A desert at the bottom of the sea? Although the waters of the North Sea exchange about every two to three years, there is evidence of decreasing oxygen content. If lower amounts of this gas are dissolved in seawater, organisms on and in the seabed produce less energy -- with implications for larger creatures and the biogeochemical cycling in the marine ecosystem. Since nutrients, carbon and oxygen circulate very well and are processed quickly in the permeable, sandy sediments that make up two-thirds of the North Sea, measurements of metabolic rates are especially difficult here.
Their methods and results are presented in the Journal of Geophysical Research: Oceans. It considers both the mixing of sediments by organisms living in it and the hydrodynamics of the water above the rough sea floor," Dr. Now we can create a more realistic picture. Information about the distribution of oxygen in the sediment was collected with a "Profiler Lander," a seafloor observatory with oxygen sensors and flow meters.
A "Benthic chamber" isolated square centimetres of sediment and took samples from the overlying water over a period of 24 hours to determine the oxygen consumption of the sediment. A variety of factors determine the timing and amount of oxygen available. Currents that provide the sandy sediment with oxygen, but also the small-scale morphology of the seafloor, ensure that small benthic organisms are able to process carbon or other nutrients.
The dependencies are so complex that they can be decrypted only by using special methods," Dr. Linke summarizes. Therefore, detailed measurements in the water column and at the boundary to the seafloor as well as model calculations are absolutely necessary to understand basic functions and better estimate future changes in the cycle of materials.
Note: Content may be edited for style and length. Science News. Journal Reference : Daniel F. Image Source. There are a number of different uses for silica sand in the industrial and commercial sectors, from golf courses to glassmaking. Silica sand is a commercial and consumer product that is widely available throughout North America.
How silica sand is used depends on physical, chemical, and mechanical characteristics such as grain size, shape, colour, structure, and distribution, as well as refractoriness, strength and stability. These characteristics can differ depending on how the mineral is processed after it is mined. Silica sand is used for bunkers and greens on golf courses, as well as for natural and synthetic sports fields. For turf fields, silica sand is used as the main structural component of an uncontaminated filtration media.
Silica sand is commonly used as a mineral abrasive for industrial blasting. One of the most common uses of silica sand is in water filtration, whether processing well water or filtering your tap water.
Because of its uniform shape and size, silica sand is an effective filtration bed that consistently removes contaminants from water. Also, it does not degrade when exposed to acidic chemicals. Silica sand is a major ingredient in the production of glassmaking—in fact, silica is the primary component in standard glass products ranging from windows to beer bottles. The purity of the silica sand used plays a role in determining the color, strength and clarity of the final product.
Silica sand is used in paints and coatings to improve the overall look and durability of the paint. Silica is an important component in the construction and glazing of all types of ceramics including tableware, floor tiles, wall tiles, and more.
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