Re: The end of Apocalypses?

Date: Thu Feb 03 2000 - 07:44:25 MST

My quick observation is that unless someone very intelligent develops mind
downloads and/or syntho bodies humanity will still need to take in air. Hence
the need for shipping anthropoid bodies (current humans) to space colonies of
some type over the 1-5 centuries to beat the clock on Volcano Winter.

Supervolcanoes could trigger global freeze

 Heat rises from under Yellowstone Park

By environment correspondent Alex Kirby
The threat of climate change caused by human activity could turn out to be a
minor problem by comparison with a scarcely acknowledged natural hazard.

Geologists say there is a real risk that sooner or later a supervolcano will
erupt with devastating force, sending temperatures plunging on a hemispheric
or even global scale.

A report by the BBC Two programme Horizon on one supervolcano, at Yellowstone
national park in the US, says it is overdue for an eruption.

Yellowstone has gone off roughly once every 600,000 years. Its last eruption
was 640,000 years ago.

Professor Bill McGuire, of the Benfield Greig Hazard Research Centre at
University College, London, told BBC News Online: "We're getting ready for
another eruption, unless the system has blown itself out.

"But the ground surface deformation and other signs measured by satellite
suggest it's still active, and on the move."

Molten rock

Typically, supervolcanoes are not mountains but depressions, huge collapsed
craters called calderas, which are hard to detect.

The Yellowstone caldera is 70 kilometres long and 30 km wide. Eight km
beneath the Earth's surface lies a huge magma chamber, containing vast
amounts of molten rock.

As pressure rises in the chamber, the surface is also rising and there is a
measurable increase in heat. But vulcanologists do not know when Yellowstone
will blow.

 Supervolcanoes are related to giant calderas

Professor McGuire, whose book, Apocalypse! A natural history of global
disasters, portrays a possible Yellowstone explosion in 2074, says there have
been two such events every 100,000 years for the last two million years.
The areas where supervolcanoes are most likely to be found, he says, are
subduction zones, where the Earth's plates are dipping below one another. The
Pacific Rim and southeast Asia are especially vulnerable.

But there is a caldera in the Phlegraean Fields near Naples in southern
Italy. Dr Ted Nield, of the Geological Society of London, told BBC News
Online: "It could do the same as Yellowstone, though on a smaller scale".

Nuclear winter

"When a supervolcano goes off, it is an order of magnitude greater than a
normal eruption. It produces energy equivalent to an impact with a comet or
an asteroid.

"You can try diverting an asteroid. But there is nothing at all you can do
about a supervolcano.

"The eruption throws cubic kilometres of rock, ash, dust, sulphur dioxide and
so on into the upper atmosphere, where they reflect incoming solar radiation,
forcing down temperatures on the Earth's surface. It's just like a nuclear

 Animals not caught in the eruption would face major climate change

"The effects could last four or five years, with crops failing and the whole
ecosystem breaking down. And it is going to happen again some day."
Ice-core records show that the eruption of Toba in Sumatra about 74,000 years
ago may have caused global cooling of from three to five degrees Celsius, and
perhaps as much as 10 degC during growing seasons in middle to high

Even ordinary volcanoes can affect the climate. When another Indonesian
volcano, Tambora, erupted in 1815, several years of globally cold weather
followed, with the annual global mean surface temperature about one degree
Celsius below normal.

The Geological Society, in evidence to the UK Parliament, is urging more
research into the risk from supervolcanoes and their probable climatic

Horizon is on BBC Two at 2130 GMT on Thursday, 3 February.

   Search BBC News Online
Advanced search options

See also:
 29 Oct 99 | Sci/Tech
 Scientists improve volcano prediction
 11 May 99 | Sci/Tech
 Early volcano victims discovered
 19 Feb 99 | Sci/Tech
 Volcano teaches deadly lessons

Internet links:
 Global Volcanism Program - Smithsonian Institution
 Volcano Information Center
 Geological Society of London
 Benfield Greig Hazard Research Centre

The BBC is not responsible for the content of external internet sites


This archive was generated by hypermail 2b29 : Thu Jul 27 2000 - 14:03:21 MDT