In the depths of the Pacific Ocean, 470 kilometers off the Oregon coast, a drama is unfolding. Axial Seamount, one of the most active underwater volcanoes in the world, is swelling with magma. Scientists believe it will erupt before the end of 2025—a bold prediction, but one based on decades of monitoring and a unique volcanic rhythm.

Bill Chadwick, a geophysicist at Oregon State University, likens the situation to a pressure cooker nearing its limit. “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 […] and the end of 2025,” he said at the 2024 annual meeting of the American Geophysical Union.

Predicting the Unpredictable

Forecasting volcanic eruptions is not something you can do reliably, although they’re a bit less capricious than earthquakes (to this day, no major earthquake has ever been predicted). Most predictions only offer hours of notice, but Axial Seamount is a special case. Situated on the Juan de Fuca Ridge, the volcano erupts with remarkable regularity. Previous eruptions in 1998, 2011, and 2015 revealed a clear pattern: the seafloor inflates as magma accumulates, seismic activity intensifies, and finally, the volcano bursts.

This consistency makes Axial an ideal laboratory for studying volcanic behavior. For over a decade, a network of sensors has documented every rumble and bulge. In late 2023, researchers noticed the volcano’s inflation rate had doubled. By mid-2024, seismic activity spiked to over 500 earthquakes a day. “It can’t do this forever,” Chadwick remarked, which means the volcano is under immense pressure and is about to burst.

Mark Zumberge of the Scripps Institution of Oceanography highlighted Axial’s exceptional monitoring environment. “It’s the most well-instrumented submarine volcano on the planet,” he said. This network includes seafloor pressure sensors, autonomous underwater vehicles (AUVs), and remotely operated vehicles (ROVs), which together provide an unparalleled view of the volcano’s behavior.

Previously, scientists could only catch subtle glimpses of magma reservoirs, which lacked the resolution to map finer details. In their new study, researchers used full waveform inversion (FWI), a cutting-edge seismic technique, to produce high-resolution images of the subsurface.

The findings show a main magma reservoir beneath the summit, with melt fractions of up to 37%—approaching the threshold for magma mobilization. Below this, a conduit carries magma from deeper in the Earth’s crust, with melt fractions of 4-11%. To the west, the team discovered a smaller reservoir connected to the main one by a thin channel. Meanwhile, to the east, a low-velocity “throat” links the main magma reservoir to the surface, guiding magma to eruptive fissures.

These structures form a strikingly asymmetric system, with most activity concentrated beneath the eastern caldera wall. This imbalance may explain why recent eruptions have largely occurred on Axial Seamount’s eastern flank.

Why It Matters

Underwater volcanoes like Axial Seamount rarely threaten human lives, but their eruptions can ripple through ecosystems and even trigger tsunamis. The 2022 Hunga Tonga eruption, for instance, caused $90 million in damages and left scientists scrambling to understand its effects.

At Axial, researchers aim to catch the next eruption in action. Rebecca Carey, a volcanologist from the University of Tasmania, sees this as a golden opportunity. “Catching the eruption occurring would offer a glimpse into its effects on hydrothermal systems and biological communities nearby,” she explained for Science News. Hydrothermal vents, which are teeming with life, could hold clues to how ecosystems respond to extreme events.

Moreover, each eruption helps refine forecasting techniques. Artificial intelligence is now being used to analyze patterns in seismic data, offering the possibility of predicting eruptions down to the hour. “Will this precursory earthquake detection work?” Chadwick wonders. If it does, it could revolutionize how scientists monitor volcanoes worldwide.

The study’s findings also have broader implications for plate tectonics and crust formation. Axial Seamount lies at the intersection of the Juan de Fuca Ridge and the Cobb Hotspot, where magma supply is particularly robust. The research shows how this magma accumulates, pools, and eventually escapes, contributing to the growth of the oceanic crust.

A Blueprint for the Future

Axial Seamount’s impending eruption is a huge learning opportunity. The 2015 eruption, which released 156 million cubic meters of lava, provided invaluable data. AUV surveys revealed that the lava had flowed along a 19-kilometer rift, creating new seafloor features. These findings laid the groundwork for the detailed maps now being used to track the volcano’s current activity.

Still, predictions come with caveats. “There’s always the risk that a volcano will follow a pattern that we haven’t seen before and do something unexpected,” warns Michael Poland of the U.S. Geological Survey. The challenge lies in translating patterns into universal principles that apply to other, less predictable volcanoes.

For now, Axial Seamount remains a unique case study.

Whatever happens in 2025, the insights gained from Axial will ripple far beyond its submerged caldera. With every quake, bulge, and burst, scientists inch closer to demystifying the forces that shape our planet.

The new findings appeared in the journal Nature.