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Etna, the top craters, the adventive ones and the Bove Valley
With a total volume of 600 km cubic, an height of 3,348 metres on sea level, Etna is the highest active volcano in Europe. The slopes of Etna accommodate more than 250 adventive cones that were once active craters opened at various altitudes. Certainly among the most famous craters we have the "Monti Rossi", that opened themselves in 1669 at the altitude of 800 m. above sea-level and the "Silvestri", that opened themselves in 1892 at about 2000 m above sea-level. On the top of Etna we observe four craters with open duct, called: Bocca Nuova (New Mouth), Voragine (Abyss), South-East Crater, North-East Crater. Each of them has a middle diameter of 250 meters. |
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The east part of the volcano accommodates the Bove Valley, a caldera which developed about 10,000 years ago, whose dimensions are about 10 km x 7 km, and that is about 900 meters deep.
The Bove Valley developed after an impressive collapse of the caldera. Today is still possible to notice the geological structure distinctly, that overbearingly dominates the landscape of the East side of Etna. |
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Short description of the formation and evolution of Etna
During the first phase of formation of Etna, occurred among 600,000 and 500,000 years ago, there were big submarine eruptions that put particular sorts of lava called "toleiti" and that formed in the area of Acicastello (CT) the so-called "pillow lavas" or "pillows". During the second phase of formation, occurred among 150,000 and 80,000 years ago, a great "shield" volcano developed and put in that place basaltic lavas.
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In the third phase different "stratum-volcanoes" formed/grew up on the pre-existent "shield" volcano (Trifoglietto and Mongibello antico). The most of eruptions are historically occurred owing to the fractures that are on the slopes of Etna. |
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Typology of lavas on Etna: basalt; content in Silica = about 52 %. High content in Iron, Magnesium, Calcium. The most of eruptive events on Etna is characterized by "strombolian" phases followed by lava flows which develop up to downhill at the lowest altitudes.
Principal eruptions of Etna: 1669 - 1792 - 93 - 1852 - 53 - 1886 - 1892 - 1910 - 1911 - 1923 - 1928 - 1950-51 - 1971 - 1979 - 1981 - 1983 - 1985 - 1991-93 - 2001 - 2002-03 - 2004 - 2006 |
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