What is ‘dark oxygen’ found 13,000 feet deep? | Science and technology news

For decades, scientists have floated theories about dark matter, which is believed to hold galaxies together by its gravitational pull. The dark matter enigma continues, and now scientists have discovered what they call dark oxygen at the bottom of the ocean.

A recent to study published in Nature Geoscience, a journal dedicated to Earth science research, shows oxygen emitted by mineral deposits 4,000 meters (about 13,000 feet) below the ocean surface on the seafloor of the Clarion-Clipperton Zone (CCZ) of the Pacific Ocean . The depth is almost half the length of Mount Everest’s highest peak.

The study by Andrew Sweetman, professor at the Scottish Association of Marine Science (SAMS) and team leader of the institution’s deep-sea ecology and biogeochemistry research group, provides evidence that there is an additional source of oxygen on the planet beyond the oxygen produced by photosynthesis.

Until now, it was well understood by scientists that the planet’s only source of oxygen comes from photosynthetic organisms, such as plants and algae, which produce oxygen for humans and other animals to breathe.

So what is the significance of this recently discovered dark oxygen and what questions does it raise about the origins of life on Earth?

What is dark oxygen?

In the Clarion-Clipperton Zone (CCZ), which spans 4.5 million square kilometers (1.7 million square miles) in the Pacific Ocean, there are coal-like mineral rocks called polymetallic nodules that typically contain manganese and iron. . Scientists discovered that these nodules produce oxygen without the process of photosynthesis.

Minerals that produce oxygen in the dark depths of the sea could change scientists’ views on how life began on planet Earth.

“The other implication of this research is that it potentially sheds light on where life began on the planet. This discovery showed that, well, maybe there was another source of oxygen a long time ago and aerobic life or oxygen-breathing life could have persisted before the emergence of photosynthesis – and if this is happening on our planet, it could be happening on other planets too,” Sweetman said in a SAMS video.

How did they find dark oxygen?

The discovery comes more than 10 years after the dark oxygen source itself was found. The 2013 research mission aimed to understand how much oxygen was consumed by organisms on the CCZ seafloor.

Landers, mechanical platforms that can freely fall to the sea floor, have been sent to 4,000 meters (13,000 feet) to track how oxygen levels in the water decline with depth.

However, what the researchers found was that oxygen levels increased at the bottom of the ocean.

This surprised Sweetman and his team. Until now, scientists believed that the oxygen available in the deep ocean came from the upper ocean and land, produced by plants, plankton and algae through the process of photosynthesis.

As a result, oxygen levels often decrease as you go deeper. Not in this case.

Thinking his measuring equipment was faulty, Sweetman recalibrated the equipment and repeated the experiment several times over many years – with the same results.

Through more experiments over the years, they discovered that the manganese nodules were the source of oxygen production. They brought these nodules back to the ship for testing and noticed that they had an electrical charge, the equivalent of an AA battery.

A process known as seawater electrolysis allows a charge to split seawater into hydrogen and oxygen. They observed this in their laboratory experiments.

What is the significance of the discovery?

Science works based on the principles of verification, so these discoveries will have to be confirmed by other independent experiments.

But research by Sweetman and his team suggests that some minerals produce oxygen while not using sunlight.

“The fact that we have another source of oxygen on the planet besides photosynthesis has profound consequences and implications,” said Nick Owens, director of SAMS.

This discovery also highlights the need to protect environments that self-produce oxygen, according to the researchers behind it.

“To drive the green economy, we need to extract metals from the ground or, potentially, from the depths of the ocean,” Sweetman said. “So what we found means we will have to think carefully about whether deep-ocean mining will proceed, where that mining should occur, because that oxygen will likely be used in whatever quantity the ecosystem produces.”

Furthermore, the implications of the discovery of another deep-ocean source of oxygen production open the door to revisiting how life began on Earth.

“The fact that we have another source of oxygen on the planet besides photosynthesis has profound consequences and implications,” Owens said.