1.
Antarctica
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It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,000,000 square kilometres, it is the fifth-largest continent, for comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km in thickness, Antarctica, on average, is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents. Antarctica is a desert, with precipitation of only 200 mm along the coast. The temperature in Antarctica has reached −89.2 °C, though the average for the quarter is −63 °C. Anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent. Organisms native to Antarctica include many types of algae, bacteria, fungi, plants, protista, vegetation, where it occurs, is tundra. The continent, however, remained neglected for the rest of the 19th century because of its hostile environment, lack of easily accessible resources. In 1895, the first confirmed landing was conducted by a team of Norwegians, Antarctica is a de facto condominium, governed by parties to the Antarctic Treaty System that have consulting status. Twelve countries signed the Antarctic Treaty in 1959, and thirty-eight have signed it since then, the treaty prohibits military activities and mineral mining, prohibits nuclear explosions and nuclear waste disposal, supports scientific research, and protects the continents ecozone. Ongoing experiments are conducted by more than 4,000 scientists from many nations, the name Antarctica is the romanised version of the Greek compound word ἀνταρκτική, feminine of ἀνταρκτικός, meaning opposite to the Arctic, opposite to the north. Aristotle wrote in his book Meteorology about an Antarctic region in c.350 B. C, marinus of Tyre reportedly used the name in his unpreserved world map from the 2nd century A. D. Before acquiring its present geographical connotations, the term was used for locations that could be defined as opposite to the north. For example, the short-lived French colony established in Brazil in the 16th century was called France Antarctique, the first formal use of the name Antarctica as a continental name in the 1890s is attributed to the Scottish cartographer John George Bartholomew. Antarctica has no population and there is no evidence that it was seen by humans until the 19th century. Explorer Matthew Flinders, in particular, has credited with popularising the transfer of the name Terra Australis to Australia. Cook came within about 120 km of the Antarctic coast before retreating in the face of ice in January 1773. The first confirmed sighting of Antarctica can be narrowed down to the crews of ships captained by three individuals, according to various organisations, ships captained by three men sighted Antarctica or its ice shelf in 1820, von Bellingshausen, Edward Bransfield, and Nathaniel Palmer
2.
Continent
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A continent is one of several very large landmasses on Earth. Generally identified by convention rather than any strict criteria, up to seven regions are regarded as continents. Ordered from largest in size to smallest, they are, Asia, Africa, North America, South America, Antarctica, Europe, in geology, areas of continental crust include regions covered with water. Islands are frequently grouped with a continent to divide all the worlds land into geopolitical regions. Under this scheme, most of the countries and territories in the Pacific Ocean are grouped together with the continent of Australia to form a geopolitical region called Oceania. By convention, continents are understood to be large, continuous, discrete masses of land, many of the seven most commonly recognized continents identified by convention are not discrete landmasses separated completely by water. Earths major landmasses all have coasts on a single, continuous World Ocean, the most restricted meaning of continent is that of a continuous area of land or mainland, with the coastline and any land boundaries forming the edge of the continent. From this perspective the edge of the shelf is the true edge of the continent. In this sense the islands of Great Britain and Ireland are part of Europe, while Australia, as a cultural construct, the concept of a continent may go beyond the continental shelf to include oceanic islands and continental fragments. In this way, Iceland is considered part of Europe and Madagascar part of Africa, extrapolating the concept to its extreme, some geographers group the Australasian continental plate with other islands in the Pacific into one continent called Oceania. This divides the land surface of Earth into continents or quasi-continents. The ideal criterion that each continent be a discrete landmass is commonly relaxed due to historical conventions, of the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by ocean. Several continents are defined not as absolutely distinct bodies but as more or less discrete masses of land, Asia and Africa are joined by the Isthmus of Suez, and North and South America by the Isthmus of Panama. In both cases, there is no separation of these landmasses by water. Both these isthmuses are very narrow compared to the bulk off the landmasses they unite, North America and South America are treated as separate continents in the seven-continent model. However, they may also be viewed as a continent known as America or the Americas. This viewpoint was common in the United States until World War II and this remains the more common vision in Latin American countries, Spain, Portugal, France, Italy and Greece, where they are taught as a single continent. The criterion of a landmass is completely disregarded if the continuous landmass of Eurasia is classified as two separate continents, Europe and Asia
3.
Indian Ocean
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The Indian Ocean is the third largest of the worlds oceanic divisions, covering 70,560,000 km2. It is bounded by Asia on the north, on the west by Africa, on the east by Australia, the Indian Ocean is known as Ratnākara, the mine of gems in ancient Sanskrit literature, and as Hind Mahāsāgar, in Hindi. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf, the oceans continental shelves are narrow, averaging 200 kilometres in width. An exception is found off Australias western coast, where the width exceeds 1,000 kilometres. The average depth of the ocean is 3,890 m and its deepest point is Diamantina Deep in Diamantina Trench, at 8,047 m deep, Sunda Trench has a depth of 7, 258–7,725 m. North of 50° south latitude, 86% of the basin is covered by pelagic sediments. The remaining 14% is layered with terrigenous sediments, glacial outwash dominates the extreme southern latitudes. The major choke points include Bab el Mandeb, Strait of Hormuz, the Lombok Strait, the Strait of Malacca, the Indian Ocean is artificially connected to the Mediterranean Sea through the Suez Canal, which is accessible via the Red Sea. All of the Indian Ocean is in the Eastern Hemisphere and the centre of the Eastern Hemisphere is in this ocean, marginal seas, gulfs, bays and straits of the Indian Ocean include, The climate north of the equator is affected by a monsoon climate. Strong north-east winds blow from October until April, from May until October south, in the Arabian Sea the violent Monsoon brings rain to the Indian subcontinent. In the southern hemisphere, the winds are milder. When the monsoon winds change, cyclones sometimes strike the shores of the Arabian Sea, the Indian Ocean is the warmest ocean in the world. Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, Indian Ocean warming is the largest among the tropical oceans, and about 3 times faster than the warming observed in the Pacific. Research indicates that human induced greenhouse warming, and changes in the frequency, among the few large rivers flowing into the Indian Ocean are the Zambezi, Shatt al-Arab, Indus, Godavari, Krishna, Narmada, Ganges, Brahmaputra, Jubba and Irrawaddy River. The oceans currents are controlled by the monsoon. Two large gyres, one in the northern hemisphere flowing clockwise and one south of the equator moving anticlockwise, during the winter monsoon, however, currents in the north are reversed. Deep water circulation is controlled primarily by inflows from the Atlantic Ocean, the Red Sea, north of 20° south latitude the minimum surface temperature is 22 °C, exceeding 28 °C to the east. Southward of 40° south latitude, temperatures drop quickly, surface water salinity ranges from 32 to 37 parts per 1000, the highest occurring in the Arabian Sea and in a belt between southern Africa and south-western Australia
4.
West Antarctica
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West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of that continent that lies within the Western Hemisphere, and includes the Antarctic Peninsula. It is separated from East Antarctica by the Transantarctic Mountains and is covered by the West Antarctic Ice Sheet and it lies between the Ross Sea, and the Weddell Sea. It may be considered a giant peninsula stretching from the South Pole towards the tip of South America. West Antarctica is largely covered by the Antarctic ice sheet, but there have been signs that climate change is having some effect, the coasts of the Antarctic Peninsula are the only parts of West Antarctica that become ice-free. These constitute the Marielandia Antarctic tundra and have the warmest climate in Antarctica, the rocks are clad in mosses and lichens that can cope with the intense cold of winter and the short growing-season. Advisory Committee on Antarctic Names approved the name in 1962, West Antarctica is mostly covered by a massive ice sheet referred to as the West Antarctic Ice Sheet. In recent decades this ice sheet has shown signs of decreasing mass, unlike East Antarctica, West Antarctica has shown some effects of global warming. The parts of West Antarctica not covered with ice, which are the coasts of the Antarctic Peninsula, tectonic evolution of the Transantarctic Mountains West Antarctic Rift This article incorporates public domain material from the United States Geological Survey document West Antarctica
5.
Transantarctic Mountains
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These mountains divide East Antarctica and West Antarctica. They include a number of named mountain groups, which are often again subdivided into smaller ranges. The range was first sighted by James Clark Ross in 1841 at what was named the Ross Ice Shelf in his honor. It was first crossed during the British National Antarctic Expedition of 1901-1904, the mountain range stretches between the Ross Sea and the Weddell Sea the entire length of Antarctica, hence the name. With a total length of about 3,500 km, the Transantarctic Mountains are one of the longest mountain ranges on Earth, the 100–300 km wide range forms the boundary between East Antarctica and West Antarctica. The summits and dry valleys of the TAM are some of the few places in Antarctica not covered by ice, the highest mountain of the TAM is 4,528 m high Mount Kirkpatrick in the Queen Alexandra Range. Isolated peaks surrounded by ice are referred to as nunataks, penguins, seals, and sea birds live along the Ross Sea coastline in Victoria Land, while life in the interior of the Transantarctic Range is limited to bacteria, lichens, algae, and fungi. Forests once covered Antarctica, including plentiful Wollemi Pine and Southern Beech, however, with the gradual cooling associated with the break-up of Gondwana, these forests gradually disappeared. It is believed that the last trees on the Antarctic continent were on Transantarctic Mountains, the Transantarctic Mountains were first seen by Captain James Ross in 1841 from the Ross Sea. The range is a barrier that must be crossed to reach the South Pole from the Ross Ice Shelf. The first crossing of the Transantarctic Mountains took place during the 1902-1904 British National Antarctic Expedition at the Ross Ice Shelf, a reconnaissance party under the command of Albert Armitage reached 2700 m altitude in 1902. The following year a party under expedition leader Robert Falcon Scott crossed into East Antarctica at a location now known as Ferrar Glacier and they explored part of Victoria Land on the Antarctic Plateau before returning via the same glacier. In 1908, Ernest Shackletons party crossed the mountains through the Beardmore Glacier, Robert Scott returned to that same glacier in 1911, while Roald Amundsen crossed the range via the Axel Heiberg Glacier. The name Transantarctic Mountains was first applied to range in a 1960 paper by geologist Warren B. It was subsequently recommended by the US-ACAN committee, a US authority for geographic names and this purely descriptive label is internationally accepted at present. The Leverett Glacier in the Queen Maud Mountains is the route through the TAM for the overland supply road between McMurdo Station and Amundsen–Scott South Pole Station. The Transantarctic Mountains are considerably older than other mountain ranges of the continent that are volcanic in origin. The range was uplifted during the opening of the West Antarctic Rift to the east, the mountains consist of sedimentary layers lying upon a basement of granites and gneisses
6.
Eastern Hemisphere
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The Eastern Hemisphere is a geographical term for the half of the earth that is east of the prime meridian and west of the antimeridian. It is also used to refer to Europe, Asia, Africa, and Australia, in contrast with the Western Hemisphere and this hemisphere may also be called the Oriental Hemisphere. In addition, it may be used in a cultural or geopolitical sense as a synonym for the Old World, the line demarcating the Eastern and Western Hemispheres is an arbitrary convention, unlike the Equator which divides the Northern and Southern Hemispheres. The prime meridian at 0° longitude and the antimeridian, at 180° longitude are the accepted boundaries. Prior to the adoption of standard time, numerous prime meridians were decreed by various countries where time was defined by local noon. The center of the Eastern Hemisphere is located in the Indian Ocean at the intersection of the equator, the land mass of the Eastern Hemisphere is larger than that of the Western Hemisphere and has a wide variety of habitats. 82% of humans live in the Eastern Hemisphere, compared to 18% in Western Hemisphere, media related to Eastern Hemisphere at Wikimedia Commons
7.
Nematode
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The nematodes or roundworms constitute the phylum Nematoda. They are an animal phylum inhabiting a broad range of environments. Nematodes are classified along with insects and other moulting animals in the clade Ecdysozoa, Nematodes have successfully adapted to nearly every ecosystem from marine to fresh water, to soils, and from the polar regions to the tropics, as well as the highest to the lowest of elevations. They are found in part of the earths lithosphere, even at great depths below the surface of the Earth in gold mines in South Africa. They represent 90% of all animals on the ocean floor, the many parasitic forms include pathogens in most plants and animals. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes, trees would still stand in ghostly rows representing our streets and highways. In 1758, Linnaeus described some nematode genera, then included in Vermes, the name of the group Nematoda, informally called nematodes, came from Nematoidea, originally defined by Karl Rudolphi, from Ancient Greek νῆμα and -eiδἠς. It was treated as family Nematodes by Burmeister, at its origin, the Nematoidea erroneously included Nematodes and Nematomorpha, attributed by von Siebold. Along with Acanthocephala, Trematoda and Cestoidea, it formed the obsolete group Entozoa and they were also classed along with Acanthocephala in the obsolete phylum Nemathelminthes by Gegenbaur. In 1861, K. M. Diesing treated the group as order Nematoda, in 1877, the taxon Nematoidea, including the family Gordiidae, was promoted to the rank of phylum by Ray Lankester. In 1919, Nathan Cobb proposed that nematodes should be recognized alone as a phylum and he argued they should be called nema in English rather than nematodes and defined the taxon Nemates, listing Nematoidea sensu restricto as a synonym. Since Cobb was the first to all but nematodes from the group, some sources consider the valid taxon name to be Nemates or Nemata. The phylogenetic relationships of the nematodes and their close relatives among the protostomian Metazoa are unresolved, traditionally, they were held to be a lineage of their own but in the 1990s, they were proposed to form the group Ecdysozoa together with moulting animals, such as arthropods. The identity of the closest living relatives of the Nematoda has always considered to be well resolved. Morphological characters and molecular phylogenies agree with placement of the roundworms as a taxon to the parasitic Nematomorpha. Together with the Scalidophora, the Nematoida form the clade Cycloneuralia, the Cycloneuralia or the Introverta—depending on the validity of the former—are often ranked as a superphylum. Due to the lack of knowledge regarding many nematodes, their systematics is contentious, an earliest and influential classification was proposed by Chitwood and Chitwood—later revised by Chitwood—who divided the phylum into two—the Aphasmidia and the Phasmidia. These were later renamed Adenophorea and Secernentea, respectively, the Secernentea share several characteristics, including the presence of phasmids, a pair of sensory organs located in the lateral posterior region, and this was used as the basis for this division
8.
Springtail
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Springtails form the largest of the three lineages of modern hexapods that are no longer considered insects. If they are considered a basal lineage of Hexapoda, they are elevated to full class status, collembolans are omnivorous, free-living organisms that prefer moist conditions. They do not directly engage in the decomposition of organic matter, but contribute to it indirectly through the fragmentation of organic matter, the Poduromorpha and Entomobryomorpha have an elongated body, while the Symphypleona and Neelipleona have a globular body. Most species have an abdominal, tail-like appendage, the furcula and it is held under tension by a small structure called the retinaculum and when released, snaps against the substrate, flinging the springtail into the air. All of this place in as little as 18 milliseconds. Springtails also possess the ability to reduce their size by as much as 30% through subsequent ecdyses if temperatures rise high enough. Since warmer conditions increase metabolic rates and energy requirements in organisms, traditionally, the springtails were divided into the orders Arthropleona, Symphypleona and occasionally also Neelipleona. The Arthropleona were divided into two superfamilies, the Entomobryoidea and the Poduroidea, but actually, these two and the Symphypleona form three lineages, each of which is equally distant from the other two. Thus, the Arthropleona are abolished in modern classifications, and their superfamilies are raised in rank accordingly, being now the Entomobryomorpha, technically, the Arthropleona are thus a partial junior synonym of the Collembola. The term Neopleona is essentially synonymous with Symphypleona + Neelipleona, the Neelipleona were originally seen as a particular advanced lineage of Symphypleona, based on the shared global body shape. But the global body of Neelipleona is realised in a different way than in Symphypleona. Subsequently, the Neelipleona were considered as being derived from the Entomobryomorpha, but analysis of 18S and 28S rRNA sequence data suggests that they form the most ancient lineage of springtails, which would explain their peculiar apomorphies. Springtails are attested to since the Early Devonian, the fossil from 400 million years ago, Rhyniella praecursor, is the oldest terrestrial arthropod, and was found in the famous Rhynie chert of Scotland. Given its morphology resembles extant species quite closely, the radiation of the Hexapoda can be situated in the Silurian,420 million years ago or more, instead, most are found in amber. Even these are rare and many amber deposits carry few or no collembola, the best deposits are from the early Eocene of Canada and Europe, Miocene of Central America, and the mid-Cretaceous of Burma and Canada. There are about 3,600 different species, springtails commonly consume fungal hyphae and spores, but also have been found to consume plant material and pollen, animal remains, colloidal materials, minerals and bacteria. In addition, a few species routinely climb trees and form a dominant component of canopy faunas, in temperate regions, a few species are almost exclusively arboreal. In tropical regions a single square meter of canopy habitat can support species of Collembola
9.
Mite
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Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology, in soil ecosystems, mites are favored by high organic matter content and by moist conditions, wherein they actively engage in the fragmentation and mixing of organic matter. Mites are among the most diverse and successful of all the invertebrate groups and they have exploited an incredible array of habitats, and because of their small size, go largely unnoticed. Many live freely in the soil or water, but there are also a number of species that live as parasites on plants, animals. It is estimated that 48,200 species of mites have been described, mites occupy a wide range of ecological niches. For example, Oribatida mites are important decomposers and occur in many habitats and they eat a wide variety of material including living and dead plant and fungal material, lichens and carrion, some are even predatory, though no species of Oribatida mite are parasites. Many mites which have well studied are parasitic on plants. One family of mites Pyroglyphidae, or nest mites, live primarily in the nests of birds and these mites are largely parasitic and consume blood, skin and keratin. Dust mites, which feed mostly on dead skin and hair shed from humans instead of consuming them from the organism directly, insects may also be infested by parasitic mites. Examples are Varroa destructor, which attaches to the body of the bee, and Acarapis woodi. There are hundreds of species of associated with other bee species. They attach to the bees in a variety of ways, for example, Trigona corvina workers have been found with mites attached to the outer face of their hind tibiae. Some are thought to be parasites, while others are beneficial symbionts, mites also parasitize some ant species, such as Eciton burchellii. Some of the plant pests include the spider mites, thread-footed mites. Among the species that attack animals are members of the sarcoptic mange mites, demodex mites are parasites that live in or near the hair follicles of mammals, including humans. Acari are mites, except for the three families of ticks, mites also hold the record speed, for its length, Paratarsotomus macropalpis is the fastest animal on Earth. The majority of species are harmless to humans, but a few species of mites can colonize humans directly, act as vectors for disease transmission. Mites which colonize human skin are the cause of several types of skin rashes, such as grain itch, grocers itch
This article incorporates public domain material from the United States Geological Survey document "East Antarctica" (content from the Geographic Names Information System).
