The number of earthquakes is decreasing Phlegraean Fields with 48 earthquakes (maximum magnitude 2.3), but the geochemical activity remains on the increase, in particular the temperature of 173°C at the main fumarole in the Solfatara crater. This is what emerges from the latest weekly bulletin of the INGV Vesuvian Observatory, relating to the period from 1 to 7 December 2025. As regards the ground lifting due to bradyseism in the area, the rising speed is confirmed to be stable at 25 ± 3 millimeters per month starting October 10th.
Earthquakes decreasing in Campi Flegrei: 48 tremors and an earthquake swarm
The seismographs of the Vesuvian Observatory recorded in the reference period 48 earthquake tremors of maximum magnitude 2.3, with 7 tremors of magnitude greater than 1.0 and one seismic swarm of 8 shocks (magnitude up to 1.8) occurred on December 1st in the Pisciarelli area.
The geochemistry of the area remains stable compared to the recent trend of increase in fumaroles, with 93°C averages recorded in the Pisciarelli fumarole e 173°C in the main fumarole of the Solfatara.
Bradyseism stable: data on ground heaving
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 Rione Terra GNSS station is 20.5cm.
Summary of the latest INGV bulletin on the Campi Flegrei
In summary, the data from the latest weekly bulletin on the monitoring of the Campi Flegrei indicate:
- Seismicity: 48 earthquakes (Mdmax 2.3), a sharp decrease compared to the 137 (Mdmax 3.3) of the previous week.
- Swarms: an earthquake swarm recorded on 1/12, for a total of 8 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: Confirmation of the warming trend of the hydrothermal system, with the Solfatara fumarole stable at 173 °C.
