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Oxygen began building up in the atmosphere at approximately 1.85 Ga. At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [ 4] In the absence of plants, the rate of oxygen production by photosynthesis was slower in the Precambrian, and the concentrations of O 2 ...
The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions, oxides, and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth. [ 1] The word oxygen in the literature typically refers to the most common oxygen allotrope, elemental/diatomic oxygen (O 2 ), as it ...
The relative importance of land- and sea-based photosynthesis may fluctuate on a 100,000-year timescale. The Dole effect describes trends in δ 18 O arising from trends in the relative importance of land-dwelling and oceanic photosynthesizers. Such a variation is a plausible cause of the phenomenon. [21] [22]
Sensor readings seemed to show that oxygen was being made on the seabed 4,000 meters (about 13,100 feet) below the surface, where no light can penetrate. The same thing happened on three ...
Cosmic rays ionize nitrogen and oxygen molecules in the atmosphere, which leads to a number of chemical reactions. Cosmic rays are also responsible for the continuous production of a number of unstable isotopes, such as carbon-14, in the Earth's atmosphere through the reaction: n + 14 N → p + 14 C.
July 27, 2024 at 6:00 AM. New research suggests that polymetallic nodules on the deep-sea floor may produce oxygen, a conclusion that could have enormous consequences for mining companies. Above ...
The Great Oxidation Event ( GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, [ 2] was a time interval during the Earth 's Paleoproterozoic era when the Earth's atmosphere and shallow seas first experienced a rise in the concentration of free oxygen. [ 3]
The World Ocean. For example, the Law of the Sea states that all of the World Ocean is "sea", [8] [9] [10] [b] and this is also common usage for "the sea". Any large body of water with "Sea" in the name, including lakes. River – a narrow strip of water that flows over land from a higher elevation to a lower one; Tributary – a small river ...