While seafloor biology often gains first attention during ROV dives, an equally fascinating seafloor world is in the pōhaku or rocks, the foundation of the seabed. During Luʻuaeaahikiikekumu, the team visited the Liliʻuokalani Ridge to investigate this chain of ancient volcanoes which had never been surveyed before. Unusually, this seamount chain is not linear like most in the Pacific, but instead seems to split into a V-shape. Collecting rocks from each arm of this ridge will allow scientists to get an age from the ancient cooled lava, reconstructing a history of the last 70 -100 million years. Through eleven ROV dives, the team collected over 600 pounds of rocks for this region. While analysis will continue for months after this expedition in research labs around the world, looking deeply at rocks reveals new information about the sequence of the eruptions and the history of this seabed area in the most recent millions of years. Enjoy this photo album that highlights a few of the rocks that were collected and processed while out at sea.
This album was created by Malanai N. Kāne Kuahiwinui.
This expedition will have E/V Nautilus returning to Papahānaumokuākea Marine National Monument (PMNM) to build on the accomplishments of the 2021 Luʻuaeaahikiikalipolipo expedition, which mapped the previously unmapped Liliʻuokalani Ridge Seamounts. The team returns for the first visual exploratory surveys of the seamount chain looking to investigate a puzzling split in the seamount trail.