IntroductionVesuvius ("Vesuvio" in Italian) is probably not only the most famous, but also one, if not the most dangerous volcano on Earth. The first eyewitness account of a volcanic eruption that has been preserved has come to us from Vesuvius: In 79 AD, after a century-long slumber, the volcano woke up with terrifying power in an eruption that buried several Roman towns like Pompeii and Herculaneum under several meters of ash. Today, parts of these cities have been excavated and are among the most remarkable archaeological sites of the world, allowing us to have an excellent view on Roman life and culture, where time and life had been frozen in a moment.
Geologically, Mt. Vesuvius, or more correctly the Somma-Vesuvius complex, is about 400,000 years old, as dating of lava sampled drilled from over 1,300 m depth have shown. Present-day Vesuvius is a medium-sized typical stratovolcano volcano reaching a height of 1,281 m a.s.l. It comprises the older volcano, the Somma, whose summit collapsed (likely during the 79 AD eruption), creating a caldera, and the younger volcano, Vesuvius, which since then has re-grown inside this caldera and formed a new cone. Although in a dormant phase at present, Vesuvius is an extremely active volcano and particular for its unusually varied style of activity: it ranges from Hawaiian-style emission of very liquid lava, extreme lava fountains, lava lakes and lava flows, over Strombolian and Vulcanian eruptions to violently explosive, Plinian eruptions that produce large pyroclastic flows.
When one thinks about Vesuvius volcano today, one aspect is eminent: due to the dense population surrounding it, and ever climbing higher and higher up on its slopes, it is certainly among Earth's most dangerous volcanoes. It is estimated that ore than 500,000 people live in the zone immediately threatened by a future eruption. When this happens is not known; it is possible that Vesuvius has entered into one of its typically century-long lasting phases of dormancy, but volcanoes can be unpredictable. The situation in the Gulf of Naples is further complicated by the presence of another highly active, and potentially as dangerous volcano: the Campi Flegrei, located immediately under a large part of the modern city of Naples proper.
Vesuvius volcano near Naples, Italy, seen from the air. The rim of the remnant of the older Somma volcano which collapsed in the 79 AD Plinian eruption is clearly visible...
On the crater rim of Vesuvius volcano, with steaming vents in the background. (Photo: Tom Pfeiffer)
Vesuvius volcano aerial (June 2017) (Photo: Martin Rietze)
The excavations of the Roman town of Ercolaneo buried by pyroclastic flows from Vesuvius volcano in the 79 AD eruption. (Photo: Tom Pfeiffer)
Voyages au volcan Vesuvius :Volcans d'Italie - le Grand Tour (15 jours d'expédition du Vésuve à l’Etna)
See also: Sentinel hub | Landsat 8 | NASA FIRMS