A not-that-large 4.4 magnitude earthquake struck the town of Pozzuoli in southern Italy on Monday, causing minor damage to the surrounding region and the major city of Naples about 12 miles to the southeast, AFP reports on a potentially ominous warning sign from the threat under Pozzuoli: the Campi Flegrei supervolcano. The quake, at a depth of just 3 km, was just one of dozens to shake the area over the last 48 hours in a “seismic swarm” that could be a sign that magma is rising under the caldera. Or just superheated gases, if the 500,000 people living in the surrounding area are lucky.