Points of Interest

Vesuvius cone from Boscotrecase
Vesuvius cone from Boscotrecase

The Volcano

Vesuvius is a characteristic example of a volcano in a volcano made by an outer broken cone, Mt. Somma, which has an almost completely destroyed crater belt. In it there is a smaller cone, the Vesuvius, divided from the former by a depression called Valle del Gigante, a part of the ancient caldera where subsequently, probably during the 79 AD eruption, the Gran Cono or Vesuvius arose.
Valle del Gigante is divided into two parts: Atrio del Cavallo in the west, and Valle dell'Inferno in the east. The northern part of Somma's ancient crater is well preserved, since it has been protected from the volcano's devastating violence by the height of the internal wall which prevented the lava from moving downslope. The slopes are furrowed by deep radial gorges produced by the erosion of the meteoric waters. The whole section is then characterized by dark volcanic rock spikes. The old crater edge is formed by a series of summits called "cognoli".
While the height of mount Somma and its profile have remained unchanged for centuries, the height and the profile of the Vesuvius have suffered considerable variations caused by the following eruptions, with raisings and lowerings.
The Vesuvius is a characteristic polygenic and mixed volcano: this means that it consists of lava of different chemical composition (for example trachytes, tephrites, leucitites) and formed both by lava flows and by pyroclastic deposits. All the areas lying on the mountain slopes are formed by soils transported by mudflows moving downslope in the rainy seasons through deep and narrow gorges called beds or more commonly "lagni". The high embankments are formed by piles of lavic scoriae, which precipitated in incandescent state and spread towards the lower slopes, being precious for the vegetation thanks to their fertile material, rich in silicium and potassium.


At the beginning of the Quaternary period (the second eruptive phase of the Flegrei), an eruption of trachytes gave origin to the primitive Mt. Somma; it was followed by further eruptions which took place between 6,000 and 3,000 BC and between 3,000 BC and the Christian era, causing above all leucitic basalt emissions. Later, after a long period of rest, the volcanic activity began again with tremors which preceded, starting from February 5th, 63 AD (the earthquake described by Seneca), the terrible eruption which took place on August 24th, 79 AD, during which the three towns of Ercolano, Pompei, and Stabia were completely destroyed and buried by a thick blanket of ashes, lapilli, and lava. Some scientists assert that this eruption, called "Plinian" eruption, gave origin to the present Gran Cono of the Vesuvius. However, it was the first historically dated and documented eruption in a famous letter to Tacitus written by Pliny the Younger, who during the cataclysm lost his uncle Pliny the Elder, victim of his naturalistic passion. Among the subsequent eruptions, we remember those of the years 202, 472, 685, 1036, 1139, and the very violent one of December 16th, 1631 during which most of the villages situated at the foot of the volcano were destroyed and about 40,000 people died: on this occasion, the lava reached the sea.
The Vesuvius was active again during the 17th, 18th, and 19th centuries (1822, 1855, 1858, 1861, 1872). Other eruptions followed, and the crater profile was completely transformed by them. After the violent paroxysm of 1906, during which millions of cubic metres of lava were erupted, a fearful crateric chasm formed in the Gran Cono. The last eruption took place in March 1944: 21 million cubic metres of lava erupted, a number of villages were destroyed, and the ashed reached Albania. Since then, the volcano has no longer erupted, although frequent seismic phenomena demonstrate that it is a dormant volcano. In the past, the volcano has been object of careful studies dealing with the eruption forecasting, studies which are still carried out today and which do not foresee any sudden awakening. The Volcanological Observatory belongs not only the history of the volcano, but also to the world volcanology; it is situated in the observatory zone in the high part of the Town of Ercolano, within the Park territory. It is easy to reach it by following the provincial road climbing to the crater and turning right at the Hotel Eremo. It was built in the 19th century, and it was the first volcanological observatory in the world, the place where the first seismic and volcanological researches took place, and where different instruments of measure were used. Among its directors there are important scientists such as Palmieri, Melloni, and Mercalli. It houses a small museum of scientific instruments used in the past to study earthquakes and volcanoes.


The Park Municipalities

The Municipalities lying at the National Park borders are 13, all within the Province of Naples. The total inhabitants are 361,783 (the reference year is 1996).

(the following links lead to Italian texts)

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