For more than 10 years, Andrew Sweetman and his colleagues have been studying the ocean floor and its ecosystems, particularly in the Pacific’s Clarion-Clipperton Zone, an area littered with polymetallic nodules. As big as potatoes, these rocks contain valuable metals—lithium, copper, cobalt, manganese, and nickel—that are used to make batteries. They are a tempting bounty for deep-sea mining companies, which are developing technologies to bring them to the surface.
The nodules may be a prospective source of battery ingredients, but Sweetman believes they could already be producing something quite different: oxygen. Typically, the element is generated when organisms photosynthesize, but light doesn’t reach 4,000 meters below the ocean’s surface. Rather, as Sweetman and his team at the Scottish Association for Marine Science suggest in a new paper, the nodules could be driving a reaction that produces this “dark” oxygen from seawater.
www.wired.com/story/dark-oxygen-deep-sea-polymetallic-nodules-discovery/
In a remarkable discovery that could reshape our understanding of Earth’s history and the origins of life, scientists have found evidence of oxygen production in the lightless depths of the Pacific Ocean.
This finding, published in Nature Geoscience, challenges the long-held belief that all Earth’s oxygen is generated through photosynthesis.
A team led by Prof Andrew Sweetman of the Scottish Association for Marine Science (SAMS) made the discovery while conducting research in the Clarion-Clipperton Zone between Hawaii and Mexico, approximately 4,000 metres below the ocean surface.
www.sciencefocus.com/news/dark-oxygen-found-on-the-ocean-floor
An international team of scientists has discovered that oxygen is produced by potato-shaped metallic nodules on the Pacific Ocean’s seafloor. The findings, published Monday in the Nature Geoscience journal, raise new concerns about the risks of deep-sea mining.
The team, led by Professor Andrew Sweetman at the UK’s Scottish Association for Marine Science, found that oxygen is produced in complete darkness approximately 4,000 meters (13,100 feet) below the ocean’s surface. It was previously thought that only living organisms, such as plants and algae, could use energy to create the planet’s oxygen through photosynthesis, which requires sunlight.
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“For aerobic life to begin on the planet, there had to be oxygen, and our understanding has been that Earth’s oxygen supply began with photosynthetic organisms,” Sweetman said in a statement.
“But we now know that there is oxygen produced in the deep sea, where there is no light. I think we, therefore, need to revisit questions like: where could aerobic life have begun?”
The mechanism behind this oxygen production remains a mystery.
Sweetman and his collaborators first noticed something amiss during fieldwork in 2013.
www.mining.com/scientists-discover-dark-oxygen-being-produced-by-seabed-metals/
So where is the oxygen source coming from?
The researchers were there to assess the potential impacts of deep-sea mining operations looking to extract materials from polymetallic nodules. These mineral concentrations on the ocean floor contain precious metals essential for the lithium-ion batteries that power electric vehicles and phones.
The results show that the nodules carry a high electric charge which could be capable of splitting seawater into hydrogen and oxygen via a process known as seawater electrolysis.
“Through this discovery, we have generated many unanswered questions and I think we have a lot to think about in terms of how we mine these nodules, which are effectively batteries in a rock,” Sweetman said.
SAMS Director Prof Nicholas Owens called the discovery “one of the most exciting findings in ocean science in recent times,” adding that it “requires us to rethink how the evolution of complex life on the planet might have originated.”
The conventional view that oxygen was first produced by ancient microbes called cyanobacteria around three billion years ago may now need to be reevaluated.
This alternative source of oxygen production could lead to a “radical rethink” of how complex life developed on Earth, Owens said.
www.sciencefocus.com/news/dark-oxygen-found-on-the-ocean-floor
h/t Digital mix guy Spock
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