Science

Supervolcanoes are catastrophic for thousands of years after a super-eruption, study warns

A ‘catastrophic’ supervolcano eruption that could severely impact Earth’s climate and tip it into a ‘volcanic winter’ is more likely to happen than previously believed, a new study suggests.

Experts at Australia’s Curtin University studied Indonesia‘s Lake Toba, the home of the supervolcano Toba Caldera, and found that supervolcanoes are active and dangerous thousands of years after a super-eruption. 

They found that between 5,000 and 13,000 years after the eruption, ‘magma continued to ooze out within the caldera,’ before ‘the carapace of solidified left-over magma was pushed upward like a giant turtle shell,’ Curtin University Associate Professor Martin Danišík said in a statement

The researchers looked at minerals feldspar and zircon left over from the eruption, which help them understand the timing of the event, as well as gases such as argon and helium that are trapped in the volcanic rocks to come up with their conclusion.  

A ‘catastrophic’ supervolcano eruption that could tip Earth into a ‘volcanic winter’ is more likely to happen than previously believed

Between 5,000-13,000 years after Toba Caldera erupted, magma continued to ooze out

Between 5,000-13,000 years after Toba Caldera erupted, magma continued to ooze out

In doing so, it may have released as much as six billion tons of Sulphur dioxide and may have lowered global temperatures by 59 degrees Fahrenheit for years afterwards, according to some researchers. 

‘The findings challenged existing knowledge and studying of eruptions, which normally involves looking for liquid magma under a volcano to assess future hazard,’ Danišík added. 

Experts looked at feldspar and zircon left over from the eruption and gases such as argon and helium trapped in volcanic rocks

Experts looked at feldspar and zircon left over from the eruption and gases such as argon and helium trapped in volcanic rocks 

‘We 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.’ 

On average, supervolcanoes erupt about once every 17,000 years. 

The most recent volcano eruption occurred beneath Lake Taupo in New Zealand around 22,600 years ago, according to the US Geological Survey.  

Toba Caldera erupted approximately 74,000 years ago and spewed out at least 1,740 cubic miles (2,800 kilometers) of ‘rhyolite magma from a ‘warm’ reservoir several times that volume,’ according to the study.  

Toba Caldera, located in Indonesia's Lake Toba (pictured) may have released 6 billion tons of Sulphur dioxide and lowered global temperatures by 59 degrees for years after the eruption

Toba Caldera, located in Indonesia’s Lake Toba (pictured) may have released 6 billion tons of Sulphur dioxide and lowered global temperatures by 59 degrees for years after the eruption

Danišík explained that super eruptions are ‘among the most catastrophic events in Earth’s history,’ releasing thousands of cubic feet of magma almost instantly.

‘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.’

Experts looked at feldspar and zircon left over from the eruption and gases such as argon and helium trapped in volcanic rocks

Experts looked at feldspar and zircon left over from the eruption and gases such as argon and helium trapped in volcanic rocks

SUPER ERUPTIONS 

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

These extra large eruptions posses devastating power, capable of releasing enough volcanic ash to cover a whole continent and have the potential to wreak havoc with the weather, as weather patterns would change for decades to come.

The largest eruption of the last two million years ago was the eruption at Toba Caldera in Sumatra, Indonesia which spewed 671 cubic miles (2,800 cubic km) of volcanic ash into the atmosphere.

That’s enough to cover about half of the United States. 

The island in the middle of Lake Toba is thought to be a direct result of the earth bulging due to increasing pressure from the increasingly active magma chambers below the Earth’s surface. 

A rapid cooling, such as the one believed to be associated with Toba Caldera eruption, are ‘consistent with catastrophic eruption,’ the authors wrote in the study.

‘In contrast, the age discordance in the post-caldera domes implies a more complex thermal history.’  

The researchers looked at minerals feldspar and zircon left over from the eruption, which help them understand the timing of the event, as well as gases such as argon and helium that are trapped in the volcanic rocks to understand how super volcanoes work and why they erupt about once every 17,000 years.

‘Using these geochronological data, statistical inference and thermal modeling, we showed that magma continued to ooze out within the caldera, or deep depression created by the eruption of magma, for 5000 to 13,000 years after the super-eruption, and then the carapace of solidified left-over magma was pushed upward like a giant turtle shell,’ Danišík said. 

Super volcanoes such as Toba Caldera have erupted multiple times in their history, but understanding what happens between these eruptions, in the lengthy dormant eruptions, can help scientists have a better idea of when they will erupt next, Danišík added.

‘While a super-eruption can be regionally and globally impactful and recovery may take decades or even centuries, our results show the hazard is not over with the super-eruption and the threat of further hazards exists for many thousands of years after,’ Danišík added.  

The findings could have implications for the other 20 supervolcanoes on Earth, including the most studied, the one under Yellowstone National Park (pictured)

The findings could have implications for the other 20 supervolcanoes on Earth, including the most studied, the one under Yellowstone National Park (pictured)

The findings could have implications for the other 20 supervolcanoes on Earth, including the most studied, the one under Yellowstone National Park.

‘Learning when and how eruptible magma accumulates, and in what state the magma is in before and after such eruptions, is critical for understanding supervolcanoes,’ Danišík said. 

The research was published in journal Nature—Earth and Environmental Sciences

NASA’S PLAN TO PREVENT A SUPERVOLCANIC ERUPTION 

Nasa believes drilling up to six miles (10km) down into the supervolcano beneath Yellowstone National Park to pump in water at high pressure could cool it.

Despite the fact that the mission would cost $3.46 billion (£2.63 billion), Nasa considers it ‘the most viable solution.’ 

Using the heat as a resource also poses an opportunity to pay for plan – it could be used to create a geothermal plant, which generates electric power at extremely competitive prices of around $0.10 (£0.08) per kWh.

But this method of subduing a supervolcano has the potential to backfire and trigger the supervolcanic eruption Nasa is trying to prevent.

‘Drilling into the top of the magma chamber ‘would be very risky;’ however, carefully drilling from the lower sides could work. 

Even besides the potential devastating risks, the plan to cool Yellowstone with drilling is not simple.

Doing so would be an excruciatingly slow process that one happen at the rate of one metre a year, meaning it would take tens of thousands of years to cool it completely. 

And still, there wouldn’t be a guarantee it would be successful for at least hundreds or possibly thousands of years. 

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