VESUVIUS, the volcano that obliterated Pompeii in AD79, has the capacity to make that event look like a sideshow, volcanologists have found.

Nearly 4,000 years ago it erupted far more violently, destroying the area of present-day Naples and sending a Bronze Age population fleeing for their lives.

Michael Sheridan, of the University of Buffalo, and a group of Italian colleagues investigated the remains of the eruption, called the Avellino catastrophe after a village that bore the brunt of it.

They studied the well-preserved remains of Nola, another village about ten miles (16 km) northeast of Vesuvius, where volcanic deposits overwhelmed the settlement 3,780 years ago. They also found evidence that thousands of people fled as the eruption began, leaving footprints solidified in cooling ash.

Most apparently escaped. Close to Nola the scientists found skeletons of a man and a woman under a metre-deep bed of volcanic debris. The ground was littered with fragments of rock up to 4 in (11 cm) in diameter that showered down at 150 mph in a lethal hailstorm.

Writing in Proceedings of the National Academy of Sciences, the team say that before the eruption the population of the area would have been low — only a few tens of thousands, compared with today’s millions. The fact that thousands of paths can be traced in the ash, all travelling north-northwest away from the eruption, indicates that most had time to make an escape.

Some people returned later and tried to set up settlements again, but the lack of archaeological evidence indicates that they failed, and that the land proved to be uninhabitable for hundreds of years.

A similar eruption today would bring extreme devastation, extending into the densely populated areas of Naples, according to the team. Within the city, they report, there is a bed of ash up to 9 ft (3m) deep, the result of the eruption 4,000 years ago.

Computer modelling shows that the same event today would be capable of overrunning Naples and causing total devastation in a region up to eight miles from Vesuvius.

Ten miles away the majority of people would survive, but some would be suffocated by the fine dust cloud.

At least three million people live within the area destroyed by the Avellino eruption, and the scientists say that planning for an orderly evacuation needs to be based on what happened then, not on the events of AD79. The nature of the eruption makes escape possible, as it did then, because it would probably start slowly. Vesuvius erupts in a characteristic fashion, known as a Plinian eruption after Pliny the Younger, who described the events of AD79. The early phases of the eruption are impressive, but not necessarily lethal. The warning period can be days or even months before the final cataclysmic event occurs.

The team believes that today’s early-warning systems would be able to provide a warning “at least weeks” before an eruption, allowing the evacuation plan to be implemented and people to be saved.

However, how much would remain of Naples if such an event occurred — and the long-term future of those who managed to escape — remains uncertain.

MOST DESTRUCTIVE VOLCANOES

• The eruption of Tambora, on the Indonesian island of Sumbawa, in 1815 is the most violent on record. It affected global weather systems and, in Europe, 1816 was known as a “year without summer”
  
  
• The Nevado del Ruiz volcano in Colombia erupted on November 13, 1985. More than 25,000 died
  
  
• The eruption of Pelée in 1902, on the Caribbean island of Martinique, killed 26,000 people
  
  
• Krakatoa, in Indonesia, erupted in August 1883 and caused a tsunami in which more than 36,000 died