If you picture Antarctica, a continent roughly the size of the US and Mexico combined, an endless white void probably comes to mind.
Volcanoes erupting isn’t what most people think of, but this scene could happen as the frozen continent melts, a study has found.
Buried under kilometres of frost are some 100 volcanoes in Antarctica, with only a few peaking above the ice sheets along the western coast.
But the ice at the bottom of the world ice melting – and fast – due climate change.
Researchers from Brown University, Rhode Island, ran 4,000 computer simulations to examine how the loss of this ice would impact the magma chambers churning underneath it.
The Antarctic ice sheet is heavy. Really, really heavy. About 24,380,000 gigatonnes heavy.
Right now, the weight of all those snowflakes is squishing most of the subterranean magma – the lifeblood of volcanoes – down. Magma chambers, hidden deep under the Earth’s crust, hold molten rock under high pressure.
So without the ice, the magma could expand and increase pressure on the chambers, triggering an eruption. Scientists call this process ‘unloading’.
In other words, the ice acts like a cork on a seriously shaken bottle of prosecco.
‘Additionally, the reduced weight from the melting ice above also allows dissolved water and carbon dioxide to form gas bubbles, which causes pressure to build up in the magma chamber and may eventually trigger an eruption,’ the authors wrote in their paper published in the journal Geochemistry, Geophysics, Geosystems.
‘Under these conditions, we find that the removal of an ice sheet above a volcano results in more abundant and larger eruptions.’
Of the at least 138 volcanoes in Antarctica, the majority are subglacial, so aren’t visible from the surface. Only two are active, according to the Global Volcanism Program.
But just because you can’t see these eruptions doesn’t mean they aren’t impacting the area surrounding them.
The heat causes the ice above the volcanoes to melt faster and let even more magma wiggle free, creating a feedback loop.
This won’t happen overnight, however. The process takes place over hundreds of years, the study found, and would continue even if humanity stopped chugging out greenhouse gases.
Ilan Kelman, a professor of disasters and health at the University College London, said the research is ‘important’ to understanding how the changing climate interacts with ancient volcanic systems.
‘While imminent eruptions from this climate-linked mechanism are unlikely, we must always consider extreme climate and volcanism scenarios to better avoid potential disasters,’ he told Metro.
‘This study helps cut through some of the difficulties underlying Antarctic climate-volcanism connections.’
The South Pole’s ice sheets – which contain up to 90% of the world’s total freshwater – are melting three times as fast as a decade ago.
Antarctica shed three trillion tons of ice between 1992 and 2017, according to Nasa.
If all the ice vanished, global sea levels would rise by about 200 feet – a little over the height of the Eiffel Tower.
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