After the strong Earthquake of magnitude 4.6 of 30 June, for the Flegrei fields, the seismic activity is slightly increased: according to what reported in the last weekly bulletin of the Vesuvian Observatory of the Ingv, in the week from 30 June to 6 July 2025 they were recorded 56 Earthquake shockswith maximum magnitude 4.6. In total, the monitoring network in the Flegrea area recorded 513 Earthquake shocks in June.
The week before the monitoring network installed on the volcanic caldera had recorded 38 earthquake shocks, with a maximum magnitude of 1.9: The seismicity, therefore, is slightly increased. The soil lifting due to bradisism, it has remained stable, with an average speed of about 15 mm per month, In line with the trend that began the first days of April.
Also for i Geochimic parameters No significant variations have been reported: an average temperature of 94 ° C, close to the condensation of the smoky fluid.
The data on earthquakes and geochemics of the Flegrei Campi
In the period June 30th – July 6th 2025 56 earthquakes were located with magnitude between 0.0 And 4.6the latter recorded on 30 June during one seismic swarm consisting of 13 earthquakes that occurred in Gulf of Pozzuoli.
As usual at the Flegrei fields, the 56 shocks took place at a very low depth, between 2.29 km And 4.17 km.
As for the Geochimic parametersno significant variations have been reported. Also in the Pisciarelli area, the values of CO flow2 From the ground they did not show significant variations after the rapid decrease in the values measured in the previous weeks. In any case, this decrease is to be considered local and will be verified with the next acquired data.
Stable bradisism at the Flegrei fields: the data on the lifting of the soil
The phenomenon of bradyseism It continues in line with the values of the previous weeks: from the beginning of April 2025 we continue to record an average land lifting speed around 15 mm per month. It is a rate halved compared to the average of 30 mm per month recorded between mid -February and late March.
From January 2024, the lifting recorded at the station GNSS of Rite (Rione Terra) is approximately 30 cm.
Weekly bulletin of 8 July 2025: the synthesis
In summary, here’s what emerged from the last weekly bulletin of the Vesuvian Observatory of the Ingv:
- Seismicity: seismic activity is slightly increased compared to the previous week, with a total of 56 earthquake shocks recorded, with a maximum magnitude of 4.6, recorded on 30 June.
- Soil deformation: the average land lifting speed (due to bradisism) remained stable at 15 mm per month, in line with the trend that began the first days of April 2025.
- Geochemistry: there are no significant variations of geochemical parameters compared to the trends of increased flows and heating of the hydrothermal system already known. The average temperature recorded at Pisciarelli’s main fumarola is approximately 94 ° C.
