Scientists have been closely observing a massive underwater volcano, called Axial Seamount, located off the coast of Oregon. This volcano, stretching more than 3,600 feet above the seabed, is about 300 miles offshore and last erupted in 2015. Recent signs, such as increased seismic activity and magma buildup, suggest it could erupt again before 2025.
What is the Axial Seamount?
Axial Seamount is a huge undersea volcano, known for its frequent eruptions. It has erupted more than 50 times in the last 800 years, making it one of the most active volcanoes in the Pacific Northwest. The summit of the volcano is 4,500 feet below sea level, so it poses no threat to humans. Even if it erupts, people at the ocean’s surface likely won’t feel or see any effects.
“If you were in a boat directly above it, you probably wouldn’t notice it erupting,” said Bill Chadwick, a volcanologist at Oregon State University. However, using underwater devices like hydrophones, scientists can detect the activity as it occurs beneath the ocean.
Why Scientists Expect It to Erupt Soon
Since its last eruption in 2015, scientists have noticed signs of Axial Seamount waking up. Its caldera (a large volcanic crater) has been gradually refilling with magma, causing the area to bulge outward. Recent data suggests that this buildup is reaching a point where an eruption is likely.
- Earthquakes: Thousands of small quakes have been recorded recently, with researchers at the University of Washington noting up to 250 quakes per hour on a single day.
- Magma Pressure: As magma fills the volcano’s chamber, the increasing pressure will eventually cause the crust to crack, releasing lava.
According to Chadwick, “A year ago, Axial seemed to be taking a nap, but now it’s waking up. We think it’s likely to erupt before the end of 2025.”
How Axial Erupts: Similar to Hawaiian and Icelandic Volcanoes
Axial Seamount sits above a geological “hot spot” where two tectonic plates, the Juan de Fuca and Pacific plates, meet. Magma rises from deep within the earth’s mantle, pushing up into the volcano. When the pressure becomes too great, cracks open, and lava spews out in what is often described as a “curtain of fire.”
On land, such eruptions are visually dramatic, but underwater, they create something called pillow lava. When the hot lava hits the cold seawater, it cools rapidly, forming large, rounded mounds resembling pillows. During its 2015 eruption, Axial created pillow lava mounds that were as deep as 450 feet—equivalent to two-thirds the height of Seattle’s Space Needle.
What Happens During an Undersea Eruption?
Unlike volcanoes on land, underwater eruptions do not create massive explosions or tsunamis. Instead, they release large amounts of lava onto the ocean floor. During the 2015 eruption, Axial spewed out 5.5 billion cubic feet of lava. Scientists expect the upcoming eruption to follow a similar pattern, but they are eager to observe it using advanced underwater technology.
To do this, researchers plan to deploy unmanned submersibles to capture real-time data and video footage while the lava is still flowing. Chadwick said, “Nobody’s ever witnessed an eruption like that.”
Why Studying Axial Seamount is Important
Axial Seamount is a valuable natural laboratory for volcanologists. Its remote location allows scientists to study it without worrying about the risks associated with land-based volcanoes. With land volcanoes, false alarms could cause panic, but here, researchers can safely test prediction models and refine their understanding of volcanic behavior.
Axial is the most extensively studied underwater volcano in the world, thanks to the Regional Cabled Array, a network of over 660 miles of undersea cables and 140 scientific instruments. These instruments continuously monitor the volcano and send real-time data to researchers, helping them track changes and predict future activity.
According to Chadwick, the information gathered from Axial can be applied to studying and predicting eruptions of more dangerous volcanoes that affect human populations.
Axial Seamount is more than just an undersea volcano—it’s a vital source of scientific knowledge. Its ability to erupt frequently while remaining far from human settlements offers researchers a unique opportunity to study the complex mechanics of eruptions. With new technologies and monitoring systems in place, scientists are ready to capture valuable data during its next eruption. As Axial prepares to wake up again, its study could help predict future eruptions and minimize risks for people living near active volcanoes.
