Track the Fate of The Axial Seamount: The NE Pacific’s Most Active Subsea Volcano and the World’s First Underwater Observatory Station

by Carolyn Sotka

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Axial Seamount base study site. Image from Interactive Oceans. 

The Axial seamount, located 300 miles off the coast of northern Oregon, is one of the best-studied underwater volcanoes in the world and is erupting for the first time since 2011.


The Axial Seamount is an underwater mountain that juts up 3,000 feet from the ocean floor, and is part of a string of volcanoes that straddle the Juan de Fuca Ridge, a tectonic plate boundary where the seafloor is spreading apart. Image credit: Bill Chadwick, Oregon State University. 

The eruption is right on time, according to forecasts from September of last year by geologists Bill Chadwick, of the Pacific Marine Environmental Laboratory and Oregon State University, and Scott Nooner, of the University of North Carolina, Wilmington.

Researcher monitor tiny changes in the seafloor as the volcano inflates with magma and then deflates – which translates to when the seamount might erupt. “It’s kind of like a balloon — as magma is going into the balloon, it’s inflating, and it pushes the seafloor up,” Chadwick told Live Science. “As more and more magma gets in, the pressure builds. Eventually, it reaches some critical pressure where [the seamount] can’t hold it in anymore, and then it squirts out.”


3D image of Axial Seamount bathymetry. Image from NOAA’s Pacific Marine Environmental Laboratory.

Chadwick and Nooner were able to watch the eruption in real-time thanks to a set of instruments connected to shore by a fiber-optic cable, installed last summer by the University of Washington and paid for by the National Science Foundation.

Last week, the number of tiny earthquakes increased from hundreds per day to thousands per day, and on April 24, there were 8,000 earthquakes in one day, and the center of the volcanic crater dropped by about 6.5 feet within a matter of just 12 hours. Researchers did note that the earthquakes are too small to cause any harm to coastal residents or to trigger a tsunami.

In addition to the volcano, the site is home to hydrothermal vents and an entire biological ecosystem, which many different scientists are studying. Follow the continuing research and fate of the Axial Seamount on NOAA’s Pacific Marine Environmental Laboratory’s blog. –CS

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