Although super-eruptions capable of altering the course of history may sound like fantasy, they are actual events with historic precedent.
Previous estimates suggested that super-eruptions happen roughly every 45,000 to 714,000 years, but a shock new study found that they could be much more frequent.
The study by a team of scientists from Bristol University found that these deadly eruptions may actually happen every 17,000 years or so.
This means our next super-eruptions might be overdue. The two most recent super-eruptions to rock Earth happened somewhere between 20 and 30 thousand years ago.
Jonathan Rougier, professor of statistical science at Bristol University, said: “On balance, we have been slightly lucky not to experience any super-eruptions since then.
“But it is important to appreciate that the absence of super-eruptions in the last 20,000 years does not imply that one is overdue. Nature is not that regular.
“What we can say is that volcanoes are more threatening to our civilisation than previously thought.”
Dr Thomas Knott, an XRF geochemist at University of Leicester, thinks that super-eruptions do not spell the end of the world but we do need to pay more attention to them.
He said: “There is definitely a lot of sensationalism when it comes to the destructive capabilities of supervolcanoes.
“I don’t think I would say a super-eruption would send us back to the ‘prehistoric age’ but there are a lot of telling signs about the dangerous effects they would have.”
Supervolcano: The Campi Flegrei is a supervolcano west of Naples, Italy
He said that the last supervolcano eruption – the Taupo super-eruption in New Zealand some 26,500 years ago – had an impact on “bottlenecking the development of civilisation”.
We don’t know what the warning signs of an imminent super eruption would be
He added: “Large super-eruptions would definitely have an effect. These would be extremely catastrophic and hard to deal with in terms of modern civilisation.”
A supervolano eruption would destroy crops and the sheer amounts of volcanic ash could choke out the sky, limit sunlight and cover the earth in a way that would “wipe out” several species.
“We should also think about the effects super-eruptions would have on climate change and global warming,” he added.
“Superimposing such large amounts of CO2, methane, sulphur dioxide ad other gases would have great impact. These effects would certainly be global.”
Aside from the theoretical impacts, the most terrifying fact is that there are currently no warning signs that could predict an imminent super-eruption.
Scientists and geologists would apply warning signs and monitoring scales applicable to lesser volcanoes, but there is no way of telling how accurate these will be.
Dr Knott said: “As far as warning signs go, then we simply don’t quite know.
“It’s a subject that is both fascinating and worrying because we don’t know what the warning signs of an imminent super eruption would be.”
He added: “Based on the measurement scales I use for calculating frequency estimates of super-eruptions, I think we certainly are overdue.
Supereruption: The Yellowstone supervolcano could cover the entire US in volcanic ash
“But again, this is dependant on the scale of measurement that you use. The frequency estimate that I use, is about one in one million.”
The closest supervolcano to the UK, is the Campi Flegrei or Phlegraean Fields, found mostly underwater west of Naples, Italy, around the Golfo di Pozzuoli.
There is no way of predicting how devastating Campi Flegrei’s eruption could be, but Dr Knott thinks all you have to do is look at the history of super-eruptions to get a rough idea.
He said: “It’s hard to tell how the Phlegraean Fields would impact the UK and Europe, but you can look at other super-eruptions to make a guess.
“The Yellowstone eruption would spread its volcanic ash all across the United States, up to the Eastern Seaboard.
“So you can assume that we would feel similar effects here in Europe if that were to go off – though I am not as familiar with this specific volcano.”
Ultimately Dr Knot underlined that humanity’s impact on Earth is nothing more than a “minor blip” compared to what our planet is capable of achieving in its own.
He stressed that super-eruptions are known to have had an impact on the development of civilisation in the past, and therefore we need to pay more attention to this field of research.
A supervolcano is anything that exceeds Magnitude 8 on the Volcanic Eruption Index (VEI). The VEI measures the volcano’s output, plume height and the characteristics of its eruption.
No two supereruptions are alike, but their destructive capabilities are fearsome.
Supervolcano: Forecast methods for lesser volcanoes may not be applicable to supereruptions
To compare, the largest historical eruptions of Tambora in 1815 and Krakatau in 1883 in Indonesia, had relatively small outputs of 30km^3.
The last large Yellowstone eruption ejected a terrifying 1,000km^3 of ash and pumice. Or to put into perspective, a cube with 10 km sides.
Mr Knott said: “Just in terms of scale, supervolcanoes are hardly comparable to regular volcanoes.
“In terms of their upper mass they can reach 10^15 or 10^16 in erupted volume, so there is absolutely no comparison.
“There are are currently about 20 supervolcanoes that we know off, but these numbers will vary depending on the scientific scales that you use to establish this.
“Whether or not there are supervolcanoes that we don’t know off is is a tricky question. There is always a chance that there are some we don’t know of, but again this depends on how you measure them.”
Despite the ongoing eruption of Bali volcano Mount Agung on Indonesia’s island of Bali, tens of thousands of people remain in the danger zone around the crater.
Agung’s last major eruption in 1963 killed over 1,100 people – a magnitude 5 eruption on the VEI.