To the Phlegraean Fields The rise of the ground continues, while seismicity increases slightly. According to the latest weekly bulletin of the Vesuvian Observatory (INGV), between 24 and 30 November 2025, 137 earthquakes, of maximum magnitude 3.3 recorded last November 26th. This is a slight increase compared to 110 events of the previous week, while on the front of the bradyseism the average lifting speed is confirmed to be increasing, reaching a 25 ± 3 millimeters per month starting October 10th.
Geochemical data also confirms the long-term trends of heating of the hydrothermal system: the average temperature at the fumarole of Pisciarelli remains stable around 93°Cwhile at Solfatara the main fumarole averaged 173°Cmarking a slight increase.
Yesterday, December 1st, a 1.7 magnitude earthquake was also recorded, felt as far as Pozzuoli. In the meantime, stay activates phase 2 of the yellow alert.
Slight increase in seismicity at Campi Flegrei: 137 earthquakes and 2 swarms
From 24 to 30 November 2025 the INGV located at the Campi Flegrei 137 earthquakeswith a magnitude between 0.0 and 3.3. Of these tremors, 55 were recorded during 2 seismic swarms:
- The first swarm began at 10:09 p.m 25/11/2025 in the Solfatara area, with 31 earthquakes of maximum magnitude 3.3.
- The second swarm started at 06:28 am 28/11/2025 in the area of Agnanowith 24 earthquakes of maximum magnitude 2.2.
As is usual in the Campi Flegrei, the tremors had a reduced depth, typical of bradyseismic seismicity which is caused by the rising of the ground and not by the activation of faults. In particular, hypocenters were detected at a depth between 0.25km And 4.25km.
Looking instead at the geochemical parameters, the already known heating and pressurization trends of the hydrothermal system are confirmed. In the Pisciarelli area, the temperature of the fumarole remains at an average value of 93°C. In the area of the Solfatara crater, however, the main fumarole (BG) confirms its increasing trend, with average values of ~173°C.
Bradyseism and soil uplift: the data
From the point of view of bradyseism, starting from 10 October 2025 the INGV has recorded a increase in ground lifting speedwith an average monthly value that has at first reached 20±5 mm/month in the previous ones, and then settled at the current ones 25±3 mm/month.
This acceleration therefore marks a increase compared to 15 ± 3 mm/month observed from early April to mid-October. Since January 2025, the total lift recorded at the RITE GNSS station (Rione Terra) is approximately 20cm.
The latest bulletin on the Campi Flegrei in summary
In summary, the data from the latest weekly bulletin on the monitoring of the Campi Flegrei indicate:
- Seismicity: 137 earthquakes (Mdmax 3.3), a slight increase compared to 110 (Mdmax 3.0) the previous week.
- Swarms: two seismic swarms recorded on 25/11 and 28/11, for a total of 55 tremors.
- Soil lifting: the average speed is confirmed at 25 ± 3 mm/month, up compared to 15 ± 3 mm/month in the period April-October 2025.
- Geochemistry: Stable parameters, with the Pisciarelli fumarole at 93 °C and the Solfatara at 173 °C.
