Supervolcano facts for kids

Kids Encyclopedia Facts
Toba overview
Satellite image of Lake Toba, the site of a VEI 8 eruption c. 75,000 years ago.

A supervolcano is a volcano that can make a volcanic eruption where the things being thrown out of the volcano have a volume bigger than 1,000 km3 (240 cu mi). This is thousands of times bigger than most volcanic eruptions which happened a long time. Supervolcanoes can occur when magma in the Earth rises into the crust from a hotspot, but can not break through the crust. More and more pressure builds up in a large and growing magma pool until the crust can no longer take the pressure.

Although there are not many Quaternary supervolcanoes, supervolcanic eruptions usually cover very big areas with lava and volcanic ash. They can also cause a long-lasting change to weather (such as the triggering of a small ice age), enough to possibly make species extinct.

Supervolcano World Map
Map of known supervolcanoes around the world:      Volcanic Explosivity Index (VEI) 8      Volcanic Explosivity Index (VEI) 7

Terminology

The term "supervolcano" was first used in the BBC popular science television program Horizon in 2000 to mean eruptions of this type.

Volcanologists and geologists do not say "supervolcanoes" in their scientific work. This is because the word can mean many different geothermal conditions. Since 2003, however, the term has been used by professionals when showing things to the public. The term megacaldera is sometimes used for calderas which are quite similar to supervolcanoes, such as the Blake River Megacaldera Complex in the Abitibi greenstone belt of Ontario and Quebec, Canada.

Massive explosive eruptions

Volcanic eruptions are classified using the Volcanic Explosivity Index, or VEI. It is a logarithmic scale, which means that an increase of one in VEI number is equivalent to a tenfold increase in volume of erupted material. VEI 7 or VEI 8 eruptions are so powerful that they often form circular calderas rather than cones because the downward withdrawal of magma causes the overlying rock mass to collapse into the empty magma chamber beneath it.

Known super eruptions

Based on incomplete statistics, at least 60 VEI 8 eruptions have been identified.

VEI 8 eruptions have happened in the following locations.
Name Zone Location Notes Years ago (approx.) Ejecta bulk volume (approx.) Reference
Flat Landing Brook Formation Tetagouche-Exploits back-arc basin New Brunswick, Canada May be a single supereruption of at least 12,000 km3 (VEI 9) or multiple 2,000+ km3 eruptions 466,000,000 2,000–12,000 km3
Wah Wah Springs Indian Peak–Caliente Caldera Complex Utah, United States The largest of the Indian Peak-Caliente Caldera Complex eruptions, preserved as the Wah Wah Springs Tuff; includes lava flows more than 4,000 metres (13,000 ft) thick 30,600,000 5,500–5,900 km3
La Garita Caldera San Juan volcanic field Colorado, United States Fish Canyon eruption 27,800,000 5,000 km3
Lake Toba Lake Toba, North Sumatra Sumatra, Indonesia Produced 2200–4400 million tons of H2SO4 74,000 2,800 km3
Atana Ignimbrite Pacana Caldera Antofagasta, Chile Part of the Altiplano–Puna volcanic complex 4,000,000 2,500 km3
Huckleberry Ridge eruption Yellowstone hotspot Idaho, United States Huckleberry Ridge Tuff 2,100,000 2,450–2,500 km3
Taupo Nui a tia Taupo Volcanic Zone North Island, New Zealand Whakamaru Ignimbrite/Mount Curl Tephra 340,000 2,000 km3
Heise Volcanic Field Yellowstone hotspot Idaho, United States Kilgore Tuff 4,500,000 1,800 km3
Heise Volcanic Field Yellowstone hotspot Idaho, United States Blacktail Tuff 6,000,000 1,500 km3
Cerro Guacha Altiplano-Puna volcanic complex Sur Lípez, Bolivia Guacha ignimbrite, two smaller eruptions identified 5,700,000 1,300 km3
Mangakino Caldera Taupo Volcanic Zone North Island, New Zealand Kidnappers eruption 1,080,000 1,200 km3
Oruanui eruption Taupo Volcanic Zone North Island, New Zealand Taupo Volcano (Lake Taupo) 26,500 1,170 km3
Cerro Galán Andes Central Volcanic Zone Catamarca, Argentina 2,500,000 1,050 km3
Lava Creek eruption Yellowstone hotspot Idaho, Montana, and Wyoming, United States Lava Creek Tuff 640,000 1,000 km3

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