The “Dark Oxygen” on the seabed of the Pacific Ocean were discovered: this is what it is

To little more than 4000 meters deep in thePacific Oceanscientists discovered the existence of the so -called “dark oxygen“, That is oxygen produced in the absence of light with processes different from photosynthesis. A study suggests that its origin would be linked to Polimetallic nodules present in abundance on the ocean seabed, which, behaving like real “batteries”, They would be able to separate hydrogen and oxygen atoms which form water molecules through electrolytic reactions. If confirmed, this discovery could open new perspectives and interpretations on the origin and evolution of oxygen cycles in the geological history of the earth.

What is the “dark oxygen”: the polymented nodules

The so -called “Dark Oxygen” was discovered in a roughly between the Mexico and the Hawaii and part of the area Clarion-Clippertonone abysmal plain over 4.5 million square kilometers and dotted with underwater mountainous reliefs. Using gods Bentonic Landeri.e. autonomous research platforms designed to carry out measurements in depth, scientists detected one production clear of oxygen on the ocean seabed. In other words, they observed that the quantity of oxygen produced exceeded that consumed by the few biological communities present at those depths. Excluding the possibility of technical-instrumental errors, the researchers have focused on identifying the source of this oxygen which, at these depths, cannot be attributed to the photosynthesis. In fact, beyond 4000 meters Under the ocean surface you are well inside the apotic areathat is that band of the water column in which Solar light does not penetrate and therefore Photosynthesis cannot take place.

After excluding several hypotheses on the possible source of this oxygen, the experts concluded that the cause should be sought in the nodules polympoline present on the seabed.

Polimetallic nodules and splitting of oxygen

On the muddy surface of Clarion-Clipperton, or just below it, are found trillion of polymented nodules. Also known by the name of Nodules of Manganesethese are solid compounds with dimensions varying from one to over ten centimeters, produced by the chemical precipitation of iron hydroxides And manganese oxides, dissolved in the sea water, around a nucleus resting on the backdrop, for example one shell. These nodules would be responsible for the production of oxygen in the deep seabed of the Pacific Ocean. In fact, in addition to the iron and manganese, the nodules would conTrate high concentrations of minor elements, such as the lithium and the nickelwhich can increase conductivity and catalytic efficiency, triggering electrolysis reactions with the surrounding water.

“If one immerses one battery in sea water, Start sparkling, “explained Professor Sweetmanauthor of the study, in an interview. “This happens because the electric current sends sea water into oxygen and hydrogen, which manifest themselves in the form of bubbles. We believe that something similar happens naturally with these nodules.”

The researchers have tested this laboratory theory, showing that nodules can generate fairly intense electrical currents to split the sea water molecules. The results of the study, conducted by an international team led by researchers of the Scottish Association for Marine Science (the Scottish Association for the Marine Sciences), have been published in July 2024 on the prestigious international magazine Nature Geoscience.

Possible implications of the study on Dark Oxygen

The hypothesis, however intriguing, however, requires more in -depth studies to clarify, for example, the role of microbial activities on the nodules of manganese and measure oxygen levels in other submarine contexts. Nevertheless, if confirmed, it could open new roads for the interpretation of the evolution of oxygen cycles in the geological history of our planet, with possible implications also for the search for oxygen on others planets And lune.

At the same time, however, the discovery rekindled the debate on mineral activities in an oceanic environment. In fact, precisely because of the presence of lithium, cobalt, nickel and others critical resourcesthe polymented nodules have long been the subject of interest for themineral extraction. Also in the Clarion-Clipperon area, the International Seabed Authoritythe organization in charge of defining the rules for the use of mining resources in the ocean seabed, has granted beyond 16 Exploratory contracts PEr the extraction of the manganese nodules.