To the Phlegraean Fields seismicity is increasing again, even if the earthquake shocks are confirmed to be of low intensity: 166 earthquakes Of maximum magnitude 2.5 recorded in the week between 6 and 12 October, of which 81 occurred during 5 seismic swarms. This is therefore a slight increase compared to the 125 earthquakes localized in the last week: on the contrary, the lifting of the ground due to the bradyseism remained unchanged, with a rate of 15 ±3 mm per month, and the geochemical parameters confirm the long-term trend, with the Pisciarelli fumarole recording an average temperature of ~94°C.
Despite a greater number of earthquakes detected, there is no need to worry: in the weekly bulletin the INGV did not highlight elements that can suggest evolutions significant in the short term.
5 seismic swarms and 166 earthquakes in the Campi Flegrei in the last week
From 6 to 12 October the INGV located at the Campi Flegrei 166 earthquakeswith a magnitude between 0.0 and 2.5. Among these, 81 tremors were recorded during five seismic swarms:
- The first seismic swarm it started at 06:05 am 06/10with a total of 7 earthquakes of maximum magnitude 1.5which occurred in the area of
Solfatara. - The second it started at 11:46 am 08/10with 5 earthquakes of maximum magnitude 1.7which occurred in the Pozzuoli-Solfatara area.
- The third it started at 02:05 am 11/10, with 17 earthquakes of maximum magnitude 1.8which occurred in the area
Pozzuoli-Solfatara. - The fourth it started at 2.33pm 11/10with 26 earthquakes of maximum magnitude 1.7which occurred in the Pozzuoli-Solfatara area;
- The fifth it started at 3.01pm 12/10with 26 earthquakes of maximum magnitude 2.5which occurred in the Solfatara area.
As often happens in areas such as the Phlegraean one, the tremors have 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 0.58 km and 2.97 km.
From the point of view of geochemistryhowever, the parameters are confirmed in line with the trends of the area, both 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.
Data on bradyseism and ground uplift
Looking instead at bradyseism, the average speed of ground rise remained unchanged with a rate of 15±3 mm per montha speed that has been stable since the beginning of April and a clear decrease compared to the average 30 millimeters per month recorded between mid-February and the end of March, but an increase 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 34.5 centimetres.
The latest bulletin on the Campi Flegrei in summary
The latest weekly bulletin on the monitoring of the Campi Flegrei did not highlight any particular signs of short-term evolution of the situation in the area. In particular, three parameters were taken into consideration:
- Seismicity: seismicity is increasing again, even if earthquakes remain of low intensity. In total, they were registered 166 earthquakes of maximum magnitude 2.5, 81 of which occurred during 5 seismic swarms.
- Soil lifting: stable a 15 ± 3mm per month, constant value since the beginning of April.
- Geochemistry: stable parameters without variations significant compared to the already known trends of heating of the hydrothermal system and increase in gas flows emitted from the subsoil.
