The 10 Biggest Volcanic Eruptions in History
une 15, 2011 marks the 20th anniversary of Mt. Pinatubo's cataclysmic eruption, which sent huge amounts of ash high into the sky and circling around the globe, lowering global temperatures by 1 degree Fahrenheit (0.5 degree Celsius) over the following year.
On this anniversary, we countdown the largest volcanic eruptions in history as measured by the Volcanic Explosivity Index (VEI) a classification system somewhat akin to the magnitude scale for earthquakes.
The system was developed in the 1980s, and uses factors such as the volume of an eruption, its rate, and other variables to quantify a volcano's power. The scale goes from 1 to 8, and each succeeding VEI is 10 times greater than the last.
There haven't been any VEI-8 volcanoes in the last 10,000 years, but human history has seen some powerful and devastating eruptions. Because it's extremely difficult for scientists to be able to rank the strength of eruptions in the same VEI category, here we present the 10 most powerful volcanoes within the last 4,000 years (within human records) first in order of strength, then within each category, in chronological order.
Mt. Tambora, Sumbawa Island, Indonesia 1815 VEI 7
The explosion of Mount Tambora is the largest ever recorded by humans, ranking a 7 (or "super-colossal") on the Volcanic Explosivity Index, the second-highest rating in the index. The volcano, which is still active, is one of the tallest peaks in the Indonesian archipelago.
The eruption reached its peak in April 1815, when it exploded so loudly that it was heard on Sumatra Island, more than 1,200 miles (1,930 km) away. The death toll from the eruption was estimated at 71,000 people, and clouds of heavy ash descended on many far-away islands.
Changbaishan Volcano, China/ North Korea border 1000 AD VEI 7
Also known as the Baitoushan Volcano, the eruption spewed volcanic material as far away as northern Japan, a distance of approximately 750 miles (1,200 kilometers). The eruption also created a large caldera nearly 3 miles (4.5 km) across and a half-mile (nearly 1 km) deep at the mountain's summit. It is now filled with the waters of Lake Tianchi, or Sky Lake, a popular tourist destination both for its natural beauty and alleged sightings of unidentified creatures living in its depths.
The mountain last erupted in 1702, and geologists consider it to be dormant. Gas emissions were reported from the summit and nearby hot springs in 1994, but no evidence of renewed activity of the volcano was observed.'
Mt. Thera, Island of Santorini, Greece approx. 1610 B.C. VEI 7
Geologists think that the Aegean Islands volcano Thera explodedwith the energy of several hundred atomic bombs in a fraction of a second. Though there are no written records of the eruption, geologists think it could be the strongest explosion ever witnessed.
The island that hosted the volcano, Santorini (part of an archipelago of volcanic islands), had been home to members of the Minoan civilization, though there are some indications that the inhabitants of the island suspected the volcano was going to blow its top and evacuated. But though those residents might have escaped, there is cause to speculate that the volcano severely disrupted the culture, with tsunamis and temperature declines caused by the massive amounts of sulfur dioxide it spewed into the atmosphere that altered the climate.
Ilopango Volcano, El Salvador 450 AD VEI 6 +
Trade routes were disrupted, and the centers of Mayan civilization shifted from the highland areas of El Salvador to lowland areas to the north and in Guatemala.
Ambrym Island, Republic of Vanuatu 50 AD VEI 6 +
The 257-square-mile (665-square-km) volcanic island, part of a tiny nation in the southwestern Pacific Ocean, witnessed one of the most impressive eruptions in history, one that sent a wave of scalding ash and dust down the mountain and formed a caldera 7.5 miles (12 km) wide.The volcano has continued to be one of the most active in the world. It has erupted close to 50 times since 1774, and has proved a dangerous neighbor for the local population. In 1894, six people were killed by volcanic bombs and four people were overtaken by lava flows, and in 1979, acid rainfall caused by the volcano burned some inhabitants.Mount Pinatubo, Luzon, Philippines 1991 VEI 6
Credit: U.S. Department of Interior, U.S. Geological Survey.A stratovolcano located in a chain of volcanoes created along a subduction zone, the cataclysmic eruption of Pinatubo was a classic explosive eruption.The eruption ejected more than 1 cubic mile (5 cubic kilometers) of material into the air and created a column of ash that rose up 22 miles (35 km) in the atmosphere. Ash fell across the countryside, even piling up so much that some roofs collapsed under the weight.The blast also spewed millions of tons of sulfur dioxide and other particles into the air, which were spread around the world by air currents and caused global temperatures to drop by about 1 degree Fahrenheit (0.5 degree Celsius) over the course of the following year.
Novarupta, Alaska Peninsula June, 1912 VEI 6
The eruption of Novarupta one of a chain of volcanoes on the Alaska Peninsula, part of the Pacific Ring of Fire was the largest volcanic blast of the 20th century. The powerful eruption sent 3 cubic miles (12.5 cubic km) of magma and ash into the air, which fell to cover an area of 3,000 square miles (7,800 square km) in ash more than a foot deep.Santa Maria Volcano, Guatemala 1902 VEI 6
Credit: U.S. Department of Interior, U.S. Geological Survey.The Santa Maria eruption in 1902 was one of the largest eruptions of the 20th century. The violent explosion came after the volcano had sat silent for roughly 500 years, and left a large crater, nearly a mile (1.5 km) across, on the mountain's southwest flank.The symmetrical, tree-covered volcano is part of a chain of stratovolcanoes that rises along Guatemala's Pacific coastal plain. It has experienced continuous activity since its last blast, a VEI 3, which occurred in 1922. In 1929, Santa Maria spewed forth a a pyroclastic flow (a fast-moving wall of scalding gas and pulverized rock), which claimed hundreds of lives and may have killed as many as 5,000 people.
Krakatoa, Sunda Strait, Indonesia 1883 VEI 6
The rumblings that preceded the final eruption of Krakatoa (also spelled Krakatau) in the weeks and months of the summer of 1883 finally climaxed with a massive explosion on April 26-27. The explosive eruption of this stratovolcano, situated along a volcanic island arc at the subduction zone of the Indo-Australian plate, ejected huge amounts of rock, ash and pumice and was heard thousands of miles away.The explosion also created a tsunami, whose maximum wave heights reached 140 feet (40 meters) and killed about 34,000 people. Tidal gauges more than 7,000 miles (11,000 km) away on the Arabian Peninsula even registered the increase in wave heights.
While the island that once hosted Krakatoa was completely destroyed in the eruption, new eruptions beginning in December 1927 built the Anak Krakatau ("Child of Krakatau") cone in the center of the caldera produced by the 1883 eruption. Anak Krakatau sporadically comes to life, building a new island in the shadow of its parent.
Huaynaputina, Peru 1600 VEI 6
Credit: © Giovanni Paccaloni.This peak was the site of South America's largest volcanic eruption in recorded history. The explosion sent mudflows as far as the Pacific Ocean, 75 miles (120 km) away, and appears to have affected the global climate. The summers following the 1600 eruption were some of the coldest in 500 years. Ash from the explosion buried a 20-square-mile (50-square-km) area to the mountain's west, which remains blanketed to this day.Although Huaynaputina is a lofty 16,000 feet (4,850 meters), it's somewhat sneaky as volcanoes go. It stands along the edge of a deep canyon, and its peak doesn't have the dramatic silhouette often associated with volcanoes.
The 1600 cataclysm damaged the nearby cities of Arequipa and Moquengua, which only fully recovered more than a century later.'
The rumblings that preceded the final eruption of Krakatoa (also spelled Krakatau) in the weeks and months of the summer of 1883 finally climaxed with a massive explosion on April 26-27. The explosive eruption of this stratovolcano, situated along a volcanic island arc at the subduction zone of the Indo-Australian plate, ejected huge amounts of rock, ash and pumice and was heard thousands of miles away.
The explosion also created a tsunami, whose maximum wave heights reached 140 feet (40 meters) and killed about 34,000 people. Tidal gauges more than 7,000 miles (11,000 km) away on the Arabian Peninsula even registered the increase in wave heights.While the island that once hosted Krakatoa was completely destroyed in the eruption, new eruptions beginning in December 1927 built the Anak Krakatau ("Child of Krakatau") cone in the center of the caldera produced by the 1883 eruption. Anak Krakatau sporadically comes to life, building a new island in the shadow of its parent.\
The summit's caldera is now home to one of El Salvador's largest lakes
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