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Deep-sea
The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combination of low temperatures, darkness, and high pressure. The deep sea is considered the least explored Earth biome as the extreme conditions make the environment difficult to access and explore. Organisms living within the deep sea have a variety of adaptations to survive in these conditions. Organisms can survive in the deep sea through a number of feeding methods including scavenging, predation and filtration, with a number of organisms surviving by feeding on marine snow. Marine snow is organic material that has fallen from upper waters into the deep sea. In 1960, the bathyscaphe ''Trieste'' descended to the bottom of the Mariana Trench near Guam, at , the deepest known spot in any ocean. If Mount Everest () were submerged there, its peak would be more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Challenger Deep
The Challenger Deep is the List of submarine topographical features#List of oceanic trenches, deepest known point of the seabed of Earth, located in the western Pacific Ocean at the southern end of the Mariana Trench, in the ocean territory of the Federated States of Micronesia. The General Bathymetric Chart of the Oceans, GEBCO Gazetteer of Undersea Feature Names indicates that the feature is situated at and has an approximated maximum depth of below sea level. A subsequent study revised the value to at a 95% confidence interval. However, both the precise geographic location and depth remain ambiguous, with contemporary measurements ranging from . The depression is named after the British Royal Navy survey ships , whose Challenger expedition, expedition of 1872–1876 first located it, and HMS Challenger (1931), HMS ''Challenger II'', whose expedition of 1950–1952 established its record-setting depth. The first descent by any vehicle was conducted by the United States N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nereus (underwater Vehicle)
''Nereus'' was a hybrid uncrewed autonomous underwater vehicle (HROV, a type of remotely operated underwater vehicle) built by the Woods Hole Oceanographic Institution (WHOI). Constructed as a research vehicle to operate at depths of up to , it was designed to explore Challenger Deep, the deepest surveyed point in the global ocean. ''Nereus'', named for Greek sea titan Nereus (who has a man's torso and a fish-tail) through a nationwide contest of high school and college students, began its deep sea voyage to Challenger Deep in May 2009 and reached the bottom on May 31, 2009. On this dive the ''Nereus'' reached a depth of , making the ''Nereus'' the world's deepest-diving vehicle in operation at the time, and the first since 1998 to explore the Mariana Trench, the deepest known part of the ocean. On 10 May 2014, ''Nereus'' was lost while exploring the Kermadec Trench at a depth of . Communications were cut off at around 2 p.m. local time, and debris retrieved later revealed that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariana Trench
The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about east of the Mariana Islands; it is the deep sea, deepest oceanic trench on Earth. It is crescent-shaped and measures about in length and in width. The maximum known depth is at the southern end of a small slot-shaped valley in its floor known as the Challenger Deep. The deepest point of the trench is more than farther from sea level than the peak of Mount Everest. At the bottom of the trench, the water column above exerts a pressure of , more than 1,071 times the standard atmospheric pressure at sea level. At this pressure, the density of water is increased by 4.96%. The temperature at the bottom is . In 2009, the Mariana Trench was established as a National monument (United States), US National Monument, Mariana Trench Marine National Monument. One-celled organisms called monothalamea have been found in the trench at a record depth of below the sea surface by researchers from the Scrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesopelagic
The mesopelagic zone (Greek language, Greek μέσον, middle), also known as the middle pelagic or twilight zone, is the part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is defined by light, and begins at the depth where only 1% of incident light reaches and ends where there is no light; the depths of this zone are between approximately below the Sea level, ocean surface. The mesopelagic zone occupies about 60% of the planet's surface and about 20% of the ocean's volume, amounting to a large part of the total biosphere. It hosts a diverse biological community that includes Gonostomatidae, bristlemouths, Psychrolutidae, blobfish, bioluminescent jellyfish, giant squid, and myriad other unique organisms adapted to live in a low-light environment. It has long captivated the imagination of scientists, artists and writers; deep sea creatures are prominent in popular culture. Physical conditions The mesopelagic zone includes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediterranean Sea
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Europe, on the south by North Africa, and on the west almost by the Morocco–Spain border. The Mediterranean Sea covers an area of about , representing 0.7% of the global ocean surface, but its connection to the Atlantic via the Strait of Gibraltar—the narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates the Iberian Peninsula in Europe from Morocco in Africa—is only wide. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccation, desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago. The sea was an important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathyscaphe
A bathyscaphe () is a free-diving, self-propelled deep-sea submersible, consisting of a crew cabin similar to a '' Bathysphere'', but suspended below a float rather than from a surface cable, as in the classic ''Bathysphere'' design. The float is filled with gasoline because it is readily available, buoyant, and, for all practical purposes, incompressible. The incompressibility of the gasoline means the tanks can be very lightly constructed, since the pressure inside and outside the tanks equalizes, eliminating any differential. By contrast, the crew cabin must withstand a huge pressure differential and is massively built. Buoyancy at the surface can be trimmed easily by replacing gasoline in the tanks with water, because water has a greater density. Auguste Piccard, inventor of the first bathyscaphe, coined the name ''bathyscaphe'' using the Ancient Greek words (), meaning 'deep', and (), meaning 'vessel, ship'. Mode of operation To descend, a bathyscaphe floods air ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metazoan
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from to . They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviour is known as ethology. The animal kingdom is divided into five major clades, namely Porifera, Ctenophora, Placozoa, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various #Units, units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the International System of Units, SI unit of pressure, the Pascal (unit), pascal (Pa), for example, is one newton (unit), newton per square metre (N/m2); similarly, the Pound (force), pound-force per square inch (Pound per square inch, psi, symbol lbf/in2) is the traditional unit of pressure in the imperial units, imperial and United States customary units, US customary systems. Pressure ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmosphere (unit)
The standard atmosphere (symbol: atm) is a unit of pressure defined as Pa. It is sometimes used as a ''reference pressure'' or ''standard pressure''. It is approximately equal to Earth's average atmospheric pressure at sea level. History The standard atmosphere was originally defined as the pressure exerted by a 760 mm column of mercury at and standard gravity (''g''n = ). It was used as a reference condition for physical and chemical properties, and the definition of the centigrade temperature scale set 100 °C as the boiling point of water at this pressure. In 1954, the 10th General Conference on Weights and Measures (CGPM) adopted ''standard atmosphere'' for general use and affirmed its definition of being precisely equal to dynes per square centimetre (). This defined pressure in a way that is independent of the properties of any particular substance. In addition, the CGPM noted that there had been some misapprehension that the previous definition (from the 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schematic Representation Of Pelagic And Benthic Zones
A schematic, or schematic diagram, is a designed representation of the elements of a system using abstract, graphic symbols rather than realistic pictures. A schematic usually omits all details that are not relevant to the key information the schematic is intended to convey, and may include oversimplified elements in order to make this essential meaning easier to grasp, as well as additional organization of the information. For example, a subway map intended for passengers may represent a subway station with a dot. The dot is not intended to resemble the actual station at all but aims to give the viewer information without unnecessary visual clutter. A schematic diagram of a chemical process uses symbols in place of detailed representations of the vessels, piping, valves, pumps, and other equipment that compose the system, thus emphasizing the functions of the individual elements and the interconnections among them and suppresses their physical details. In an electronic circuit d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salinity
Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to per mille, ‰). Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a state function, thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. A contour line of constant salinity is called an ''isohaline'', or sometimes ''isohale''. Definitions Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autotroph
An autotroph is an organism that can convert Abiotic component, abiotic sources of energy into energy stored in organic compounds, which can be used by Heterotroph, other organisms. Autotrophs produce complex organic compounds (such as carbohydrates, fats, and proteins) using carbon from simple substances such as carbon dioxide,Morris, J. et al. (2019). "Biology: How Life Works", 3rd edition, W. H. Freeman. generally Photosynthesis, using energy from light or Chemosynthesis, inorganic chemical reactions. Autotrophs do not need a living source of carbon or energy and are the primary production, producers in a food chain, such as plants on land or algae in water. Autotrophs can Redox, reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide. The primary production, primary producers can convert the energy in the light (phototrop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
