To the Phlegraean Fields there seismicity stay low for the third consecutive week: the latest weekly bulletin of the INGV Vesuvian Observatory (relating to the period from 26 January to 1 February 2026) recorded 36 earthquake tremors of maximum magnitude 1.4 (a slight increase compared to the 24 earthquakes of the previous week) and a rate of soil lifting due to bradyseism which, after a period of increase, returned to a stable value of 15 millimeters per month.
Of the 36 shocks, only 3 had magnitudes greater than 1.0at the limit of the perceptible: this, however, does not mean that in the Phlegraean area seismicity will not increase again in the coming weeks. The phenomenon of bradyseism, in fact, is not constant, but it is characterized by cycles of raising and lowering of the groundwhich lead to increased seismic activity or a period of temporary quiet.
Looking at the geochemical parameters, however, the already known warming trends are confirmed, with the temperature of the fumarole in the Solfatara crater standing at around 173°C. For now, elements that suggest significant short-term developments have been excluded.
Campi Flegrei, 36 earthquakes and only 3 tremors with a magnitude greater than 1.0
In the week from 26 January to 1 February 2026, they were recorded at the Campi Flegrei 36 earthquakesOf maximum magnitude 1.4to the limit of what is perceptible for the local population: of these, only 3 had magnitudes greater than 1.0.
Just like last week, they were not detected seismic swarms by INGV, while the depth average of the shocks was relatively lowbetween 1.51 km and 3.18 km. This happens because in the Phlegraean area, we repeat, the seismicity is due to bradyseism: In other words, earthquakes are not caused by the activation of faults, but by soil rise.
Bradyseism: soil lifting still at 15 mm per month
As of mid-December 2025, the average speed of soil lifting (due to bradyseism) it settled back to values equal to 15 ± 3 mm per monthbucking the trend after a 2-month period – officially starting on 10 October 2025 – in which lifting had increased to 25±3 mm/month.
The effect of this cumulative speed over the years has brought the total lifting recorded at the Rione Terra GNSS station (RITE) to approximately 23.5 cm from January 2025.
Once again, the geochemical parameters are confirmed in line with the already known increasing trends, both in terms of gas flows emitted and in terms of temperature of the fumaroles. In the reference week, the temperature in the Pisciarelli fumarole showed an average value of ~95°Cwhile at the main fumarole (BG) in the crater of Solfatara an average value of approximately is confirmed 173°C.
The INGV weekly bulletin in summary
In summary, the INGV in its latest weekly bulletin on the Campi Flegrei reports:
- Seismicity: it is confirmed at low values, with 36 localized earthquakes of maximum magnitude 1.4 and only 3 tremors of Md>1.0.
- Bradyseism: Soil heave rate decreasing to 15 ± 3 mm/month with total heave from January 2025 to 23.5 cm.
- Temperatures: the fumarole in the Solfatara crater is confirmed at high values (~173°C).
