With monstrous plumes bursting from the water and shimmery streaks of electric light, Devon Massyn said it was one of the craziest things he has ever experienced.

Hidden in the Pacific, two very different volcanoes are forcing scientists to rethink what counts as “biggest.” Tamu Massif, ...

Axial Seamount is situated 300 miles off the Oregon coast and is getting closer to erupting for the first time in 10 years.