Antarctica ice melt could cause 100 hidden volcanoes to erupt

By Madeline Reinsel, Eos.org published 10 hours ago

More than 100 volcanoes lurk beneath the surface in Antarctica. Ice sheet melt could set them off.

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an aerial view of an Antarctic volcano

New research finds that ice melt in Antarctica could lead to more subglacial eruptions, affecting volcanoes such as Mount Erebus, seen here. (Image credit: Josh Landis, U.S. Arctic Program, Public Domain)


A slow climate feedback loop may be bubbling beneath Antarctica's vast ice sheet. The continent, divided east to west by the Transantarctic Mountains, includes volcanic giants such as Mount Erebus and its iconic lava lake. But at least 100 less conspicuous volcanoes dot Antarctica, with many clustered along its western coast. Some of those volcanoes peak above the surface, but others sit several kilometers beneath the Antarctic Ice Sheet.

Climate change is causing the ice sheet to melt, raising global sea levels. The melting is also removing the weight over the rocks below, with more local consequences. Ice sheet melt has been shown to increase volcanic activity in subglacial volcanoes elsewhere on the globe. Coonin et al. ran 4,000 computer simulations to study how ice sheet loss affects Antarctica's buried volcanoes, and they found that gradual melt could increase the number and size of subglacial eruptions.

The reason is that this unloading of ice sheets reduces pressure on magma chambers below the surface, causing the compressed magma to expand. This expansion increases pressure on magma chamber walls and can lead to eruptions.

Some magma chambers also hold copious amounts of volatile gases, which are normally dissolved into the magma. As the magma cools and when overburden pressure reduces, those gases rush out of solution like carbonation out of a newly opened bottle of soda, increasing the pressure in the magma chamber. This pressure means that melting ice can expedite the onset of an eruption from a subglacial volcano.

More:
https://www.livescience.com/planet-earth/antarctica/antarctica-ice-melt-could-cause-100-hidden-volcanoes-to-erupt