Antarctica is the Earth's southernmost continent. It contains the South Pole and is situated in the Antarctic region of the Southern Hemisphere, entirely south of the Antarctic Circle. It is the fifth-largest continent and is surrounded by the Southern Ocean. As Antarctica's temperature can dip below - 112 0F or -80 0C, no one lives there all the time. No country owns Antarctica. Scientists from different countries visit research stations to carry out experiments throughout the year. Despite the extreme cold, Antarctica is home to animals such as penguins, seals, and seabirds.
In this lesson, we will cover essential facts about Antarctica - its location, physical features, climate, flora and fauna, and human life. We will briefly talk about the Antarctic Treaty System (ATS).
The total area of Antarctica is 14 million km2 or 5.4 million square miles. About 98% of Antarctica is covered by ice. The average thickness of this ice is at least 1.6 kilometers or 1 mile. Antarctica is not a country; it is a continent managed according to the Antarctic Treaty System.
The Antarctic Treaty System (ATS) was signed in 1959 and took effect in 1961. So far, it has been signed by 46-48 countries. The ATS is used for governing the continent. The main idea of the ATS is to make sure that Antarctica is:
There are no countries in Antarctica, although seven nations claim different parts of it: New Zealand, Australia, France, Norway, the United Kingdom, Chile, and Argentina. Eighteen countries regularly send scientists and researchers to various stations on the continent. The USA, Russia, Chile, Argentina, and Australia have the most and biggest stations. The largest research station is McMurdo station, where more than 1000 scientists work on various research projects during summertime.
Antarctica has the highest average elevation of all continents. Most of the continent is higher than 3000m (9900ft) above sea level. The highest mountain in Antarctica is Mount Vinson at 4,900m or 16,000 feet.
More than 98% of the continent is covered with ice, which contains about 70 percent of the world's freshwater. The thick ice cover makes it the highest of all continents, with an average elevation of about 2300m or about 7500 feet. The highest point on the continent is Vinson Massif, 4,897m or about 16,066 feet, and the lowest point yet found is the Bentley Subglacial Trench (2499 m/8,200 ft below sea level) in West Antarctica. This trench is covered with more than 3,000m (9,840 feet) of ice and snow. Lower points may exist under the ice but have not yet been discovered.
Antarctica is covered by an ice sheet. The Antarctic ice sheet dominates the region. It is the largest single piece of ice on Earth. The ice surface increase in size from 1.2 million square miles at the end of summer to 7.3 million square miles during winter. Ice sheet growth mainly occurs at the coastal ice shelves, primarily the Ross Ice Shelf and the Ronne Ice Shelf. Ice shelves are floating sheets of ice that are connected to the continent. Glacial ice moves from the continent's interior to these lower-elevation ice shelves at rates of 10-1000 meters per year.
If you stood on the great Antarctic ice sheet all you would see would be ice and snow. It would be far from a continuous smooth sheet though, as it is continuously moving. Glaciers, huge rivers of ice drain the interior of the continent and form ice shelves at the coasts.
Under the ice, it is mostly land, although the ice shelves are over the ocean. Antarctica has a number of mountain summits, including the Transantarctic Mountains, which divide the land between East Antarctica in the Eastern Hemisphere and West Antarctica in the Western Hemisphere. Antarctica has some important features hidden by the ice. One is Lake Vostok, which has been covered by ice for at least 15 million years. The lake is 250km long and 50km wide. Another is the huge Gamburtsev mountain chain, which is the size of the Alps, yet entirely buried under the ice.
The Transantarctic Mountains (source: transantarcticmountains.com)
Scientists use radar that can work under the ice to survey the whole of Antarctica.
Without any ice, Antarctica would emerge as a giant peninsula and archipelago of mountainous islands, known as Lesser Antarctica, and a single large landmass about the size of Australia, known as Greater Antarctica. These regions have different geologies.
The oceans surrounding Antarctica provide an important physical component of the Antarctic region. The waters surrounding Antarctica are relatively deep, reaching 4,000 to 5,000 meters (13,123 to 16,404 feet) in depth.
Antarctica is the coldest, and also the windiest continent. The lowest temperature ever recorded anywhere on Earth, -89.2° C (-128.6 °F) was on July 21, 1983, at the Russian Vostok base at the Southern Geomagnetic Pole. It is close to the Pole of Inaccessibility, the point on the Antarctic continent that is the furthest from any other, and so is the most difficult or inaccessible place to get to.
The continent has very strong winds. Calm periods are rare and typically last just a few hours. In July 1972, a wind speed of 320 km/h (200mph) was recorded at the French Dumont d'Urville base. The strong winds of Antarctica are called katabatics, formed by cold, dense air flowing out from the polar plateau of the interior down the steep vertical drops along the coast. It is at the steep edge of Antarctica that the strong katabatic winds form as cold air rushes over the landmass.
The strong winds blowing in Antarctica
Antarctica is a frozen desert with little rain. Any region that receives less than 10inches of annual rainfall or precipitation is classified as a desert. Antarctica is considered a desert because its annual precipitation can be less than 2 inches (50) mm in the interior and less than 8 inches (200mm) in the outer regions. The average yearly rainfall at the South Pole over the past 30 years was a tiny 10 mm (0.4 in). Most of the continent is covered by ice fields carved by the wind, and craggy mountains covered in glaciers.
There are three climatic regions in Antarctica:
Despite the low precipitation levels, it frequently appears that more snow is falling than really is. The strong winds pick up snow that has already fallen and move it around from place to place. Blizzards are therefore common and frequently result in disorienting white-out conditions where everything in front of you becomes a white blanket with no distinguishable features.
Plants and Animals
Antarctica has no trees or bushes at all, vegetation is limited to about 350 species of mostly lichens, mosses, and algae. This is because Antarctica does not have much moisture (water), sunlight, good soil, or a warm temperature. Plants usually only grow for a few weeks in the summer. More of this vegetation grows in the northern and coastal regions of Antarctica, while the interior has little if any vegetation.
The ocean has abundant fish and other marine life. In fact, the waters surrounding Antarctica are among the most diverse on the planet. The most important organisms in Antarctica are the plankton which grows in the ocean. Plankton serves as food for thousands of species such as krill. A large variety of whales like blue, fin, minke, humpback, right, sei, and sperm thrive in the cold waters of Antarctica. Leopard seal is one of the top predators in Antarctica. It is a very aggressive marine predator and eats penguins and fish.
Leopard Seal in Antarctica
Penguins in Antarctica
Penguins are the most commonly known animal in Antarctica. They have adapted to the cold, coastal waters. They have thick skin and lots of fat (blubber) under their skin to keep warm in cold weather. They also huddle together with their friends to keep warm. Their tightly packed feathers overlap to provide waterproofing and warmth. They coat their feathers with oil from a gland near the tail to increase impermeability. Waterproofing is critical to penguins' survival in water, as Antarctica water is as cold as -2.2°C (28°F). Their feathers retain a layer of air, helping them keep warm in the freezing water. Their wings serve as flippers as they fly through the water in search of prey such as squid and fish.
Antarctica is a unique continent in that it does not have a native population. While there are no permanent residents, the region is a busy outpost for a variety of research scientists who come from different countries and work at government-supported research stations. They study Antarctica as a unique environment as well as an indicator of broader global processes.
Research scientists from different backgrounds come to Antarctica:
The number of scientists conducting research varies throughout the year, from about 1,000 in winter to around 5,000 in summer.
