An undersea volcano that is just 300 miles off the coast of Oregon has been blasting out lava for a week now, backing up predictions made last fall that an undersea volcano is about to erupt.

Two previous eruptions of the volcano, called the “Axial Seamount” due to being located on the axis of a mountain ridge deep underwater, happened in 1998 and 2011, but were not detected until well after the fact — months or even years, according to media reports.

The peak of the volcano sits nearly 5,000 feet below the surface of the ocean, and last year researchers sent gear down to it in order for them to gather live data on its activities.

With this gear, scientists now have sensors and monitoring instruments connected to an undersea cable that will allow them to watch what’s happening in real time to this deep ocean hotspot. Researchers had formerly had to send battery-operated monitoring stations, and could only crunch the data after bringing them back to the surface.

The new equipment has detected via pressure sensors that an eruption had begun on April 23, and scientists had noticed thousands of small earthquakes each day near the Axial Seamount, including 8,000 small rumbles in a 24-hour period.

Pressure sensors have captured data that suggests the seafloor is descending, a sure sign that magma is spilling out and that the highly pressurized chamber is beginning to deflate. So far, the seafloor has dropped a full 8 feet over the past week.