Supervolcano eruptions can wipe out civilization

New Delhi: A study has found that 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 team of geologists from the Swiss Federal Institute of Technology in Zurich (ETH) modeled a supervolcano – such as Yellowstone in Wyoming – using synthetic magma heated up with a high-energy X-ray to see what could create a powerful discharge. A separate international team, led by Luca Caricchi of the University of Geneva, conducted more than 1.2 million computer simulations of eruptions. Both groups have arrived at similar conclusions, with two studies simultaneously published in Nature Geoscience magazine. It was previously thought that supervolcanoes – which spew out hundreds more times of lava and ash than ordinary ruptures – could be triggered by earthquakes or other outside tectonic phenomena. It was also clear that these volcanoes do not operate like ordinary eruptions, which rely on magma filling their chambers, and spurting through an opening, once the pressure gets to a certain point, since the chambers of supervolcanoes are too large to be over pressurized to the same degree. Now, the studies have identified the unique supervolcano mechanism that makes their discharge more like powerful explosions than normal eruptions. The molten magma in the mostly underground supervolcano is lighter than the surrounding rocks, and the difference in pressure, creates a 'buoyancy effect', meaning the super-hot terrestrial soup is always attempting to burst out. 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. 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. 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.