Scientists are forecasting that the Pacific Northwest鈥檚 most active volcano will erupt sometime between 2020 and 2024.
The volcano isn鈥檛 one you鈥檒l see driving along the Cascade Range, instead you鈥檇 have to look 1.5 miles deep in the ocean to find it. It鈥檚 called the Axial Seamount and it鈥檚 located about 300 miles due west of Astoria at the edge of the Juan de Fuca plate. If the volcano were on land, it would be one of the taller mountains in Oregon鈥檚 Coast Range.
Oregon State University鈥檚 Bill Chadwick made the eruption forecast at a scientific meeting this month. His forecast is based on measurements taken on the seafloor around the seamount.
鈥淥ne of the ways that volcanoes are monitored around the world is to look for changes in their shape, like if the ground is being uplifted or subsiding,鈥� Chadwick said. 鈥淲hat you're interested in is [if] magma moving in or moving out or is it just slumbering?鈥�
Axial Seamount has changed quite a bit over the last decades, with the surface gradually rising between eruptions, then suddenly dropping back down.
鈥淚t's erupted three times in the last 21 years. That鈥檚 more than Mount St. Helens and any of the volcanoes in our neighborhood. So it's gotten a lot of our attention and we're trying to learn as much from it as we can,鈥� he said.
has allowed Chadwick to monitor Axial Seamount in real time. Over the past few years, he鈥檚 watched the volcano slowly grow.
鈥淲e're using that repeated pattern of inflation and deflation to try to anticipate when the next eruption might be,鈥� he said.
Chadwick says making such a straightforward and public forecast is its own kind of experiment.
Other scientists in the Pacific Northwest are also monitoring the seamount for signals of eruption.
University of Washington鈥檚 William Wilcock studies earthquakes at Axial Seamount. The seismic activity gives indications of what鈥檚 happening inside the volcano.
鈥淚mmediately after an eruption, there are very few earthquakes and then the number of earthquakes steadily increases as the volcano inflates,鈥� he said. 鈥淪o after the eruption in 2015, the number of earthquakes that we recorded went down to just a handful and it's now up to maybe 50 a day.鈥�
Wilcock says he believes that Bill Chadwick鈥檚 forecast is in the right ballpark.
鈥淢y personal view is it鈥檚 probably more likely in 2022 to 2024. But I think there鈥檚 some uncertainty,鈥� he said.
Unlike the eruption of land-based volcano, like Mount St. Helens, the eruption of the Axial Seamount won鈥檛 cause any problems for humans.
鈥淔or the size of eruptions we've seen in the last 20 years 鈥� if you were on top of it on a boat, you would never know it,鈥� OSU鈥檚 Chadwick said.
But the forecast eruption does provide a unique opportunity scientifically.
鈥淭here's a lot of interest in trying to set up experiments, to basically observe more of [the volcanic processes] as it's happening,鈥� Wilcock said.
Chadwick says the Axial Seamount is a relatively simple volcano in terms of where it occurs and how it behaves. And being able to study the volcano at such close range as it erupts could provide insight to the behavior and forecasting of volcanoes on land.
鈥淚 think in that way we have an opportunity to understand a relatively simple system. And hopefully the lessons we learn there would have applications to forecasting eruptions and other more complicated settings.鈥�
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