But it's not dangerous.
Axial underwater vent. Image: OSU
This past week has seen the steady rumble of thousands of tiny earthquakes radiating from off the coast of Oregon. Coupled with a sudden 8 foot drop in the seafloor—indicative of magma being withdrawn from reservoirs deep underneath the seabed—it seems likely that a powerful volcanic eruption is underway, most likely courtesy of the Axial Seamount, a massive underwater volcano located about 250 miles offshore.
An Axial eruption would be no surprise: Geologists Bill Chadwick of Oregon State University and Scott Nooner of the University of North Carolina forecasted the event last fall, a claim they reiterated just last week at the NOVAE scientific workshop in Seattle. Their prediction is based on recent research demonstrating how the Axial volcano is able to inflate and deflate like a magma balloon. (Disclosure: the author is a student at Oregon State and unaffiliated with the research in question.)
As Chadwick noted in a blog post on Thursday (the duo maintain a regular blog dedicated to Axial Seamount activity and forecasts), confirming the eruption will require a journey out to the scene of the crime: "There are some hints that lava did erupt, but we may not know for sure until we can get out there with a ship," he said. It may be possible for researchers to get to the site as early as this month, but it likely won't be until August until Chadwick and Nooner are able to get to the volcano with a remotely operated undersea vehicle.
This is hardly the first Axial eruption geologists have observed. The last one occured in 2011, an event also "loosely" predicted by Chadwick and Nooner. Since that eruption, inflation around the volcano has increased by about 400 percent, an observation leading to the pair's prediction last fall. The magma balloon has to burst.
"We've learned that the supply rate of magma has a big influence on the time between eruptions," Nooner offered in an OSU statement. "When the magma rate was lower, it took 13 years between eruptions. But now when the magma rate is high, it took only four years."
The geologists are sure to note that, in any case, the eruption poses no danger to coastal residents. The seabed changes happen too slowly to trigger a tsunami, while the quakes are too small. So, fear not.