Ice caps can delay volcanic eruptions

The Westdahl Peak volcano adds to the magnificence of the Aleutian Island chain in Alaska. Still, it’s important to remember that after its 1992 eruption, the volcano was predicted to erupt again in 2010. However, here we are in 2022, and so far, no eruption. 

Researchers at the University of Illinois decided to take advantage of this opportunity to investigate why Westdahl Peak has not exploded. Specifically, the scientists wanted to determine whether ice caps affect volcanic eruption cycles in high-latitude regions.

“Volcanic forecasting involves a lot of variables, including the depth and size of a volcano’s magma chamber, the rate at which magma fills that chamber and the strength of the rocks that contain the chamber, to name a few,” said undergraduate researcher Lilian Lucas. “Accounting for overlying pressure from polar ice caps is another critical, yet poorly understood, variable.”

The researchers found that having an ice cap does affect volcanic cycles by increasing the eruption time. The data indicate that ice can delay an eruption for decades, depending on the thickness of the ice. 

“More specifically, the models without the presence of the confining pressure of the ice cap calculated a time to eruption of about 93 years,” said Lucas. “Adding a 1-kilometer-thick ice cap to the model then increases the eruption date to approximately 100 years. Models are not a perfect tool to use in forecasting future eruptions, however, we are mainly interested in the increase in this time as a result of the increased ice load.”

These results imply that ice thickness should be considered when estimating eruption cycles, especially since volcanic eruptions have a significant impact on human life. 

“Volcanic ash in the atmosphere is hazardous to aircraft engines and can cause major disruptions in air traffic, so more accurate forecasting – even on the scale of months – can provide critical safety information for air traffic and nearby inhabitants,” said study co-author Jack Albright.

“Furthermore, it will be important to consider how climate change and glacial ice melt might impact Westdahl Peak and other high-latitude volcanoes in the future,” said study co-author Yan Zhan.

The research is published in the journal Frontiers in Earth Science.

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By Erin Moody , Earth.com Staff Writer