Magnitude 4.7 earthquake, strongest ever recorded at Campi Flegrei, injures 26 and displaces 300 near Naples

A magnitude 4.7 earthquake struck the Campi Flegrei volcanic area west of Naples at 19:46 on 31 July 2026, the strongest ever recorded on the available instrumental record. The tremor injured 26 people, five of whom remained hospitalised (two in serious condition), and forced about 300 residents from their homes in Pozzuoli.

The quake and immediate damage

The epicentre was in the Solfatara area at a depth of about 2.6 km. The shaking caused building collapses, including unoccupied structures, and rockfalls that damaged cars. Health services treated 21 people at the Pozzuoli hospital and five at Giugliano; five were still in hospital on Saturday, two classified code red. The Cumana railway line was suspended between Bagnoli and Torregaveta, with replacement buses deployed. Power outages were resolved within hours by rerouting electricity through undamaged network sections.

Seismic swarm and monitoring

The main shock triggered a swarm of 189 tremors over the following 24 hours, ending around 20:47 on 1 August, according to the Vesuvius Observatory of the National Institute of Geophysics and Volcanology (INGV). The intensity of the aftershocks diminished significantly; by Saturday morning about 170 events had been recorded. A quiet night followed, with only four minor tremors between midnight and 06:50 on 2 August, the strongest a magnitude 2.0.

Bradyseism: no change in parameters

The earthquake is part of a bradyseism crisis that began in 2005, characterised by slow ground uplift and gas emissions. Lucia Pappalardo, director of the Vesuvius Observatory, said all key indicators remain constant: the rate of soil uplift, CO2 flux, and magma depth at 7.8 km have not changed. The 4.7 event surpasses the previous strongest recorded shocks of magnitude 4.0 in October 1983 and March 1984. Since 2023, 11 earthquakes of magnitude 4 or above have occurred in the area.

Nothing has changed, neither for better nor for worse.

Displacement and emergency response

Fabio Ciciliano, head of the Civil Protection Department, said 300 people from 150 family units had been displaced, all residents of Pozzuoli. They were housed in facilities including the Palatrincone sports hall in Monteruscello. The prefect of Naples, Michele di Bari, convened a new meeting of the Rescue Coordination Centre on Sunday morning to review the situation and plan further interventions. Minister for Civil Protection Nello Musumeci warned that the seismic swarm was still ongoing and that further events with magnitude above 3 could occur.

Building safety and political tensions

The earthquake reignited debate over building safety. Lorenzo Benedetto, president of the Campania geologists' order, said that over 10,000 inspections had identified about 700 homes at high risk, but no applications for the state's 50% repair subsidy had been received. Many residents who applied for earlier funding were rejected because of past building abuses or bureaucratic irregularities dating back decades. The mayor of Bacoli, Josi Della Ragione, criticised delays in securing unstable cliffs.

They have had to secure the slopes for three years.

A parliamentary commission will open a dossier on a landslide at Monte Olbiano to verify whether consolidation work completed in February was regular. The government has allocated over €600 million for safety in the area, but the slow pace of interventions remains a source of friction.