Underwater Volcano Off Oregon Coast Expected to Erupt in '25

An underwater volcano percolating 300 miles off the Oregon coast could erupt at any time, according to multiple media reports.

The Axial Seamount that rises from the Juan de Fuca Ridge, an underwater mountain range in the northeastern Pacific, has been showing signs of swelling, with changing rates that hint at an upcoming eruption, Earth.com reported Wednesday.

In attempts to forecast volcanic eruptions at the site, researchers Bill Chadwick and Scott Nooner noted the rate of seafloor swelling around Axial Seamount was virtually zero in the fall of 2023, but that started to change in January 2024, according to IFLScience.

Over the next six months, the swelling doubled from 2 to 4 inches a year before leveling off at 6 inches a year by late July. At the caldera center, the swelling reached 9.8 inches per year, leaving Axial Seamount "fully reinflated" in relation to the level seen immediately before the 2015 eruption, according to IFLScience.

During this same period, seismic activity skyrocketed, with more than 500 earthquakes recorded on some days, indicating a major shift in magma supply. By October, Chadwick and Nooner reported that this situation remained unchanged for six months and that the volcano "can't do this forever."

In other words, Axial Seamount is going to have to unload some of that pressure soon, which is why scientists are forecasting an eruption within the next 12 months.

"It's the most well-instrumented submarine volcano on the planet," said Mark Zumberge, a geophysicist at the Scripps Institution of Oceanography, according to Earth.com.

But if and when it erupts, it's not expected to have as grave an impact as the January 2022 eruption of the Hunga Tonga underwater volcano, which triggered a tsunami across the Pacific that reportedly caused $118 million in damages and sent a cloud of smoke and ash 36 miles into the atmosphere.

The most recent eruption at the Axial Seamount occurred in 1998, according to the National Oceanic and Atmospheric Administration. In the past 15 years, three volcanic eruptions have been detected in the northeast Pacific by a formerly top-secret U.S. Navy system originally designed to track submarines.

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