Undersea volcano off Oregon coast could erupt in 2025, but isn't a threat to people

Widely shared social media posts claimed a massive underwater volcano "the size of a city" was "showing signs it could erupt any day now" in July 2025. The volcano, which is apparently off Oregon's coast, is "completely unpredictable" and could "blow tomorrow" or later in the year, according to the posts.

One Facebook post (archived) about the volcano racked up over 130,000 reactions in four days. Instagram (archived) and X (archived) accounts with over 1 million followers each also posted about the volcano.

While the choice of language in the social media posts was a bit alarmist, it is true that scientists forecast the Axial Seamount, an underwater volcano off the coast of Oregon, would erupt in 2025.

Axial is "quite large," William Wilcock, a professor in the University of Washington School of Oceanography, told a reporter for the school's news website. While there's no definitive threshold for what makes something city-sized, maps of the volcano show it's at least a dozen miles in both width and length, which is roughly comparable to some cities within the United States.

Axial has erupted multiple times in the 21st century and does not typically do so violently, so an eruption would be unlikely to endanger or disrupt people on land.

At the annual American Geophysical Union conference in December 2024, a group of researchers led by William Chadwick, a research associate at Oregon State University's Cooperative Institute for Marine Ecosystem and Resources Studies, presented a paper in which they forecasted Axial Seamount could erupt between July 2024, when the paper was written, and the end of 2025. Their prediction was based on the rising rate of earthquakes around the volcano — often an indicator that a volcano may erupt soon — and the extent to which the volcano was inflating.

The cause of the volcano's inflation was the buildup of magma beneath the surface, according to an article from the University of Washington College of the Environment, something the Axial Seamount has done before. In fact, the U.S. Geological Survey (USGS) said in a May 2025 article that this inflation occurred shortly before all three of Axial's most recent eruptions in 1998, 2011 and 2015. While the inflation was significant enough to warrant an eruption forecast, the volcano doesn't actually inflate all that much in absolute terms; the researchers measured Axial's annual rate of inflation in centimeters.

At the time Chadwick and the other researchers wrote their paper, Axial hadn't quite inflated as much as it had prior to the 2015 eruption, although it was on its way to doing so. But by the time the University of Washington wrote about it in April 2025, the volcano had surpassed its pre-eruption inflation from 2015 without an eruption.

Chadwick and Scott Nooner, one of the co-authors of the original Axial eruption forecast, have run a blog with short updates on Axial since 2012. Posts from the middle of 2025 suggested little was changing about the volcano's behavior. On April 30, 2025, Chadwick wrote, "It feels to me like Axial is just 'treading water' lately." At the time, the researchers reported that the rate of inflation had been continuing at a steady clip and that earthquake rates kept going up and down.

Axial is the most active submarine volcano in its region of the ocean, but even so "it poses no threat to people or ocean travel," the USGS wrote. That's because the volcano is very deep — about 4,600 feet beneath the ocean's surface — and erupts relatively calmly. Its prior eruptions were effusive eruptions, in which runny lava flows out of the volcano. Another example of a volcano that has effusive eruptions is Kilauea in Hawaii.

Researching "benign" submarine volcanoes like Axial helps scientists better understand, monitor and provide warning of future eruptions at more hazardous volcanoes, the USGS said.

"The bottom line – Axial is exciting, not hazardous."