Pillow Basalts and Hotspot Origins of Tutuila Ridge
Part of the E Mamana Ou Gataifale II expedition includes exploring the geology of the seafloor throughout American Samoan waters. Check out this introduction to the region’s geology as the team on Nautilus views lava tubes and ribbons of volcanic basalt along Tutuila Ridge, off the north coast of Tutuila, the largest island in American Samoa. All the islands of the Samoan Archipelago were formed sequentially above a hot spot (or mantle plume) named the Samoan Hotspot. Volcanoes that today remain subsea and that have grown so large as to become islands have erupted from this hotspot. As the Pacific tectonic plate moved overtop, the hotspot remained relatively stationary forming new volcanoes and elongating the island chain. On a much smaller scale, watch as ROV Hercules explores seafloor landscapes shaped by volcanism in this highlight video.
The E Mamana Ou Gataifale II 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.
E Mamana Ou Gataifale II - American Samoa
American Samoa is the southernmost U.S. territory, centered in the South Pacific, 2,300 miles southwest of Hawaiʻi, and 1,500 miles northeast of New Zealand. It is home to the cradle of Polynesia’s oldest culture.
