Yellowstone Has Bulged as Magma Pocket Swells

[irishspirit]

Brian Handwerk
for National Geographic News (http://news.nationalgeographic.com/news)
Published January 19, 2011

(http://travel.nationalgeographic.com/travel/national-parks/yellowstone-national-park/)
Yellowstone National Park (http://travel.nationalgeographic.com/travel/national-parks/yellowstone-national-park/)'s supervolcano just took a deep "breath," causing miles of ground to rise dramatically, scientists report.
The simmering volcano (http://environment.nationalgeographic.com/environment/natural-disasters/volcano-profile/) has produced major eruptions—each a thousand times more powerful than Mount St. Helens's 1980 eruption—three times in the past 2.1 million years. Yellowstone's caldera, which covers a 25- by 37-mile (40- by 60-kilometer) swath of Wyoming (http://travel.nationalgeographic.com/travel/united-states/wyoming-guide/), is an ancient crater formed after the last big blast, some 640,000 years ago.


(See "When Yellowstone Explodes" (http://ngm.nationalgeographic.com/2009/08/yellowstone/achenbach-text) in National Geographic magazine.)
Since then, about 30 smaller eruptions—including one as recent as 70,000 years ago—have filled the caldera with lava and ash, producing the relatively flat landscape we see today.


But beginning in 2004, scientists saw the ground above the caldera rise upward at rates as high as 2.8 inches (7 centimeters) a year. (Related: "Yellowstone Is Rising on Swollen 'Supervolcano.'" (http://news.nationalgeographic.com/news/2007/11/071108-yellowstone.html))


The rate slowed between 2007 and 2010 to a centimeter a year or less. Still, since the start of the swelling, ground levels over the volcano have been raised by as much as 10 inches (25 centimeters) in places.

"It's an extraordinary uplift, because it covers such a large area and the rates are so high," said the University of Utah's Bob Smith (http://www.uusatrg.utah.edu/RBSMITH/public_html/rbs-home.index.html), a longtime expert in Yellowstone's volcanism.

http://news.nationalgeographic.com/news/2011/01/110119-yellowstone-park-supervolcano-eruption-magma-science/

[irishspirit]

"Yellowstone National Park's supervolcano just took a deep "breath," causing miles of ground to rise dramatically, scientists report. The simmering volcano has produced major eruptions - each a thousand times more powerful than Mount St. Helens's 1980 eruption - three times in the past 2.1 million years. Yellowstone's caldera, which covers a 25- by 37-mile (40- by 60-kilometer) swath of Wyoming, is an ancient crater formed after the last big blast, some 640,000 years ago. (See "When Yellowstone Explodes" (http://ngm.nationalgeographic.com/2009/08/yellowstone/achenbach-text) in National Geographic magazine.)

http://2.bp.blogspot.com/_oUc6WpOAwto/TTilhYjzxWI/AAAAAAAAdSU/gx9M8t1JJYY/s1600/from_clipboard.jpg (http://2.bp.blogspot.com/_oUc6WpOAwto/TTilhYjzxWI/AAAAAAAAdSU/gx9M8t1JJYY/s1600/from_clipboard.jpg)
Since then, about 30 smaller eruptions - including one as recent as 70,000 years ago - have filled the caldera with lava and ash, producing the relatively flat landscape we see today. But beginning in 2004, scientists saw the ground above the caldera rise upward at rates as high as 2.8 inches (7 centimeters) a year. (Related: "Yellowstone Is Rising on Swollen 'Supervolcano.'" (http://news.nationalgeographic.com/news/2007/11/071108-yellowstone.html)) The rate slowed between 2007 and 2010 to a centimeter a year or less. Still, since the start of the swelling, ground levels over the volcano have been raised by as much as 10 inches (25 centimeters) in places. "It's an extraordinary uplift, because it covers such a large area and the rates are so high," said the University of Utah's Bob Smith, a longtime expert in Yellowstone's volcanism.

Scientists think a swelling magma reservoir four to six miles (seven to ten kilometers) below the surface is driving the uplift. Fortunately, the surge doesn't seem to herald an imminent catastrophe, Smith said. (Related: "Under Yellowstone, Magma Pocket 20 Percent Larger Than Thought." (http://news.nationalgeographic.com/news/2009/12/091215-yellowstone-volcano-magma-plume-larger.html)) "At the beginning we were concerned it could be leading up to an eruption," said Smith, who co-authored a paper on the surge published in the December 3, 2010, edition of Geophysical Research Letters. "But once we saw [the magma] was at a depth of ten kilometers, we weren't so concerned. If it had been at depths of two or three kilometers [one or two miles], we'd have been a lot more concerned." Studies of the surge, he added, may offer valuable clues about what's going on in the volcano's subterranean plumbing, which may eventually help scientists predict when Yellowstone's next volcanic "burp" will break out.

http://beforeitsnews.com/story/368/105/Volcanology:_Yellowstone_Supervolcano_Bulges_as_Magma_Pocket_Swells.html

[irishspirit]

http://www.youtube.com/watch?v=g-y9qYzTPMc&feature=player_embedded

[irishspirit]

http://www.unmuseum.org/supervol.htm

Is the Super Volcano Beneath Yellowstone Ready to Blow?


About 4 miles beneath Yellowstone National Park's beautiful scenery is a forty-mile-wide chamber full of molten rock under incredibly high pressure. This magma is what powers Yellowstone's fantastic geysers and hot springs, but is it about to erupt in a cataclysmic explosion that will decimate the western United States and push mankind to the brink of extinction?

Yellowstone is the crown jewel of the United States national park system. Its mountain vistas, wildlife and geographic features are visited and admired by people from around the world. More than any of those, however, it's the park's thermo-geological features that make it unlike any other part of the globe. No place on earth has as many steam vents, hot springs and active geysers (http://www.unmuseum.org/geysers.htm) as Yellowstone.



To create these features requires two elements in abundance: lots of water and lots of heat. The water is provided by the generous rain and snow the region gets. The heat comes from deep inside the earth: volcanic heat. Though you might not be able to tell from just looking at it, Yellowstone National Park is built on an ancient volcano. Not just a regular volcano, either. It lays on top of what some people have started to call a "super volcano."


Super Volcanos



There is no exact definition for a super volcano, but the term is often used to refer to volcanos that have produced exceptionally large eruptions in the past. When one of these large eruptions occurs, a huge amount of material is blasted out of the super volcano, leaving a giant crater or caldera. Such a caldera can be as much as forty or fifty miles wide. At Yellowstone, the caldera is so big that it includes a fair amount of the entire park. In fact, it is so big that scientists confirmed that the region had a caldera by looking at photographs from space.



Since there is no firm definition of what a super volcano is, it's hard to say how many of them are found on the earth. Usually people list Long Valley in eastern California and Taupo in New Zealand as super volcano sites along with Yellowstone. The last known explosion of what might be considered a super volcano was Toba in Indonesia. Toba erupted with a titanic explosion about 74,000 years ago. The force of the explosion was estimated to be 10,000 more powerful than the blast that destroyed Mount St. Helens, in Washington. Tremendous amounts of rock and ash were ejected into the air, blocking the sun for months. The temperature around the globe was thought to have plummeted as much as 21 degrees. Perhaps as much as 75% of plant life on the North American continent may died out.

http://www.unmuseum.org/geyoldf.jpg

Old Faithful geyser, as well as Yellowstone's other geothermal wonders, is powered by the heart of one of the most powerful volcanos on Earth. (Copyright Lee Krystek, 2000)



A super volcano differs from a regular volcano in that there is often no mountain peak associated with it. In a regular volcano hot magma under pressure flows up from the depths of the earth. A hole forms in the surface and the magma, now lava, pours out. As it cools, it forms a cone that eventually builds up into a mountain. If the passage is blocked off, the pressure can build up in the mountaintop and explode with a monstrous force. That's what happened at Mount St. Helens. The pit formed by the explosion becomes the new caldera.

[WyoSeeker]

I used to live not far from the south gate of Yellowstone and have been there many times. Now I live in the opposite corner of the state, but we're used to "activity" stories about the park. Nothing rumbling here at the moment!