Melting glaciers could awaken hundreds of dormant volcanoes

According to a study of six Chilean Andes volcanoes presented at the Goldschmidt conference in Prague, retreating glaciers may silently prepare hundreds of dormant volcanoes around the world for more frequent and explosive eruptions.

The study shows that as climate change accelerates glacier retreats, sudden loss of ice weight decompresses underground magma chambers and may trigger violent volcanic activity across glacier-covered areas, including the Antarctic.

The phenomenon creates an unsettling feedback loop, and the melted glacier triggered outbreaks may help further global warming, which in turn accelerates more glacier retreats. Although Iceland has documented the link between retreating ice and increasing volcanic activity since the 1970s, it is one of the earliest studies to explore the mechanisms of continental volcanic systems.

Ice-heavy controls volcanic behavior

Researchers at the University of Wisconsin-Madison used argon dating and crystal analysis to study how the advancement and retreat of the Patagonian ice sheet affected volcanic behavior for thousands of years. Their analysis of six volcanoes in southern Chile, including the present Moorish cho-Choshuenco volcano, revealed the role of glacial ice like geological pressure cookware.

At the peak of the last Ice Age (26,000-18,000 years ago), thick ice caps suppressed eruptions while allowing a large number of silicon dioxide-rich magma reservoirs to accumulate 10-15 kilometers below the ground. As borneol melts rapidly at the end of the Ice Age, sudden weight loss can cause crust relaxation and gas expansion in the magma, triggering explosive eruptions in the deep reservoir.

Pablo Moreno-Yaeger of the University of Wisconsin-Madison, who explained the mechanism: “Glaciers tend to suppress the eruptions of the volcanoes below. However, due to the glacier retreat caused by climate change, our findings suggest that these volcanoes are increasingly frequent and erupting more frequently.”

Global Meanings Beyond Iceland

These findings bring concerns about glacier-Valcano interactions far beyond the well-documented examples in Iceland. There are hundreds of under-iceberg volcanoes around the world, and Antarctica has a particularly concentrated ice-covered volcanic system that may become more active as the ice sheet retreats.

Key areas that require additional monitoring include:

• Antarctica’s extensive under-icochorocer volcanic system
• Parts of North America have glacier-covered volcanoes
• Glacier volcanic areas in New Zealand
• Ice-covered volcanic areas in Russia

“The key need for increased explosion rates was initially having very thick glacier coverage on the magma chambers, and the trigger point was that when these glaciers began to retreat and release pressure, it was currently happening in places like Antarctica,” Moreno-Yaeger noted.

Climate feedback loops and timing

The study reveals the complex interactions between volcanic activity and the global climate system. Although a single eruption can temporarily cool the planet by releasing aerosols, just like when the 1991 eruption of Pinatubo Mount decreased by about 0.5 degrees Celsius, multiple eruptions have the opposite effect.

“The cumulative effects of multiple outbreaks over time may lead to long-term global warming because of the accumulation of greenhouse gases,” Moreno-Yaeger explained. “This creates a positive feedback loop, with melted glaciers triggering an outbreak that, in turn, may contribute to further warming and melting.”

Volcano responses to glacier melting occur almost immediately at a geological angle, but changes in magma systems gradually develop. This timeline provides opportunities for enhanced monitoring and early warning systems in vulnerable areas.

Monitoring and predicting challenges

Research shows that scientists need to extend monitoring efforts beyond traditionally active volcanic areas to include glacially covered systems that may become more active with ice retreats. Understanding the relationship between ice thickness, magma chamber depth and eruption potential can help predict which volcanic systems pose the greatest future threat.

The research, funded by the National Science Foundation and led by Professor UW-Madison, is scheduled to be published in peer-reviewed journals later this year. This work involved working with researchers at Lehigh University, University of California, University of Los Angeles, and Dickinson College.

As climate change continues to accelerate glacial retreats, the study highlights another unintended consequence of warm temperatures, a result that could cause new volcanic hazards in areas previously considered geologically stable due to its ice sheet.

Related