martes, 4 de noviembre de 2008

Project Work: Carlos Landoni, Valentìn Delauro y Paola Fernandez

Project Work: Carlos Landoni, Valentìn Delauro y Paola Fernandez

Antarctica

1) Climate;
2) Flora;
3) Fauna;
4) Territories Claims;
5) History;
6) Natural Resources;
7) The Antarctic Treaty


1) Climate
Antarctica is classified into three basic climate regions: the peninsula, coastal regions, and the interior.
Antarctic Peninsula Reaching farther north than any other part of the continent, the peninsula has the most moderate climate with its warmer temperatures and increased precipitation. Antarctica's wildlife is more dominant in this region. Here, millions of seabirds, and hundreds of thousands of marine mammals, come to breed and feed in the summer months. Although the peninsula has milder temperatures than the rest of the continent, it sustains the fiercest winds, with gusts recorded as high as 200 mph.
Coastal Regions
The coastal regions are a balance between the Antarctic peninsula and the interior. The coasts are milder in temperature than the interior, and receive less precipitation that the peninsula. In the summer, warm ocean currents give this area a more moderate climate, but as winter approaches and the waters freeze, ice grows and the shoreline quickly cools. Coastal temperatures drop much lower than the peninsula. These regions rarely see rainfall, rather their precipitation usually occurs in the form of snow.

Antarctic Interior
The coldest part of the continent is found in the interior. It is categorized primarily by its extreme cold and lack of precipitation. The coldest temperature ever recorded was at the Vostok research station, east of the South Pole; in July, 1983 the temperature reached -129 degrees Fahrenheit, creating a new world low. The sun stays below the horizon beginning in March and lasting through September. During these winter months the interior is almost in complete darkness with zero solar radiation to help heat the surface. Far away from the ocean, the interior receives no warming effects from the waters like the coastal regions and peninsula. Indirect sunrays and high elevation also add to the chilling temperatures of Antarctica's interior.



2) Flora

Lichens
Of all the plants, lichens are best adapted to survive in the harsh polar climate. Some lichens have even been found only about 400 km from the South Pole. Lichens have proliferated in Antarctica mainly because there is little competition from mosses or flowering plants and because of their high tolerance of drought and cold. The peculiarity of lichens is that they are not one homogeneous organism but a symbiosis of two different partners, a fungus and an alga. The fungus part supplies the plant with water and nutritious salt, meanwhile the alga part organic substance, like carbohydrate produce. With this ideal "job-sharing", lichens can survive the hardest conditions. Far from the border of highly developed plants, lichens are the pioneers of the vegetation. Lichens aren’t only frugal and robust, they jug out because of their very low sensibility against frost. Some lichens, in an experiment, survived a bath in liquid nitrogen at minus 195 degrees. On icy rock, lichens have the same strategy as plants have developed in the sand of the Sahara: they form an "oasis". Like in the desert they miss water. They have only a chance to survive, if they settle in an area with a convenient, damp microclimate. Since what stops lichens to spread over the whole of Antarctica is not so much the big cold as the lack of water. For this reason they don’t settle in a place with the most sunshine, but in recesses and cracks between rocks. They like scanty soils, created by weathered rocks. They often quicken this process with secretion of acid. Snowflake are captured in the cracked rock and smelt on the dark lichens, they can absorb the vitally liquid. Especially unfavourable conditions are in the "dry valley" of East Antarctica, where big coldness and low snowfall meet. But even there scientists have found a dark cover on the north side of some rocks, which prove to be lichens. Under the microscope it was shown that the lichens penetrate the upper coat of the rock. With the dark colour the lichens absorb more light. This strategy enables the lichens to scrape a humble living in that quite high southern latitude.


Mosses Only a small number of moss species are found in Antarctica. Extensive fields occur in a few places on this continent and these are rarely more than 100 mm deep, even in the most favourable areas where there is shelter and plenty of water. Short moss turf and cushion moss is found most frequently in sandy and gravelly soils. No extensive peat formations are to be found. Mosses, like lichens, gather in colonies which make them possible to collect and retain more water. They also lose less by evaporation and show a marked ability to use water rapidly whenever it becomes available. Mosses have also become well adapted to the almost continuous light during the long days of a polar summer. One Antarctic moss, Bryum argenteum, produces more energy by photosynthesis in low light at 5°C than it does at 15°C, or higher. Photosynthesis can start within a few hours of thawing after a prolonged period of freezing, and almost immediately following short periods.
Algae More than 300 species of non-marine algae have been found in Antarctica. These very simple plants take many diverse forms and a few have become adapted to living in difficult polar environments. Blue-green and other algae are found growing in damp sand and gravel around lakes and tarns, along meltwater streams or in low-lying areas, where snowdrifts or seepage may collect. Some such as Prasiola crispa can tolerate high levels of nutrients and are found near bird colonies. Others – the snow algae - may form extensive and spectacular red, yellow or green patches in areas of permanent snow. Recent studies have shown that some blue-green algae live inside rocks in dry valleys. Commonly they are found under stones, particularly light-coloured quartz stones, where the microclimate is more favourable than in the surrounding sand or soil. Together with lichens, they are the only living things in a barren landscape.
3) Fauna
Antarctic Birds Millions of seabirds breed along the coast and offshore islands of Antarctica. To survive in the biting environment, Antarctic birds have waterproof plumage, and large compact bodies with a dense layer of fat under their skin. There are nineteen species of seabirds that breed along the continent. Due to the shortage of snow-free nesting regions, most seabirds tend to procreate in large, impressive concentrations making for ideal viewing conditions for the bird enthusiasts. The birds will migrate north as the summer months come to an end, spending the winter in more temperate climates.
Penguins One of Antarctica's most familiar wildlife, penguins are considered by many to be the continent's signature species. They spend over 75% of their lives as sea where they are most comfortable. Their bodies are designed for swimming. Powerful paddle muscles and a compact hydrodynamic body shape allow penguins to swim up to 25 mph. Impressive and elegant in the water, by contrast penguins awkwardly waddle and hop once ashore. While seventeen species of penguins can be found in the subantarctic regions - including coastal islands - only four types of the flightless birds breed on the continent itself: the Emperor, Adelie, Chinstrap, and Gentoo penguins.
Antarctic Seals Much of the early exploration of Antarctica and the Southern Ocean was do to the search for new seal communities. During the 19th and 20th century, many seals were hunted for their valuable skins and oils. Entire populations of species were driven to the brink of extinction. Thankfully, today, the seals are protected by a collection of agencies, and their numbers have continued to thrive. Because of the nutrient-rich feeding regions, and the lack of polar bears, the Antarctic has a much larger seal population than the Arctic. Most of their life is spent in water, but seals must return to land to breed. The best locations to view their breeding grounds are on the pack ice surrounding Antarctica, or along the coastal shores of the northern islands.

Whales Whales are divided into two main groups: toothed and baleen. The only toothed whales found in the Antarctic are the Orca and the Sperm whale, while a variety of baleen whales have been sited: Blue, Fin, Humpback, Minke, and Southern Right. Unlike the other wildlife of Antarctica, whales do not breed in the region. However, they do take advantage of the nutrient-filled waters in the austral summer, traveling great distances from their temperate breeding waters in the north. Like seals, several species of whales were hunted until near extinction in the mid-1900s. While regulations have been placed on whaling activities, these magnificent giants have not seen their populations recover as well as the seals. Today, the entire area surrounding Antarctica is recognized as a whale sanctuary.
4) Territories Claims
5) History
The idea of a large southern continent first appeared in the Greek writings of both Pythagoras and Aristotle. It was believed the earth would topple if a sizable landmass did not exist to balance out the northern continents. Today, we refer to that region as Antarctica. Although Captain James Cook was the first recorded explorer to cross the Antarctic Circle in 1773, he was not the first to see Antarctica's landmass. That acclaim would go to Russian Fabian van Bellinshausen fifty years later. Cook's accounts of the large seal and whale populations, however, helped influence further exploration of the Southern Ocean from sealers in search of the mammals' valued skins. In the 19th century over one thousand sealing ships traveled to the Antarctic regions and its shoreline. In the early 20th century, reaching the South Pole became a top priority for explorers. The first expeditions to actually declare the South Pole as their primary purpose were led by Robert F. Scott in 1902, and Irishman Ernest Shackleton in 1908. Neither would reach their desired destination, but Shackleton came frustratingly close, just 97 miles from the Pole before terminating his crusade. Shackleton had failed in his quest for the South Pole, but he returned to the continent in 1914 to claim a new prize: the first crossing on foot of the Antarctic continent. With a crew of 27, they set sail in early December. A month into the expedition, their ship, Endurance, was trapped and slowly crushed by pack ice. Salvaging what supplies they could, the crew was forced to abandon the ship, and struggle to stay alive in one of the most inhospitable environments in the world. The men would endure sub-zero temperatures and starvation for nearly 20 months, with no communication to the outside world. Incredibly, not a single man would be lost. Shackleton's journey of survival would become one of the most noted in Antarctica's history. Interest in Antarctica continued through the World Wars and into the Cold War. At that time, an American training facility was created to give US troops experience in polar conditions. In early spring of 1954, the first permanent scientific station was established by the Australian National Antarctic Research Expeditions. No single nation controls Antarctica, nor does the continent have any nations of its own. The Antarctic Treaty governs Antarctica. Originally signed in 1961 by 12 nations (Argentina, Australia, Belgium, Chile, French Republic, Japan, New Zealand, Norway, Union of South Africa, Union of Soviet Socialist Republics, United Kingdom of Great Britain and Northern Ireland, and United States of America) it now contains the signature of 44 countries. The treaty recognizes Antarctica's unique position on the planet as a shared environment to be used for peaceful purposes, and international cooperative scientific research. Together, Antarctica would be used in the interests of all human progress and to better humankind.
6) Natural Resources
IceOne of Antarctica's most important resources is ice. It is said that Antarctica's ice accounts for 90% of the worlds fresh water. As a resource it has potential as a fresh water supply. Some people have considered towing icebergs from Antarctica to parts of the world in need of fresh water. At present the delivery costs make these ventures unprofitable. Another possible use of the ice on Antarctica is as a long term deep freeze storage site for grain and other foods. Again the costs of shipping and handling are prohibitive. CoalThere are coal deposits found along the coast of Antarctica. It is also very wide spread throughout the Transantarctic Mountains. These deposits were formed between 35 million and 55 million years ago when Antarctica was covered by ancient swamps. Coal forms in swamps as plants die and are buried before they can be completely decomposed. They are then covered by other sediments such as sand and mud. This burial allows the hydrocarbons in the coal to be preserved for future generations to use. Coal is used as a source of direct heat and also to generate electricity incoal burning power plants. The main problem of developing coal in Antarctica is that the cost of mining and delivering the coal is so much higher than the cost of coal in the rest of the world market. It may bepossible for coal to be used in some small research stations for a source of heat. PetroleumPetroleum deposits are formed when plants and small animal remains are buried in a marine environment by sand and mud. These remains then build up as hydrocarbons and are trapped by a layer of rock that the hydrocarbons cannot pass through. These cap rocks then store the petroleum underground until it is pumped out by wells. At this time there has been no petroleum exploration attempted and there are no known petroleum resources in Antarctica. Most of the speculation about petroleum in Antarctica comes from finding petroleum on the other Southern continents which were at one time connected together. The petroleum deposits thought to be on the offshore regions of Antarctica would probably be most feasible to obtain although they would have to be exceptionally large to be considered for exploitation because of the following enormous exploration and development problems: Deeper water over the continental shelves;The presence of sea ice and icebergs;Short work season and hostile climate. Comparisons with other Gondwana continents suggest the existence of petroleum reserves in the interior of Antarctica. But these lie below the thick ice, ruling out development. This is due not only to the thickness of the ice but also the fact that it is sliding slowly towards the coast. Metallic MineralsMineral resources have not been found in great quantities so far due to the small amount of rock that is exposed. It is believed that since the other continents that were once attached to Antarctica to form Gondwana have metallic and nonmetallic minerals, that Antarctica probably has similar minerals. It is also known that rock layers such as those in Antarctica commonly contain large amounts of cobalt, chromium, nickel, vanadium, copper, iron and platinum group minerals. The search for sizable concentrations of metallic minerals below the ice will be a difficult prospecting venture which will require costly geophysical and geochemical surveying and core drilling. Geologists have found small deposits of minerals in Antarctica but these deposits are low in quality and occur in widely scattered places. The peninsula seems to have the highest probability of containing economic base-metal deposits. HydrothermalWhen fluids such as water are heated by the earth's interior, they can carry dissolved minerals in their fluid state such as quartz, gold, etc. When the solution of liquid and dissolved minerals cools in a new environment, the minerals are deposited as a solid. (The same way that candy forms crystals as it cools and hardens.) Magmatic SegregationAs liquid rock (magma) cools, the minerals in it separate. This is because the minerals have different densities and will separate with the denser minerals towards the bottom. (Think of how a bottle of Italian dressing separates into layers.) This separates the minerals into different layers resulting in concentrations of minerals in different places as the magma cools and hardens. SedimentationAs the earth is worn down and broken into pieces by wind, water, ice and other weathering processes, the pieces of the earth are carried by water into the oceans where they are deposited in layers. Since the pieces are different sizes and have different solubilities in water, they settle to the bottom and form different layers. This results in concentrations of the minerals separated into layers.
7) The Antarctic Treaty
The Antarctic Treaty was signed in 1959 by the 12 countries which had Antarctic stations during the International Geophysical Year (1957-58). These 'original signatories' were Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, United Kingdom, the United States and the USSR. The Treaty came into operation in 1961, and since then a further 14 countries have joined the original 12 as "Consultative Parties", i.e. 26 nations have full voting rights at meetings. Any Party to the Treaty which shows a genuine interest in Antarctica by conducting scientific research activities is entitled to become a Consultative Party. All decisions are made by consensus, i.e. all Consultative Parties must agree. The Treaty is open to any member of the United Nations and aims to further the principles of the UN Charter. It stipulates that the Antarctic should forever be used for peaceful purposes and prohibits military activity. Freedom of scientific research is guaranteed, and inspections can be carried out to ensure the Treaty is being observed. It applies to the area south of 60°South latitude. Seven nations claim territory, or 'sovereignty rights', in Antarctica: Argentina, Australia, Chile, France, New Zealand, Norway, and the United Kingdom, and two reserve the right to claim territory: the United States and Russia. These claims are not universally recognised and the Antarctic Treaty puts them legally on-hold to prevent disputes. Antarctic Treaty meetings are held every year, and deal with a range of scientific, environmental and operational issues related to cooperative activities in Antarctica.

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