17-05-2025
Underwater Pacific volcano expected to erupt. What would that mean for WA?
If you've never heard of the Axial Seamount, you'd be forgiven. But the underwater volcano has made national news recently after research suggested it is likely nearing its first eruption in 10 years.
The mountain is located around 300 miles off the northern Oregon coast, where the Pacific and Juan de Fuca plates meet — 4,600 feet below the surface.
'It's on an ocean spreading center, which is on one side of the Juan de Fuca tectonic plate, and the other side is the side that's subducting beneath the subduction zone,' William Wilcock, a University of Washington professor researching the volcano, told McClatchy in a phone call.
The volcano has erupted three times since 1998, with the most recent one in 2015. Recently, researchers have noticed that magma build-up has caused the volcano to inflate to near the levels seen in previous eruptions.
'The model that Bill Chadwick, who's at Oregon State University, and Scott Nooner at North Carolina, Wilmington, they basically observed… So there have been eruptions in 1998, 2011 and 2015. And they noted that the eruption in 2011 occurred at about the same amount of inflation,' Wilcock said.
If the theory is correct, it will provide insight into how researchers can predict other volcanic eruptions, Wilcock said.
'Why this volcano is interesting is the magma chamber beneath the volcano is pretty shallow. It's less than a mile deep… I think this volcano behaves in a more simple way than other volcanoes. So I think other volcanoes, they're not as predictable like this,' Wilcock said.
Another key indicator of when the volcano will erupt is seismic activity.
At the time of a UW news release in late April, the volcano was seeing around 200 to 300 earthquakes a day on average, with that number reaching 1,000 some days. That's well below the 2,000 earthquake-a-day average that it was seeing in the lead-up to its last eruption, and Wilcock said there's actually been a decrease in seismic activity.
'That's actually gone down a little bit down to more like between 100 to 200 a day at the moment, but it varies from week to week,' Wilcock said.
According to Wilcock, he expects the number of earthquakes a day to reach 500 before the volcano erupts.
'Over that six months, the number increased from basically 500 a day to 2,000 a day,' Wilcock said. 'And so we're not at 2000 a day at the moment, but then it was inflating at two feet a year. Now it's inflating more slowly. So we might not expect quite as many, but I think I would expect at least 500 a day.'
According to Wilcock, experts expect the volcano to erupt sometime this year or next year, but that it's difficult to pinpoint exactly when
'I think, based on the seismicity, we think it might be a little further away than the other predictions… But I think everybody would say that if it's not going to go this year, it's probably next year,' Wilcock said.
While a volcanic eruption and thousands of earthquakes a day off the coast of northern Oregon might sound frightening, Wilcock said the volcano is too far away from land for its effects to be noticeable.
'These earthquakes are really small,' Wilcock said. 'They're magnitude twos and threes. It's a very small effect, and so it's not going to have any impact in the subduction zone 300 miles away.'
Additionally, seismic activity around the volcano isn't linked to seismic activity on land, so it isn't expected to trigger any earthquakes in Washington or Oregon.
It will have an effect on the marine ecosystem, but Wilcock said that the impacted species will recover quickly.
'When it erupts, you know, many of those are many of those, the bigger organisms we kill, but they will repopulate pretty quickly,' Wilcock said. 'Then the nutrients that come out of the volcano are actually very good for the microbial community.'
