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.Know More
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 about Volcanoes
Noxious fumes and tremendous amounts of ash and molten lava spewed from Mount Etna in 1669 and killed more than 20,000 Sicilians. Just prior to this eruption, an associated earthquake killed an additional 15,000 people.Full Answer >
In March 1991 and April 1991, magma rising 20 miles beneath the surface of the Pinatubo volcano caused many earthquakes and small explosions, which destroyed parts of the volcano. Then on June 12, 1991, magma filled with gas reached the surface, and the volcano erupted.Full Answer >
While it is not yet possible to predict volcanic eruptions decades in advance, the U.S. Geological Survey’s Cascades Volcano Observatory continually monitors Mount St. Helens to gather data for more accurate short-term predictive models. According to “Future Eruptions at Mount St. Helens,” this volcano is the most likely to erupt in the Cascade Mountains of Washington again in the coming decades.Full Answer >
The largest eruption of Mount St. Helens in recent history occurred on May 18, 1980, when a cataclysmic eruption removed most of the northern face of the mountain. At 8:32 a.m. PDT, the summit collapsed into a rock debris avalanche that released a lateral gas explosion.Full Answer >