Risk of supervolcano eruption big enough to 'affect the world' far greater than thought, say scientists

The eruption of a “supervolcano” hundreds of times more powerful than conventional volcanoes – with the potential to wipe out civilisation as we know it – is more likely than previously thought, a study has found.

An analysis of the molten rock within the dormant supervolcano beneath Yellowstone National Park in the United States has revealed that an eruption is possible without any external trigger, scientists said.

Scientists have analysed magma from the Yellowstone caldera, a 55-mile-wide underground cavern containing between 200 and 600 cubic kilometres of molten rock, to see how it responds to changes in pressure and temperature. Using a powerful X-ray source at the European Synchrotron Radiation Facility in Grenoble, France, the researchers found that the density of the magma decreased significantly at the high temperatures and pressures experienced underground.

[link to www.independent.co.uk]