Beneath the Pacific Ocean, about 300 miles off the coast of Oregon, a massive underwater volcano is preparing to erupt. Scientists monitoring Axial Seamount have detected a surge in seismic activity, with hundreds of small earthquakes occurring daily. Based on these signs, experts predict an eruption before the end of 2025.
Unlike the dramatic, explosive eruptions we often imagine, Axial Seamount’s eruption will be a slow and steady release of lava, reshaping the ocean floor without posing a tsunami risk. But why is this happening, and what can it teach us about Earth’s geology?
Axial Seamount is a shield volcano, meaning it erupts in a way that spreads lava across a wide area rather than producing a sudden explosion. When magma rises from deep within the Earth, it pushes against the seafloor, causing the volcano to swell. Eventually, the crust cracks open, and lava escapes, cooling into new seafloor around the massive underwater volcano.
This process is part of a larger geological cycle: Axial sits along the boundary between the Juan de Fuca and Pacific tectonic plates, where Earth’s crust is constantly shifting. Every time magma emerges, it contributes to the slow but steady expansion of the ocean floor.
This massive underwater volcano’s current swelling isn’t exactly a mystery—it actually follows a pattern scientists have been tracking for years. Past eruptions have occurred in 1998, 2011, and 2015 and each eruption happened after the volcano had inflated to a critical level, similar to what we’re now seeing.
Seismic data from the past six months suggests the volcano is once again reaching this breaking point. The number of small earthquakes has increased, a sign that magma is moving and exerting pressure on the rock above it.
Scientists also recently discovered multiple magma reservoirs connected to the massive underwater volcano. These reservoirs feed the eruption, but scientists are still investigating how they might connect to past eruption sites.
By studying this underwater volcano, researchers hope to improve prediction methods for more dangerous eruptions on land, such as those in the Pacific Ring of Fire. The data collected also contributes to our understanding of tectonic activity, deep-sea ecosystems, and how Earth’s crust evolves over time.
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