DSV Alvin
Axial Seamount was first detected in the 1970s by satellite altimetry, and mapped and explored by "Pisces IV", "DSV Alvin", and others through the 1980s. A large package of sensors was dropped on the seamount through 1992, and the New Millennium Observatory was established on its flanks in 1996. Axial Seamount received significant scientific attention following the seismic detection of a submarine eruption at the volcano in January 1998, the first time a submarine eruption had been detected and followed in situ. Subsequent cruises and analysis showed that the volcano had generated lava flows up to thick, and the total eruptive volume was found to be . Axial Seamount erupted again in April 2011, producing a mile-wide lava flow. There was another eruption in 2015.