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Earth Science

Mystery Oxygen Source Discovered on the Sea Floor 48

Something is pumping out large amounts of oxygen at the bottom of the Pacific Ocean, at depths where a total lack of sunlight makes photosynthesis impossible. Nature: The phenomenon was discovered in a region strewn with ancient, plum-sized formations called polymetallic nodules, which could play a part in the oxygen production by catalysing the splitting of water molecules, researchers suspect. The findings are published in Nature Geoscience. "We have another source of oxygen on the planet, other than photosynthesis," says study co-author Andrew Sweetman, a sea-floor ecologist at the Scottish Association for Marine Science in Oban, UK -- although the mechanism behind this oxygen production remains a mystery. The findings could also have implications for understanding how life began, he says, as well as for the possible impact of deep-sea mining in the region.

The observation is "fascinating," says Donald Canfield, a biogeochemist at the University of Southern Denmark in Odense. "But I find it frustrating, because it raises a lot of questions and not very many answers." Sweetman and his collaborators first noticed something amiss during field work in 2013. The researchers were studying sea-floor ecosystems in the Clarion-Clipperton Zone, an area between Hawaii and Mexico that is larger than India and a potential target for the mining of metal-rich nodules. During such expeditions, the team releases a module that sinks to the sea floor to perform automated experiments. Once there, the module drives cylindrical chambers down to close off small sections of the sea floor -- together with some seawater -- and create "an enclosed microcosm of the seafloor," the authors write. The lander then measures how the concentration of oxygen in the confined seawater changes over periods of up to several days.

Without any photosynthetic organisms releasing oxygen into the water, and with any other organisms consuming the gas, oxygen concentrations inside the chambers should slowly fall. Sweetman has seen that happen in studies he has conducted in areas of the Southern, Arctic and Indian oceans, and in the Atlantic. Around the world, sea-floor ecosystems owe their existence to oxygen carried by currents from the surface, and would quickly die if cut off. (Most of that oxygen originates in the North Atlantic and is carried to deep oceans around the world by a 'global conveyor belt.')
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Mystery Oxygen Source Discovered on the Sea Floor

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  • by chuckugly ( 2030942 ) on Monday July 22, 2024 @01:58PM (#64646794)

    I read about this a long time ago ... it ain't good.

  • After how, the next question is how common this is. If it's one freakish little zone in the whole world, it is fascinating but probably not significant. If it's happening in many places... That's going to change some models.

    • Since this was found in an otherwise unspectacular part of the seabed, there is every reason to expect to find the same organisms (or processes) somewhere else.

      No doubt, they are looking. Or, more likely, some competitor/ collaborator group is adding "BOD" (biological oxygen demand) measurements to their planned programmes.

    • It's common enough that mining companies want to dig it all up and bring it to the surface. We barely even know what this is, or what it does for the world as a whole and we're already looking to destroy it completely. I swear humans are the idiot who saws the branch they're sitting on.

  • I't's not aliens. They discovered Atlantis. Those are oxygen emitters to get rid of the oxygenic pollution in their city.

    • Those are oxygen emitters to get rid of the oxygenic pollution in their city.

      oxygenic (adjective):

      2: generating or producing oxygen

      Surely, the last thing they need to get deal with oxygenic pollution is an oxygen source. On the other hand, they mention that they aren't sure that the battery effect would explain this and if Atlantis is generating large amounts of oxygenic pollution then this would both explain the excess oxygen and provide an excellent way of locating Atlantis. Of course, given that Atlantis is clearly shielded against sonar, that would need huge numbers of robotic s

  • ...or somebody ?!? (ducks...)
  • White hydrogen deposits exist in vast quantity. One theory for their presence is subterranean electrolysis. Of course that would also produce oxygen, and it's gotta go somewhere...

    • by Rei ( 128717 )

      Believe it or not, Earth's crust isn't full of massive electrolysis currents.

      It's much simpler: there are plenty of chemicals that emit oxygen when they decompose. Peroxides, many perchlorates, some chlorates, even some some oxides (like manganese dioxide). Sulfuric acid reduction of some minerals also releases oxygen. Spoiler alert: it's just going to be chemistry.

  • Was there other gases like methane? Also were the samples taken after Taco Tuesday and Chili Wednesday. Just checking
  • They should look for one around.

  • From the plants in Hollow Earth, where Godzilla comes from. Hollow earth leaks a little.
  • It's been assumed till now that the discovery of oxygen in the atmosphere of an exoplanet would be evidence of life. This appears a lot less secure now...

    • Planetary scientists have been compiling lists of ways that planets can produce oxygen without photosynthesis or life since the 1950s - it was a significant consideration in the design of the "Miller-Urey" experiment producing biologically "interesting" molecules by sparking (imitating lightening) in a mixture of ammonia, CO2, nitrogen and water vapour as a proxy for then-popular models of the early Earth's atmosphere.

      (There are, of course, about a half-dozen types of biological photosynthesis that don't p

      • Exoplanets are not something I've learnt much about. Appreciated.

        • OTOH, chemistry is something we understand fairly well, and can perform a range of experiments to elaborate what actually happens (as opposed to what happens in theory ; as I used to say to my trainees, in theory, there is no difference between theory and practice ; and in practice, there is. See also - Feynmann's meaning of "wrong.

          We can reconstruct any environment between the vacuum of space and the core of Jupiter in our labs. finding out what actually happens in those environments is a question of calc

  • "No Billy, it's not Godzilla farts."

  • If you spit water you get H2 and O2

  • by RockDoctor ( 15477 ) on Monday July 22, 2024 @08:25PM (#64647978) Journal
    The linked article is a Nature house-journalist's take on a paper - not the paper itself.

    The paper is "Evidence of dark oxygen production at the abyssal seafloor [nature.com]", and is published as Open Access.

    Valuable points missed by the journalism include :

    • they tried injecting various materials ("dead-algal biomass, dissolved inorganic carbon and ammonium (NH4+) or cold filtered surface seawater") into the isolated seabed patches to see if they enhanced/ suppressed the O2 production, revealing clues to it's origin. No obvious results. They had control areas too.
    • There is a moderate correlation between the "Dark Oxygen Production" (DOP) and the area covered in poly-metallic nodules. But, for example, no significant difference between DOP measured on different cruises (suggesting that it's not an equipment/ operator issue).
    • "we would urge caution when temporally upscaling our results, as the nonlinear production of O2 suggests that DOP may not be continuous in nature." They said that for a reason. It won't stop people extrapolating their results, but it needed to be said.
    • "diffusion of O2 from trapped air bubbles within the chamber was unlikely because each chamber uses two one-way valves in the lid to purge air from the chambers as the lander sinks. Even if an air bubble could be trapped long enough to reach the seafloor, gaseous diffusion of O2 into the water phase would take " - but I'm sure the wiser heads of Slashdot will suggest that this "discovery" is the result of air trapped in the apparatus. Because Slashdot sees the obvious beams in other people's eyes, not having any motes in Slashdot's communal eye.
    • The authors don't express a strong preference for a particular origin mechanism, but have electrical potential measurements suggesting the origin may be by electrolysis from a "geobattery" formed by exposed grains of different metals. But the drop off in production rates would then be puzzling - why would the production rates decrease with time? They suggest a mechanism : "Assuming the âgeo-batteryâ(TM) is partly responsible for the DOP observed, the initial high DOP rate may have been related to the âbow-waveâ(TM) of the lander removing sediments from the surface of the nodules and exposing electrochemically active sites on the nodules. The slowdown in DOP seen later in the incubations could have then been caused by a reduction in voltage potential and/or degradation of metal-oxide catalysts that has been observed in Mn oxide catalysts previously."

    There are probably other important points in there - I just gave it a quick skim. But RTFP for yourself - that's why it was written.

    • Another possible source of electrolysis is the battery in the sensor devices. Or a reaction between the metals on the ocean floor and the materials in the devices.
      • Possible ... well, yes. If you believe that the instrument designers are incompetent, and the ROV operators can't install and operate a sensor package in their machines. Which, frankly, having worked with both groups, is a belief I don't share.

        Hell, having designed and built sensor arrays myself at school (not immersed in sea-water, but operating in the kilovolt range), and having had to install and maintain dozens of electronic and electrical sensors in a marine (salt water) environment, insulation is som

  • If those nodules are catelizing water, where's the hydrogen going? Nobody light a match!
  • I ain't no chemist, but splitting HO to get O should leave a bunch of H behind, shouldn't it? Where can I pump it into my future hydrogen car and hydrogen helicopter?

  • Somebody has been to the nether and brought back some soul sand and placed it on the bottom of the ocean. It's the most obvious explanation.

Ocean: A body of water occupying about two-thirds of a world made for man -- who has no gills. -- Ambrose Bierce

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