Magnitude 4.7 earthquake hits Naples' Campi Flegrei, strongest in 40 years, leaves 21 injured

Earthquake and immediate impact

At 19:46 local time on July 31, a magnitude 4.7 earthquake struck the Campi Flegrei area west of Naples. The National Institute of Geophysics and Volcanology placed the epicenter within the Phlegraean Fields supervolcano caldera, at a depth of 3 kilometers. The tremor was felt strongly across the city, its province, and the islands of Procida and Ischia. Many residents rushed out of their homes in fear. About an hour later, a 2.6 aftershock was recorded, followed by dozens of smaller tremors throughout the night. The quake was the most powerful in the region in 40 years, surpassing previous events tied to ongoing bradyseism in the Pozzuoli area.

Casualties and damage

Italian civil protection authorities reported 21 people injured by early August 1, two of them seriously. The evening of the quake, only four minor injuries had been tallied. In Pozzuoli, a building facade collapsed, and cornices and plaster fell in other areas. Cars were damaged by falling debris. A high-voltage pylon operated by Terna toppled, causing power outages, and E-Distribuzione technicians rerouted electricity to affected customers. On the island of Procida, a brief blackout was reported, and on Ischia, residents in areas like Ischia Porto, Barano, and Casamicciola felt the shaking without reports of significant damage. The fire brigade received calls about stuck elevators and downed power lines.

Rail network disruptions

Rail traffic at the Naples hub was suspended immediately after the quake to allow Rete Ferroviaria Italiana inspectors to check track conditions. High-speed, intercity, and regional trains were affected. Trenitalia reported that some trains were diverted to alternative routes, and regional services faced cancellations and route restrictions, with delays reaching up to 380 minutes. Circulation resumed around 1:30 a.m. after the infrastructure was deemed safe.

Official response

Prefect of Naples Michele di Bari convened a coordination meeting at the Pozzuoli Civil Protection Operations Center with the mayor and personnel from law enforcement, civil protection, and health services. He stressed the need for continued checks and later traveled to Bacoli. In Procida, mayor Luigi Muro activated the local Civil Protection center, and by morning authorities had confirmed no significant damage on the island despite widespread alarm.

Geological context

The Campi Flegrei, a vast caldera, is Europe's largest active supervolcano. It has been in a phase of ground uplift and small seismic events for some time. The July 31 tremor occurred in a shallow area of the caldera, and volcanologists continue to monitor activity closely for any further signs of unrest.