The discovery that lumps of metal on the seafloor produce oxygen raises questions over plans to mine the deep ocean.

Scientists have discovered “dark oxygen” being produced in the deep ocean, apparently by lumps of metal on the seafloor.

About half the oxygen we breathe comes from the ocean. But, before this discovery, it was understood that it was made by marine plants photosynthesising - something that requires sunlight.

Here, at depths of 5km, where no sunlight can penetrate, the oxygen appears to be produced by naturally occurring metallic “nodules” which split seawater - H2O - into hydrogen and oxygen.

Several mining companies have plans to collect these nodules, which marine scientists fear could disrupt the newly discovered process - and damage any marine life that depends on the oxygen they make.

    • MartianSands@sh.itjust.worksEnglish
      10·
      5 months ago

      They should last indefinitely so long as the process of accretion which created these nodules keeps going. A battery becomes drained when the chemical interaction between the two metals uses up all the available metal, which happens quite fast in our modern batteries because we’ve designed them that way.

      We’ve made them powerful and cheap by using relatively small amounts of each metal, spread thin and sandwiched together. The downside is that those things films of metal get used up fast.

      These nodules, meanwhile, are lumps of metal. They won’t produce lots of power all at once, but they can generate small amounts for ages, and so long as they grow faster than the metal gets used up (it doesn’t actually go anywhere, it just changes chemically) they’ll keep going

    • Krauerking@lemy.lolEnglish
      5·
      5 months ago

      Chemical reaction that basically through charge split water into basic elements slowly through direct interaction.

      Like a magnet never runs out of magnetism juice but isn’t nearly as strong as an electromagnet. These are just a bunch of metals that clumped together.

      • Docus@lemmy.worldEnglish
        51·
        5 months ago

        Electrolysis requires an electric current, so energy. What I don’t understand from this article is where that energy is coming from. Magnets have nothing to do with it, they don’t produce energy. Batteries do, and different metals in salt water may act as a battery, but then they get used up in the process.

        • Krauerking@lemy.lolEnglish
          2·
          5 months ago

          What are you taking a test on this?

          They are lumps of conductive metals that when touching create a small charge that is able to respond to the charge that is held by water to be able to strip the oxygen atoms off.

          It’s just a bunch of them in series together finally surpasses the threshold, they just all hold a very weak charge potential individually my comparison to magnets was meant to just imply that they naturally hold a very weak charge that isn’t a strong force like a more direct applied method would.

          • Docus@lemmy.worldEnglish
            1·
            5 months ago

            Taking a test lol no, way too old for that. But while these lumps of metal in sea water may generate some electricity, I can’t see them magically lining up in series like in a 9V battery, and below a certain voltage (1.5) there is no electrolysis - not even a little bit. But I have since found the original article and raw data, and it seems the people that wrote it don’t know either exactly how this oxygen is created.

            • Krauerking@lemy.lolEnglish
              2·
              5 months ago

              You seem hung up on electricity being a literal function of this here. Expecting them to be a literal battery.

              They said they knew how. The nodules have a potential charge, when touching it increases the charge which means it can separate the oxygen. There is already companies that are performing hydrogen separation without electricity on water.

              The voltage potential is grabbing at the polar ends with likely a light chemical interaction with the zinc and other volatile metals present.

              An exact process might not be here but the function here makes sense as long as you stop looking for direct current.

              Edit: also this is not some rapid process this is a slow trickle. Nothing fancy just the physics of the world inspiring entropy.

              • Docus@lemmy.worldEnglish
                11·
                5 months ago

                The reason I questioned the literal battery theory / electrolysis is based on this quote from the BBC article The scientists worked out that the metal nodules are able to make oxygen precisely because they act like batteries. I have since found the original research paper (i linked it elsewhere in this post) which suggests the authors did not actually say that and aren’t sure of the exact mechanism. Your ‘voltage potential grabbing polar ends’ is not one on the known methods of splitting water into oxygen and hydrogen (see wikipedia, which all require electricity, light, radiation or extreme heat. None of which seem to apply here, and the paper also does not mention hydrogen being produced. So maybe there isn’t water being split here by these nodules

                • Verat@sh.itjust.worksEnglish
                  2·
                  5 months ago

                  The metals are forming a Galvanic cell with the salt water as an electrolyte, the section of the linked article labeled Galvanic corrosion mentions the splitting off of hydrogen in salt water. There is no membrane so electricity just goes through the conductive salt water. The exact voltage depends on which two metals were involved, this page has a table of the voltages in sea water (in mV)