WLW: UC geologist explains giant floating rock in Pacific

Thomas Algeo tells "Eddie and Rocky" the pumice island will disappear over time

"Eddie and Rocky" on 700-WLW spoke to University of Cincinnati geologist Thomas Algeo about the discovery this month of a giant island of rock floating in the Pacific Ocean off Australia.

A couple sailing in the South Pacific reported finding an island of pumice the size of Manhattan floating off Tonga, according to CNN.

UC geology professor Thomas Algeo spoke about his research paper in his lab at Geo-Phys. UC/Joseph Fuqua II

UC geologist Thomas Algeo. Photo/Joseph Fuqua II/UC Creative Services

Algeo, a professor of geology in UC's McMicken College of Art and Sciences, said the island was formed from a volcanic eruption deep underwater.

"The rock floats because it's full of air bubbles," Algeo told  show hosts Eddie Fingers and Rocky Boiman. "The air bubbles form in the lava. A pumice rock can consist of up to 90 percent air bubbles. That allows it to float. It's actually less dense than water."

News accounts suggested the pumice island could help the imperiled Great Barrier Reef. But Algeo said any benefits would be short lived.

"It might have a very positive short-term influence," he said. "A lot of marine organisms can latch onto these pumice fragments. You might repopulate some corals in the Great Barrier Reef from pumice floating in. But the main stresses on the Great Barrier Reef are much greater than that."

Algeo said half of the reef has died because of recent warming of ocean currents.

As for the pumice island? Algeo said once the gas escapes from the rock, the pumice eventually will sink to the ocean floor.

Featured image at top: Lava from an eruption pours into the ocean. Photo/Buzz Andersen/Unsplash

Related Stories

1

How AI might help nonprofits

November 7, 2025

University of Cincinnati Professor Victoria LaPoe examined whether people respond differently to AI-created messaging in nonprofit advertising.

2

Shining like a disco ball: Rachel Hoermann’s story of finding passion and purpose at UC

November 6, 2025

Rachel Hoermann has dreamed of becoming a writer since childhood. But like many who grew up in Ohio’s rust belt, the idea of going to college felt out of reach. For years, she cycled through work that never quite satisfied her creative drive. That changed when she came across a box that once belonged to her father—a discovery that would alter the course of her life.

3

New hires reflect UC’s commitment to research, innovation and impact

November 6, 2025

With the 2025-26 school year in full swing, the College of Arts and Sciences has welcomed five faculty members to lead departments that span from chemistry to journalism. Dean James Mack said these new hires “reflect our unwavering commitment to ‘Discovery in Action,’ as we continue to enhance our academic and research excellence”. With these additions, the future of UC is in good hands, and students can look forward to new opportunities for learning, research, and innovation.