According to geologists, a massive underwater volcano is displaying signals of an imminent eruption hundreds of miles off the coast of Oregon.

Nearly a mile (1.4 kilometers) below the surface, the volcano, called Axial Seamount, is situated on a geological hot zone where molten rock gushes rise from the Earth’s mantle and into the crust. On the seafloor, hotspot volcanoes are frequent. However, Axial Seamount is also situated on the Juan de Fuca Ridge, which is a region where two enormous tectonic plates—the Pacific and Juan de Fuca plates—are continuously separating, leading to a persistent increase in pressure beneath the surface of the earth.

Researchers at the National Science Foundation’s Ocean Observatories Initiative Regional Cabled Array, a facility run by the University of Washington that tracks Axial Seamount activity, have found that the frequency of earthquakes has recently increased dramatically as the volcano inflates with more and more magma, suggesting an eruption may be imminent.

“At the moment, there are a couple hundred earthquakes a day, but that’s still a lot less than we saw before the previous eruption,” said William Wilcock, a marine geophysicist and professor at the University of Washington School of Oceanography who studies the volcano.

“I would say it was going to erupt sometime later (this year) or early 2026, but it could be tomorrow, because it’s completely unpredictable,” he said.