Mount Etna erupts and is active because it lies on the subduction fault boundary between the African and Eurasian tectonic plates as well as the fault between the African and the Ionian microplate. The Ionian plate is tilted backward, allowing space for mantle magma to well up to the surface.
Experts believe that the position of Mount Etna is critical to its activity. While most volcanic lava is made up of melted crust, the lava from Mount Etna comes directly from the mantle below the crust because of the way the African and Eurasian plates and Ionian microplate are positioned. Experts also theorize that this mantle magma wells up from a crack in the African plate that is situated just beneath Mount Etna. Another theory suggests that Mount Etna lies on a hotspot.
Not only is Mount Etna the largest active volcano in Italy, it also boasts the longest history of eruptions of any volcano in the world. Some of the first records of its eruptions date back to 425 B.C. Other records state that the volcano erupted in 122 B.C., 40 A.D., 1169, 1185 and 1669. In the 1900s it erupted three separate times, completely destroying Mascali as well as nearby land.Learn More
The three volcanoes of Krakatoa Island – Perboewatan, Danan and Rakata – are thought to be extinct following the cataclysmic 1883 eruption. The first two volcanoes, Perboewatan and Danan, were completely destroyed in the eruption, along with two-thirds of Krakatoa Island.Full Answer >
Popular volcanic mountain names are Mount St. Helens in the United States mainland, Mauna Loa in Hawaii, Mount Rainier in Washington, Mount Edziza in British Columbia and Hoodoo Mountain in Canada. Many of the highest volcanoes are located in Chile and Argentina, such as Ojos del Salado, Tacora, Tromen, Copahue and Risco Plateado.Full Answer >
Mount Shasta's magma is composed of basalts and basaltic andesite. These two types of magma are very runny, forming large shield cones and steep, loose tephra cones. The basaltic andesites at Mount Shasta are unusually rich in magnesium.Full Answer >
Volcanologists wear heavy boots, long-sleeved shirts and heavy work gloves in order to protect their bodies from lava near a volcano. According to Oregon State University, volcanologists might also wear jeans, a rock-climbing helmet for protection and a gas mask.Full Answer >