Supervolcanoes can be found all around the world, sometimes perched atop crowded cities.
Almost all of them are waiting to blow their lids and cover vast swathes of land in ash, lava, and molten rock.
To be a supervolcano, a volcano must have at one point in history had an eruption with a Volcanic Explosivity Index (VEI) of 8, the largest recorded value on the index.
Some supervolcanoes are the world’s most famous volcanoes, the likes of Yellowstone in the US and Lake Toba in Indonesia the subjects of countless documentaries and films.
While we know supervolcanoes will erupt, little serious work has gone into monitoring them and figuring out what to do in the event of an eruption — with a team of geologists previously warning that ensuing chaos has largely been ignored.
Supervolcanoes often erupt several times with tens of thousands of years lapsing between each event, the last eruption coming at New Zealand’s Taupo some 27,000 years ago.
The problem, according to Professor Martin Danisik, from the John de Laeter Centre based at Curtin University, is that little is known about what happens at the supervolcanoes during the intervals.
Writing in a paper published in the science journal Nature in 2021, he noted that, “gaining an understanding of those lengthy dormant periods will determine what we look for in young active supervolcanoes to help us predict future eruptions.”
He continued: “Super-eruptions are among the most catastrophic events in Earth’s history, venting tremendous amounts of magma almost instantaneously.
“They can impact global climate to the point of tipping the Earth into a ‘volcanic winter,’ which is an abnormally cold period that may result in widespread famine and population disruption.
“Learning how supervolcanoes work is important for understanding the future threat of an inevitable super-eruption, which happen about once every 17,000 years.”
Yet, while scientists know a lot about the world’s supervolcanoes, few if any of them are regularly monitored and examined.
Professor Christopher Kilburn, a volcanologist at University College London (UCL), previously told Express.co.uk it was a “myth” that the world’s supervolcanoes were being watched by the appropriate authorities.
Worryingly, he said, supervolcanoes are of such a size that it is near impossible to prepare against their eventual eruptions.
“When hazards like these things become so huge, you really can’t prepare very much,” he said.
“We see with very large earthquakes, the best you can do is to try and build buildings that are unlikely to fall — but for the rest, what can you do?”
He added: “You just have to hope to god that when the earthquake strikes they stay up, but of course, we see around the world where buildings do inevitably collapse after regular earthquakes, but there are very few contingency plans after that: there are just emergency measures to help people.”
In the paper, Prof Danisik and his team investigated the magma left behind after Lake Toba’s super eruption a whopping 75,000 years ago.
Using various data and modelling, they showed that magma continued to ooze out of the caldera — a large dip in the ground created by the eruption — for between 5,000 to 13,000 years after the eruption.
The leftover magma was then pushed upward into the sky like a giant shell.
The findings, the team said, “challenged existing knowledge and studying of eruptions,” and scientists must now, “consider that eruptions can occur even if no liquid magma is found underneath a volcano—the concept of what is ‘eruptible’ needs to be re-evaluated.”
