About 20 of these volcanoes, which scientists believed to be semi-dormant, may still pose a current risk, according to research.
Until now, it was generally believed that the probability of an eruption depended on the presence of liquid magma under a volcano.
But the new research – coordinated by Oregon State University, US, with scientists around the world – has found evidence that “eruptions can occur even if no liquid magma is found. “.
If so, it means that various supervolcanoes that were previously thought to contain only potential future danger could still be very dangerous to humanity at this time.
“The concept of what is ‘eruptible’ needs to be re-evaluated,” said Associate Professor Martin Danisik of Curtin University in Australia, one of the lead authors of the research published this week in the journal Communications Earth & Environment.
The team came to the conclusion after investigating what happened after the Lake Toba super-eruption some 75,000 years ago in what is now Indonesia.
The event itself is said to have caused a multi-year global winter that reduced the human population at the time to just 3,000 people.
Professor Danisik said: “Super-eruptions are among the most catastrophic events in Earth’s history, discharging huge amounts of magma almost instantly. They can impact the global climate to the point of tipping the earth into a “volcanic winter,” which is an unusually cold period that can lead to widespread famine and population disruption.
“Learning how supervolcanoes work is important to understanding the future threat of an inevitable super-eruption. “
He added: “While a super-eruption can have a regional and global impact and recovery can take decades or even centuries, our results show that the danger is not over with the super-eruption and that the threat of other dangers exists for several thousand years later.
“Learning when and how eruptible magma accumulates, and what state the magma is in before and after such eruptions, is essential to understanding super volcanoes. “