Hyaloclastite is a hydrated tuff-like breccia rich in black volcanic glass, formed during volcanic eruptions under water, under ice or where subaerial flows reach the sea or other bodies of water. It has the appearance of angular flat fragments sized between a millimeter to few centimeters, the fragmentation occurs by the force of the volcanic explosion, or by thermal shock during rapid cooling. Several minerals are found in hyaloclastite masses, sideromelane is a basalt glass rapidly quenched in water. It is transparent and pure, lacking the iron oxide crystals dispersed in the commonly occurring tachylite. Fragments of these glasses are usually surrounded by a waxy layer of palagonite. Hyaloclastite ridges, formed by subglacial eruptions during the last glacial period, are a prominent landscape feature of Iceland and British Columbia. Hyaloclastite is usually found at subglacial volcanoes, such as tuyas, in lava deltas, hyaloclastites form the main constituent of foresets formed ahead of the expanding delta.
The foresets fill in the topography, eventually building up to sea level. Volcanoes of Canada, Types of volcanoes Accessed Jan
Caloplaca is a lichen genus, composed of a number of distinct species. Members of the genus are commonly called firedot lichen, jewel lichen, gold lichens, orange lichens, but they are not always orange, as in the case of C. albovariegata. The distribution of this genus is worldwide, extending from Antarctica to the high Arctic. It includes a portion of northern North America and the Russian High Arctic, there are about thirty species of Caloplaca in the flora of the British Isles. A new species of Caloplaca, C. obamae, the first species to be named in honor of Barack Obama, was discovered in 2007 on Santa Rosa Island in California and published in March 2009
Mosses are small flowerless plants that typically grow in dense green clumps or mats, often in damp or shady locations. Although some species have conducting tissues, these are poorly developed. Mosses do not have seeds and after fertilisation develop sporophytes with unbranched stalks topped with single capsules containing spores and they are typically 0. 2–10 cm tall, though some species are much larger. Dawsonia, the tallest moss in the world, can grow to 50 cm in height, mosses are commonly confused with lichens and liverworts. Lichens may superficially look like mosses, and have names that include the word moss. This contrasts with the pattern in all plants, where the diploid sporophyte generation is dominant. Mosses are now classified on their own as the division Bryophyta, the main commercial significance of mosses is as the main constituent of peat, although they are used for decorative purposes, such as in gardens and in the florist trade. Traditional uses of mosses included as insulation and for the ability to absorb liquids up to 20 times their weight, mosses are non-vascular plants in the land plant division Bryophyta.
They are small plants that absorb water and nutrients mainly through their leaves and harvest carbon dioxide. They differ from plants in lacking water-bearing xylem tracheids or vessels. As in liverworts and hornworts, the gametophyte generation is the dominant phase of the life cycle. This contrasts with the pattern in all plants, where the diploid sporophyte generation is dominant. Mosses reproduce using spores, not seeds, and have no flowers, Moss gametophytes have stems which may be simple or branched and upright or prostrate. Their leaves are simple, usually only a layer of cells with no internal air spaces. They do not have roots, but have threadlike rhizoids that anchor them to their substrate. Mosses do not absorb water or nutrients from their substrate through their rhizoids and they can be distinguished from liverworts by their multi-cellular rhizoids. Spore-bearing capsules or sporangia of mosses are borne singly on long, unbranched stems, thereby distinguishing them from the polysporangiophytes, the spore-bearing sporophytes are short-lived and dependent on the gametophyte for water supply and nutrition.
Also, in most mosses, the capsule enlarges and matures after its stalk elongates
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 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, fungi, protista, where it occurs, is tundra. The continent, 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
Hauling-out is the behaviour associated with pinnipeds temporarily leaving the water. This occurs between periods of foraging activity, instead of being in the water, the pinnipeds explore sites on land or ice. Hauling-out is necessary in seals for mating and giving birth, other benefits of hauling-out may include predator avoidance, thermal regulation, social activity, parasite reduction and rest. There is much variation in haul-out patterns among different seal species, haul-out sites may be segregated by age and sex within the same species. Many species of pinniped have only a few localized rookeries where they breed, but periodically occupy hundreds of haul-out sites throughout the range
A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi in a symbiotic relationship. The combined lichen has properties different from those of its component organisms, Lichens come in many colours and forms. The properties are sometimes plant-like, but lichens are not plants, Lichens may have tiny, leafless branches, flat leaf-like structures, flakes that lie on the surface like peeling paint, or other growth forms. A macrolichen is a lichen that is either bush-like or leafy, here and micro do not refer to size, but to the growth form. Common names for lichens may contain the word moss, and lichens may superficially look like and grow with mosses, Lichens do not have roots that absorb water and nutrients as plants do, but like plants, they produce their own food by photosynthesis. When they grow on plants, they do not live as parasites, Lichens occur from sea level to high alpine elevations, in many environmental conditions, and can grow on almost any surface.
Lichens are abundant growing on bark, mosses, on other lichens and they grow on rock, gravestones, exposed soil surfaces, and in the soil as part of a biological soil crust. Different kinds of lichens have adapted to survive in some of the most extreme environments on Earth, arctic tundra, hot dry deserts, rocky coasts and they can even live inside solid rock, growing between the grains. It is estimated that 6% of Earths land surface is covered by lichen, there are about 20,000 known species of lichens. Some lichens have lost the ability to reproduce sexually, yet continue to speciate, Lichens may be long-lived, with some considered to be among the oldest living things. They are among the first living things to grow on fresh rock exposed after an event such as a landslide, the long life-span and slow and regular growth rate of some lichens can be used to date events. In American English, lichen is pronounced the same as the verb liken, in British English, both this pronunciation and one rhyming with kitchen /ˈlɪtʃən/) are used.
Lichens grow in a range of shapes and forms. The shape of a lichen is determined by the organization of the fungal filaments. The nonreproductive tissues, or vegetative body parts, is called the thallus, Lichens are grouped by thallus type, since the thallus is usually the most visually prominent part of the lichen. Thallus growth forms typically correspond to a few basic internal structure types, Common names for lichens often come from a growth form or color that is typical of a lichen genus. When a crustose lichen gets old, the center may start to crack up like old-dried paint, old-broken asphalt paving and this is called being rimose or areolate, and the island pieces separated by the cracks are called areolas. The areolas appear separated, but are connected by an underlying prothallus or hypothallus, when a crustose lichen grows from a center and appears to radiate out, it is called crustose placodioid
Graham Land is the portion of the Antarctic Peninsula that lies north of a line joining Cape Jeremy and Cape Agassiz. The line dividing them is roughly 69 degrees south, Graham Land is named after Sir James R. G. Graham, First Lord of the Admiralty at the time of John Biscoes exploration of the west side of Graham Land in 1832. It is claimed by Argentina and Chile, Graham Land is the closest part of Antarctica to South America. Until the discoveries of the British Graham Land Expedition of 1934–1937, mount Brading,4 nautical miles east of the northeast corner of Larsen Inlet. Argentina calls the area Tierra de San Martín and calls the northern peninsula Península Trinidad or Tierra de la Trinidad, Chile calls the entire Antarctic Peninsula Tierra de OHiggins. British Graham Land Expedition U. S. Geological Survey Geographic Names Information System, Graham Land Media related to Graham Land at Wikimedia Commons
The Madder Cliffs are reddish rock cliffs which form the north side of the entrance to Suspiros Bay, at the west end of Joinville Island, Antarctica. They rise steeply from the sea to about 305 metres, the cliffs were surveyed by the Falkland Islands Dependencies Survey in 1953–54. The name, given in 1956 by the UK Antarctic Place-Names Committee, is descriptive of the red colour of the rocks, other birds nesting at the site in smaller numbers include gentoo penguins, kelp gulls and snowy sheathbills. This article incorporates public domain material from the United States Geological Survey document Madder Cliffs
The Weddell seal, Leptonychotes weddellii, is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. Weddell seals have the most southerly distribution of any mammal, with a habitat that extends as far south as McMurdo Sound. It is the species in the genus Leptonychotes, and the only member of the Antarctic tribe of lobodontine seals to prefer in-shore habitats on shore-fast ice over free-floating pack ice. Genetic evidence suggests that Weddell seal population numbers may have increased during the Pleistocene, because of its abundance, relative accessibility, and ease of approach by humans, it is the best-studied of the Antarctic seals. An estimated 800,000 individuals remain today, Weddell seal pups leave their mothers at a few months of age. In those months, they are fed by their mothers warming and they leave when they are ready to hunt and are fat enough to survive in the harsh weather. The Weddell seal was discovered and named in the 1820s during expeditions led by James Weddell, however, it is found in relatively uniform densities around the entire Antarctic continent.
The Weddell seal shares a recent ancestor with the other Antarctic seals. These include the seal, the Ross seal, and the leopard seal. These species share teeth adaptations including lobes and cusps useful for straining smaller prey items out of the water, Weddell seals measure about 2. 5-3.5 m long and weigh 400–600 kg. Males weigh less than females, usually about 500 kg or less and female Weddell seals are generally about the same length, though females can be slightly larger. However, the male tends to have a thicker neck. A molecular genetic based technique has been established to confirm the sex of individuals in the laboratory, the Weddell seal face has been compared to that of a cat due to a short mouth line and similarities in the structure of the nose and whiskers. Their upturned mouths give them the appearance of smiling, the Weddell seal grows a thin fur coat around its whole body except for small areas around the flippers. The colour and pattern of the varies, often fading to a duller colour as the seal ages.
This coat moults around the beginning of summer, adults are generally brown, with lighter ventral pelage. They are mottled with darker and lighter patches, those on the belly being silvery white. Adult males usually bear scars, most of them around the genital region, young Weddell seals have gray pelage for the first 3 to 4 weeks, they turn a darker color
The long-tailed gentoo penguin is a penguin species in the genus Pygoscelis, most closely related to the Adélie penguin and the chinstrap penguin. The first scientific description was made in 1781 by Johann Reinhold Forster with a point of the Falkland Islands. They call in a variety of ways, but the most frequently heard is a loud trumpeting which is emitted with its head thrown back, the application of gentoo to the penguin is unclear. The Oxford English Dictionary notes that gentoo used to be an Anglo-Indian term used as early as 1638 to distinguish Hindus in India from Muslims, the English term may have originated from the Portuguese gentil. The gentoo penguin is one of three species in the genus Pygoscelis and nuclear DNA evidence suggests the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes. In turn, the Adelie penguins split off from the members of the genus around 19 million years ago. Two subspecies of this penguin are recognised, Pygoscelis papua papua, the gentoo penguin is easily recognized by the wide white stripe extending like a bonnet across the top of its head and its bright orange-red bill.
It has pale whitish-pink webbed feet and a long tail - the most prominent tail of all penguins. Chicks have grey backs with white fronts, as the gentoo penguin waddles along on land, its tail sticks out behind, sweeping from side to side, hence the scientific name Pygoscelis, which means rump-tailed. Gentoos reach a height of 51 to 90 cm, making them the third-largest species of penguin after the two giant species, the penguin and the king penguin. Males have a weight of about 8.5 kg just before molting. For females, the weight is 8.2 kg just before molting. Birds from the north are on average 700 g heavier and 10 cm taller than the southern birds, southern gentoo penguins reach 75–80 cm in length. They are the fastest underwater swimming penguins, reaching speeds of 36 km/h, Gentoos are adapted to very harsh cold climates. The breeding colonies of penguins are located on ice-free surfaces. Colonies can be directly on the shoreline or can be located considerably inland and they prefer shallow coastal areas and often nest between tufts of grass.
In South Georgia, for example, breeding colonies are 2 km inland, whereas in colonies farther inland, where the penguins nest between tufts of grass, they shift location slightly every year because the grass may get trampled over time. Gentoos breed on many sub-Antarctic islands, the total breeding population is estimated to be over 300,000 pairs