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Iceberg A-74
Iceberg A-74 is an iceberg that calved from the north side of the Antarctic Brunt Ice Shelf in February 2021. Its calving had been anticipated due to large ice rifts that opened up in September 2019 and spread in the Antarctic summer of 2020–21. The iceberg measured soon after calving. It has moved away from the Antarctic coast which allowed, on 13–14 March 2021, the research vessel ''Polarstern'' to complete a circumnavigation as part of a research expedition. The ''Polarstern'' has photographed the sea bed which has provided an insight into fauna that can survive up to from the nearest daylight. Calving The calving of the iceberg was much anticipated due to large rifts in the ice that appeared in September 2019, in the vicinity of the McDonald Ice Rumples. The rift spread very rapidly across part of the Brunt Ice Shelf in summer 2020–21. GPS equipment belonging to the British Antarctic Survey (BAS) first reported that the iceberg had calved on 26 February. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brunt Oli 2021059 Lrg
Brunt is a surname. Notable people with the surname include: *Chris Brunt, Northern Irish football player * David Brunt, British meteorologist * Dominic Brunt, English actor *John Brunt, soldier in World War II who was posthumously awarded the Victoria Cross ** John Brunt V.C. (public house), the pub that bears his name *Jon Brunt (born 1974), American curler *Katherine Brunt, English cricketer and 2006 England women's Cricketer of the Year *Martin Brunt, crime correspondent for Sky News *Maureen Brunt (1928–2019), Australian economist and professor * Maureen Clark née Brunt, American Olympic curler *Peter Brunt, ancient historian at Oxford University *Stephen Brunt, Canadian sports journalist *Tony Brunt (born 1947), New Zealand journalist, activist and politician. *Van Brunt House, historic home in Miccosukee, Florida Fictional characters: *Abraham "Brom" van Brunt, fictional character in Washington Irving's short story ''The Legend of Sleepy Hollow'' *Liquidator Brunt, charac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operational Land Imager
The Operational Land Imager (OLI) is a remote sensing instrument aboard Landsat 8, built by Ball Aerospace & Technologies. Landsat 8 is the successor to Landsat 7 and was launched on February 11, 2013. OLI is a push broom scanner that uses a four-mirror telescope with fixed mirrors. Overview and mission OLI operates alongside TIRS (Thermal Infrared Sensor) on board the LDCM. The build and design of OLI differs from previous generations of instruments, while still maintaining data continuity with archived Landsat data from the last 40 years by keeping the same spectral and spatial resolutions of previous instruments. OLI aids the Landsat-8 mission in the imaging of Earth's surface and the collection of moderate resolution data that is used to monitor changing trends on the surface and evaluate how land usage changes over time. The images and data that OLI has helped collect have practical applications today in agriculture, mapping, and monitoring changes in snow, ice, and wate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brittle Star
Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to in length on the largest specimens. The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1,200 of these species are found in deep waters, greater than 200 m deep. Range The ophiuroids diverged in the Early Ordovician, about 500 million years ago. Ophiuroids can be found today in all of the major marine provinces, from the poles to the tropics. Basket stars are usually confined to the deeper parts of this range; Ophiuroids are known even from abyssal (>6,000 m) depths. However, brittle stars are also common members of reef communities, where t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Cucumber
Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothurian () species worldwide is about 1,717, with the greatest number being in the Asia-Pacific region. Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as '' trepang'', ''namako'', ''bêche-de-mer'', or ''balate''. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter, after which bacteria can continue the decomposition process. Like all echinoderms, sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles (or sclerietes) joined by connective tissue. In some species these can sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sessility (motility)
Sessility is the biological property of an organism describing its lack of a means of self-locomotion. Sessile organisms for which natural ''motility'' is absent are normally immobile. This is distinct from the botanical concept of sessility, which refers to an organism or biological structure attached directly by its base without a stalk. Sessile organisms can move via external forces (such as water currents), but are usually permanently attached to something. Organisms such as corals lay down their own substrate from which they grow. Other sessile organisms grow from a solid such as a rock, dead tree trunk, or a man-made object such as a buoy or ship's hull. Mobility Sessile animals typically have a motile phase in their development. Sponges have a motile larval stage and become sessile at maturity. Conversely, many jellyfish develop as sessile polyps early in their life cycle. In the case of the cochineal, it is in the nymph stage (also called the crawler stage) that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter-feeding
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms. Fish Most forage fish are filter feeders. For example, the Atlantic menhaden, a type of herring, lives on plankton caught in midwater. Adult menhaden can filter up to four gallons of water a minute and play an important role in clarifying ocean water. They are also a natural check to the deadly red tide. Extensive article on the role of menhaden in the ecosystem and possible resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Wegener Institute For Polar And Marine Research
The Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (German: ''Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung'') is located in Bremerhaven, Germany, and a member of the Helmholtz Association of German Research Centres. It conducts research in the Arctic, the Antarctic, and the high and mid latitude oceans. Additional research topics are: North Sea research, marine biological monitoring, and technical marine developments. The institute was founded in 1980 and is named after meteorologist, climatologist, and geologist Alfred Wegener. History The foundation of the AWI happened in a political environment that was characterized by system competition between East and West. The East Germany, GDR had been conducting its own Antarctic research for decades. In the 1970s it became clear that there would be one scarcity of biological- and mineral resources. Also due to the experience of the Oil crisis of 1973, oil crisis of 1973, the We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarstern Awi Hg
RV ''Polarstern'' (meaning pole star) is a German research icebreaker of the Alfred Wegener Institute for Polar and Marine Research (AWI) in Bremerhaven, Germany. ''Polarstern'' was built by Howaldtswerke-Deutsche Werft in Kiel and Nobiskrug in Rendsburg, was commissioned in 1982, and is mainly used for research in the Arctic and Antarctica. The ship has a length of 118 metres (387 feet) and is a double-hulled icebreaker. She is operational at temperatures as low as . ''Polarstern'' can break through ice thick at a speed of . Thicker ice of up to can be broken by ramming. History On 7 September 1991, ''Polarstern'', assisted by the Swedish arctic icebreaker , reached the North Pole as the first conventional powered vessels. Both scientific parties and crew took oceanographic and geological samples and had a common tug of war and a football game on an ice floe. In 2001, ''Polarstern'' together with reached the pole again. She returned for a third time on 22 August 2011. This ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iceberg A-68
Iceberg A-68 was a giant tabular iceberg adrift in the South Atlantic, having calved from Antarctica's Larsen C ice shelf in July 2017. By 16 April 2021, no significant fragments remained. With a surface area of , twice the size of Luxembourg, over a quarter the Size of Wales, and larger than Delaware, it was one of the largest recorded icebergs, the largest being B-15 which measured before breaking up. The calving of reduced the overall size of the Larsen C shelf by 12 percent. Historical data shows that many icebergs that break off from the Antarctic Peninsula reach South Georgia and the South Sandwich Islands. The name was assigned by the US National Ice Center. It broke into parts with the mother berg dubbed . The larger child icebergs were designated in order of birthing, as , , , , , and in January 2021, splitting almost in half to birth . On 30 January 2021, Iceberg broke into other icebergs called , , , , , . History and recent developments was part of La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Gyre
The Weddell Gyre is one of the two gyres that exist within the Southern Ocean. The gyre is formed by interactions between the Antarctic Circumpolar Current (ACC) and the Antarctic Continental Shelf. The gyre is located in the Weddell Sea, and rotates clockwise. South of the ACC and spreading northeast from the Antarctic Peninsula, the gyre is an extended large cyclone. Where the northeastern end ends at 30°E, which is marked by the southward turn of the ACC, the northern part of the gyre spreads over the Southern Scotia Sea and goes northward to the South Sandwich Arc. Axis of the gyre is over the southern flanks of the South Scotia, America-Antarctic, and Southwest Indian Ridges. In the southern part of the gyre, the westward return flow is about 66sverdrup(Sv), while in the northern rim current, there is an eastward flow of 61Sv. Physical oceanography Due to the Coriolis force acting to the left in the Southern Hemisphere and the resulting Ekman transport away from the cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landsat 8
Landsat 8 is an American Earth observation satellite launched on 11 February 2013. It is the eighth satellite in the Landsat program; the seventh to reach orbit successfully. Originally called the Landsat Data Continuity Mission (LDCM), it is a collaboration between NASA and the United States Geological Survey (USGS). NASA Goddard Space Flight Center in Greenbelt, Maryland, provided development, mission systems engineering, and acquisition of the launch vehicle while the USGS provided for development of the ground systems and will conduct on-going mission operations. It comprises the camera of the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS), which can be used to study Earth surface temperature and is used to study global warming. The satellite was built by Orbital Sciences Corporation, who served as prime contractor for the mission. The spacecraft's instruments were constructed by Ball Aerospace & Technologies and NASA's Goddard Space Flight Center (GSFC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice-sheet Dynamics
Ice sheet dynamics describe the motion within large bodies of ice, such those currently on Greenland and Antarctica. Ice motion is dominated by the movement of glaciers, whose gravity-driven activity is controlled by two main variable factors: the temperature and the strength of their bases. A number of processes alter these two factors, resulting in cyclic surges of activity interspersed with longer periods of inactivity, on both hourly and centennial time scales. Ice-sheet dynamics are of interest in modelling future sea level rise. General Boundary conditions The interface between an ice stream and the ocean is a significant control of the rate of flow. Ice shelves are thick layers of ice floating on the sea – can stabilise the glaciers that feed them. These tend to have accumulation on their tops, may experience melting on their bases, and calve icebergs at their periphery. The catastrophic collapse of the Larsen B ice shelf in the space of three weeks during Feb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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