Glaciers melting from climate change may reawaken the world’s most dangerous volcanoes

Glaciers are melting. It may reawaken the world’s most dangerous volcanoes As the planet warms, humans could face a much more risky and explosive future.

A powerful swarm of earthquakes in January suggested one of Iceland’s giant “ice volcanoes” may be awakening after a decade of slumber. In the months that followed, more earthquakes have rocked the ground.

They are a sign that hot, viscous magma is flowing to the roots of Bardarbunga, which lies beneath Europe’s largest glacier Vatnajökull. It’s not a matter of if Bardarbunga erupts, but when — and it could be a big one.

The volcano's 25 square-mile caldera is filled with ice, and when lava and ice meet, the consequences are explosive. When it last awoke in 2014, Bardarbunga produced Iceland’s biggest eruption in more than 200 years, spewing out fountains of lava hundreds of feet high.

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Scientists in Iceland have their eyes on this volcano, along with others nestled under the frozen landscape — roughly half of the country’s 34 active volcanic systems are covered in ice. They are trying to unravel whether a decades-old theory could be correct: that retreating ice, fueled by the climate crisis, is triggering more frequent and more explosive volcanic eruptions.

At the heart of this quest is an effort to understand how the planet functions at a fundamental level, and how what humans are doing at the surface — namely, warming the Earth — could be interacting with natural processes deep beneath the ground.

It’s “a connection that we haven't always understood,” said Ben Edwards, a professor of geosciences at Dickinson College.

If the theory is proven correct, the consequences could be enormous, spelling a much more risky, explosive future, as global warming continues to eat away ice sheets and glaciers at a frenetic pace.

Fire under the ice

Iceland is a perfect natural laboratory for studying the intricacies of volcanoes and ice.

Perched astride two tectonic plates that are wrenching apart, and above a plume of superheated rock, it’s a hotspot of volcanic activity. It’s also icy, albeit much less so than in the past.

About 15,000 years ago, during the last Ice Age, the country was enveloped in a thick ice sheet.