Date: February 24, 2017
Location: 14°, 13.102' S ; 169°, 03.739' W
Maximum Dive Depth: 929 meters (3,048 feet)
On February 24, 2017, the ninth dive of the 2017 American Samoa expedition, we explored Vailulu'u Seamount, an active volcano lying in the eastern region of the Samoan hotspot. Prior to the dive, the last visual survey of the volcano had taken place in 2005, but new bathymetric data collected via NOAA Ship Okeanos Explorer just days before the February 24 dive showed that the volcanic cone in the crater, called Nafanua, had grown substantially since the seamount was last mapped in 2012, having formed two distinct volcanic features.
During the dive, we explored the newly formed cones in the center of the Nafanua crater, observing spectacular pillow basalts, angular lava flows, and evidence of a potential recent landslide. We also encountered interesting biology, including a fish caracas being consumed by worms, corals, carnivorous sponges and anemones, and hydroids. Much can be learned in terms of succession and how species colonize the seafloor over time, and the dive represented an exciting opportunity to observe a very dynamic environment both in terms of geology and biology.
Dive Location Map