Look Alert: The Most Active Volcano In the Pacific Northwest Is Probably About To Blow, Maybe

Wait, what? Yellow… stone? No, never heard of her. We’re talking about Axial Seamount.

Where in the world is Axial Seamount?

It’s one of the Pacific Northwest’s most active volcanoes – but there’s a good reason you’ve probably not heard of it before: Axial Seamount is located not just 480 kilometers (300 miles) west of the continental US, but roughly 1.5 kilometers (4900 feet) below it, too.

It is, of course, an underwater volcano – the youngest, in fact, in the Cobb–Eickelberg Seamount chain in which it resides. That position is the result of tectonic movements over what’s called a “hotspot” – an area where the Earth’s mantle is unusually hot compared to its surroundings. As tectonic plates move across the surface of the planet, these hotspots stay put, creating a chain of volcanoes in their wake.

But that’s not the only interesting thing about its location. By chance, Axial Seamount also happens to sit on top of the Juan de Fuca Ridge, where the Pacific and Juan de Fuca tectonic plates meet. At least, they sort of meet – they’re currently pulling away from each other as the latter subducts underneath the North American plate, forcing new seafloor to get churned up from magma below the lithosphere. 

It is, in total, very complex and mysterious – and the kind of volcano that gets oceanographers excited. “It’s pretty unusual,” William Wilcock, a professor at the University of Washington School of Oceanography, explained in a recent UW News article. “It’s a genuine hotspot, and the volcano itself is quite large, rising about 3600 feet above the seafloor.”

“The summit, bisected by the Juan de Fuca Ridge, is marked by a large caldera [a type of crater formed by volcanic eruptions], where the magma chamber has collapsed during multiple eruptions,” he continued. “That combination of features, located right on top of a mid-ocean ridge, is not very common.”

Even when it’s not popping off geologically, it’s still a hub of activity. Reaching temperatures of more than 370°C (700°F), hydrothermal vents are one of the most extreme environments on Earth, but they nevertheless teem with life: microbes, living off dissolved volcanic gases; tubeworms and crabs that feed off the microbes; even octopuses eke out a living thanks to these inhospitable bursts of super-hot water.

“When you get to the vent fields, you realize that the volcano is an oasis of life,” Deborah Kelley, a professor in the UW School of Oceanography, told UW. And “even though the chemistry is similar at the different vents, the microbial life can be very different. They’re like little islands with distinctive communities.”

A volcano on the edge

So it’s large, active, ecologically diverse, weirdly shaped, and uniquely placed – but none of that is the reason Axial Seamount has been in the news this year. Instead, the volcano hit headlines for a much more dramatic reason: because, at the end of 2024, researchers at the annual American Geophysical Union conference announced it was about to explode.

Well – okay, that’s overstating it a bit. “Axial Seamount has suddenly woken up!” read the abstract to a talk given by Oregon State University geophysicist William Chadwick. “Based on the current trends, and the assumption that Axial will be primed to erupt when it reaches the 2015 inflation threshold, our current eruption forecast window is between now (July 2024) and the end of 2025.” 

Now, you may well think such a sentiment falls short of “definitely about to blow” – and you’d be totally correct. The fact is that forecasting volcano eruptions is far from an exact science, and being able to predict them any more than a few hours in advance is “pretty unique,” Chadwick told Science News in December last year.

But there’s nevertheless good reason for the announcement. Axial Seamount is “the most well-instrumented submarine volcano on the planet,” Mark Zumberge, a geophysicist at Scripps Institution of Oceanography in California, told Science News – and lately, those instruments have been reporting a lot of spookily familiar information.

Last November, the surface of the volcano had swollen to almost the same size as it had been just before its previous eruption in 2015 – a sign that the magma within might be reaching a bursting point. “Some researchers have hypothesized that the amount of inflation can predict when the volcano will erupt,” Wilcock told UW, “and if they’re correct it’s very exciting for us, because it has already inflated to the level that it reached before the last three eruptions.” 

“That means it could really erupt any day now,” Wilcock said, “if the hypothesis is correct.”

Again, you may note some wiggle room there, and that’s because not all signs are pointing to “erupt”. Also thought to be a harbinger of imminent explosion is a huge uptick in earthquake activity nearby – and so far, that isn’t happening. 

“The volcano has already surpassed the inflation we observed in 2015, but the earthquake activity is still quite low,” Kelley explained. “We’re seeing 200 to 300 earthquakes per day, with some spikes around 1,000 per day due to the tides.” 

“If what we learned in 2015 is correct, I would expect to see more than 2,000 per day for a few months before the eruption,” she said.

What will happen when Axial Seamount erupts?

We’re not going to draw it out any longer: The fact is, unless you’re an oceanographer or geophysicist, you probably won’t notice when the Axial Seamount blows. There won’t be any tsunamis or major earthquakes on land; no smoke plumes, and no risk to life or limb.

“People’s lives aren’t in the equation,” Chadwick told The Oregonian earlier this year. “On land, you can’t do this forecasting without worrying about false alarms and freaking people out and having economic impacts. You don’t want to evacuate towns and all that without knowing for sure that you need to.”

If, on the other hand, you are an oceanographer or a geophysicist, then – well, it’s going to be a good time.

“Three quarters of all of the volcanic activity on Earth takes place at mid-ocean spreading centers,” Kelley said. “But people have never directly witnessed an eruption along this mountain chain, so we still have a lot of unanswered questions.”

“Until it happens, we won’t know which of these hypotheses are right,” Wilcock added. “Whatever it does, we’re going to learn something new.”