Facts About Mount Vesuvius

Mount Vesuvius is not currently erupting and is better known for its conspicuous presence amidst the beautiful Bay of Naples. Mount Vesuvius is responsible for the destruction of the Roman cities of Herculaneum and Pompeii in AD 79. Mount Vesuvius lies at the boundary convergent to the African plate and the Eurasian plate.

Mount Vesuvius is regarded as one of the most dangerous volcanoes in the world because of the potential danger it poses to the population of 3,000,000 people living close to it. In fact, it is the most densely populated volcanic region in the world.

Mount Vesuvius is a distinct hump-backed mountain, with a large cone that is partially encircled by the steep caldera. This rim was caused by the collapse of the much higher structure - Monte Somma. This large cone or as the locals call it – the Gran Cono was the result of the 79 eruption. This is also the reason why Mount Vesuvius is referred to as Somma-Vesuvius or Somma-Vesuvio. The term ‘somma’ stands for ‘volcano with a summit caldera surrounding a newer cone’.

The height of the main cone is 1,281 m or 4,202 ft! The slopes of the mountain are scarred by lava flows; nevertheless, they are heavily vegetated. At higher altitudes there are scrubs, while vineyards adorn the lower plains.

Vesuvius is regarded as an active volcano even though it produces little or no steam at all that escapes from the vents at the bottom of the crater. The lava is composed of adesite, viscous in nature. The whole of Mount Vesuvius comprises layers of lava, volcanic ash and pumice.

Mount Vesuvius was formed due to the African plate being pushed beneath the Eurasian plate. The heated crust material melted into a type of liquid rock and because the magma was less dense than the surrounding rock, it was pushed upward, producing the volcano.

Mount Vesuvius is the only volcano within the Campanian Volcanic Arc to have erupted within recent history. Many others are either extinct or have not erupted for tens of thousands of years. The Mount Vesuvius mountain started forming around 25,000 years ago and the lowest layer of eruption material lies on top of the 34,000 year-old Campanian Ignimbrite.

The eruptions at Mount Vesuvius vary greatly in severity and are characterized by explosive outbursts. Several times, the eruptions have been large enough to blanket the whole of southern Europe in ash. In fact, in the 472 and 1631 eruptions, Mount Vesuvius has gone on record for the ash falling as far away as Constantinople in Istanbul – a good 1,200 km away!

Mount Vesuvius was built up by a series of lava flows and a number of smaller explosive eruptions interspersed in-between. However, the style of eruption changed to large explosive plinian eruptions, which are each named tephra deposits produced by them.

The mountain is on record as ‘quiet’ for hundreds of years and was described as ‘covered with vineyards and gardens’. However, the top remained craggy. Mount Vesuvius, within the large circle of almost perpendicular cliffs was the encampment site of Spartacus in 73 BC.

Mount Vesuvius has many references to its existence. The historian Strabo described the mountain in Geographica as a predominantly flat and barren summit with sooty, ash-coloured rocks. He also credited the fertility of the surrounding slopes to the volcanic activity.

Pompeii, located around the base of Mount Vesuvius, had a substantial agrarian dependent population. During the 79 eruption, which lasted for nearly 19 hours, the volcano released about 4 cubic kilometres of ash and rock and about 10 ft of tephra that settled over Pompeii.

The eruption of Vesuvius on the 24th and 25th of August, 79, unfolded Plinian and Pelean phases. The former lasted eighteen to twenty hours, producing a rain of pumice southward of the cone; while the latter reached as far as Misenum and was largely concentrated to the west and northwest.

Pompeii and Herculaneum were never rebuilt. The towns' locations were accidentally rediscovered in the 18th century. The area around Vesuvius is now open to visitors as a national park.