Italy’s Rumbling Supervolcano Has Half a Million Residents on Edge

Campi Flegrei, not far from ill-fated Pompeii, has had 2,500 earthquakes since August

POZZUOLI, Italy—Diners at restaurants around this tiny port streamed outside while moored boats and an eight-story crane began to sway. Some cats milled about, unfazed by the umpteenth tremor to hit this picturesque seaside town.

“You feel that? It’s nonstop earthquakes here,” said Luca Averna, a part-time fisherman, as he paused from working on his small boat during the 3.6-magnitude tremor. “We’re used to it, but that doesn’t mean we aren’t afraid.”