Antarctica is the land of ice, where average inland temperatures consistently hit −43.5C all year round.
So you’d be forgiven for not knowing that the icy continent is home to several volcanoes. Perhaps the most famous volcano is Mount Erebus, the tallest active anywhere in Antarctica.
Erebus last erupted in 2020, and scientists rushed to observe and absorb all the data they could get from it.
But there is an altogether more sinister side to Antarctica that researchers only discovered in recent years, a system of more than 100 volcanoes scattered beneath the ground – which could affect serious global change should they erupt.
In 2017, a team from Edinburgh University charted Antarctica’s dark underbelly and found the largest volcanic region on Earth.
Located just two kilometres beneath the surface and hiding beneath an ice sheet, it stretches across the content’s western front.
The researchers involved suggested the region was even bigger than East Africa’s volcanic ridge, rated as once having the world’s densest concentration of volcanoes.
John Smellie, Professor of Volcanology at the University of Leicester, proposed that the slightest movement from these volcanoes could create significant amounts of meltwater.
That is because this water would trickle into the sea via streams and slowly but surely raise global levels.
“The volcanoes would melt huge caverns in the base of the ice and create enormous quantities of meltwater,” he wrote in a piece for The Conversation.
“Because the West Antarctic Ice Sheet is wet, rather than frozen to its bed – imagine an ice cube on a kitchen worktop – the meltwater would act as a lubricant and could cause the overlying ice to slip and move more rapidly.
“These volcanoes can also stabilise the ice, however, as they give it something to grip onto – imagine that same ice cube snagging onto a lump-shaped object.
“In any case, the volume of water that would be generated by even a large volcano is a pinprick compared with the volume of overlying ice.
“So a single eruption won’t have much effect on the ice flow. What would make a big difference, is if several volcanoes erupt close to or beneath any of West Antarctica’s prominent ‘ice streams’.”
Some 80 percent of the planet’s freshwater reserves are located in Antarctica, and in a scenario in which those ice stores melted, global sea levels could rise by around 60 metres.
It would create an uninhabitable environment for humans, flooding much of the world’s coastal regions and leading to crop failures and potentially famine.
“Ice streams are rivers of ice that flow much faster than their surroundings,” said Prof Smellie.
“They are the zones along which most of the ice in Antarctica is delivered to the ocean, and therefore fluctuations in their speed can affect the sea level.
“If the additional ‘lubricant’ provided by multiple volcanic eruptions was channelled beneath ice streams, the subsequent rapid flow may dump unusual amounts of West Antarctica’s thick interior ice into the ocean, causing sea levels to rise.
“Under-ice volcanoes are probably what triggered a rapid flow of ancient ice streams into the vast Ross Ice Shelf, Antarctica’s largest ice shelf.”
Researchers believe something similar may have happened around 2,000 years ago after a small eruption in the Hudson Mountains.
They lie beneath Antarctica’s western ice sheet, which if erupted today, could cause the nearby Pine Island Glacier to speed up its melt rate.
Prof Smellie added: “Most dramatically of all, a large series of eruptions could destabilise many more subglacial volcanoes.
“As volcanoes cool and crystallise, their magma chambers become pressurised and all that prevents the volcanic gases from escaping violently in an eruption is the weight of overlying rock or, in this case, several kilometres of ice.
“As that ice becomes much thinner, the pressure reduction may trigger eruptions. More eruptions and ice melting would mean even more meltwater being channelled under the ice streams.”
For now, Antarctica seems fairly quiet on the volcanic front, as most of its volcanoes are either dormant or haven’t erupted for at least 10,000 years — but this doesn’t stop scientists from keeping a close eye on them.
