Will an undersea volcano erupt near Oregon in 2025? Here's what we know

PORTLAND, Ore. (KOIN) – One of the most active volcanoes in the Pacific Northwest is waking up -- leading some scientists to believe it will erupt in 2025.

The volcano, named Axial Seamount, sits on the Juan de Fuca Ridge about 300 miles off the coast of Astoria, Oregon.

In the last 30 years, Axial has erupted three times -- in 1998, 2011, and 2015. After the 2015 eruption, the volcano saw a period of decreased earthquake activity and seafloor rise, which has since ramped up around late 2024.

After tracking this increased activity, Oregon State University Research Associate Bill Chadwick projects Axial will erupt by the end of 2025.

“Because it's had these three eruptions in the last 30 years, that's why we call it the most active volcano in the Pacific Northwest, because most of the ones on land aren't active that frequently, and they spend a lot of their time slumbering, whereas Axial has a pretty active magma supply," Chadwick told KOIN 6 News on Thursday. "So, if it's not erupting, it's inflating and getting ready for the next one. And so that's why we're kind of monitoring what's happening to it all the time."

Axial saw hundreds, then thousands of earthquakes every day in the months leading up to its eruption in 2015, Chadwick said during a November presentation at OSU's Hatfield Marine Center -- noting 9,000 earthquakes occurred the day of the eruption.

The thickest lava flows from that eruption were 450-feet thick. That's equivalent to two-thirds the height of the Space Needle, Chadwick said, adding, “The eruptions are pretty big.”

After the 2015 eruption, Axial's sea floor rose about five centimeters per year before slowing down to one centimeter in 2023. Then in 2024, Chadwick began to see the seafloor re-inflate to about 25 centimeters per year.

“Volcanoes like this tend to, between eruptions when magma is accumulating underground, they inflate like a balloon. So, the accumulating magma actually pushes the sea floor upward, and we can measure that," Chadwick said.

“What's leading us to talk about an eruption in the next year and by the end of 2025 is we're almost fully reinflated to the level it was before the 2015 eruption, and the rate of inflation is pretty robust. And in the last year, especially, there was the number of earthquakes, which is also monitored by this cable observatory, has really increased. So, all these signs are pointing toward the final stages of the buildup to the next eruption, but there's certainly no certainty in it. The volcano could decide to do something different that we haven't seen before. That's always a risk,” Chadwick said.

The OSU research team uses a variety of tools to monitor Axial, including the Jason remotely operated vehicle, which dives into the ocean and captures images and lava flow samples for the team back on the research ship.

As the team monitors the volcano, Chadwick emphasized there is no danger to the public during these eruptions, and despite the volcano's location on the Juan de Fuca Ridge, it poses no danger of triggering the "Big One" in the Cascadia Subduction Zone.

“If you were out there on a ship right over the seamount, you would never know anything was happening unless you dangled a hydrophone, an underwater microphone, into the water, then you might be hearing some commotion from down deep. But there's no effect at the surface. You'd have to make a dive with a submersible or remotely operated vehicle or something to see what's happened," Chadwick explained.

Chadwick's motivation is to possibly take lessons from these eruption forecasts and see if they can be applied to other volcano eruptions around the world.

“Now that we see this pattern, we're paying attention to it, trying to use it to see if we can forecast the timing of eruptions," Chadwick said. “We're not trying to save lives or anything, because nobody lives out there. This is the bottom of the ocean, a mile deep and 300 miles offshore. But if we can forecast eruptions here, then potentially there's lessons to be learned for other more dangerous volcanos around the world."