Overdue Supervolcanoes 'May Erupt Soon'

Sky News ^ | January 30, 2005

[HAL9000]

SUPERVOLCANOES WARNING

Slumbering supervolcanoes powerful enough to wipe out much of the planet may awaken much sooner than it had previously been thought.

Experts believed it would take hundreds of thousands of years for reservoirs of molton rock, or magma, beneath a supervolcano to build for an eruption.

But a new study indicates the time between super-eruptions can actually be tens of thousands of years - and many are already long overdue.

A blast from a supervolcano would be strong enough cause mass extinction and change the world's climate.

The findings, published in the Journal of Petrology, are bad news for anyone living in the centre of the US.

An overdue monster supervolcano is hidden underneath one of the country's premier holiday spots - Yellowstone National Park in Wyoming.

The last blast there, which occurred more than 600,000 years ago, covered half the US - around 3,000sq miles - with volcanic ash.

Researchers in New Zealand analysed zircon crystals, which grow within volcanic magma, to calculate how long build up takes before eruptions.

Their answer was no more than 40,000 years - a relatively short time in geological terms.

Supervolcanoes are estimated to carry a force thousands of times that of a normal explosion.

They spew thousands of cubic yards of ash, dust and poisonous sulphur dioxide into the atmosphere and create a giant crater, or caldera.

Recent measurements indicate that over the past century the earth above the Yellowstone magma chamber has risen almost 19 inches. Scientists say this is telling evidence of pressure building below.

[Judith Anne]

Yes, and 3000 miles square is 9 million sqaure miles. ;-D

Re-read--I was the *first* to correct the poor poster, heh-heh.

[Nataku X]

Yeah, the Easterners will die in a few hours to weeks from suffocation and lung infections. Westerners will riot & finally starve to death over the course of months and years.

[IllumiNaughtyByNature]

Their answer was no more than 40,000 years

I'll leave a not for the future grandkids to let them know that we knew about this. Thanks for he heads-up. :o)

[Nataku X]

Humilation will be the least of the world's problems if the supervolcano goes. We will enter an instant ice age and we won't be able to grow any kind of meaningful crops for many years.

[Strategerist]

Reading the abstract of the paper, Sky News completely misunderstood the original scientific paper. Consider everything from the article posted beginning this thread as worthless garbage.

[Lokibob]

I'm sure it isn't going to happen in my lifetime, and if it does, I'm even more sure I won't know that it happened, living in Utah.

USGS web site for the Yellowstone Volcano Observatory:
http://volcanoes.usgs.gov/yvo/

[Youngblood]

But hasn't the hotspot that causes the volcano been moving east in relation to the crust? I remember seeing a programme on the Yellowstone volcano, and they showed a couple of remnants of its previous supereruptions spread along a line to the west.

[NutCrackerBoy]

A blast from a supervolcano would be strong enough [to] cause mass extinction and change the world's climate. -Sky News

Well, who the heck cares what the climate will be WHEN WE'RE ALL DEAD!

[moonhawk]

No need to re-read, I caught it the first time...I was just playing with the words.

[IllumiNaughtyByNature]

Thanks for the note. What did the original paper say? Readers Digest version.

[John Valentine]

In an eruption of the size contemplated (i.e. HUGH), the winds won't be what you would expect, and there is no way that normal winds (and you are really only thinking of sea-level winds) could keep all that ash to the east of the eruption.

No offense, but you are just wrong on this one.

[Strategerist]

No offense, but you are just wrong on this one.

There was no ash at San Francisco from the last caldera blast from Mammoth Lakes. You're just wrong on this one.

[Strategerist]

Here's an article that appears to accurately summarize the article. Notice there's no actual mention of Yellowstone. It was a study of Taupo as I suspected.

http://cepsar.open.ac.uk/News/Supervolcanoes%20Jan05.htm

Supervolcanoes Can Wake Up Fast!
Dr Bruce Charlier and colleagues have found that the time period for the production of magma below a supervolcano is much shorter than the interval between eruptions.

"The devastation caused by the eruption of supervolcanoes is of the same magnitude as all but the largest meteorite impacts. Eruption of hundreds to thousands of cubic kilometres of lava can cause climate change and mass extinction.

"Our findings mean that we have to reassess our understanding of the speed at which the volcano can reactivate, and this has important implications for volcanic monitoring and hazard mitigation at Taupo and similar volcanoes worldwide," says Dr Charlier.

The study of Lake Taupo supervolcano in the central North Island of New Zealand has found that the common perception that the rhyolitic magma (molten rock) is held in a huge 'vat' beneath the volcano for hundreds of thousands of years prior to a large eruption is incorrect.

The study shows that magma is produced rapidly (in one case over only a few years at most) and that even the largest eruption, such as the one that formed Lake Taupo, 26,500 years ago, had a build-up time of only about 40,000 years - a short time-period geologically speaking.

The time periods over which the magma accumulated before each eruption have been calculated by measuring the ages of zircon crystals that were growing in the rhyolitic magma. The ages of successive growth bands of the zircons indicate that some zircon crystals were growing during successive episodes of magma formation. It is the age succession that can be observed in cross-sections of zircons that has led to a new model of magma production, which allows the regeneration of material from earlier periods of the volcano's life back into its 'engine room', the magma chamber.

This study of Lake Taupo volcano is the most comprehensive study of its type, and is published in the Journal of Petrology.

[Lokibob]

From the USGS web site:

 

 

Figures and pictures used with permission from "Windows into the Earth, The Geologic Story of Yellowstone and Grand Teton National Park", Robert B. Smith and Lee J. Siegel, Oxford University Press, 2000.

Figure 1. Path of the Yellowstone hotspot. Yellow and orange ovals show volcanic centers where the hotspot produced one or more caldera eruptions- essentially "ancient Yellowstones"- during the time periods indicated. As North America drifted southwest over the hotspot, the volcanism progressed northeast, beginning in northern Nevada and southeast Oregon 16.5 million years ago and reaching Yellowstone National Park 2 million years ago. A bow-wave or parabola-shaped zone of mountains (browns and tans) and earthquakes (red dots) surrounds the low elevations (greens) of the seismically quiet Snake River Plain. The greater Yellowstone "geoecosystem" is outlined in blue. Faults are in black.

[Birdsbane]

That would be 3,000 miles squared...but 600,000 years ago the hot spot underneath present day Yellowstone would have been a long ways to the west. Draw a line between Lincoln City, Oregon and Yellowstone and you will have plotted the migratory path of said magma chamber. The ash cloud would have been carried to the east by prevailing winds, enabling it to easily cover 9,000,000 square miles in North America. I live in Oregon. The hot spot has moved away. Oregon needs "Breadbasket" Conservatives to move to Portland to offset the Liberal Pinheads. Any takers?

[Dat Mon]

"There is a blatant flaw in this sentence making it unbelievable to anyone with an IQ above 95."

I sorta get it. It must be like the big bang theory. The universe must be expanding......like a mofo.

And global warming makes it even worse.

[grey_whiskers]

"The last blast there, which occurred more than 600,000 years ago, covered half the US - around 3,000sq miles - with volcanic ash." There is a blatant flaw in this sentence making it unbelievable to anyone with an IQ above 95.

Make that *TWO* flaws: 1) US wasn't around back then 2) Area of US in square miles is wrong.