Scientists have warned that an underwater volcano off the coast of the northwestern US is likely to blow sometime in 2025.

The volcano, called Axial Seamount, is more than 3,600-feet-tall and sits half a mile underwater just 300 miles off the coast of Oregon. 

Experts made the prediction on December 10 after detecting seafloor swelling around Axial that mimicked a level seen immediately before an eruption in 2015.

Seismic activity has also increased, with hundreds of earthquakes generated around the volcano per day and earthquake swarms greater than 500 per day.

‘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,’ researchers said in the new study.

The team first noticed the swelling in November using a suite of tools to meticulously monitor this volcano’s activity, collecting real-time data about its rumbling, shaking, swelling and even tilting.

Located on the Juan de Fuca ridge, Axial is the most active underwater volcano in the northeast Pacific.

Because Axial erupts with some regularity, it provides a unique opportunity for scientists to study the warning signs leading up to an eruption, and learn how to forecast one.

Scientists have warned that an underwater volcano off the coast of the northwestern US is likely to blow sometime in 2025

Experts made the prediction on December 10 after detecting seafloor swelling around Axial that mimicked a level seen immediately before an eruption in 2015

Fortunately, eruptions from Axial pose little threat to people and infrastructure on the West Coast. 

That’s largely because it is a shield volcano, which generally do not have very explosive eruptions. 

What’s more, the seismic activity around it is too minimal to cause a tsunami or a major earthquake. 

Oregon State University geophysicist William Chadwick started investigating the volcano in November when he noticed its surface had swelled to nearly the same height it reached before its last eruption nearly 10 years ago.

Surface swelling is a strong indication that a shield volcano is about to blow, because it means magma has accumulated underground and is building pressure. 

The swelling that occurred prior to the 2015 eruption allowed Chadwick and his colleagues to predict that event. 

It was their ‘best forecasting success,’ he told Science News. 

Since the last eruption, Axial has re-inflated to more than 95 percent of its last pre-eruption threshold, Chadwick and his colleagues explained in a statement.

 Because Axial erupts with some regularity, it provides a unique opportunity for scientists to study the warning signs leading up to an eruption, and learn how to forecast one

This swelling hasn’t been constant. The rate of inflation slowed between 2015 and 2023, and by the summer of 2023 it nearly stalled out. 

Simultaneously, the rate of seismic activity remained relatively low during this time. 

But starting in the fall of 2023, and especially since January 2024, both the volcano’s swelling and seismic activity have been gradually increasing, ‘apparently signaling a fundamental change in the magma supply to the volcano,’ the researchers explained.

By July 2024, the rate of swelling had increased to roughly 10 inches per year and was still growing. 

‘If the rate of inflation and seismicity continue to increase, an eruption may be likely before the end of 2024,’ the team shared. 

The ability to forecast an eruption event more than 24 hours ahead is ‘pretty unique,’ let alone providing months of advanced notice, Chadwick told Science News. 

But the massive research effort surrounding Axial has allowed researchers to dive deeper into the mechanisms driving undersea volcanic eruptions than ever before.

They have even developed a new tool that can estimate the magma burst that will set off the next eruption. Others have used artificial intelligence to dig through earthquake records prior to the 2015 eruption and learn more about the imminent warning signs.

Even though Axial is not a particularly dangerous undersea volcano, the forecasting capabilities scientists have gained from studying it could help them predict eruptions from those that are. 

For example, in January 2022, an extremely powerful eruption of the Hunga underwater volcano in the Tonga archipelago in the southern Pacific Ocean triggered a tsunami that caused an estimated $90 billion in damages.

This massive wave impacted California, Hawaii, and parts of Canada, Chile, Fiji, Japan, New Zealand, Mexico and Peru. 

The West Coast won’t have to worry about Axial causing an event like that. But its imminent eruption will provide yet another opportunity for scientists to learn about how these powerful geological structures work.