Supervolcano

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 , which is a Volcanic Explosivity Index (VEI) of 8. If the definition is expanded, supervolcanoes also include volcanoes that have volcanic eruptions with a volume bigger than , which is a Volcanic Explosivity Index (VEI) of 7. This is thousands of times bigger than most volcanic eruptions which happened a long time.Questions About Super Volcanoes . Volcanoes.usgs.gov (2009-05-08). Retrieved on 2011-11-18. 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 causing a volcanic winter which can trigger a small ice age), enough to possibly make species extinct.

 Terminology 

The term "supervolcano" was first used in the BBC popular science television program Horizon in 2000 to mean eruptions of this type.Supervolcanoes. Bbc.co.uk (2000-02-03). Retrieved on 2011-11-18.USGS Cascades Volcano Observatory. Vulcan.wr.usgs.gov. Retrieved on 2011-11-18. 

Volcanologists (who study with volcanoes) 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.

 Super Eruptions 

VEI 8 eruptions are considered super-eruptions due to their large scale. The Earth's most recent supereruption is the Oruanui eruption, occurring 26,500 years ago.

 Related pages 
 Toba catastrophe theory

 References 

 More reading 





 Other websites 

 Information on the original BBC program
 Yellowstone Supervolcano and Map of Supervolcanoes Around The World 
 USGS Fact Sheet – Steam Explosions, Earthquakes, and Volcanic Eruptions – What's in Yellowstone's Future?
 Discovery Channel's site on "Supervolcano"
 Scientific American's The Secrets of Supervolcanoes