These Metallic Rocks Produce 'Dark' Oxygen: What It Means

Metallic rocks, typically found around 4,000 metres (13,100 feet) below the surface in the Clarion-Clipperton Zone, can produce oxygen even where no light can penetrate, according to a study.

During the initial research, scientists discovered that the potato-size nodules rich in metals produced oxygen on the Pacific Ocean's seabed. The study challenges the age-old idea that oxygen could only be made through sunlight via photosynthesis, CNN reported.

These rocks release an electrical charge that splits the seawater into oxygen and hydrogen through electrolysis. The findings were made public in July.

'Dark' Oxygen

Andrew Sweetman, a professor at the UK's Scottish Association for Marine Science, has embarked on a three-year project to investigate the production of "dark" oxygen.

As part of their $2.7 million research project announced last week, the team is using custom-made rigs equipped with sensors that can be deployed to depths of 11,000 metres. It is funded by the Nippon Foundation.

"Our discovery of dark oxygen was a paradigm shift in our understanding of the deep sea and potentially life on Earth, but it threw up more questions than answers," Mr Sweetman, who is leading the study, said in a statement, adding the new research will enable them to investigate "some of these scientific questions".

The Clarion-Clipperton Zone is now being explored for the deep-sea mining of rare metals in the rock nodules.

As part of their research, Mr Sweetman and his team will determine whether the production of dark oxygen is possible in other Clarion-Clipperton Zone areas where the nodules are found. Then, they will look into how the oxygen is being produced.

Further understanding of this scientific phenomenon may help space scientists search for life beyond Earth, Mr Sweetman said, adding it might be a wider concept that's overlooked.

Emil Ruff, a microbiologist at the Marine Biological Laboratory in Massachusetts, earlier detected oxygen in freshwater samples in Alberta. This discovery was made tens to hundreds of metres beneath the Canadian prairie. The findings were published in June 2023.