Huge Eruption May Have Been Bigger (Super-Volcano)

Discovery Channel ^ | 12-21-2006 | Larry O'Hanlon

[blam]

Eruption May Have Been Bigger

Larry O'Hanlon, Discovery News

Dec. 21, 2006 — One of the largest volcanic eruptions on record just got bigger.

The Taupo Volcanic Zone of New Zealand appears to have had twin eruptions only 20 miles apart within days of each other a quarter-million years ago. Each eruption belched out more than 25 cubic miles (100 cubic kilometers) of rock and volcanic ash.

This is the first evidence of twin supervolcanic eruptions.

"It's possible one of these triggered the other," said geologist Darren Gravley of the University of Auckland, New Zealand. But exactly how the triggering might have worked is uncertain.

What is clear from the explorations of Gravley and his colleagues of the Mamaku and Ohakuri volcanic deposits is that they were created very close in time. That's surprising, since most caldera or "supervolcano" eruptions in any one region tend to be tens of thousands of years apart, or at least that's been the general idea until now.

Among the signs that the rocks from the two eruptions were piled on one another is the conspicuous lack of erosion on the first volcanic deposits — which is striking, considering the rainy climate.

Previous studies that looked only at the radioisotope dates of the volcanic rocks from the eruptions missed the timing details, Gravley said, because they have a margin of error of 10,000 years — way too low a resolution.

"You’ve got to look at the physical evidence," said Gravley. "It's really getting into the nitty-gritty. From the stratigraphy (rock layers) it’s clear two were erupting at the same time. That just blows away any (regional frequency) studies out of the water."

Gravely and his colleagues have published their double eruption discovery in the latest issue of the Bulletin of the Geological Society of America.

The bad news is that double eruption represents a whole new way that supervolcanoes can threaten humanity.

"This is of course a major issue to consider for volcanic risk," said caldera researcher Gerardo Aguirre-Díaz of the Universidad Nacional Autónoma de Mexico in Juriquilla, Mexico.

Caldera eruptions are far less frequent than other volcanoes, but when they do erupt, "the consequences for the surroundings and in general for the world would be enormous, because these explosive eruptions are many orders of magnitude bigger than a more common eruption from a volcano, such as Mount St. Helens or Vesuvius."

[blam]

Catastrophism ping.

[COEXERJ145]

Speaking of volcanoes, there is a movie coming on the SciFi channel in two hours called "Magma: Volcanic Disaster." It's really, really bad but worth watching for a good laugh.

[SoldierDad]

So, where's the video?

[Valin]

Karl Rove has it hidden away. If it ever got out that he was responsible....well it would be bad...very bad.

[Valin]

If memory serves Yellowstone is a supervolcano.

[blam]

Magma: Volcanic Disaster

[WestVirginiaRebel]

We're doomed, again...

[blam]

"If memory serves Yellowstone is a supervolcano."

Yup. Forty thousand years overdue too.

[RightWhale]

Is this even in the same league with Yellowstone?

[COEXERJ145]

I've seen it before and the review doesn't say how bad it really is. I and some of my friends from a "24" message board who are fans of Reiko Aylesworth like to watch it and make fun of it. Only her and Xander Berkeley are good in this movie as they do well despite the crappy script.

But Yellowstone will go BOOM in the movie. It's the cause of all the disasters that is the uber-lame part.

[mikrofon]

This could be twice as Hugh!

[COEXERJ145]

Did you see "Supervolcano" on the Discovery Channel?

[pankot]

1/4 million years ago? Que sera, sera.

[SoldierDad]

LOL!

[Harmless Teddy Bear]

It's the cause of all the disasters that is the uber-lame part.

Underground Nuclear testing?

[Cheburashka]

Oh, God I've been worrying about supervolcanos, meteor strikes, transfats, global warming, Britney Spears, mercury in the tuna, the heartbreak of whatever that skin disease that I can't spell is, and now it turns out instead of mere supervolcanos I should have been worrying about twin supervolcanos!!

This is so confusing, I just can't keep up.

[_Jim]

The bad news is that double eruption represents a whole new way that supervolcanoes can threaten humanity.

Single barrel vesus double-barrel; I guess the difference will be in the rifling ...

[Cheburashka]

"If memory serves Yellowstone is a supervolcano."

Yup. Forty thousand years overdue too.
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Can you be more specific about when it's going to erupt?

I want to include it in my day planner on the right day.

[blam]

Yes. If you're into that sort of thing, look what happened 75,000 years ago when the super-volcano Toba blew:

Late Pleostocene Human Population Bottlenecks. . . (Toba)

It's recorded in our DNA.

BTW, if Yellowstone blew, it wouldn't end the way the movie did.