Vesuvius' Shadow: A Major Volcanic Blast Could Threaten Naples
Gramling, C., Science News
When Italy's Mount Vesuvius begins to rumble again, nearby Naples maybe in danger, a new study shows. In 4,000-year-old ash beds buried under the city, researchers have uncovered the first geologic evidence that the volcano's power could extend so far--and they warn that the city's hazard planners should take heed.
The 25,000-year-old volcano has had eight major explosive eruptions in recorded history, including the blast in A.D. 79 that buried Pompeii in ash, says volcanologist Michael Sheridan of the State University of New York at Buffalo. Violent explosions of ash and gases have been interspersed with dozens of less dramatic lava flows.
The most powerful eruption recorded occurred around 1780 B.C., sending billowing clouds of ash far to the northwest. Sheridan and his colleagues at the Vesuvius Observatory in Naples and the Universita degli Studi di Napoli Federieo II speculated that Naples, 15 kilometers from Mount Vesuvius, might have been in the path of that blast. The researchers dug under the city's paved streets to search for evidence of the eruption.
They found signs of a "prehistoric catastrophe" both in the city and in neighboring villages, Sheridan says. Within Naples' current metropolitan area, the researchers uncovered 3-meter-thick ash deposits from the eruption. They probably resulted from settling clouds of dry ash followed by denser lahars, deadly flows of water-saturated ash and rock, Sheridan adds. …