Hidden thr...

Hidden threat discovered under the ice in Antarctica: could have major consequences

Using a wide range of computer simulations, climate researchers have identified an overlooked mechanism under the Antarctic ice sheet that could have severe consequences for global sea levels.

Ice such as this will eventually make sea levels rise. Beneath the ice, a threat is lurking that has not been factored into current climate models - but it should be, scientists say.

Text Søren Rosenberg Pedersen | Published on

You will find the largest mass of ice on Earth in Antarctica; ice that is sometimes 2+ km thick and covers almost 14 million square km.

This is where 90+ % of Earth's freshwater reserves are located, which is why climate researchers are also very focused on the consequences of the ice melting.

If the entire ice sheet were to disappear, it would make sea levels rise by 61.1-70 m, but even partial melting could have major consequences for global sea levels.

Now geologists have located a new threat beneath the ice sheet.

According to a research team led by Brown University in the US, the melting of the Antarctic ice sheet could fuel hidden volcanoes beneath the ice, causing them to erupt and melt even more ice from below.

Antarctica is one of the most volcanically rich regions on the planet, with 100+ of the smouldering giants discovered over the years.

Most of them are located far below the ice sheet and are referred to as subglacial or glaciovolcanoes. Many of them are clustered along the west coast.

May have irreversible consequences

Scientists have already observed that the activity of the ice-covered volcanoes intensifies with the melting of the ice sheet.

Therefore, the team of geologists ran 4,000 computer simulations with scenarios of how the melting of the ice sheet would affect the continent's ice-covered giants.

The conclusion was clear: most scenarios produced an outcome in which the gradual melting of the ice sheet led to an increased number of volcanic eruptions.

mount erebus — Famous for its permanent lava lake, Mount Erebus is one of the volcanoes that scientists believe will be influenced.
© Josh Landis, U.S. Antarctic Program, Public Domain

As the volume of ice above the volcanoes is reduced, so is the pressure on the magma chambers below the volcanoes, making the compressed magma expand.

This increases the pressure on the chamber walls, possibly leading to volcanic eruptions.

Several magma chambers contain large quantities of volatile gases. As the magma cools and the pressure drops, the gases dissolve, increasing the pressure in the magma chamber.

The heat from the eruptions will cause the ice sheet to melt faster, generating more eruptions and raising sea levels. Scientists call it a feedback loop.

The team points out that the process is slow and happens over hundreds of years.

This also means that the mechanism can continue once it has started - even if we limit man-induced global warming.

The ice sheet has already shrunk significantly and is a major contributor to rising sea levels.

The results have been <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GC011743" ‘target’="‘_blank’">published in Geochemistry, Geophysics, Geosystems.