Tag: volcano

By Joseph Pinkstone For Mailonline

Original Article

• An eruption would be capable of returning humanity to a pre-civilisation state
• The mammoth explosions could release over 1,000 gigatons of ash into the air
• Super eruptions may occur as regularly as once every 17,000 years
• The window between super-eruptions could be as short as every 5,200 years

The next volcanic ‘super eruption’ with the power to return humanity to a pre-civilised state could be due much sooner than previously thought.

Experts have previously predicted that the massive eruptions are likely to occur roughly once every 45,000 to 714,000 years.

This assessment, made in 2004, is now being challenged by new findings which say that the most likely time frame is just 17,000 years.

Researchers also estimate the eruptions could happen as often as once every 5,200 years.

Geological records studied by researchers from the University of Bristol shows that the most recent volcanic super-eruptions occurred on Earth between 20,000 and 30,000 years ago.

They looked at a database of eruptions, called the LaMEVE database, to make the findings.

By using statistical analysis they discovered that, while large eruptions of around 100 million metric tonnes are less frequent than previously thought, the very largest eruptions of 1,000 gigatonnes or more are much more frequent. 

Jonathan Rougier, professor of statistical science at the university, said: ‘According to geological records, the two most recent super-eruptions were between 20,000 and 30,000 years ago. 

‘On balance, we have been slightly lucky not to experience any super-eruptions since then.

‘It is important to appreciate that the absence of super-eruptions in the last 20,000 years does not imply that one is overdue.

‘What we can say is that volcanoes are more threatening to our civilization than previously thought.

‘The technology and techniques used to determine the average time between super-eruptions can also be used to change the approach of seismologists looking at earthquakes.’ 

The full findings of the study were published in the journal Earth and Planetary Science Letters.  

In human history there have been thousands of sizeable eruptions, but not a genuine super eruption, at least not yet.

By Elana Glowatz

Earth might be due for its next volcanic super-eruption, an event that would devastate the planet and wipe out civilization.

A team of scientists looked into the average time between such monstrous eruptions of volcanoes and found that these catastrophic explosions happen more often than previous scientific estimates would indicate, according to a study in the journal Earth and Planetary Science Letters. The new research put the schedule at roughly 17,000 years after the last one, although it said super-eruptions can occur as quickly as 5,200 years or as late as 48,000 years after its predecessor.

“Volcanoes pose a larger risk to human civilization than previously thought,” the study says.

The University of Bristol explained that geological evidence shows the last two super-eruptions occurred between 20,000 and 30,000 years ago.

“On balance, we have been slightly lucky not to experience any super-eruptions since then,” researcher Jonathan Rougier said in the university statement. “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.”

Previous scientific estimates have calculated a range of 45,000 to 714,000 years between eruptions.

A volcanic explosion is classified as a super-eruption when it spews more than 1,000 gigatons of material into the air and onto the planet’s surface. That’s equal to 2.2 quadrillion pounds of ash, gas and rock. It’s “enough to blanket an entire continent with volcanic ash, and change global weather patterns for decades,” the university explained. “One recent assessment described them as capable of returning humanity to a pre-civilization state.”

The new timeframe for super-eruptions comes as the public, bracing for a large eruption, has been watching Mount Agung in Indonesia spit out ash and molten rock for the last few days and as scientists have warned that glaciers melting due to climate change could change the pressure on Iceland’s icy volcanoes and cause them to explode.

Activity at Mount Agung had changed by Wednesday. While the volcano had previously been upgraded to a red alert level within the Volcano Observatory Notice for Aviation, or VONA for short, it was brought back down to an orange level alert based on information from the Agung Volcano Observatory. Emissions of ash were continuing, possibly reaching as high as 16,500 feet into the air and blowing toward the southeast. There is also seismic activity, including tremors.

When volcanoes erupt, they can kill people by spitting out projectiles or triggering tsunamis, but many die in the dark clouds of rock, ash and gas known as pyroclastic flows, which move faster than people can run or drive to flee the natural disaster.