Much has been written lately about “supervolcanoes.” A supervolcano is a Volcano capable of producing a volcanic eruption with ejecta (particles that come out of a volcano’s vent, travels through the air or under water, and falls back on the ground surface or on the ocean floor) greater than 240 cubic miles (1,000 cubic kilometers). This is thousands of times larger than most historic volcanic eruptions.
Supervolcanoes can occur when magma in the Earth rises into the crust from a hotspot but is unable to break through the crust. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure. They can also form at convergent plate boundaries and continental hotspot locations.
There are currently six known supervolcanoes: the Yellowstone, Long Valley, and Valles Caldera in the United States; Lake Toba, North Sumatra, Indonesia; Taupo Volcano, North Island, New Zealand; and Aira Caldera, Kagoshima Prefecture, Kyūshū, Japan. Although there are only a handful of Quaternary supervolcanoes, supervolcanic eruptions typically cover huge areas with lava and volcanic ash and cause a long-lasting change to weather (such as the triggering of a small ice age) sufficient to threaten the extinction of species.
Due to its location in Yellowstone Park, the Yellowstone supervolcano has attracted a lot of attention. Between Homes members Buccaneer Braveheart and Xanadu Dominquez have both pointed to me that we are all living atop a ticking time bomb—when it finally goes, much of civilization as we now know it will be wiped out.
I am not much of a fan of doomsday scenarios (why worry about something that: (a) we have no control over and (b) may happen today, tomorrow or not until a million years from now). Still, there is sufficient interest on this subject that I thought I would bring to you this write-up on the Yellowstone Supervolcano.
Enjoy (sort of).
Underground Yellowstone ‘Supervolcano’ Causing Earth to Rise in Some Spots
By Brett Michael Dykes
(Reprinted from Yahoo News)
It's like something one of those disaster movie trailers with a basso profundo voiceover: Man, or perhaps woman, on a family vacation takes in the breathtaking scope of nature found in Yellowstone National Park--only to see the earth beneath their feet violently explode. Will our hero and his or her family be swallowed in the molten horror of -- "Supervolcano"?
But this scenario isn't the stuff of Hollywood fantasy--scientists caution that there's a chance that Yellowstone could blow. One day, anyway.
Yes, there apparently exists an underground volcano whose past eruptions -- the last one estimated at some 640,000 years ago -- have been, according to National Geographic, "a thousand times more powerful than Mount St. Helens's 1980 eruption." The supervolcano lurks a few miles underground and spreads out across an area roughly the size of Los Angeles. But here's the best part: It's taking deep "breaths," as the magazine puts it, causing miles of ground around it to rise dramatically. Since 2004, researchers say that the ground above the supervolcano rose as much as 2.8 inches per year.
So is the "swelling magma reservoir" ready to blow? Well, scientists say it will eventually--and when it does it could spew ash as high as 25 miles into the air, rendering an estimated two-thirds of the country inhabitable. Remember, it was a massive volcanic eruption that some scientists think wiped out the dinosaurs. And here we thought that Icelandic volcano last year was a major calamity.
Yellowstone Park - National Geographic video
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