Researchers discovered that magma chambers beneath Cascade Vary volcanoes persist even when the volcanoes are dormant, difficult earlier assumptions. This discovery might enhance volcanic monitoring and eruption prediction.
New analysis led by Cornell College challenges the long-standing perception that lively volcanoes include massive magma our bodies which can be expelled throughout eruptions and progressively dissipate because the volcanoes change into dormant.
Utilizing seismic waves, researchers recognized magma chambers beneath six volcanoes of various sizes and dormancy throughout the Cascade Vary, which incorporates half of the U.S. volcanoes designated as “very excessive risk” by the U.S. Geological Survey. The crew found that the entire volcanoes, together with dormant ones, include persistent and sizable magma our bodies.
The research, led by postdoctoral researcher Guanning Pang, was printed in Nature Geoscience and co-authored by Geoffrey Abers, professor in geological sciences.
Their results are surprising given that some of these volcanoes, such as the Crater Lake volcano in Oregon, have not been active in millennia.
Magma Bodies Exist Throughout a Volcano’s Lifetime
“Regardless of eruption frequency, we see large magma bodies beneath many volcanoes,” Pang said. “It appears that these magma bodies exist beneath volcanoes over their whole lifetime, not just during an active state.”
The fact that more volcanoes have sustained magma bodies is an important consideration for how researchers may monitor and predict future volcanic activity. The U.S. Geological Survey has been expanding and upgrading its volcanic monitoring networks in the Cascade Range and elsewhere as part of the National Volcano Early Warning System, with the aim of detecting signals of an impending eruption as early as possible.
“We used to think that if we found a large amount of magma, that meant increased likelihood of eruption,” Pang said, “but now we are shifting perception that this is the baseline situation.”
The results suggest that an eruption does not completely drain a magma chamber, instead, it lets off some of the excess volume and pressure. The chamber can be slowly expanded and refilled over time due to gradual melting of the crust.
“If we had a better general understanding of where magma was, we could do a much better job of targeting and optimizing monitoring,” Abers said, noting that there are a “great many volcanoes that are sparsely monitored or have not been subject to intensive study.”
Plans are already in the works to expand the magma monitoring system and see if the Cascade discovery translates to other locations, including Alaska.
Reference: “Long-lived partial melt beneath Cascade Range volcanoes” by Guanning Pang, Geoffrey A. Abers, Seth C. Moran and Weston A. Thelen, 23 January 2025, Nature Geoscience.
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