- When the supervolcano that lies beneath Yellowstone
Park in Wyoming finally awakes from its 640,000-year slumber, it will spew
out enough ash and magma to change the world as we know it. This is the
prediction of scientists who have calculated that the global risk posed
by a supervolcanic eruption somewhere in the world is between five and
ten times greater than the probability of being struck by a giant
- But it is the huge lake of molten magma lying dormant
under the lush landscape of Yellowstone that is causing the greatest
to vulcanologists studying the special threat posed by
- Earth scientists commissioned by the Geological Society
of London have calculated that there may be several super-eruptions big
enough to cause a global disaster every 100,000 years - whereas an asteroid
larger than 1km (0.62 miles) in diameter would be expected to hit the Earth
once in about 600,000 years.
- Supervolcanoes may not look much - most do not even have
the traditional cone of a Vesuvius or a Mount St Helens - but their
for destruction is many times greater than a traditional volcanic
- A super-eruption at Yellowstone would be far more
for the world than the eruptions at Tambora in 1815, Krakatoa in 1883 and
Pinatubo in 1991 which all caused global climate disturbances for several
years after the event. Super-eruptions are hundreds of times larger than
- biggest volcanic explosions of recorded history and their
effects on the global climate are much more severe, said Professor Stephen
Self, a vulcanologist at the Open University.
- "An area the size of North America can be devastated
and pronounced deterioration of global climate would be expected for a
few years following the eruption," Professor Self explained.
could result in the devastation of world agriculture, severe disruption
of food supplies and mass starvation. These effects could be sufficiently
severe to threaten the fabric of civilisation."
- A two-part drama-documentary - Supervolcano - to be
this Sunday and Monday on BBC1 spells out what could happen if the
under Yellowstone National Park should erupt in the near future. The
makers worked closely with volcano specialists, including scientists at
the US Geological Survey, who are closely monitoring Yellowstone, to depict
the most realistic scenario leading up to and in the immediate aftermath
of a massive eruption.
- It shows what would happen if some 2,000 million tons
of sulphuric acid were ejected into the atmosphere to block out sunlight
over much of the planet causing global temperatures to plummet by between
10C and 20C.
- It also describes the chaos and panic caused by the
of billions of tons of volcanic ash over huge swaths of North America.
Scientists calculate that it would be equivalent to covering an area the
size of Britain in four metres of ash.
- Ailsa Orr, the series producer, said the film-makers
consulted the US Federal Emergency Management Agency (Fema), which handled
the aftermath of the 11 September terror attack on New York and Washington,
and found there was little planning for such a natural disaster.
- "Fema had no contingency plans for a disaster on
this scale. The largest disaster they ever had to deal with was 9/11 and
that stretched their resources to the limit," Ms Orr said.
- "Our scenario would affect an area 10 million times
greater than 9/11 did. Fema were extremely interested in working with us
to come up with a theoretical plan as to how they might deal with it. They
gave us data on how many people would be affected by the eruption in the
- Satellite images show that the mouth or caldera of the
Yellowstone supervolcano is 85km (53 miles) long and 45km (28 miles) wide
- which amounts to an area big enough to swallow Tokyo, the largest city
in the world.
- Five miles underneath the surface of Yellowstone sits
the volcanic chamber itself which is estimated to hold 25,000 cubic
of molten rock or magma. Seismologists and vulcanologists working for the
Yellowstone Volcano Observatory routinely monitor the regular swellings
and subsidences of the land as it responds to shifting underground lake
of molten rock below.
- Ms Orr said that the makers of the drama-documentary
liaised closely with the scientists at the observatory as well as other
specialists and consultants. "We started by examining data from the
first super-eruption of Yellowstone which happened 2.1 million years ago.
We also looked at the evidence of the last supervolcanic eruption on the
planet which happened at Toba in Indonesia 74,000 years ago," she
- Some scientists believe that the Toba eruption, which
caused global climatic disturbances, may have even caused a genetic
in human genetic diversity following a dramatic decline in the global
If the Yellowstone supervolcano were to erupt in a similar fashion the
ash that it would spew out would cover three-quarters of North America
in a layer deep enough to kill crops and other plants.
- Few people would survive in the zone immediately around
the eruption as the volcanic gases and choking sulphur dioxide would burn
the lungs of anyone caught in the open air. Those sheltering in their homes
would not be safe because layers of heavy volcanic ash would eventually
cause their roofs to collapse.
- The supervolcanic eruption of the Toba volcano in Sumatra
ejected about 300 times more volcanic ash than the eruption of Tambora
in Indonesia in 1815 - which caused a "year without a summer"
in 1816 and prompted Lord Byron to write his poem
- A report on supervolcanoes compiled by the Geological
Society states: "It is easy to imagine that an eruption on the scale
of Toba would have devastating global effects. A layer of ash estimated
at 15 cm thick fell over the entire Indian subcontinent with similar
over much of south-east Asia. Most recently, the Toba ash has been found
in the South China Sea, implying that several centimetres also covered
- "Just one centimetre of ash is enough to devastate
agricultural activity ... Many millions of lives throughout most of Asia
would be threatened if Toba erupted today," it says.
- Ms Orr said the University of Utah and the UK Met Office
had helped to compile a map of the fallout that might result from the
of ash from the Yellowstone supervolcano.
- "From this, we created an ash projection map which
took into account wind direction and time of year of our eruption. Every
time we refined our storyline we would send it back to them for approval
so they were closely involved," she said.
- But it is the emission of sulphuric acid into the
that would create the greatest long-term problems for countries further
afield, as the biggest volcanic eruptions of the past 200 years have shown,
warns Professor Steve Sparks of Bristol University, a consultant to the
programme. "They caused major climatic anomalies in the two or three
years after the eruption by creating a cloud of sulphuric acid droplets
in the upper atmosphere. These droplets reflect and absorb sunlight, and
absorb heat from the Earth - warming the upper atmosphere and cooling the
lower atmosphere," Professor Sparks said.
- "The global climate system is disturbed, resulting
in pronounced, anomalous warming and cooling of different parts of the
Earth at different times."
- If enough sulphuric acid were released - and Yellowstone
could emit 2,000 million tons - then what could take place would be the
equivalent of a "nuclear winter", when the dust and debris from
the fallout of a nuclear war block out sunlight for several years causing
- The Max Planck Institute in Hamburg helped the makers
of Supervolcano to model the spread of sulphuric acid around the
- "We're talking about catastrophic amounts of
acid circling the world within just a few weeks. It forms a veil that
out sunlight, causing temperatures to plummet," Ms Orr said.
- "The Met Office models predicted a drop of about
15C across Europe and 20C in the southern hemisphere, the monsoon would
stop, crops would fail and somewhere in the region of one billion people
would die through climate change and starvation," she added.
- Supervolcano depicts the Yellowstone caldera erupting
over several days, progressively "unzipping" the build-up of
underground pressure in a series of eruptions around the rim of the crater
rather than releasing everything all at once in one giant eruption.
- Ms Orr said: "The first thing we had to get right
was to understand the dynamics of a super-volcanic eruption - how it would
unfold, what it would look like. It's very difficult to know for sure
nobody has ever seen a super-eruption happen but we consulted with a lot
of scientists and the consensus of opinion was that a super-eruption is
not just one big massive eruption but a series of separate eruptions around
the rim of the caldera.
- "Only towards the end of the eruption process do
they all converge into one. Once this scenario had been signed off by the
scientists, we got a storyboard artist to visualise it so everyone was
clear on what we had to create in the film."
- Nobody knows whether a supervolcanic eruption at
is imminent. The programme-makers say at the start of their film that they
have not made fiction, and they have made a true story - it's just that
it hasn't happened yet.
- The Yellowstone supervolcano is know to have erupted
three times in the past 2.1 million years at a regularity of about 600,000
years. The last one happened 640,000 years ago.
- Yet vulcanologists such as Professor Sparks point out
that this does not mean that another eruption is overdue. "It doesn't
work like that. We just don't know when the next eruption will occur,"
- Neither do scientists know how much warning the world
will be given. "Frankly we don't really know, that's the real
Professor Sparks said.
- But what we do know is that we are ill-prepared for such
an event if it should take place in the near future. "You can't stop
it. One could have to start to think about the strategies for dealing with
consequences and to be frank, that's not been thought through at all,"
Professor Sparks said.
- One thing remains certain in this uncertain world of
low-risk, high-impact disasters. If the Yellowstone supervolcano should
ever blow, our world will never be the same again, and might not even
in its present form.
- HOW THE RISKS MEASURE UP
- According to scientists, the risk of a super-eruption
somewhere in the world is five to 10 times greater than that of the world
being hit by an asteroid. How does that compare with the other dangers
we face daily?
- The chances of being killed by being struck by lightning
is thought to be about one in 10 million. In the UK, an estimated five
people, out of a population of about 50 million, are killed by lightning
- Air crash
- The chances of being involved in an aircraft accident
are about one in 11 million, while the chances of being killed in a car
accident is one in 8,000.
- Train crash
- The risk of dying in an accident on the railway is one
- Nuclear accident
- The risk of an individual dying from radiation from a
nuclear power station is one in 10 million.
- Dangerous jobs
- The occupational risk of being killed in deep-sea fishing
is one in 750. With coal mining, it is one in 7,500. In construction, this
increases to one in 10,000, and for the service industries, it is one in
- Playing football
- The risk of dying while playing a game of football is
one in 25,000.
- Asteroid collision
- Some scientists believe that an asteroid spotted in
2004 had a one-in-four chance of hitting the planet within 36 hours.
contemplated a call to President George Bush before new data finally showed
there was no danger. The bookmakers William Hill, meanwhile, said the odds
of the asteroid hitting Earth on March 2014 and wiping life off the planet
was 909,000 to one.
- ©2005 Independent News & Media (UK) Ltd.