Venting Chimneys of Vailuluʻu Seamount

While diving ROV Hercules around the caldera rim of Vailuluʻu Seamount, we explored some beautiful golden hydrothermal vents. ROVs flying too high could easily miss these structures, but thanks to our skilled team, we flew close enough to explore these active vents with clear fluids flowing out of delicate structures. The vent’s yellow color comes from iron oxide. As microbes living on the vents make energy using dissolved iron from the vent fluid and oxygen from the seawater via the process of chemosynthesis, the waste product left behind is the yellow-colored rust you see here. As vents age or reduce in volcanic activity, their microbial communities can change, and the vents can get darker in color too. 

Vailuluʻu Seamount is the only active underwater volcano within the National Marine Sanctuary of American Samoa and one of the important sites of our E Mamana Ou Gataifale expeditions to explore the waters in and around the Sanctuary. 

The E Mamana Ou Gataifale II expedition (NA165) is led by Ocean Exploration Trust and funded by NOAA Ocean Exploration, NOAA Office of Marine and Aviation Operations Uncrewed Systems Operations Center, and the Bureau of Ocean Energy Management via the Ocean Exploration Cooperative Institute in partnership with the National Marine Sanctuary of American Samoa and with support from Woods Hole Oceanographic Institution and Air/Sea Heritage Foundation.