The Lōʻihi Seamount is an active underwater volcano just over a half-mile below the ocean’s surface, 21 miles southeast of the island of Hawaiʻi.
Now there is a greater understanding of the youngest volcano in the Hawaiian island chain, and the role submerged volcanoes play in Earth’s history, after a scientific expedition in the summer of 2014 led by researchers from the University of Hawaiʻi at Mānoa’s School of Ocean and Earth Science and Technology.
“Lōʻihi is a very wonderful natural laboratory in our backyard for studying earth processes that have happened in the past,” said Brian Glazer, a UH Mānoa associate professor of oceanography. “So while today, Lōʻihi might be unique, there are times in Earth’s history that much of the global ocean looked like Lōʻihi does today.”
The other key collaborators in the groundbreaking expedition were the Schmidt Ocean Institute, Woods Hole Oceanographic Institution and the University of Minnesota, along with scientists from France and Germany.
“Descending the pit crater of Lōʻihi, the summit of Lōʻihi, is a lot like walking around Volcanoes National Park, except of course, it’s three thousand feet below the sea’s surface,” said Glazer.
The team mapped Lōʻihi’s deepest reaches more than 16,000 feet below aboard Schmidt’s research vessel Falkor using the ship’s multibeam data and Woods Hole’s autonomous underwater vehicle Sentry.
“Cutting edge technology, pioneer vehicle that targets and just doesn’t get tired, and maps at higher resolution and takes photographs that we couldn’t otherwise gain,” said Glazer.
Glazer said the expedition had three fundamental objectives: “One: the geology of how the seamounts grow, how the Hawaiian islands have grown through time. Two: the chemistry of the impacts of a leaky, iron-rich volcano, spewing an iron plume out into the Pacific Ocean. And three: how the microbiology of the system around interacts with the ocean around it.”
Marine microorganisms, or microbes, play a crucial role in sustaining life on Earth by producing oxygen, serving as the base of a food chain. At volcanically active areas like Lōʻihi, they provide a glimpse into the vast diversity of harsh conditions under which life has thrived, even raising questions about the possibility of life on other planets and moons.
“Microbes are actually taking advantage of the energy that’s locked up in the rock and locked up in the hydrothermal fluids, rusting that iron and making a living at it,” said Glazer.
UH scientists and researchers from the Hawaiʻi Undersea Research Laboratory have been on the forefront of discovery at Lōʻihi for more than 25 years. That work paved the way for this latest wave of discovery including mapping the base of the volcano, more than three miles below the surface of the ocean.
“There are acres and acres of this energetic microbial community that was previously unaccounted for,” said Glazer.
The wealth of new data is providing answers and leading to even more questions, as UH continues to offer tremendous opportunities to undergraduate and graduate students and prove that it is home to one of the world’s premiere oceanography programs.
“The Department of Oceanography has a long history of working with students, working in the environment and answering some of the big questions,” said Glazer. “Whether they be exploration based or hypotheses-driven, science-based. On this particular expedition, we had a nice blend of being able to do both.”
More about the expedition
- UH News story: “Lōʻihi Seamount’s iron-oxidizing bacteria focus of ocean expedition”
- UH News Schmidt Ocean Institute story: “Iron eaters of Lōʻihi Seamount”