University of Hawaii researchers, working with colleagues in California and France, have discovered evidence of a third major shield volcano making up the island of O‘ahu.
Previously, geologists believed the island’s current profile is the remnants of two volcanoes, Wai‘anae and Ko‘olau. But extending almost 100 km WNW from Ka‘ena Point, the western tip of the island of O‘ahu, is a large region of shallow bathymetry, called the submarine Ka‘ena Ridge. It is that region that has now been recognized to represent a precursor volcano to the island of O‘ahu, and on whose flanks the Wai‘anae and Ko‘olau Volcanoes later formed.
The team included scientists from the University of Hawai‘i–Mānoa, Laboratoire des Sciences du Climat et de L’Environment in France, and Monterey Bay Aquarium Research Institute.Read more