To the Phlegraean Fields seismicity drops slightly, with 135 earthquakes Of maximum magnitude 2.9 and one seismic swarm detected in the week between 13 and 19 October 2025. This is what emerges from the latest weekly bulletin published by the INGV Vesuvian Observatory: seismicity still remains high, although decreasing compared to the previous week, when 166 tremors with a maximum magnitude of 2.5 were recorded.
The lifting of the ground due to bradyseism instead it remained stable, with a rate of 15 ±3 mm per month, as did the geochemical parameters, which confirm the long-term trend, with the Pisciarelli fumarole recording an average temperature of ~94°C.
The earthquakes located in the last 7 days in the Campi Flegrei, therefore, had a modest magnitude: however, based on the data collected, INGV has excluding significant short-term developments.
Week of modest seismic activity: 135 tremors recorded
From 13 to 19 October, INGV located at the Campi Flegrei 135 earthquakeswith a magnitude between 0.0 and 2.9. Of these tremors, 50 were recorded during a seismic swarm occurred in the Pozzuoli-Cigliano areawhich began at 10.53pm on 10/18/2025 and continued until midnight on 10/19/2025, during which the M2.9 earthquake occurred.
The seismic swarm then continued until 2.39pm on 10/20/2025, with another 41 earthquakes of maximum magnitude 2.5, which will be counted in the next weekly bulletin.
As usual, the tremors had a reduced depthtypical 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 depths between 0.77 km and 2.97 km.
From the point of view of geochemistry, however, the parameters are confirmed in line with the trends of the areaboth in terms of gas flows emitted and in terms of temperature of the fumaroles. In the last week, in particular, the temperature has shown an average value of ~94°Ctemperature close to the condensation of the fumarolic fluid.
Bradyseism and soil uplift: the data
From the point of view of bradyseism, the average speed of ground rise remains unchanged with a rate of 15±3 millimeters per montha value that has been stable since the beginning of April and clearly decreasing compared to the average 30 millimeters per month recorded between mid-February and the end of March. Ground lifting, however, is increasing compared to the 10 millimeters per month recorded between the last months of 2024 and the beginning of 2025.
Since January 2024, the total uplift recorded at the RITE GNSS station (Rione Terra), at the center of the volcanic caldera, has been 35 centimetres.
The latest bulletin on the Campi Flegrei in summary
In summary, the latest weekly bulletin on the monitoring of the Campi Flegrei:
- Seismicity: from 13 to 19 October, 135 earthquakes with a maximum magnitude of 2.9 were recorded, 50 of which occurred during a seismic swarm located in the Pozzuoli-Cigliano area.
- Soil lifting: remains stable at 15 ± 3 mm per month, a constant value since the beginning of April.
- Geochemistry: stable parameters without significant variations compared to the already known trends of heating of the hydrothermal system and increase in gas flows emitted from the subsoil.
