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Transcript of Antarctica
By Alice Nguyen
Antarctica is a continent surrounded by ocean, unlike the Arctic which is an ocean surrounded by land. Ninety-eight percent of Antarctica is covered by polar ice and snow.
Being the driest continent in the world, it is classified as a desert. It is also the coldest and windiest continent with temperatures rarely above freezing and winds flying hundreds of kilometres per hour.
Antarctica, Australia and New Zealand
Penguins on an iceberg at Weddell Sea
Antarctica is located in the Southern Hemisphere, approximately centred around the South Pole, one of the two the earth's rotation axis, the other being the North Pole.
The Antarctic Circle is one of the five major parallels of latitude, and is about 66.5 degrees south of the equator. The South Pole is 90 degrees south of the equator.
Antarctica has no native population nor any permanent human settlement. All the people living there are scientists, engineers, astronomers and other workers exploring Antarctica.
Antarctica is unevenly divided into the East and West by the Transantarctic Mountains that crosses entirely through Antarctica. The East is greater than the West. These sections are also known as Greater and Lesser Antarctica.
Ross Ice Shelf
Ronne Ice Shelf
Amery Ice Shelf
Map of Antarctica
Mt Erebus is an active volcano in Antarctica. It is the highest volcano, measuring 3.8m tall! It is also the most well-known. Vinson Massif is the highest peak at 4897m tall. The Antarctic Peninsula sticks out of the Antarctic Circle towards South America.
South Atlantic Ocean
South Pacific Ocean
Ice, Ice and more Ice!
There is a giant ice sheet that covers the majority of Antarctica that contains seventy percent of the world's fresh water and ninety percent of the world's ice! In fact, Antarctica would be smaller if there was no ice. Snow falling annually, creates a new layer over the previous ice sheet, and then would soon turn to ice. Did you know that the ice on the South Pole is 2 836m thick?
Ice shelves and icebergs are pieces of ice that have been broken off the ice sheet and float in the water. The largest ice shelf is the Ross Ice Shelf, which is over 500 000 square kilometres.
Icebergs will drift into warmer waters and eventually melt.
Seasons and Climate
Without large land areas to preserve the sun's heat and repel freezing winds, Antarctica experiences extremely harsh weather conditions, especially in the winter months where temperatures drop way below freezing. Temperatures are colder in the inner mountainous regions and is warmest in the Antarctic Peninsula.
The average wind speed is 150km per hour, but can reach up to 300km per hour. The annual temperature averages -50 degrees Celsius, but the lowest ever recorded is -89.2 degrees Celsius! Only about 50mm of rain falls each year. That's equal to a night's storm in Australia! It is essential to wear many layers of clothing, including goggles, gloves, a thermal and other snow gear.
Antarctica has two main seasons, Summer and Winter. Summer lasts from mid-September to mid-March the next year and Winter goes from mid-March to mid-September the next year. Temperatures are still cold in Summer because the ice reflects the sunlight and is unable to retain the sun's heat. The mean Winter temperature is -70 degrees Celsius.
Due to the tilted position of the Earth when it orbits the sun, during Summer, there is almost endless sunlight but in Winter, the sun might not even rise.
There are no living land mammals native to Antarctica, though there are krill, toothed and baleen whales, penguins, seals, fish, squids and birds.
Some of the birds living there are albatross, cormorants, petrels, skuas, terns, sheathbills, gulls, shags, shearwaters and subantarctic ducks. Albatross are the largest sea birds that travel tens of thousands of kilometres each year from the Arctic to Antarctic and back. The whales include blue, humpback, killer, fin, minke, right, sei, sperm, Cuvier’s beaked and Gray’s beaked whales. The blue whale is the largest animal, measuring 30m long.
Emperor, king, royal, gentoo, chinstrap, Rockhopper, Adelie and macaroni penguins live in Antarctica. Adelie penguins have the largest population of penguins with emperor penguins being the largest. Some seals in Antarctica are elephant, leopard, Weddell, fur, crabeater, Ross seals and sea lions. Elephant seals are the largest Antarctic seals, measuring 7m long, 3m tall and weighing up to 400kg.
As only two percent of Antarctica is not covered by ice and snow, it is difficult for much plant life to survive. Antarctica has neither tree line nor tundra, but has lichens, mosses, algae, phytoplankton, kelp, fungi and the only two flowering plants that survive in Antarctica: 'deschampsia antarctica' and 'colobanthus quitensis' that grow in the northern regions of the Antarctic Peninsula.
Lichens are one of the plants in Antarctica that do not require soil for survival. Instead, they cling onto rocks and stones in which they get their nutrients to last. Algae is another plant that can be found in Antarctica. There is a vast range of different algae. They are critical foods for krill and other animals in Winter when there is little phytoplankton. Phytoplankton is a microscopic plant that rapidly increases in number when there is intense sunlight. Phytoplankton plays an important role in the food chain.
Many of the animals and plants have needed to adapt to Antarctica's harsh weather conditions to survive.
Antarctica measures fourteen million square kilometres in Summer, which is twice the size of Australia! But then doubles its area in Winter due to the freezing of water into ice.
Bases and Territories
There are currently seven Antarctic territories, over 40 scientific stations and thousands of scientists visiting each year. Antarctica is not completely owned by any certain country, but is shared between countries that claim their own territories. Did you know that there is an unclaimed portion of Antarctica?
Scientists have traveled to Antarctica to study it over many years. They can measure weather patterns in Antarctica as winds and ocean currents travel thousands of kilometres to other continents around the globe. They can study what the climate was like millions of years ago and see how much it has changed. Without any pollution or artificial lights, astronomers travel to Antarctica to view the clear skies, day and night. One of the most well-known occurrences in Antarctica is the Aurora Australis.
The Antarctic Treaty
On 1 December 1959, the Antarctic Treaty was signed in Washington by twelve countries who already had scientists in or around Antarctica
during the International Geophysical Year (IGY) from 1957-1958. The Treaty bans any military action, nuclear explosions and release of nuclear waste. The treaty insures that Antarctica remains as it is and be used only for peaceful purposes. Today, the Antarctic Treaty has been signed by 50 countries.
The beautiful display of lights is causes by particles of light with atoms entering the earth's atmosphere.
Hundreds of millions of years ago, Antarctica was connected to a continent named Gondwana, as well as Australia, South America, India, Africa and New Zealand. These today-know continents were separated by continental drift. In 1890, the Race for the Antarctic began, attracting many explorers, scientists, whalers and seal hunters.
Seal hunters came from all over the world to hunt for seals, and trade their fur and oil. The seal's blubber would be boiled, to become oil. Whalers hunted down whales in the Antarctic regions, using all the different parts for all sorts of things. They might've even wiped out a whole species that made the most profit!
Australia has been involved in many Antarctic Expeditions over the years. Australia has their own Antarctic territory (Australian Antarctic Territory) that was established on 25 August 1936. It covers almost six million square kilometres (forty-two percent of Antarctica). They have three stations: Mawson, Davis and Casey Station. Mawson Station is located on the coast of MacRobertson Land, and was created in 1954. Davis Station is in Princess Elizabeth land and Casey Station is found in the Windmill Islands.
Sir Douglas Mawson
Douglas Mawson's first expedition was with Ernest Shackleton from 1907-1909. He led the Australasian Antarctic Expedition from 1911-1914 and the Britain Australia New Zealand Antarctic Research Expedition, from 1929-1931. His picture appeared on the Australian $100 note (1984-1991).
During December 1911, Douglas Mawson
traveled with Belgrave Ninnis and Xavier
Mertz to Antarctica. While exploring, Ninnis fell into a deep crevasse and died, as well as some sled dogs and most of the supplies. Mawson and Mertz were left, struggling for survival, and were eventually forced to eat their dogs. Soon later, Mertz also died from food poisoning and Mawson was on his own. He arrived at safety a month later.
Hazards and Issues
In Antarctica there are many hazards and issues that occur. A huge hazard for ships and boats entering Antarctica is the icebergs. Icebergs have sunk many ships and have caused deaths to passengers. Planes are also at risk of crashing due to Antarctica's harsh conditions, like blizzards and snow storms. The strong winds can easily blow you off balance. These conditions make it very difficult to travel to and around Antarctica. Frostbite is another issue. Frostbite occurs when flesh gets too cold and so the blood can't reach it. The flesh eventually rots and falls off. Also, the ultraviolent rays that reflect off the ice can cause blindness, so wearing protective goggles is necessary.
In 1985, scientists realised that the hole in the ozone layer was increasing in size.
This may lead to Global Warming and Climate Change. Scientists estimate that if all
of the ice in Antarctica melts, the sea level will rise 60-70m! Also the burning of
fossil fuels produces carbon dioxide, adding to greenhouse gases. Tourism is another
problem. It causes a disturbance to the wildlife, stepping on plants, pollution and
possible the spreading of diseases. This will affect the survival of Antarctica's flora and fauna.
Earth's Orbit of the Sun
Mining for resources like oil and gas has not began yet in Antarctica. It would be too difficult in the cold and windy conditions, and expensive to pay for machines and other equipment. Companies wouldn't make any profit.
Factory burning Fossil Fuels
Phytoplankton is very important to the survival of other animals in Antarctica, being the base of the food chain. During Summer when there is intense sunlight, the population of phytoplankton grows very fast. In Winter, there isn't enough sunlight to produce phytoplankton, and the rest gets trapped in ice, so algae is the main source of food during that time. Without phytoplankton, animals like orcas, who don't even eat them, could become
Brasch, N. 2001. Antarctica
Banes, J. 1997. Antarctica
Mawson on the $100 note