Melting Glaciers Could Awaken Hundreds of Dormant Volcanoes todayheadline

Retreating glaciers could be silently preparing hundreds of dormant volcanoes worldwide for more frequent and explosive eruptions, according to research on six Chilean Andes volcanoes presented at the Goldschmidt Conference in Prague.

The study reveals that as climate change accelerates glacier retreat, the sudden loss of ice weight allows underground magma chambers to decompress, potentially triggering violent volcanic activity across glacier-covered regions including Antarctica.

The phenomenon creates a troubling feedback loop where melting glaciers trigger eruptions that could contribute to further global warming, which in turn accelerates more glacier retreat. While the link between retreating ice and increased volcanic activity has been documented in Iceland since the 1970s, this represents one of the first studies to explore the mechanism in continental volcanic systems.

Ice Weight Controls Volcanic Behavior

Researchers from the University of Wisconsin-Madison used argon dating and crystal analysis to investigate how the Patagonian Ice Sheet’s advance and retreat influenced volcanic behavior over thousands of years. Their analysis of six volcanoes in southern Chile, including the now-dormant Mocho-Choshuenco volcano, reveals how glacial ice acts like a geological pressure cooker.

During the last ice age peak (26,000-18,000 years ago), thick ice cover suppressed eruption volumes while allowing large reservoirs of silica-rich magma to accumulate 10-15 kilometers below the surface. As the ice sheet melted rapidly at the ice age’s end, the sudden weight loss caused crustal relaxation and gas expansion in the magma, triggering explosive eruptions from deep reservoirs.

Pablo Moreno-Yaeger from the University of Wisconsin-Madison, who presented the research, explained the mechanism: “Glaciers tend to suppress the volume of eruptions from the volcanoes beneath them. But as glaciers retreat due to climate change, our findings suggest these volcanoes go on to erupt more frequently and more explosively.”

Global Implications Beyond Iceland

The findings extend concerns about glacier-volcano interactions far beyond Iceland’s well-documented examples. Hundreds of subglacial volcanoes exist worldwide, with Antarctica hosting a particularly large concentration of ice-covered volcanic systems that could become more active as ice sheets retreat.

Key regions requiring increased monitoring include:

• Antarctica’s extensive subglacial volcanic systems
• Parts of North America with glacier-covered volcanoes
• New Zealand’s glaciated volcanic regions
• Russia’s ice-covered volcanic areas

“The key requirement for increased explosivity is initially having a very thick glacial coverage over a magma chamber, and the trigger point is when these glaciers start to retreat, releasing pressure—which is currently happening in places like Antarctica,” Moreno-Yaeger noted.

Climate Feedback Loops and Timing

The research reveals complex interactions between volcanic activity and global climate systems. While individual eruptions can temporarily cool the planet by releasing aerosols—as seen when Mount Pinatubo’s 1991 eruption reduced global temperatures by approximately 0.5 degrees Celsius—multiple eruptions create opposite effects.

“Over time the cumulative effect of multiple eruptions can contribute to long-term global warming because of a buildup of greenhouse gases,” Moreno-Yaeger explained. “This creates a positive feedback loop, where melting glaciers trigger eruptions, and the eruptions in turn could contribute to further warming and melting.”

The volcanic response to glacial melting occurs almost instantly in geological terms, but changes in magma systems develop gradually over centuries. This timeline provides opportunities for enhanced monitoring and early warning systems in vulnerable regions.

Monitoring and Prediction Challenges

The research suggests that scientists need to expand monitoring efforts beyond traditionally active volcanic regions to include glacier-covered systems that may become more active as ice retreats. Understanding the relationship between ice thickness, magma chamber depth, and eruption potential could help predict which volcanic systems pose the greatest future threats.

The study, funded by the National Science Foundation and led by Professor Brad Singer at UW-Madison, is scheduled for publication in a peer-reviewed journal later this year. The work involved collaboration with researchers from Lehigh University, University of California Los Angeles, and Dickinson College.

As climate change continues accelerating glacier retreat worldwide, this research highlights yet another unexpected consequence of warming temperatures—one that could create new volcanic hazards in regions previously considered geologically stable due to their ice cover.

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