Axial Seamount, an underwater volcano 300 miles off Oregon’s coast, shows signs of an impending eruption—the first since 2015. Though lesser-known than the Cascade Range volcanoes, scientists are eager to study it, as it offers valuable insights into Earth’s geological and biological processes.
In December 2024, scientists announced at the American Geophysical Union conference that Axial Seamount, an underwater volcano off Oregon’s coast, was likely to erupt before the end of 2025.
The news sparked global interest and local concerns: Would the eruption be dangerous on land? Could it trigger a major earthquake? How might it impact marine life, such as orcas and salmon?
The Ocean Observatories Initiative Regional Cabled Array (RCA), run by the University of Washington, is one of the largest underwater observatories. It has 150 real-time sensors spread across the Juan de Fuca plate, from the Oregon coast to Axial Seamount, 300 miles offshore.
Since 2014, the RCA has provided high-resolution images, live video feeds, and vital oceanic data. When Axial Seamount erupts, scientists will have a direct, real-time view, offering valuable insights into underwater volcanic activity.
Axial Seamount’s hydrothermal vents are underwater hot springs where seawater, heated by magma, erupts in superheated, mineral-rich plumes. Despite the extreme conditions, these vents support microbes and marine life, forming a unique deep-sea ecosystem.
What happens when Axial Seamount erupts?
Axial Seamount is too deep and far offshore for its eruption to be noticeable on land. It also won’t trigger earthquakes or tsunamis in the Pacific Northwest. While most people are happy to stay far away, scientists are eager to observe it, since no one has ever directly seen an eruption at mid-ocean spreading centers, leaving many questions unanswered.
The first sign of an Axial Seamount eruption is a sudden increase in earthquakes as magma pushes toward the surface. Lava flows spread across the caldera within an hour, and fissures open up to 25 miles away. Seismic activity rapidly decreases over the next few days, but the eruption continues for about a month, gradually shaping the seafloor.
Axial Seamount’s eruptions create snowblowers—plumes of warm fluid carrying billions of microbes and white clumps of their waste. These rare events reveal how life thrives in extreme environments, possibly making underwater volcanoes key sources of life in our oceans.
Though Axial Seamount’s eruptions aren’t particularly violent, they produce startling sounds. When seawater gets trapped beneath lava, it turns to steam. As the steam escapes, it forms a bubble that collapses rapidly, causing a loud implosion detectable by hydrophones. Scientists use these sounds to study the eruption process in real-time.
Axial Seamount’s eruptions create low-frequency sounds that some whale species might hear, but are unlikely to be affected. However, hydrothermal vent ecosystems face a greater impact—in 2011, lava flows wiped out an entire venting area. Yet, within three months, life began to recolonize, showing the remarkable resilience of these deep-sea communities.
How do we know an eruption is near?
Scientists predict Axial Seamount’s eruptions by monitoring two key signs: how much the volcano is inflating as magma builds up beneath it and the frequency of earthquakes under the seafloor.
Over time, magma pressure causes the volcano to swell, and some researchers believe this inflation can indicate when an eruption is imminent. If the hypothesis is correct, Axial Seamount has already reached the same inflation levels as before its last three eruptions, meaning it could erupt at any moment. However, inflation alone doesn’t provide the whole picture—scientists are eager to study this eruption to improve their prediction methods.
Axial Seamount has inflated beyond 2015 levels, indicating magma buildup, but earthquake activity remains low. Scientists observe 200 to 300 quakes per day, with occasional spikes around 1,000, influenced by tides. If past patterns hold, earthquake counts need to exceed 2,000 per day for months before an eruption occurs.
Axial Seamount eruptions are influenced by underground magma movement and tidal forces from the sun and moon. The moon’s gravity pulls on the ocean, subtly stressing the Earth’s crust.
The ocean’s weight presses down on the volcano at high tide, reducing seismic activity. At low tide, that pressure eases, leading to more earthquakes. Scientists are eager to see whether these tidal shifts also increase the likelihood of an eruption by adding stress to the magma chambers.
This unexpected connection between volcanic activity and celestial forces is a fascinating area of research, revealing how deeply interconnected Earth’s systems are.
Axial Seamount’s past eruptions occurred between January and May, when Earth moves away from the sun and its gravitational pull weakens. Scientists are eager to see if the next eruption follows this pattern.
While the exact timing remains uncertain, experts agree that an eruption is imminent. When it happens, the Regional Cabled Array will stream real-time data, capturing earthquakes, explosions, and seafloor collapse.
This will provide a unique opportunity to study underwater volcanic activity and refine eruption predictions.
Researchers are excited to share their findings, as each eruption brings new insights and fosters collaboration in the scientific community.
