There are around 20 known
supervolcanoes on Earth, with major eruptions occurring on average once every
100,000 years, according to the BBC resulting in mass starvation, with a
prolonged volcanic winter potentially prohibiting civilization from having enough
food for the current population. In 2012, adds the BBC, the United Nations
estimated that food reserves worldwide would last 74 days.
NASA Jet Propulsion
Laboratory scientist Brian Cox said that "I came to the conclusion that
the supervolcano threat is substantially greater than the asteroid or comet
threat." He proposes that the logical solution could simply be to cool a
supervolcano down by extracting its heat. NASA estimates that if a 35% increase
in heat transfer from the Yellowstone supervolcano --essentially a gigantic
heat generator, equivalent to six industrial power plants--could be achieved
from its magma chamber, it would no longer pose a threat.
Six hundred thousand years
ago there was a colossal explosion from a cauldron of magma, the most massive
known supervolcano, the 2.2 million acre Yellowstone caldera that forms the
world's highest plateau capping a seething magma chamber forty-five miles
across-the size of Rhode Island- and eight miles thick of hot molten rock that
rises up from 125 miles from the Earth's core. When Yellowstone explodes, and
it will again, someday, Hiroshima will look like child's play. What no knows
for sure is, when.
The ancient Yellowstone
caldera exploded with such violence that it left an ash layer almost ten feet
deep a thousand miles away in eastern Nebraska killing all plant life and
covering almost all of the United States west of the Mississippi.
Modern geological surveys
have shown that this supervolcano erupts approximately every 600,000 years. The
Blackfoot Indians called it the land of evil spirits -what we know today as
Yellowstone National Park.
A volcano the size of
Yellowstone, says Wilcox, currently leaks about 60-70% of the heat coming up
from below into the atmosphere, via water which seeps through cracks into the
magma chamber. The remainder builds up inside the magma, enabling it to
dissolve more and more volatile gases and surrounding rocks. Once this heat reaches
a certain threshold, then an explosive eruption is inevitable.
Building a massive water
aqueduct uphill into a mountainous region like tyhe Yellowstone Plateau
"would be both costly and difficult," says Wilcox. "and people
don’t want their water spent that way. People are desperate for water all over
the world and so a major infrastructure project, where the only way the water
is used is to cool down a supervolcano, would be very controversial.”
NASA has come up with
different plan to drill up to 10km down into the supervolcano, and pump down
water at high pressure. The circulating water would return at a temperature of
around 350C (662F), thus slowly day by day extracting heat from the volcano.
And while such a project
would come at an estimated cost of around $3.46 billion, it comes with an
enticing catch which could convince politicians to make the investment.
“Yellowstone currently leaks
around 6 giga watts in heat,” Wilcox says. “Through drilling in this way, it
could be used to create a geothermal plant, which generates electric power at
extremely competitive prices of around $0.10/kWh. You would have to give the
geothermal companies incentives to drill somewhat deeper and use hotter water
than they usually would, but you would pay back your initial investment, and
get electricity which can power the surrounding area for a period of
potentially tens of thousands of years. And the long-term benefit is that you
prevent a future supervolcano eruption which would devastate humanity.”
“The most important thing
with this is to do no harm,” Wilcox says. “If you drill into the top of the
magma chamber and try and cool it from there, this would be very risky. This
could make the cap over the magma chamber more brittle and prone to fracture.
And you might trigger the release of harmful volatile gases in the magma at the
top of the chamber which would otherwise not be released.”
Instead, the idea is to
drill in from the supervolcano from the lower sides, starting outside the
boundaries of Yellowstone National Park, and extracting the heat from the
underside of the magma chamber. “This way you’re preventing the heat coming up
from below from ever reaching the top of the chamber which is where the real
threat arises,” Wilcox says.
“With a project like this,
you’d start the process and the main ongoing benefit you’d see in everyday
terms is this new supply of electrical power,” Wilcox says.
“When people first
considered the idea of defending the Earth from an asteroid impact, they
reacted in a similar way to the supervolcano threat,” Wilcox says. “People
thought, ‘As puny as we are, how can humans possibly prevent an asteroid from
hitting the Earth.’ Well, it turns out if you engineer something which pushes
very slightly for a very long time, you can make the asteroid miss the Earth.
So the problem turns out to be easier than people think. In both cases it
requires the scientific community to invest brain power and you have to start
early. But Yellowstone explodes roughly every 600,000 years, and it is about
600,000 years since it last exploded, which should cause us to sit up and take
notice.”
Via Dailygalaxy