To the Flegre fieldsthe seismicity is increasing again: in detail, the bulletin of the Vesuvian Observatory highlighted an increase in seismic activity between 23 February and 1 March, during which 70 shocks, more than double compared to 34 tremors the previous week. The maximum magnitude also increased, from 2.8 to 3.5the latter detected on 28 February with an epicenter approximately 4 kilometers from Pozzuoli. However, the bradyseism – with the average speed of soil lifting confirmed at 10 mm per month – ei geochemical parameterswith an average temperature of 173°C to the Solfatara fumarole.
70 earthquakes in the Campi Flegrei: the most intense of magnitude 3.5
In the week between February 23rd and March 1st, the number of earthquakes in the Campi Flegrei therefore rises to 70 shocksmore than double compared to the previous week. Most of the seismic activity was concentrated in the area of Pozzuoli-Agnano where on February 28, starting at 11.18am, it occurred a swarm composed of 52 events.
The most intense shock, of magnitude 3.5was recorded at 11:19: according to what was detected by the National Institute of Geophysics and Volcanology (INGV), the epicenter was located approximately 4 kilometers from Pozzuoli, in the area below the Solfatara Tunnel of the Ring Road, with the hypocenter at 2.7 kilometers deep.
Bradyseism remains stable at 10 mm/month
The bradyseismor that volcanic phenomenon which consists in a periodic lowering or raising of the ground level, is confirmed stable: the Vesuvian Observatory once again recorded an average speed of 10 millimeters monthlya solid figure since the beginning of February, a clear decrease compared to the 30 mm/month of February 2025 and the 25 mm/month recorded between October and December 2025. Since the beginning of January 2025, the RITE GNSS station has recorded a ground lifting equal to approximately 24.5 centimetres.
The same ones geochemical parameters remain stable and continue to highlight the trend already observed for some time: the hydrothermal system shows constant warming and gas and vapor flows remain high, as reported in the monthly bulletins. In particular, the BG fumarole, inside the Solfatara craterhas recorded a progressive increase in temperature in recent months, which in the period considered averaged around 173°Cwhile at Pisciarelli fumarole the temperature showed an average value of ~96°Ctemperature close to the condensation of the fumarolic fluid.
Summary of the INGV weekly bulletin
In summary, the INGV weekly bulletin on the Campi Flegrei area reports:
- Seismicity: increasing, with 70 earthquakes and maximum magnitude 3.5.
- Seismic swarm: an earthquake swarm that began at 11:18 am on February 28, during which 52 tremors were detected.
- Bradyseism: stable ground lifting speed compared to the previous week, approximately 10 mm/month.
- Temperatures: the BG fumarole in the Solfatara crater confirms the increasing trend (~173 °C).
