Axial Seamount, located about 300 miles off Oregon’s coast in the northeast Pacific. Experts say it could erupt “any day now.” Though an eruption won’t threaten land or people, thanks to its mile-deep and remote location, it could reveal fascinating changes on the ocean floor.
Axial Seamount is an immense undersea volcano, around a mile wide, and situated approximately 5,000 feet below the Pacific surface. It has erupted three times in recent history: in 1998, 2011, and 2015, each time causing rapid shifts in the ocean floor. Following the 2015 eruption, the seafloor sank nearly eight feet, altering the hydrothermal vent communities.
What makes Axial Seamount so special is how well scientists can track it, as it slowly refills with magma, the seafloor literally swells. Researchers constantly monitor pressure and seismic activity and have noticed that swelling has now reached levels seen before previous eruptions. This offers a rare, real-time window into volcanic forecasting.
Since 1997, a network of sensors has tracked the pressure and uplift on the volcano’s seafloor. Here’s what they’ve found:
- Seafloor inflation slowed at times but surged again in late 2023, reaching about 10 inches of uplift per year by mid-2024.
- Earthquakes are occurring daily, 200–300 per day, spiking over 1,000 on some tidal cycles. That’s notable, even if it’s fewer than the ~2,000 quakes/day noted before the 2015 eruption.
- Experts William Wilcock (U. of Washington) and Bill Chadwick (Oregon State) explain that once inflation hits the pre‑eruption threshold, an eruption may follow “any day now.”
Tidal forces play a role, too: variations in ocean pressure during tides cause small but measurable increases in quake activity. Scientists are eager to see whether this tidal stress translates into eruption triggers.
Thanks to its remote, deep-water setting, Axial Seamount poses no threat to humans. Boats or coastal towns won’t notice if it erupts. “If you were on a boat above the volcano, you probably wouldn’t know it,” says Bill Chadwick.
That makes it a perfect “living laboratory.” Unlike land volcanoes that require evacuation warnings and can threaten lives, this undersea giant gives scientists the freedom to learn. Each eruption helps refine quake‑inflation signals and tags ideal eruption cues.
When magma erupts at this depth, it cools instantly in contact with seawater. This process pushes steam pockets that collapse with implosive pops, sounds captured by underwater microphones.
These events also shape hydrothermal vents: new fissures appear and hot fluids flow, altering the habitat for deep‑sea creatures like tube worms and clams. After an eruption, the ocean floor falls away again, resetting the terrain and showing scientists how geology and ecosystems interact.
Axial’s pattern, consistent inflation, quake increase, and eruption are now being tracked using AI and machine learning, yielding predictive models that could work even for unmonitored or land-based volcanoes.
Successful forecasting here, where human impact is nil, supports efforts to apply the same tools to more volatile hotspots near populated regions. Each eruption teaches scientists how seismic tremors, tilt changes, and gas chemistry combine to spark eruptions.
Though an explosion at Axial Seamount won’t break the surface, past submarine eruptions show their global reach. For instance, the undersea 2022 eruption of Hunga Tonga–Hunga Haʻapai sent massive tsunamis and shockwaves across oceans, causing widespread impact.
While Axial Seamount is a quieter shield volcano, the data it provides helps improve tsunami forecasting and eruption prediction systems globally. The goal? Better preparedness when other submarine giants near shore become active.
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