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<div data-thumb = "https://scx1.b-cdn.net/csz/news/tmb/2019/oceanographe.jpg" data-src = "https://scx2.b-cdn.net/gfx/ news / 2019 / oceanographe.jpg "data-sub-html =" Global distributions of dissolved O2 and so42- in underwater sediments. In yellow regions, SO dissolved42- should disappear in sediments and the HCO3– should be the predominant net electron acceptor at greater depths. In the white regions, SO dissolved42- should penetrate sediment from the seabed to the igneous subsoil. The dark blue and light blue regions represent respectively the minimum and maximum areas on which O2 should enter sediments from the sea floor to the subsoil16. SO42- The reduction is expected to dominate the net organic oxidation of the subsoil in the yellow and white regions. O2 The reduction is expected to dominate the net organic oxidation of the subfloor in blue regions. Orange dots mark drilling sites where SO42- disappears in the first 500 meters of sediment. White dots mark drilling sites where SO42- penetrates the entire sediment sequence. Dark blue dots indicate where O dissolved2 and dissolved SO42- penetrate the entire sediment sequence. Average blue dots indicate core sites where O2 and so42- penetrate up to the bottom of the cores (meters to a few tens of meters) and can penetrate up to the basement. X symbols mark sites where the full extent of SO42- penetration is unknown because SO42- is present in all measured samples, but the sedimentary sequence continues well below the last measurement. ">
Dr. Steven D "Hondt, an oceanographer at the University of Rhode Island, and his collaborators have spent more than 20 years studying the microbial life that lives deep in the seabed – including the speed at which it breathes and the amount of food that he consumes – discoveries.
Now, Hondt and other URI oceanographers Robert Pockalny, Victoria Fulfer and Arthur Spivack have synthesized the results of dozens of related studies to determine the impact of underwater life on the world over the world. above the waterline. Their results are somewhat surprising.
Their analysis was done at the request of the editors of the journal Nature Communications, as part of a series of papers on Earth's biogeochemical cycles.
"Breathing underground life has long-term impacts on surface chemistry and climate," said D'Hondt summing up his findings.
According to D "Hondt, the world enriches with oxygen because the organic matter sinks into the bottom of the sea and is buried there and the underground life – microbial cells of many varieties – devours the buried organic matter in leaving behind oxidized chemicals This process is a vital link in the carbon cycle, in which carbon compounds travel from the atmosphere to the Earth and the oceans and return to the atmosphere.
"If the underground life was completely effective, the surface world would be much less oxidized," he said. "But it's not completely effective – what they leave behind – the remains of their meals – is what determines the amount of oxygen in the world around us." .
"Thus, the only way to generate oxygen in the air over the course of billions of years is to continuously bury organic matter," added D "Hondt. When underground organisms eat organic matter, they reverse photosynthesis and suppress the oxidative power of the material. world above. "
The URI scientist thinks that it is useful to study the complex details of the carbon cycle and the role of underwater life on the global climate in order to develop a better understanding of the world. 39, evolution of the Earth.
"Some scientists even think that the surface world and the subsoil world are decoupled, but they are not," he said. "The surface world feeds the subterranean world, and the underworld affects the chemistry of the surface world.They are in communication with each other.The underground organisms change the chemistry of the ocean and they change the chemistry of the l & # 39; atmosphere. "
According to D'Hondt, many questions about the details of this process and their implications remain unanswered, including the factors that limit subterranean respiration, how fast the process occurs, and how these processes change over time. confident that the answers will be forthcoming.
"These microbes breathe orders of magnitude slower than necessary to divide themselves, yet they live in sediments 100 million years old," he said. "Have they lived 100 million years, or do they divide and accumulate energy over millennia and divide very slowly, or do their sources of energy include some form of energy? something we have not thought of? Our assumptions are fundamentally based on bad ideas. "
Underwater sediments in the South Pacific Gyre, one of the least populated places on the planet
Steven D & Hondt et al. Underwater life and its biogeochemical impacts, Nature Communications (2019). DOI: 10.1038 / s41467-019-11450-z. https://www.nature.com/articles/s41467-019-11450-z
Quote:
Oceanographer reveals link between underwater life and global climate (21 August 2019)
recovered on August 21, 2019
since https://phys.org/news/2019-08-oceanographer-reveals-link-subseafloor-life.html
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