Melting ice in Antarctica could trigger volcanic eruptions beneath the continent’s vast ice sheet, creating a slow but dangerous feedback loop, scientists warn.
A new study suggests the melting of Antarctica’s ice sheet, driven by the climate crisis, may increase volcanic activity under the surface.
Antarctica is home to over 100 volcanoes, many of which lie hidden beneath the ice sheet, particularly along the western coast. While some of these volcanoes peak above the ice, many are buried deep below, making them harder to detect and study.
Researchers ran 4,000 computer simulations to examine how the gradual loss of ice affects magma chambers buried under the Antarctic ice sheet.
The findings indicate that as the ice melts, it relieves pressure on the rocks below, allowing the compressed magma to expand. This process increases pressure on the walls of magma chambers, potentially triggering volcanic eruptions.
The study highlights how the weight of the ice sheet acts as a cap on the magma below. When the ice melts, the overburden pressure drops, allowing gases dissolved in the magma to escape — much like opening a soda bottle. This gas release builds pressure in the magma chamber, increasing the likelihood of an eruption.
Though these eruptions occur beneath the surface and may not be visible, they can have significant consequences. Heat from subglacial volcanic eruptions can accelerate melting deep below the surface, weakening the ice sheet and potentially leading to further volcanic activity.
Scientists warn that this process could create a slow feedback loop: melting ice reduces surface pressure, leading to more volcanic eruptions, which in turn produce heat that accelerates ice melting.
“Eruptions beneath the ice sheet could add to the melting, compounding the challenges already posed by rising global temperatures,” the study states.
The research suggests that this feedback mechanism operates over centuries, meaning the effects could persist even if humanity drastically reduces greenhouse gas emissions. Historical evidence indicates that similar processes may have occurred during the last ice age when Antarctica’s ice sheet was much thicker.
While the study emphasizes the slow pace of these changes, it raises concerns about Antarctica’s long-term stability and the implications for global sea levels. The continent’s ice sheet is already a major contributor to rising seas, and increased volcanic activity could amplify the problem.
Antarctic sea ice has been shrinking in recent years, hitting near-record lows in 2024.
The 2024 winter maximum for Antarctic sea ice was the second lowest on record.
