Overview
- A shallow magnitude 3.6 earthquake struck beneath Campi Flegrei at 4:17 a.m. Thursday, with instruments locating the epicentre near Monte Nuovo roughly 2–4 kilometres from Pozzuoli and Bacoli.
- Seismologists say the quake is part of an ongoing seismic swarm driven by bradyseism, a slow ground uplift caused by accumulating magmatic gases at a few kilometres depth.
- The volcanic field is emitting very large amounts of carbon dioxide—about 5,000 tonnes per day according to INGV—which led sensors to record dangerous CO₂ levels inside the metro tunnel and to suspend service between Napoli Campi Flegrei and Pozzuoli Solfatara.
- Local authorities convened crisis teams, ordered inspections of public buildings and infrastructure, and set up replacement bus service while reporting no injuries or major structural damage so far.
- Campi Flegrei is Europe’s largest active supervolcano with a history of large uplift episodes, the alert level remains elevated but non-emergency, and scientists say continued monitoring is needed because similar quakes and gas episodes are possible.