Researchers from the Scottish Institute for Marine Science have discovered that the deep ocean floor of the Pacific Ocean, covered with polymetallic nodules, produces so-called “dark oxygen.”
Polymetallic nodules recovered from the ocean floor in a Northwestern University lab. Image courtesy of Camille Bridgewater/Northwestern University.
Polymetallic nodules – naturally occurring mineral deposits that form on the seafloor – are commonly found in the sediment-covered abyssal plains of oceans around the world.
These consist primarily of iron and manganese oxides, but also contain metals such as cobalt and rare earth elements, which are essential components of many advanced, low-carbon energy technologies.
For the new study, Dr Andrew Sweetman from the Scottish Institute for Marine Science and his colleagues carried out experiments using chambers placed on the seafloor at a depth of around 4,200 metres to measure oxygen levels at multiple sites more than 4,000 kilometres apart in the Clarion-Clipperton Zone in the central Pacific Ocean, where polymetallic nodules are found.
Nearly every experiment showed a steady increase in oxygen levels over the two days.
The researchers conducted additional laboratory analysis and claim that the source of the detected oxygen release is polymetallic nodules.
Based on numerical simulations, they hypothesize that the electrical properties of the nodes are responsible for oxygen production.
While the researchers note that it is difficult to estimate how much oxygen polymetallic nodules produce over a wide area, they suggest that this source of oxygen may support ecosystems on the deep seafloor, which could be affected if these nodules are mined.
“We understand that oxygen was needed for aerobic life to begin on Earth, and Earth's oxygen supply began with photosynthetic organisms,” Dr Sweetman said.
“But we now know that oxygen is produced even in the deep ocean, where there is no light.”
“So I think we need to rethink questions like where did aerobic life begin.”
of result Published in a journal Nature Chemistry.
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A.K. Sweetman othersEvidence for dark oxygen production on the deep seafloor. National GeographyPublished online July 22, 2024, doi: 10.1038/s41561-024-01480-8
This article is based on a press release provided by Springer Nature and Northwestern University.
Source: www.sci.news
