Why does Italy have volcanoes


Italy - volcanic provinces and causes of volcanism

The volcanoes of Italy are spread over 4 volcanic provinces: the first comprises the volcanic chain along the Apennines with the volcanoes in Tuscany and Vesuvius, the second the Aeolian Islands in the Tyrrhenian Sea off Sicily. The third volcanic province is Mount Etna in the east of Sicily and the fourth volcanic group can be found south of Sicily in the "Strait of Sicily".

Basically, the clash of the continental plates of Africa and Europe is responsible for volcanism in Italy. Strictly speaking, the floor of the eastern Mediterranean has broken up into several small plates that are assigned to Africa. The Ionian plate is pressed against the mainland, which belongs to Europe, off the Adriatic coast of Italy. The ionic plate dips into the earth's mantle and partially melts. This creates magmas that rise in the area of ​​the west coast of southern Italy and in the Tyrrhenian Sea and form volcanoes.

Another result of the plate collision is the folding of the Alps and the Apennines. The latter mountain range runs in a north-south direction over most of the Italian mainland.
The Alps form a mountain range running west-east. For a long time, the subduction of crustal material along the plate boundaries was considered the main cause of volcanism in Italy. Characteristics of the volcanoes and the lava composition that differed from this were for a long time explained by the contamination of calcareous crustal material; a theory that is out of date today. Rather, a number of regional tectonic peculiarities seem to be responsible for the very different types of volcanoes in Italy. A confused juxtaposition of subduction of smaller lithospheric plates, rift formation and local fault zones gave rise to various origins theories that have not yet been fully deciphered.

Images volcanoes in Italy

Ash cloud from the eruption of Mount Etna in 2001

3 D radar image of the submarine volcano Marsili

False color image of Vesuvius

The volcanoes along the Apennines are said to have arisen through a combination of subduction and simultaneous "back-arc rifting" in the interior of the country. The best-known representatives of this volcanic province are Vesuvius and Campi Flegrei. Further volcanoes like Monte Amiata, Vulsini and Cimino in Tuscany are less known and were not active in historical times. Nevertheless, there are post-volcanic phenomena such as hot springs and fumaroles in Tuscany.

The volcanoes of the Aeolian Islands, especially Stromboli and Vulcano, can be traced back to the subduction of part of the African plate; they are therefore directly related to the volcanic arch of the Aegean islands, to which the caldera of Santorini also belongs

The submarine Marsili volcano in the South Tyrrhenian Sea, on the other hand, seems to be the product of an oceanic ridge and thus has similarities to the volcanoes of the Azores. The summit of this volcano is 450 m below sea level. Its base is located in a water depth of 3000 meters. The volcano is classified as active and volcanologists found that its flank is very unstable. In the event of an outbreak, the researchers expect large landslides that could trigger tsunamis. Since the volcano is only 140 km off the coast of Calabria, such a tsunami could have catastrophic consequences. The major cities of Naples and Rome would be particularly affected.

The situation on Etna is even more varied: on the one hand, it extracts basaltic lava, but on the other hand, it also produces an intermediate type of lava. A pure subduction theory is out of the question here. Etna is located on a complex fault system, on which Sicily broke into many smaller plates. It is possible that basaltic magma from the earth's mantle is looking for a path along the fault zones, while at the same time molten crust material that was previously subducted rises.

The fourth volcanic province in southwest Sicily owes its existence to an underwater rift system, similar to the East African Rift Valley. The last eruption occurred here in 1891; A submarine eruption occurred off the island of Pantelleria.

The most famous volcanic eruption in Italy is likely to have been the eruption of Vesuvius, which destroyed the ancient city of Pompeii in 79 AD. The excavated ruined city attracts 2 million visitors annually.
Pompeii was on the Gulf of Naples in the Campania region. Herculeum and Stabiae were also buried in the eruption. The city, inhabited by Etruscans, Greeks and Romans, was buried under the lava avalanches, but at the same time it was preserved. From the 18th century, excavations began with valuable archaeological finds. Today researchers assume that an earthquake already favored the eruption in AD 62. Ultimately, the chimney was burst by a strong negative pressure, the Vesuvius threw ash and pumice stone. The eruption also hurled lava outwards. The people were killed by flying stones, suffocated from the poisonous gases or were overrun by the glowing avalanches.

Status 2011

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