Mount Etna

Mount Etna is a large active volcano located near the northeast corner of Sicily, an island found off Italy's southern tip. Rising to a height of approximately 10,900 feet (3,322 meters), Mount Etna has a long history of eruptions dating as far back as 1500 BCE. These eruptions, which typically feature spewing ash, lava fountains, and pyroclastic flows of hot gas and rock, frequently pose a serious threat to the densely populated communities found in the volcano's surrounding areas. Many of Mount Etna's historic eruptions caused widespread death and destruction. Among the most notable and deadly of these was a series of eruptions that destroyed the city of Catania and several other towns in March of 1669 CE, killing about twenty thousand people and leaving many more homeless. Since that time, Mount Etna has remained quite active, with eruptions and other volcanic activity occurring on a regular basis. Mount Etna has erupted at least 190 times since 1500 BCE and is Europe's most active volcano, erupting almost every year into the twenty-first century.

Brief History

Mount Etna has a recorded history of eruptions than stretches back further than that of any other volcano in the world. Its earliest known eruption occurred in 1500 BCE. Other early eruptions occurred in 479, 396, and 141 CE. In 122 BCE, the ash plume from a particularly large eruption blocked out the sun and left the region in darkness for days. Damage to the nearby city of Catania was so extensive that the Roman government suspended tax collection there for ten years while repairs were slowly made.

Visible from virtually anywhere in Sicily, Mount Etna gradually assumed a place of great cultural importance. Locals eventually came to know the volcano as Mongibello, which means "beautiful mountain." The Roman poet Virgil solidified Mount Etna's cultural significance when he mentioned it in The Aeneid, an epic poem he wrote between 29 and 19 BCE.

Mount Etna's most notorious eruption took place over the course of several weeks starting in March of 1669 CE. Three days after it began rumbling and belching gas, a large cloud of poisonous fumes spewed out of the volcano and quickly killed about three thousand people living on its slopes. As the eruption grew in intensity, the volcano ejected large amounts of ash and lava, with some of the ash falling over Sicily and mainland Italy. In due course, the lava flow began approaching Catania. Although a group of Catanians managed to divert the lava flow temporarily, it was unintentionally redirected to the nearby city of Paterno. Enraged, the residents of Paterno attacked the Catanians. While this brief battle was under way, the lava flow began heading back toward Catania and eventually overtook the city walls. In the end, approximately seventeen thousand Catanians were killed and around twenty-seven thousand more were left homeless.

In the years that followed, Mount Etna's regular eruptions continued to pose a serious threat to the surrounding communities. A flank eruption that occurred when a fissure opened at the mountain's foot in 1928 destroyed the town of Mascali in just two days. A 1992 eruption threatened to destroy the town of Zafferana, but successful volcano control efforts prevented any serious damage. Less threatening eruptions continued to occur, such as frequent shorter flank eruptions, Strombolian explosions, and lava flow eruptions recorded in the early 2000s through the 2020s.

Between 2012 and 2022, Mount Etna experienced a notable increase in eruption frequency and intensity. Significant events included a three-year sequence of lava fountaining from 2011 to 2013 and a series of eruptions at the South East Crater between December 2020 and February 2022. During this decade, periods of dominant effusive activity, such as in 2014 and 2017–20, were interrupted by powerful paroxysmal events at the Voragine Crater in December 2015 and May 2016.

In 2024, Mount Etna experienced several eruptions. On August 14, a violent eruption sent an ash cloud 9.5 kilometers (5.9 miles) high. The following day, a paroxysmal event caused lava to overflow from the Bocca Nuova Crater, with ashfall leading to the closure of Catania Airport.

Overview

In 2013, the United Nations Educational, Scientific and Cultural Organization (UNESCO) named Mount Etna a UNESCO World Heritage site. Due to its unique features, Mount Etna stands apart from many of the world's other volcanoes. Rather than being one single formation, Mount Etna is actually a chain of nested stratovolcanoes. Stratovolcanoes are composed of alternating layers of lava and ash and typically have steep upper slopes that become gentler as they descend. Within the Mount Etna range, there are four different summit craters. The two central craters are known as Bocca Nuova and Voragine. The other two are referred to as the Northeast crater and the Southeast crater. The latter, which was formed by an eruption in 1978, is the youngest of the four. Most of Mount Etna's eruptions are Strombolian eruptions, meaning that they involve the ejection of ash, lava, and other volcanic materials. Mount Etna is also prone to flank eruptions, which take place on the side of a volcano rather than from the top. Flank eruptions usually result when a vent or fissure opens up at a point where a volcano is breaking apart.

Outside of its peaks and craters, Mount Etna's most distinguishing feature is the Valle del Bove, or Valley of the Ox. Located on the volcano's eastern slope, the Valle de Bove is a large horseshoe-shaped caldera, or cauldron-like depression formed after the contents of a magma chamber are emptied in the event of an explosion or the collapse of part of a crater. Thanks to Mount Etna's constant eruptions, much of the surrounding area boasts ash-enriched soil that is ideal for growing olives, grapes, and other fruits.

The questions of how Mount Etna formed and why it is so active are somewhat shrouded in mystery. Much like Vesuvius and Stromboli, two of Italy's other notable volcanoes, Mount Etna is located along a subduction zone where the Eurasian tectonic plate meets the African and Ionian (or Adriatic) plates. Unlike those other volcanoes, however, Mount Etna actually sits just in front of the subduction zone instead of directly on top of it. At the active fault where Mount Etna is situated, the African and Ionian plates are being pushed under the Eurasian plate. Scientists believe that the Ionian plate may have broken at some point and, as a result, part of it may have been forced backward by the African plate. It is theorized that this may have caused the Ionian plate to tilt and, in turn, created an open space into which magma from Earth's mantle was sucked, thus setting the stage for Mount Etna's formation. While this theory helps to explain how magma reaches the surface at Mount Etna, it does not entirely explain the source of that magma. Although this source has not been definitively identified, some scientists suggest that Mount Etna might be sitting atop a hot spot—a zone where rocks are melted into magma—like the one below the Hawaiian Islands.

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