Mountain eruptioned welsy an explanation text

Natural Phenomenon

Etna Mountain

Etna is Europe's most powerful volcano. With a height of 3352 meters, it dominates the eastern coast of Sicily (Map). Again and again was the case on its flanks

dramatic: Earthquakes shake the region, ash clouds darken the sky and lava flows destroyed homes high on the slopes of the volcano. It is not surprising that the Etna was known in ancient ages as the residence of various gods. Only few decades ago, the people were behind what causes the mysterious natural phenomena in reality.

The ground mountain of Sicily is anything but stable. In the Mediterranean Sea south of the island runs the plate boundary between Africa and Europe. A part of the African plate pushes under the European continent and is melted in the mantle. Along the west coast of Italy the ridge of the Apennines pushes on. This leads to a host structure with a Rift.

After the great eruption of 1669, the maincrater collapsed. In this way the resulting caldera filled with scoria during an couple of minor eruptions. It formed the plateau Piano del Lago. 1788, the present central cone began to grow up. At its base it has now a diameter of 1000 meters, at the summit of 500 meters. It rises 400 meters above the plateau. In a large eruption of 1911, the Northeast-crater-cone was born. The Bocca Nuova originated in 1968. Two years later, this new crater already had a diameter of 100 meters. The Voragine, the real main crater, was separated by a narrow ridge of the Bocca Nuova. For the most part this crater filled during the high peaks of activity in the years 1999 and 2000. It remained two smaller craters. The thin line between Voragine and the northwestern crater collapsed, so that was a large crater.

Along the northern coast of Sicily, the Comiso-Messina fault runs, created the Strait of Messina, and separated Scicily from the mainland. Besides these two fault zones are perpendicular to one another taken there in the basement of Mount Etna, still further, local faulting.

The eruptions, which created such craters usually conveys large amounts of magma. Storn explosions are typically for this kind of eruptions.. During one of these eruptions a conduct-system was opened in 1669, deep at the base of the

volcano. A column of seven craters was formed close to Nicolosi. Lava flows destroyed the city Malpasso and even cut a path through Catania before the

lava flowed into the sea. In that eruption the magmachamber was emptied and collapsed. A caldera was formed.

Etna is one of the best understood volcanoes in the world. It is located in a densely populated area, and its lava flows threaten the goods and chattels of

thousands.

This complex tectonic situation favors the emergence and rise of magma. Moreover occur along the fault zones of major earthquakes over again - like that of 28 Dezember 1908th In this gr600,000 years ago, volcanism began in the area of Mount Etna. He first manifested itself on the coast at Aci Trezza. The Kyklopen-rocks off the coast are basaltic vents plug of an eroded volcano. The formation of the actual Etna began about 100,000 years ago, at the beginning of the Quaternary. The original Etna already promoted Trachybasalts and trachyandesits, similar to the current volcano.

The Bocca Nuova originated in 1968. Two years later, this new crater already had a

diameter of 100 meters. The Voragine, the real main crater, was separated by a narrow ridge of the Bocca Nuova. For the most part

this crater filled during the high peaks of activity in the years 1999 and 2000. It

remained two smaller craters. The thin line between Voragine and the northwestern

crater collapsed, so that was a large crater. The greatest changes occurred in the past few years on the southwest crater. His birth was in

1979. Since then, it was grown up from a column, to a 300 m high crater-come with

several vents on the top. The activity of recent years has focused on these crater. .

. This chamber has a sponge-like structure: The magma collects in small pockets in the pores of the rocks.Phases ongoing activities are evidence of an open vent system and a more or less high magmalevel in the conduct. If the magmalevel is deep, the volcano is steaming only.

When it comes to high magmalevels strombolian eruptions occurs from the central crater system. An imbalance of this condition results in lateral flank eruptions. The magma chooses its way along existing fault zones in the volcano, starting from the central conduct system. In eccentric eruptions the magma seeking one way independently of the central conduct.

Only when Magma blazes a new path and is expecting a flank eruption, the scientists will receive the unmistakable signs of an impending eruption. Etna is one of the best understood volcanoes in the world.

Phases ongoing activities are evidence of an open vent system

and a more or less high magmalevel in the conduct. If the magmalevel is deep, the volcano

is steaming only. When it comes to high magmalevels strombolian

eruptions occurs from the central crater system.