Facts about Mount Vesuvius

The eruption that buried Pompeii spewed out lava weighing the same as 250 000 fully grown elephants per second. And there are other interesting facts about Mount Vesuvius

Walking up the spiral path to the crater of Mount Vesuvius may seem like a picnic, but I was glad when it was over. Up here in the national park on the edge of the gaping mouth of a huge crater, you sense the fumes and vapours disgorged from the pit. A slightly surreal and awe-inspiring experience considering the impact Mount Vesuvius has had on its surroundings.

This may explain why a hike on the only active volcano in mainland Europe gave me the jitters. After all, Vesuvius has erupted many times and is regarded as one of the most dangerous volcanoes in the world. And even though I know, the danger is not due to the immediate risk of a sudden deadly explosion, but to the density of the population living in nearby Naples; it is still kind of scary.

Here’s a collection of facts about Mount Vesuvius:

Fact 1: Not one, but two volcanos

What is commonly called Mount Vesuvius is in fact an amalgam of two mountains: Monte Somma and Vesuvius. The two peaks are easily distinguishable, as can be seen in the photo above.

Fact 2: 17 000 years old

The active cone of Vesuvius was constructed within a large caldera of the ancestral Monte Somma volcano, thought to have formed incrementally beginning about 17 000 years ago.

Fact 3: Classification

Mount Vesuvius is a complex stratovolcano, built by layers of hardened lava, pumice, and volcanic ash. conical volcano. Such composite volcanos have a conical shape with gentle lower slopes that rise steeply. The crater is at the summit.

Fact 4: Eight major eruptions

Eight major explosive eruptions have taken place in the last 17 000 years. Major eruptions were often accompanied by surges and large pyroclastic flows which is like an avalanche of hot toxic gasses and fluidized rock that rushes down the side of a volcano at up to 100 km/hour.

Fact 5: Roman cities buried

The major eruption that made Mount Vesuvius generally known took place on August 24th in AD 79. It buried the Roman cities Pompeii and Herculaneum.

Fact 6: Signs that an eruption were underway

Before the eruption, the area had been hit by a series of earthquakes. The most devastating of these earthquakes took place in the year 62 AD.

Fact 7: 24 hours

The eruption on the 24th, August 79 AD was said to have lasted more than 24 hours. The first rain of ash and pumice was not necessarily lethal. People who fled immediately stood a chance of survival. But most tried to weather the storm and were caught by the pyroclastic flows.

Fact 8: Death toll unknown

The eruption released a hundred thousand times the thermal energy released by the Hiroshima bombing. The remains of 1 500 people have been found, but the exact number of casualties is unknown.

Fact 9: Crushing heat

The eruption in AD 79 spewed ash, mud and rocks burying the victims under thick layers of ash. Most of the victims died instantly of extreme heat, when temperatures rose up to 300°C [570°F] and more.

Fact 10: Preserved for posterity

The casts of hot ash and pumice covering the victims helped to preserve their clothes and faces.

Fact 11: Heavy artillery

When the eruption in AD 79 was at its height, Mount Vesuvius spewed 1.5 million tons lava per second. Like shooting out 250 000 fully grown elephants each second and letting them fall through the air.

Fact 12: The name and shape of the eruption column

Volcanologists have adopted the term “Plinian” from Vesuvius to describe large volcanic eruption clouds. This is due to Pliny the Younger, who described the 79 AD eruption as a tall, “umbrella pine” shaped cloud that rose above the volcano.

Fact 13: Dangerous minerals

Most rocks erupted from Vesuvius are andesite. Andesite lava creates explosive eruptions, which makes Vesuvius especially dangerous and unpredictable.

Fact 14: Numerous eruptions

Vesuvius has erupted many times since then. The eruption in 472 was said to spew ash that ended up as far away as present day Istanbul.

Fact 15: Tax exemption

The eruptions of 512 were so severe, that people living on the the fertile slopes of Vesuvius were granted tax exemption.

Fact 16: 3 000 people killed

A major eruption in December 1631 killed around 3 000 people and buried many villages under lava flows.

Fact 17: The eruption of 1906

On April 7, 1906 Mount Vesuvius ejected more lava than ever and killed 100 people.

Fact 18: Aircraft destroyed

The last major eruption took place in March 1944. It lasted two weeks and destroyed almost 80 allied planes stationed at the Pompeii Airfield. The were no people among the casualties.

Fact 19: Dormant but dangerous

None of the later eruptions were as large or destructive as the Pompeian one, but Mt. Vesuvius is still considered one the the world’s most dangerous volcanoes.

Fact 20: In case of a new eruption

Ongoing efforts are being made to reduce the number of people living within the red zone, where there is a high risk of pyroclastic flows. Today  600 000 people are living within the red zone and the authorities have a plan for their emergency evacuation. Depending on the direction of the wind, an eruption may affect the inhabitants of large cities such as Naples, Avellino and Salerno.

In spite of this the only activity I saw during my walk along the summit rim was small clouds of dirt or steam forming at the bottom of the crater. And the souvenir geologist collection of pumice, andesite and other volcanic rocks, I’ve got stored away as a somewhere is peacefully dormant under layers of dust.

More on hiking and outdoor adventures in Italy

UNESCO World Heritage in Liguria

Hikes on Etna – the edge of an active volcano

Hike to Cava Grande del Cassibile

Hiking in Calabria