In the recent issue of Nature Geoscience, researchers have revealed that the dormant supervolcano that lies beneath Yellowstone National Park could have an eruption without any external trigger. That is bad enough but there is more and it gets worse. An eruption of this type of “supervolcano” is hundreds of times more powerful than conventional volcanoes – and has the potential to wipe out civilization as we know it – and is more likely than previously thought.
Well, maybe it doesn’t need to be on your risk assessment anyway if we aren’t going to survive it!
Scientists previously believed many supervolcanic eruptions needed earthquakes to break open the Earth’s crust so magma could escape. But new research suggests that this can happen as a result of the build-up of pressure.
Supervolcanoes represent the second most globally cataclysmic event – next to an asteroid strike – and they have been responsible in the past for mass extinctions, long-term changes to the climate and shorter-term “volcanic winters” caused by volcanic ash cutting out the sunlight.
The last known supervolcanic eruption was believed to have occurred about 70,000 years ago at the site today of Lake Toba in Sumatra, Indonesia. It caused a volcanic winter that blocked out the sun for between six to eight years, and resulted in a period of global cooling lasting a thousand years.
A supervolcano under Yellowstone Park in Wyoming last erupted about 600,000 years ago, sending more than 1,000 cubic kilometres of ash and lava into the atmosphere – about 100 times more than the Mount Pinatubo eruption in the Philippines in 1982, which caused a noticeable period of global cooling.
Following Pinatubo’s eruption, the global average temperature fell by about 0.4C for several months. Scientists predict that a supervolcanic eruption would cause average global temperatures to fall by about 10C for a decade – changing life on earth.
Preventing a supervolcanic eruption is not possible, but scientists are currently trying to devise methods of monitoring the pressure of underground magma in order to predict whether one is imminent.