Underwater volcano off the US coast could erupt at any moment

Axial Seamount sits under the Pacific Ocean about 300 miles from the U.S. coast. Since 1997, scientists have kept a careful eye on it using instruments that measure pressure on the ocean floor.

Data shows that the volcano has been swelling, with changing rates that hint at an upcoming eruption.

Its activity caught the attention of experts because it shows a pattern of erupting after reaching a particular level of inflation.

Observers have noted that the volcano’s swelling slowed from 2015 to 2023, then sped up again in late 2023. By mid-2024, that rate hit 10 inches per year, while daily earthquakes soared into the hundreds.

Mark Zumberge, a geophysicist at Scripps Institution of Oceanography, has described it this way: “It’s the most well-instrumented submarine volcano on the planet.”

He and others use pressure sensors and AI-driven analysis to gauge shifts in earthquake patterns. William Chadwick of Oregon State University once referred to a 2015 eruption forecast as their “best forecasting success.”

Where continental plates pull apart

Axial Seamount rises from the Juan de Fuca Ridge, an underwater mountain range in the northeastern Pacific.

At this ridge, the Earth’s crust pulls apart due to the motion of tectonic plates, allowing molten rock to rise up and shape new crust.

Plates moving apart have built a chain of peaks called a mid-ocean ridge. These ridges rarely capture the public’s imagination, yet they form one of Earth’s largest continuous geological features.

The ridge separates the Pacific Plate and the North American Plate. When those plates drift away from each other, magma surfaces and hardens.

Volcanic and seismic events dot this region, including those at Axial. Repeated eruptions at this particular volcano have given researchers a real-time window into volcanic processes that most can only study from old rocks on land.

Axial Seamount eruptions

Because Axial Seamount experiences frequent eruptions, it provides chances to fine-tune eruption predictions.

Its swelling has reached levels that match those seen before past eruptions, prompting discussions about the next event possibly coming by the end of 2025.

Since these eruptions have been fairly similar each time, scientists are learning which signs point to magma movement and what those signals might mean for future activity.

Hydrothermal vents play a role in shaping local marine ecosystems. Lava flows and bursts of heated fluid feed specialized life, such as tube worms and clams, that flourish in dark, high-pressure environments.

This small spot of deep-sea life is a reminder of how volcanic activity can spur biological communities in unexpected places.

AI and new prediction methods

A recent effort involves analyzing quake patterns prior to 2015. That study leverages machine learning to recognize signals that precede an eruption.

Experts see these methods as a way to identify shifts in ground motion more quickly than manual approaches.

As inflation picks up again, this automated tracking could help identify the precise moment when molten rock nears the surface.

Zumberge and others draw on a network of sensors that map every tremor and change in ground tilt. “At Axial, we don’t have to worry about false alarms,” said Chadwick.

Thanks to these tools, false starts – common in volcano monitoring – have not posed much confusion here.

Beyond Axial Seamount’s slopes

Underwater eruptions may seem distant to folks on land, but they have global significance. The 2022 Hunga Tonga event, for example, triggered a tsunami that caused an estimated $90 billion in losses.

Though Axial Seamount itself poses little direct threat – shield volcanoes are less violent, and tremors here lack the force to create large waves – insights gained may aid efforts to forecast other, more hazardous sites.

“There’s no crystal ball,” noted volcanologist Valerio Acocella, from University Roma Tre in Italy, who studies both submarine and terrestrial volcanoes.

That simple fact drives efforts to refine predictive science, using a wide range of data: ground deformation, quake frequency, and the chemistry of volcanic gases.

Any improvement in these forecasts could limit harm in regions where eruptions might strike without warning.

Refining models with real-time data

When Axial erupts, molten rock pours out across the seafloor, and new vents appear. These events offer a direct look at how magma moves underground.

Instruments feed constant streams of measurements to shore-based labs, revealing changes that happen within hours or even minutes.

That trove of information helps experts see common threads that tie Axial’s predictable nature to more erratic volcanoes around the world.

Each new episode produces extra details, clarifying where magma is stored and how it shifts in the days or weeks before an eruption.

According to Acocella, “We need these ideal cases to understand how volcanoes work.”

Because Axial has such robust instrumentation, these “ideal cases” are more complete than anything available from many land-based sites.

Why does any of this matter?

Even though the undersea location of Axial Seamount means there is minimal risk to nearby shorelines, scientists still keep track of everything that happens beneath the waves.

If a future submarine volcano shows similar signals but lies closer to inhabited regions, the same methods could help governments plan.

Real-time data streams might allow them to evacuate at-risk areas or safeguard critical infrastructure.

At Axial, repeated eruptions give a sense of certainty about what might unfold next.

Unlike volcanoes that lie dormant for decades, this one reactivates on a cycle, creating a chance to track repeated patterns. That cyclical aspect has turned Axial into a natural classroom for geophysicists.

Global impact of Axial Seamount

To sum it all up, technological advances have made it easier to keep watch on both shallow and deep sections of Earth’s crust. Long cables connect sensors, offering near-instant awareness of quake swarms and ground shifts.

By combining those tools with AI algorithms, research teams spot subtle shifts that might have gone unnoticed in older data sets.

The anticipation of Axial’s next eruption has galvanized experts who study volcanic forecasting.

Axial’s shield structure, real-time monitoring, and location on a mid-ocean ridge present a unique scenario where everything lines up for practical research.

Overall, many specialists see this site as a key test bed for learning about submarine eruptions.

Eruptions at Axial allow researchers to gather immediate, detailed data that refine future warnings and guide planning for potentially dangerous underwater volcanoes elsewhere.

The study is published in the journal Nature.

Image Credit: University of Washington

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