As glaciers around the world melt at an alarming rate due to climate change, scientists are warning that this may lead to a surge in volcanic eruptions. Research presented at the Goldschmidt Conference in Prague suggests that hundreds of dormant volcanoes could become more active as glacier retreat accelerates. The findings have significant implications for understanding and predicting volcanic activity, particularly in regions with extensive glacial coverage like Antarctica.

The study, led by researchers from the University of Wisconsin-Madison, USA, examined six volcanoes in the Chilean Andes, including the dormant Mocho-Choshuenco volcano. By precisely dating previous eruptions and analyzing crystals in erupted rocks, the team found that thick ice cover suppresses the volume of eruptions but allows a large reservoir of silica-rich magma to accumulate beneath the surface. As glaciers melt rapidly at the end of an ice age, this buildup of pressure triggers explosive volcanic eruptions.

Pablo Moreno-Yaeger from the University of Wisconsin-Madison emphasized that “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.” This phenomenon is not limited to Iceland, where increased volcanicity has been observed, but could also occur in Antarctica and other continental regions.

While the volcanic response to glacial melting is almost instant in geological terms, the process of changes in the magma system is gradual and occurs over centuries. This gives some time for monitoring and early warning. However, increased volcanic activity could have global climate impacts. In the short term, eruptions release aerosol that can temporarily cool the planet. But with multiple eruptions, the effects reverse.

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

The research was funded by the National Science Foundation as part of a grant led by Professor Brad Singer at UW-Madison, and is due to be published in a peer-reviewed journal later this year. The findings have significant implications for understanding and predicting volcanic activity in regions with extensive glacial coverage and could contribute to mitigating the effects of climate change on our planet.

In recent years, climate change has been at the forefront of global concerns, and one of the most critical regions affected by this phenomenon is Antarctica. Researchers from the University of Copenhagen have made a groundbreaking discovery that sheds new light on the mechanisms behind the collapse of Antarctic ice shelves, which are crucial for predicting sea level rise in the Northern Hemisphere.

On November 28, 1966, an American aeroplane flew over the Antarctic Peninsula, capturing an aerial photo of the Wordie Ice Shelf. This image, taken just south of the southernmost tip of Chile, marked the beginning of a unique dataset that would provide unparalleled insights into the collapse of ice shelves. The researcher’s analysis of historical aerial photos and satellite data has revealed that melting under the ice where the sea and ice meet is the primary driver of Wordie’s collapse.

The study’s findings have already altered the foundation of scientists’ knowledge about ice shelf collapse, suggesting that these events may be slower than previously thought. However, this longer process will make it even harder to reverse the trend once it has started, highlighting the urgent need to prioritize halting greenhouse gas emissions now rather than sometime in the future.

The consequences of ice shelf collapse are far-reaching and have significant implications for global sea level rise. As the glaciers lose their support, they can begin to float and melt more rapidly, contributing to rising ocean levels. Although Antarctica is far away, areas like Denmark are being affected significantly by sea level rise caused by gravitational forces.

In conclusion, the study’s findings mark a new era of climate adaptation, emphasizing the need for urgent action to address the consequences of ice shelf collapse. By prioritizing halting greenhouse gas emissions now rather than sometime in the future, we can reduce the risk of violent sea level rise and mitigate its impact on global communities.

A new study has challenged the long-held notion that a massive ice shelf once sealed the Arctic Ocean during the coldest periods of the last 750,000 years. Researchers from the European Research Council Synergy Grant project Into the Blue — i2B have found no evidence for the presence of a giant ~1km thick ice shelf, instead discovering that seasonal sea ice dominated the region.

The study, published in Science Advances, used sediment cores collected from the seafloor of the central Nordic Seas and Yermak Plateau, north of Svalbard. These cores hold tiny chemical fingerprints from algae that lived in the ocean long ago. Some of these algae only grow in open water, while others thrive under seasonal sea ice.

“Our sediment cores show that marine life was active even during the coldest times,” said Jochen Knies, lead author of the study, based at UiT The Arctic University of Norway and co-lead of the Into The Blue — i2B project. “That tells us there must have been light and open water at the surface. You wouldn’t see that if the entire Arctic was locked under a kilometre-thick slab of ice.”

One of the key indicators the team looked for was a molecule called IP25, which is produced by algae that live in seasonal sea ice. Its regular appearance in the sediments shows that sea ice came and went with the seasons, rather than staying frozen solid all year round.

To test their findings, the research team used the AWI Earth System Model to simulate Arctic conditions during two especially cold periods: the Last Glacial Maximum around 21,000 years ago, and a deeper freeze about 140,000 years ago when large ice sheets covered a lot of the Arctic. The models supported what was found in the sediments – even during these extreme glaciations, warm Atlantic water still flowed into the Arctic gateway.

The study not only reshapes our view of past Arctic climates but also has implications for future climate predictions. Understanding how sea ice and ocean circulation responded to past climate extremes can improve models that project future changes in a warming world.

“These reconstructions help us understand what’s possible — and what’s not — when it comes to ice cover and ocean dynamics,” said Gerrit Lohmann, co-author of this study, based at Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and co-lead of Into The Blue — i2B. “That matters when trying to anticipate how ice sheets and sea ice might behave in the future.”

The full paper, “Seasonal sea ice characterized the glacial Arctic-Atlantic gateway over the past 750,000 years,” is available in Science Advances. This research is part of the European Research Council Synergy Grant project Into the Blue — i2B and the Research Council of Norway Centre of Excellence, iC3: Centre for ice, Cryosphere, Carbon, and Climate.