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Antarctica, a land of ice and FIRE: Active volcano is discovered under continent - and it could speed up melting

The new volcano was found buried beneath an ice sheet in West Antarctica, close to the Executive Committee Range of mountains, pictured. While trying to establish the weight of the ice sheet in the region, seismometers measured two swarms of tremors suggesting the volcano is active

 The volcano is buried 1km beneath the ice sheets of West Antarctica
Swarms of tremors were detected in January 2010 and February 2011
It was found near the extinct volcanoes of the Executive Committee Range
Ash found trapped in the ice came from an eruption 8,000 years ago
The volcano could cause the ice sheet to melt faster than first thought
Forget global warming, the ice sheets of Antarctica face a different and a potentially more imminent threat in the form an active volcano buried deep beneath.
Researchers from Washington University discovered the volcano - which is yet to be named - by accident in the Marie Byrd Land region of West Antarctica.
Swarms of tremors were detected in January 2010 and February 2011 and ash found trapped in the ice suggest it has been active for around 8,000 years.

Scientists now believe that a large eruption could cause the ice sheet to melt faster than first thought and cause sea levels to rise.
In January 2010, a team of scientists from the St. Louis-based university set up two crossing lines of seismographs across Marie Byrd Land in West Antarctica.
Doug Wiens, professor of earth and planetary science at Washington University, and his team wanted to weigh the ice sheet to help create a picture of Antarctica's climate history.

Like a giant CT machine, the seismograph array used disturbances created by distant earthquakes to make images of the ice and rock deep within the region.
The technology found two bursts of seismic events between January 2010 and March 2011, which Wiens' PhD student Amanda Lough believed were caused by a previously unseen volcano buried over half a mile (1 kilometre) beneath the ice sheet.
‘I started seeing events that kept occurring at the same location, which was odd,’ Lough said.
‘Then I realised they were close to some mountains - but not right on top of them.
‘My first thought was, "Okay, maybe it’s just coincidence." But then I looked more closely and realised that the mountains were actually volcanoes and there was an age progression to the range.
'The volcanoes closest to the seismic events were the youngest ones.’
The tremors were weak and very low frequency, which Lough said suggested they weren't caused by movements in tectonic plates, associated with earthquakes.

For example, low-magnitude seismic tremors caused by tectonic movement typically have frequencies of 10 to 20 cycles per second, continued Lough.
The shaking she discovered was in frequencies of 2 to 4 cycles per second.
Lough then used a global computer model of seismic speeds to find exactly where the seismic events were taking place.
It is thought that the newly discovered volcano is near the Executive Committee Range of extinct volcanoes.
The researchers also found that almost all of the events happened between 25 to 40 kilometres below the surface.
Lough said this is ‘extraordinarily deep - deep enough to be near the boundary between the Earth's crust and mantle, called the Moho.’ This suggested to Lough that the tremors weren’t caused by shifting ice or glacial movement. It also further ruled out the tectonic theory.
‘A tectonic event might have a hypocentre 10 to 15 kilometres deep, but at 25 to 40 kilometres, these were way too deep,’ Lough said.
This led Lough and her colleague to conclude the tremors and the waveforms they created looked like Deep Long Period earthquakes, or DPLs, which occur in volcanic areas.
The seismologists also talked to Antarctica experts Duncan Young and Don Blankenship from the University of Texas.
‘Their best guess is that it came from Mount Waesche, an existing volcano near Mount Sidley. But that is also interesting because scientists had no idea when Mount Waesche was last active, and the ash layer sets the age of the eruption at 8,000 years ago.‘
‘Most mountains in Antarctica are not volcanic,’ Wiens said. ‘But most in this area are. Is it because East and West Antarctica are slowly drifting apart? We don't know exactly. But we think there is probably a hot spot in the mantle here producing magma far beneath the surface.’
People aren't really sure what causes DPLs,' Lough continued. ‘It seems to vary by volcanic complex, but most people think it's the movement of magma and other fluids that leads to pressure-induced vibrations in cracks within volcanic and hydrothermal systems.’
Lough added that the volcano will ‘definitely’ erupt in the future but can’t be sure when. Such a subglacial eruption would cause enough heat flow to melt a substantial part of ice sheet.
‘The volcano will create millions of gallons of water beneath the ice - many lakes full,’ said Wiens.
This water will cause surrounding streams and sea levels to rise.
Lough added, though, that only an enormous eruption - one that released a thousand times more energy than a typical eruption - would be strong enough to breach the ice above the volcano.
The findings are published in the Nature Geoscience journal.

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