Thursday, May 31, 2012

Safe for the moment

Volcanic super-eruptions may have surprisingly short fuses

While the article's heading may sound like a bit of a worry, the story indicates that there might be at hundreds of years warning of a truly massive super-eruption:
These eruptions are known as super-eruptions because they are more than 100 times the size of ordinary like Mount St. Helens. They spew out tremendous flows of super-heated gas, ash and rock capable of blanketing entire continents and inject enough particulate into the to throw the into decade-long volcanic winters. In fact, there is evidence that one super-eruption, which took place in Indonesia 74,000 years ago, may have come remarkably close to wiping out the entire human species.

Geologists generally believe that a super-eruption is produced by a giant pool of that forms a couple of miles below the surface and then simmers for 100,000 to 200,000 years before erupting. But a new study suggests that once they form, these giant magma bodies may only exist for a few thousand years, perhaps only a few hundred years, before erupting.

But the better news:
As far as geologists can tell, no such giant crystal-poor magma body currently exists that is capable of producing a super-eruption. The research team believes this may be because these magma bodies exist for a relatively short time rather than persisting for hundreds of thousands of years as previously thought.

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