatara from August 2024, but without significant variations in the short term. This increase is in line with the increase in seismicity And with the increase in the intensity of bradisism, therefore all aspects are consistent and remain within substantial limits with what can be expected during a braiseismic crisis in the Flegrei fields. Also in this case, therefore, there are no elements to think that something big in the near future is about to happen.
What is the link between earthquakes, gas and bradisism?
The link between soil lifting, seismicity and hydrothermal emissions It is not particularly complex from a purely qualitative point of view. Beyond the technical details, the bradyseismic crises are linked to the fact that the magmatic fluids manage to trace through fractures in the subsoil, substantially “inflating” the soil. What it actually is that the soil is inadeforming both vertically (rises) and horizontally a bit like the “dome” of a panettone that is rising.
The inception of the soil therefore goes to induce dynamic stress which can be in low depth fractures that therefore generate earthquakes. The new fractures can then represent new ski channels of magmatic fluids.
