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South Sandwich Trench
The South Sandwich Trench is a deep arcuate trench in the South Atlantic Ocean lying to the east of the South Sandwich Islands. It is the deepest trench of the Southern Atlantic Ocean, and the second deepest of the Atlantic Ocean after the Puerto Rico Trench. Since the trench extends south of the 60th parallel south, it also contains the deepest point in the Southern Ocean. The deepest point in the entire trench is the Meteor Deep, whose location prior to February 2019 was identified as at a depth of . This sounding was made during the German Meteor expedition. The depth is named after the German survey ship Meteor, which first surveyed the area as part of its namesake expedition in 1926. The deepest point below the 60th parallel south, the deepest point in the Southern Ocean, is dubbed by Victor Vescovo as the Factorian Deep, a name that he hopes will become official. This point lies at a depth of , and is the only subzero Hadal zone in the world. The trench is long and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Scotia Ridge Vents Map
East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the fact that east is the direction where the Sun rises: ''east'' comes from Middle English ''est'', from Old English ''ēast'', which itself comes from the Proto-Germanic *''aus-to-'' or *''austra-'' "east, toward the sunrise", from Proto-Indo-European *aus- "to shine," or "dawn", cognate with Old High German ''*ōstar'' "to the east", Latin ''aurora'' 'dawn', and Greek ''ēōs'' 'dawn, east'. Examples of the same formation in other languages include Latin oriens 'east, sunrise' from orior 'to rise, to originate', Greek ανατολή anatolé 'east' from ἀνατέλλω 'to rise' and Hebrew מִזְרָח mizraḥ 'east' from זָרַח zaraḥ 'to rise, to shine'. ''Ēostre'', a Germanic goddess of dawn, might have been a personification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Oceanography
Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub-domains into which oceanography is divided. Others include biological, chemical and geological oceanography. Physical oceanography may be subdivided into ''descriptive'' and ''dynamical'' physical oceanography. Descriptive physical oceanography seeks to research the ocean through observations and complex numerical models, which describe the fluid motions as precisely as possible. Dynamical physical oceanography focuses primarily upon the processes that govern the motion of fluids with emphasis upon theoretical research and numerical models. These are part of the large field of Geophysical Fluid Dynamics (GFD) that is shared together with meteorology. GFD is a sub field of Fluid dynamics describing flows occurring on spatial and temporal scales that are greatly influence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotia Sea
The Scotia Sea is a sea located at the northern edge of the Southern Ocean at its boundary with the South Atlantic Ocean. It is bounded on the west by the Drake Passage and on the north, east, and south by the Scotia Arc, an undersea ridge and island arc system supporting various islands. The sea sits atop the Scotia Plate. It is named after the expedition ship Scotia (barque), ''Scotia''. Many icebergs melt there. Location and description The Scotia Sea is the area of water between the Drake Passage, Tierra del Fuego, South Georgia Island, South Georgia, the South Sandwich Islands, the South Orkney Islands, and the Antarctic Peninsula. These island groups all sit atop the Scotia Arc, which frames the sea on the north, east, and south. The Scotia Sea covers an area around . About half of the sea stands above the continental shelf. History The sea was named about 1932 after the ''Scotia (barque), Scotia'', the expedition ship used in these waters by the Scottish National Antarcti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Hydrographic Organization
The International Hydrographic Organization (IHO) is an intergovernmental organisation representing hydrography. , the IHO comprised 98 Member States. A principal aim of the IHO is to ensure that the world's seas, oceans and navigable waters are properly surveyed and charted. It does this through the setting of international standards, the co-ordination of the endeavours of the world's national hydrographic offices, and through its capacity building program. The IHO enjoys observer status at the United Nations, where it is the recognised competent authority on hydrographic surveying and nautical charting. When referring to hydrography and nautical charting in Conventions and similar Instruments, it is the IHO standards and specifications that are normally used. History The IHO was established in 1921 as the International Hydrographic Bureau (IHB). The present name was adopted in 1970, as part of a new international Convention on the IHO adopted by the then member nations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Bathymetric Chart Of The Oceans
The General Bathymetric Chart of the Oceans (GEBCO) is a publicly available bathymetric chart of the world's oceans. The project was conceived with the aim of preparing a global series of charts showing the general shape of the seafloor. Over the years it has become a reference map of the bathymetry of the world’s oceans for scientists and others. Organisation GEBCO operates under the joint auspices of the International Hydrographic Organization (IHO). and the Intergovernmental Oceanographic Commission (IOC) of UNESCO. Its work is done by an international group of experts in seafloor mapping who develop a range of bathymetric data sets and data products. Data sets and products Although originally GEBCO published paper contour charts, today it has moved into the digital age and collects digital depths of the ocean from wherever they are available. GEBCO provides a range of bathymetric data sets and data products, including: *Global gridded bathymetric data sets: **GEBCO_08 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limiting Factor To Be Prepared For A Dive Into The Atlantic Ocean
In electronics, a limiter is a circuit that allows signals below a specified input power or level to pass unaffected while attenuating (lowering) the peaks of stronger signals that exceed this threshold. Limiting is a type of dynamic range compression. Clipping is an extreme version of limiting. Limiting is any process by which the amplitude of a signal is prevented from exceeding a predetermined value. Limiters are common as a safety device in live sound and broadcast applications to prevent sudden volume peaks from occurring. Limiters are also used as protective features in some components of sound reinforcement systems (e.g., powered mixing boards and power amplifiers) and in some bass amplifiers, to prevent unwanted distortion or loudspeaker damage. Types Limiting can refer to a range of treatments designed to limit the maximum level of a signal. Treatments in order of decreasing severity range from clipping, in which a signal is passed through normally but sheared off ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montagu Island
Montagu Island ( es, Isla Jorge) is the largest of the South Sandwich Islands, located in the Scotia Sea off the coast of Antarctica. It is a part of the British Overseas Territory, South Georgia and the South Sandwich Islands. It is located northeast from Bristol Island and south from Saunders Island. The island was first sighted by James Cook in 1775, and named after John Montagu, 4th Earl of Sandwich and the First Lord of the British Admiralty at the time of its discovery. The first recorded landing was made by the Norwegian whaler and explorer Carl Anton Larsen in 1908. Geography The desolate, uninhabited island measures approximately , with over 90% of its surface permanently covered in ice. The volcano Mount Belinda is its most notable geographic feature, rising to above sea level. It was believed to be inactive prior to the sighting of low-level ash emission and suspected lava effusion in 2002 by the British Antarctic Survey The British Antarctic Survey (BAS) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Belinda
Mount Belinda is a stratovolcano on Montagu Island, in the South Sandwich Islands of the Scotia Sea. A part of the British Overseas Territory, South Georgia and the South Sandwich Islands, Mount Belinda is also the highest peak in the South Sandwich Islands, at 1,370 m (4,490 ft). Belinda was inactive until late 2001, when it erupted. The eruption produced large quantities of basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...ic lava, melting the thick cover of ice that had accumulated while the volcano lay dormant, and "producing a marvelous 'natural laboratory'; for studying lava-ice interactions relevant to the biology of extreme environments as well as to processes believed to be important on Mars." The activity throughout 2005 marked the highest levels yet. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Island Arc
Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle along the subduction zone. They are the principal way by which continental growth is achieved. Island arcs can either be active or inactive based on their seismicity and presence of volcanoes. Active arcs are ridges of recent volcanoes with an associated deep seismic zone. They also possess a distinct curved form, a chain of active or recently extinct volcanoes, a deep-sea trench, and a large negative Bouguer anomaly on the convex side of the volcanic arc. The small positive gravity anomaly associated with volcanic arcs has been interpreted by many authors as due to the presence of dense volcanic rocks beneath the arc. Inactive arcs are a chain of islands which contains older volcanic and volcaniclastic rocks. The curved shape of many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
