What are Supervolcanoes?

Answer 1

A supervolcano refers to a volcano that produces the largest and most voluminous kinds of eruption on Earth. The actual explosivity of these eruptions varies, but the sheer volume of extruded magma is enough to radically alter the landscape and severely impact global climate for years, with a cataclysmic effect on life.

Answer 2

Superheroes in with the power of volcanoes!

Seriously, it's a supervolcano refers to a volcano that produces the largest and most voluminous kinds of eruption on Earth. The actual explosivity of these eruptions varies, but the sheer volume of extruded magma is enough to radically alter the landscape and severely impact global climate for years, with a cataclysmic effect on life.

Answer 3

The answers below are vague and worthless. Please note that the examples they gave of specific supervolcanoes are correct. There are currently no supervolcanoes on Earth. There is one very large supervolcano on Mars though. Look at a map of Mars and you will see it. It is huge!

Answer 4

supervolcano
A supervolcano refers to a volcano that produces the largest and most voluminous kinds of eruption on Earth. The actual explosivity of these eruptions varies, but the sheer volume of extruded magma is enough to radically alter the landscape and severely impact global climate for years, with a cataclysmic effect on life.

The term was originally coined by the producers of the BBC popular science program, Horizon, in 2000 to refer to these types of eruption. That investigation brought the subject more into the public eye, leading to further studies of the possible effects. At first, supervolcano was not a technical term used in volcanology, but more recently, in 2003 and 2004, the term has been used in articles. Though there is no well-defined minimum size for a "supervolcano", there are at least two types of volcanic eruption that have been identified as supervolcanoes: massive eruptions and large igneous provinces.


Large igneous provinces
Main article: Large igneous province
A large igneous province (LIP) is an extensive region of basalts on a continental scale, resulting from flood basalt eruptions. When created, these regions often occupy several million km2 and have volumes on the order of 1 million km3. In most cases, the majority of this is laid down over an extended but geologically sudden period of less than 1 million years.


Massive eruptions
Eruptions with a Volcanic Explosivity Index of 8 (VEI-8) are mega-colossal events that extrude at least 1000 km³ of magma and pyroclastic material. Such an eruption would erase virtually all life within a radius of hundreds of kilometers from the site, and entire continental regions further out can be buried meters deep in ash. VEI-8 eruptions are so powerful that they form circular calderas rather than mountains because the downward collapse of land at the eruption site fills emptied space in the magma chamber beneath. The caldera can remain for millions of years after all volcanic activity at the site has ceased.


Known eruptions
VEI-8 volcanic events have included eruptions at the following locations (with estimates of the volume of erupted material at the event):

Lake Toba, Sumatra, Indonesia - 73,000 years ago (2,800 km³)
Yellowstone Caldera, Wyoming, United States - 2.2 million years ago (2500 km³), 1.2 million years ago (280 km³), and 640,000 years ago (1000 km³)
La Garita Caldera, Colorado, United States - 27.8 million years ago (over 5,000 km³)
Bruneau-Jarbidge, Idaho, United States - 10-12 million years ago (responsible for the Ashfall Fossil Beds)
The most recent VEI-8 eruption was at Lake Toba, Sumatra, and occurred around 74,000 years ago, plunging the Earth into a volcanic winter.

The largest known explosive eruption on Earth occurred at the La Garita Caldera in the San Juan Mountains in southwestern Colorado approximately 28 million years ago.

Many other supermassive eruptions have also occurred in the geological past, although these listed below measure at 6-7 on the VEI scale, but they were still even larger than Tambora's eruption in 1815, which was the largest known in recorded history.

Aira Caldera, Kyūshū, Japan - 22,000 years ago (110 km³)
Aso, Kyūshū, Japan - four large explosive eruptions between 300,000 to 80,000 years ago (Total volume 600 km³)
Campi Flegrei, Campania, Italy - 35,000 years ago (80 km³)
Kikai Caldera, Ryūkyū Islands, Japan - 6,300 years ago (150 km³ (bulk volume))
Lake Taupo, North Island, New Zealand - 26,500 years ago 800 km³
Long Valley Caldera, California, United States - 760,000 years ago (600 km³)
Valle Grande, New Mexico, United States - 1.12 million years ago (~600 km³)
For large igneous province eruptions, see that article


Media portrayal
A two-part television docudrama entitled Supervolcano was shown on BBC, the Discovery Channel, and other TV networks worldwide. It looked at the events that would take place if the Yellowstone supervolcano (the largest supervolcano on Earth according to the program) erupted. It featured footage of volcano eruptions from around the world and computer-generated imagery depicting the event. According to the program, the eruption would have devastating effect across the globe and would cover virtually all of the United States with at least 1 cm of volcanic ash, causing mass destruction in the nearby vicinity and killing plants and wildlife across the continent. The showings were followed by Supervolcano: The Truth About Yellowstone, a documentary about the evidence behind the movie. The program had originally been scheduled to be aired in early 2005, but it was felt that this would be insensitive so soon after the real-life tragedy of the 2004 Indian Ocean earthquake. The program and its accompanying documentaries were released on DVD region 2 simultaneously with its broadcast. The Stargate: Atlantis TV series featured an episode titled "Inferno" where the Atlantis team travels to another planet and learns that because of a city's use of their Ancient shield, they have caused a supervolcano (that their city is located in) to become active.

U CAN ALSO TRY THESE LINKS =
http://www.answers.com/topic/supervolcano
http://en.wikipedia.org/wiki/Supervolcano
http://www.reference.com/browse/wiki/Supervolcano

HOPE THIS HELPS

Answer 5

Volcanoes that are very active