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Silicon enters the ocean in a dissolved form such as silicic acid or silicate. [103] Since diatoms are one of the main users of these forms of silicon, they contribute greatly to the concentration of silicon throughout the ocean. Silicon forms a nutrient-like profile in the ocean due to the diatom productivity in shallow depths. [103]
The global average residence time of a water molecule in the ocean is about 3,200 years. By comparison the average residence time in the atmosphere is about nine days. If it is frozen in the Antarctic or drawn into deep groundwater it can be sequestered for ten thousand years. [32] [33]
They discovered that the higher the rock/water ratio within the container, and the faster the container spun, the more silica dissolved into solution. After analyzing and upscaling their results, they estimated that anywhere from 3.2 ± 1.0 – 5.0 ± 2.0 Tmol Si yr −1 of lithogenic DSi could enter the ocean from sandy beaches, a massive ...
For example, microscopic particles of silica called phytoliths can be found in grasses and other plants. Silica is an amorphous metalloid oxide formed by complex inorganic polymerization processes. This is opposed to the other major biogenic minerals, comprising carbonate and phosphate , which occur in nature as crystalline iono-covalent solids ...
The ammonia molecule (NH 3), like the water molecule, is abundant in the universe, being a compound of hydrogen (the simplest and most common element) with another very common element, nitrogen. [51] The possible role of liquid ammonia as an alternative solvent for life is an idea that goes back at least to 1954, when J. B. S. Haldane raised ...
Some silicon analogues of imines, with a Si=N double bond, are known: the first found was Bu t 2 Si=N–SiBu t 3, which was discovered in 1986. [21] Silicon carbide. Silicon carbide (SiC) was first made by Edward Goodrich Acheson in 1891, who named it carborundum to reference its intermediate hardness and abrasive power between diamond (an ...
[21] [22] These algae polymerise the silicic acid to so-called biogenic silica, used to construct their cell walls (called frustules). [ 23 ] In the uppermost water column the surface ocean is undersaturated with respect to dissolved silica, except for the Antarctic Circumpolar Current south of 55°S.
The remaining opal silica is exported to the deep ocean in sinking particles. [11] In the deep ocean, another 26.2 Tmol Si Year −1 is dissolved before being deposited to the sediments as opal silica. [11] At the sediment water interface, over 90% of the silica is recycled and upwelled for use again in the photic zone. [11]