They tend to inflate like a balloon in between eruptions. At Axial, the sea floor is actually rising, and that’s a big signal."

The Axial Seamount is one of the most active but least well-known volcanoes in the Pacific and all signs point to it erupting very soon—for the first time in a decade.

A recent study found increased seismicity and swelling at Axial Seamount, suggesting an eruption could occur sometime this year.