The most active volcano in the Pacific Northwest may explode as early as tomorrow, according to a dire warning from scientists.

Located more than 4,900 feet below the Pacific Ocean’s surface and 300 miles off the coast of Oregon, the Axial Seamount is a mile-wide underwater volcano.

Magma surging to the surface has generated a huge increase in earthquakes beneath the seamount, according to researchers from the National Science Foundation’s Ocean Observatories Initiative.

William Wilcock, a marine geophysicist and lecturer at the University of Washington, claims that the seafloor has expanded to its pre-eruption level from 2015.

The bulge indicates the accumulation of extremely hot magma under the surface.