Earthquake Swarm Strikes Campi Flegrei, Italy

A new earthquake swarm began at 14:09 UTC on August 31, 2025, in the Campi Flegrei caldera, Italy. By 07:30 UTC on September 1, 94 earthquakes were recorded, including a shallow M4.0 event near Pozzuoli at 02:55 UTC.

Italy’s National Institute of Geophysics and Volcanology (INGV) reports an ongoing earthquake swarm in the Campi Flegrei caldera that started at 14:09 UTC on August 31. as of its latest update, INGV has preliminarily counted 94 earthquakes with magnitudes up to 4.0±0.3.

The strongest event was an M4.0 earthquake at 02:55 UTC (04:55 LT local time) on September 1, at an estimated depth of 2 km (1.2 miles),with an epicenter near Pozzuoli. The sequence included two M3.3 earthquakes on August 31 at depths of 0.7 km (0.4 miles) and 1.8 km (1.1 miles), followed by several events of M2.0-M2.8 later that day. These included two M2.8 quakes at depths of 0.4 km (0.2 miles) and 0.8 km (0.5 miles) hours before the M4.0.

Residents in Pozzuoli and nearby districts reported strong shaking.