The current crisis

Last update - May 2025

Seismicity. Since 2018, the ground uplift has been followed by a gradual increase in seismic activity, both in terms of the number of earthquakes and their magnitude. In 2023, while most quakes had low magnitudes (about 90% had magnitudes below 1.0), a new increase in their frequency was recorded. Most of the events occurred between Astroni, Solfatara-Pisciarelli-Agnano, Pozzuoli, and the Gulf of Pozzuoli, with maximum depths of about 4 km, primarily concentrated in the first 2 km. In the same year, the strongest events occurred on September 27 and October 2, with respective magnitudes of 4.2 and 4.0. In 2024, the strongest earthquake occurred on May 20 with a magnitude of 4.4 in the Solfatara of Pozzuoli area. In 2025, the strongest earthquake to date occurred on March 13 during a seismic swarm. With a magnitude of 4.6, it has been the most powerful event of the ongoing bradyseismic crisis.

Ground deformation. A new uplift phase of the Phlegraean Fields caldera began in 2005 and is still ongoing. Since 2018, ground uplift has shown a progressive trend, accompanied by significant variations in deformation rates. In particular, during certain periods, the uplift rate has reached values exceeding 30 mm/month before returning to lower values, typically around 20 mm/month or less.

At the end of March, the maximum uplift value reached in Rione Terra, Pozzuoli (the point of maximum caldera deformation), was approximately 146.5 cm, of which about 28 cm since January 2024. These variations significantly indicate the evolution of the volcanic system concerning the dynamics of the underground fluids.

Comparison with the bradyseismic crisis of the 80's. The current situation is marked by ground uplifts and earthquakes of a magnitude comparable to those experienced in the bradyseismic crisis of 1982-84, while in terms of impact on buildings and infrastructure, the scenario is very different. The 1980s crisis caused extensive damage to buildings, particularly in the municipality of Pozzuoli, leading to the evacuation of the population from their homes in the historic center. This was similar to what happened during the bradyseismic crisis of the 1970s when the inhabitants of the Rione Terra had to be evacuated.

The current bradyseismic crisis has not caused significant damage so far due to the different vulnerabilities of the buildings and the evolution of the phenomenon in terms of quake frequency and uplift rate. Currently, most buildings in the area do not exceed three stories and are primarily constructed of reinforced concrete or masonry, which have undergone seismic retrofitting interventions since the 80's. To this end, with the Ministerial Decree issued by the Ministry of Public Works on March 7, 1981, the municipalities in the Phlegraean area were classified as seismic with strict adherence to construction regulations.

Initial response to the crisis. The recent escalation of bradyseismic events, culminating in September and October 2023, required the strengthening of volcanic monitoring activities by INGV and other Centers of Competence and, more generally, an enhancement of preventive measures by the Civil Protection System.

The opinion of the National Major Risks Commission. In this context, the Department consulted the National Major Risks Commission - Volcanic and Seismic Risk Sector several times on the current situation, requesting further research and analyses, given the complexity of the issue and the potential evolution of the volcano's dynamics. Several national and international experts were also called to provide further assessments.

As a result of these meetings, the Commission concluded that their scientific findings provided additional evidence of the presence of deep-seated magma as the root cause of the current bradyseismic crisis. However, without proof of rising magma, it was concluded to confirm "the yellow alert level for volcanic risk." Therefore, according to the Commission, all monitoring activities by the Centers of Competence and prevention activities by the various components of the National Service (NCPS) should be further strengthened and prepared for the potential need to increase the alert level.