Brian Wilcox of Nasa’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology came to the conclusion that the supervolcano threat is substantially greater than the asteroid or comet threat.
There are around 20 known supervolcanoes on Earth, with major eruptions occurring on average once every 100,000 years. One of the greatest threats an eruption may pose is thought to be starvation, with a prolonged volcanic winter potentially prohibiting civilization from having enough food for the current population. In 2012, the United Nations estimated that food reserves worldwide would last 74 days.
What is a Supervolcano?
A volcano which erupts and throws magma and rocky particles over an area greater than 240 cubic miles (1000 cubic kilometers) is considered a supervolcano. These massive eruptions dwarf typical volcanic eruptions. It is like comparing a small shock from static electricity to a lightning bolt: Mount Vesuvius produced 100,000 cubic yards of magma per second during its massive explosion in A.D. 79. The damage from this “ordinary” volcano was legendary. If Mount Vesuvius had been a supervolcano, it would have produced 100 million cubic yards of magma per second.
Yellowstone National Park is a famous supervolcano. The last time Yellowstone erupted, 640,000 years ago, the ash blanketed an area from California to Minnesota. If Yellowstone were to erupt again, the ash would be thick enough to collapse roofs on houses in neighboring states. The loss of life would be massive: Tens of thousands of people would die from the immediate eruption and pyroclastic (lava) flow.
The most logical solution could simply be to cool a supervolcano down. A volcano the size of Yellowstone is essentially a gigantic heat generator, equivalent to six industrial power plants. Yellowstone currently leaks about 60-70% of the heat coming up from below into the atmosphere, via water which seeps into the magma chamber through cracks. 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.
Nasa estimates that if a 35% increase in heat transfer could be achieved from its magma chamber, Yellowstone would no longer pose a threat. The only question is how?
One possibility is to simply increase the amount of water in the supervolcano. But from a practical perspective, it would likely be impossible to convince politicians to sanction such an initiative.
Nasa have conceived a very different plan. They believe the most viable solution could be 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 $3.46bn (£2.69bn), it comes with an enticing catch which could convince politicians to make the investment.
“Yellowstone currently leaks around 6GW 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 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.
Cooling Yellowstone in this manner would happen at a rate of one meter a year, taking of the order of tens of thousands of years until just cold rock was left.
4 in the USA
Yellowstone in Wyoming and Montana is the most famous -and potentially dangerous
Long Valley Caldera, California
La Garita Caldera, Colorado
Valles Caldera, New Mexico
1 in Canada
Bennett Lake Volcanic Complex, Yukon, Canada
A supervolcano exists in Naples, Italy. The Campi Flegrei, or Phlegraean Fields.
Several supervolcanoes exist in Asia, including:
Toba in Indonesia
Tambora in Indonesia
Baekdu Mountain on the border of North Korea and China
Aira Caldera, Japan
Kurile Lake, Russia
Pacana Caldera, Chile – Pacana Caldera, San Pedro de Atacama, Antofagasta Region, Chile
Cerro Galan, Argentina – Galán – Catamarca Province, Argentina
Pastos Grandes Caldera, Bolivia
Lake Taupo, New Zealand – Lake Taupo, Waikato, New Zealand
Macauley Island, New Zealand