Brief reminder of Part 1 (without mistake ) : Volcanoes are created from eruptions of magma , originating from deep within the earth , where the movement of tectonic plates . releases the gas , then the magma , causing the volcanic eruption . There are two types of volcanic eruptions : effusive or explosive . Effusive volcanic eruptions produce abondant lava flows but are rather quiet . Explosive volcanic eruptions are very spectacular and dangerous . There are loud explosions with volcanic bombs of molten rock being throw into the air , causing large amounts of ash . Let ' s talk about the particularity of some volcanoes . Etna , locate in Sicily , is still active with more than 80 eruptions during the 20th century . Its eruptions are varied , with flows of fluid lava as well as explosive episodes . With a peek of 3350 m , it is the largest volcano in Europe . On Reunion Island , the Piton de la Fournaise is one of the most active volcanoes on the planet and probably ranks first in the world for its volume of lava . The island of Vulcano , in the north of Sicily , lies on a saebed more than 1000 metres deep , generating mud baths with therapeutic propertyes . Here , the earth ' s crust is only 12km deep . Soulphur compounds escape from every crack at high temperatures . This volcano contains aciedic magma rich in silica which hardens very quickly at the top of the chiminey . When cooled , it forms a real plug trapping the gases . The longer the volcano remains inactive , the more deadly its awakening is likely to be . The volcano ' s eruptions are made up of very pasty lava and are manifested by strong explosions of ash and blocks rising very high . In Lanzarote (Canary Islands ) , the Timanfaya volcano is the only active volcano in spite of the 1000 volcanoes present on the island . At a depth of only 13 m , its temperatures vary from 100 to 600°C . Despite the incredible spectacle they present , volcanoes are very terifying beauty whose eruptions help shape the Earth ' s surface .
