polar region on the Earth's northern hemisphere From Wikipedia, the free encyclopedia
The Arctic is the area around the Earth's North Pole. It includes parts of Russia, Alaska, Canada, Greenland, Iceland, Lapland, and Svalbard. It is an ocean, mostly covered with ice.
The word 'Arctic' comes from the Greek word αρκτος, meaning "bear". The North Pole aims at the stars called the Great Bear and the Little Bear.
Most scientists call the area north of the tree line "Arctic."
The tree line follows [1]
Across the world, trees cannot grow in places that are too high and/or too cold.[2] Above the tree line, trees cannot survive. Forests on several continents have regions north of the tree line. These areas are part of the Arctic.
The area north of the tree line is not an empty ice field. In fact, the only large ice-covered land in the Arctic is central Greenland, which is covered year-round by a continental glacier.
The land of the Arctic (located around the edges of the Arctic Circle) is mostly tundra. A tundra is a cold, almost treeless plain covered with moss and sedges (grass-like plants). Tundras get little rain or snow.
During Arctic summers, there are nights when the Sun never sets. This happens because the North Pole points toward the Sun during summertime. For this reason, people sometimes call the Arctic the Land of the Midnight Sun.
Though they get little precipitation, tundras can get very wet during the summertime. In warmer temperatures, the snow on the ground melts. However, there is a permanent layer of ice (called permafrost) under the ground. Permafrost can be thousands of miles thick and is rock-hard, so melting snow cannot soak into it. As a result, water can only form lakes and puddles on top of the ground until it freezes again or dries up.
In some parts of the Arctic, the ground is covered with bright-colored flowers during the short summer. These little plants have very short stems. They must stay close to the ground, because the earth is warmer than the cold winds that blow above it.
Even some rocks have plants growing on them.[3] These plants are called lichens, and they grow on bare rocks. The Arctic reindeer's summer food, which is called yellow reindeer moss, is actually a lichen. It grows slowly, but can eventually grow to be six inches tall (15 cm) or higher. It is spongy and full of water.
Trees are rare on the tundra. Small trees are only able to grow in protected valleys or along the banks of rivers. Rivers come into the Arctic from the warmer south, so their banks are a little warmer than the rest of the tundra - warm enough for trees to grow there. Outside of these areas, there are rare clusters of bushes. Berries are the only fruits that grow in the Arctic.[3]
As ice and snow on the ground's surface melt during the summer, plants are able to flower and animals are able to find food. Because of the permafrost, melted snow stays near the top of the ground's surface. Plant roots can use this water for their growth.
Less than half of the tundra has plants growing on it. In many Arctic places, the soil is too poor for plants to grow.
The polar bear is the world's largest meat-eating land animal. They are excellent swimmers, and even the coldest water on Earth does not bother them.[3]
Polar bears have an excellent sense of smell, which they use to find prey. They prefer to eat seals and walruses, but most often they eat fish, birds' eggs, seaweed, and dead whales. They get most of their food on pack ice.
Polar bears have to eat and store fat before the ice is gone: they cannot catch seals in open water. However, they are well adapted to hunt seals out on the ice. If they smell a seal, they wait by breathing holes in the ice. They can also break through the ice where it is thin. Sometimes they can also sleep up on sleeping seals.
After mating, female polar bears dig themselves into a den of snow on land for the rest of the winter. There they have their cubs, usually twins.
Arctic foxes often follow bears out onto the ice to eat their leftover food. They also eat rabbits, as well as the rodents of the Arctic: lemmings and voles.[3] Lemmings live underground in the summer, and under the snow during colder months when the ground is too frozen to burrow into. There they eat plants and roots.
In a year with plenty of food, millions of lemmings roam the tundra. Owls and foxes have plenty to eat, and they have more young in these years. However, the tundra does not have enough food for millions of lemmings. When there is not enough, the lemmings rush across the tundra looking for food. There they starve, get eaten by predators, or drown while trying to swim across lakes or rivers. This decreases the Arctic fox's food supply.[3]
Caribou and their relative, the reindeer, also live in the Arctic.
Today, caribou are found mostly in North America, and they are larger than reindeer. During the warmer months, large herds feed on grass and lichens. When fall comes, they move south to winter feeding grounds. They dig through the snow with their sharp hooves for food. Their hollow fur creates a cushion of air around them that helps them to stay warm. In the spring they return north to the summer pastures, where their calves are born. An hour or so after being born, the calves are able to follow the herd toward the Arctic Ocean.
Most of the world's reindeer live in Europe and Asia. Some of these reindeer are not wild. They have been tamed by herdsmen who protect them from wolves and lead the migrations each spring and fall.[3]
The musk ox, which looks like a shaggy buffalo, also lives in the Arctic.
In summer, many birds visit the Arctic. Most of them are water birds, such as geese, ducks, swans, loons, and Arctic terns. Flying in for the summer, they raise their young and return south for the winter.
Unlike other Arctic birds, the snowy owl and the ptarmigan stay all year.[3] They are well adapted for the snow. The snowy owl's color matches the snow. Meanwhile, the ptarmigan's summer plumage changes to white when it gets colder.
The smallest animals of the Arctic are the flies and the mosquitoes. Thick swarms bite both men and animals in the summer. The reindeer try to escape the mosquitoes by running to higher pastures, but the only real help comes with the snow and cold, when the swarms die off for another season.[3]
Many people live in the Arctic. Some groups have lived there for thousands of years. For example, Eskimo and Lapp people lived in the Arctic long before electric heaters, snowmobiles, and modern houses.
In an extremely northern part of Europe there is a place called Lapland. It is not a country, but parts of four countries. The people who lived there are called Lapps by outsiders. They call themselves Sami. The Lapps of these four countries lived there long before the countries of Northway, Sweden, Finland, and Russia were created. There were several kinds of Lapp people. Some lived by the ocean and lived mostly on fish. Another group lived along the warmer rivers. These people did a little farming, hunting, and fishing to live.[3]
But the best known of the Lapp people were the nomads who raised reindeer. The Lapps survived in their harsh homeland by domesticating the reindeer. The Lapps were able to get everything they needed from the deer. They ate mostly meat, milk, and cheese. Their clothes were made from reindeer skins and wool. Their tents were also made from deer skins. They are known for the beautifully decorated woollen clothing they made.[3]
The Lapps protected the herds, moving with them as they migrated from summer to winter pastures. They used trained reindeer to pull sleds carrying their supplies. During the winter, the herds moved south of the treeline. The Lapps would live nearby in homes made of logs or sod. The Lapps were very careful not to waste anything they got from the reindeer. Milk was taken from the reindeer to drink or make cheese. Meat was taken for food. The blood was frozen in chunks and used for soup and pancakes. Knives and belt buckles were carved from the bones and antlers. The sinews were used as sewing thread. Cleaned-out stomachs were used to carry milk or cheese. Every part of a dead reindeer was used.
Winter clothing was made from layers of deer skin. The inside layer would be worn with the fur facing in toward the person's skin. The second layer was worn with the fur facing out.[3] Boots were also made of fur, lined with grass that had been gathered during the short summer. Every evening the grass would be taken out and dried by the fire, so it would be ready to use again the next day. Thus, a Lapp could be warm and comfortable in even the coldest weather.
Today only a few of the Lapp people still follow the herds. Those few use modern tools on their ancient migration. They use snowmobiles to herd the reindeer and rifles to kill the wolves that chase them. Even helicopters and radios are used to locate and move the reindeer.[3] Most of the Lapp people now live on small farms in one of the four nations of Lapland. They raise crops and animals, including a few reindeer, to meet their needs. The sale of reindeer meat is an important source of income for the Lapp people.
Eskimos are Arctic people, too. They sometimes ate raw meat. Eskimos were also nomads, but they did not have any animals except for dogs, which they used for pulling their sleds and helping them hunt. They were hunters and gatherers, and they lived off on whatever they found or killed. Like the Lapps, though, they were very careful to make good use of every part of the animals they killed. Eskimos lived in tents during the summer, and sod houses or igloos in the winter. The Eskimos made very clever things from the bones, antlers, and wood they had. They built different kinds of boats.
Eskimos did not have a government or laws. They learned early in life to help each other to survive. Always sharing food, they usually moved around in small groups looking for food. Sometimes they'd get together in a large group when they hunted big animals such as whales. The men did the hunting and building the homes, and the women cooked, made the clothes, and took care of the children.
The Arctic region has many minerals that are important to people. Iron, lead, coal, copper, gold, and tin are all mined in different parts of this cold land. Large amounts of petroleum have been discovered in the Arctic in Russia, Alaska, and Canada. People live and work in the Arctic to remove these valuable minerals and sell them.
The oil in Alaska, for example, is very important to the United States. The main source is the Prudhoe Bay Oil Field on Alaska's north coast. It was discovered in 1968. Plans were quickly made to build a pipeline to bring the oil to an ice-free port so it could be shipped south. Oil companies spent billions of dollars to build the Trans-Alaska Pipeline in the mid-1970s. It had to be built above the ground in the northern section because of the permafrost. The warm oil in the pipes could have melted the permafrost and caused the ground to sink. That would have broken the pipes and caused an oil spill. The pipeline was completed in 1977. It brings oil to the seaport of Valdez on Alaska's south coast. From there the oil is taken by huge tankers to refineries along the west coast of the United States. If you live in western America, your family car may have Alaskan gasoline in its tank.
Russia has more land in the Arctic than any other nation. The Russian Arctic in Asia and the area just south of it are called Siberia. It is such an empty, harsh place that it has been used as a penal colony for many years. The old Russian rulers and the modern communist Soviets would send criminals and people who disagreed with the government to live there. However, many people were also sent there to remove minerals, harvest trees from forests, and build cities.[4]
Russia has a huge port city right in Lapland, within the Arctic Circle. Murmansk is the largest city north of the Arctic Circle. The port is kept ice-free by the warm waters of the Gulf Stream coming up around Norway and Sweden from the South Atlantic. Huge icebreakers work to keep a path open so ships can reach the port. The port ships out fish, minerals, and lumber to Russia and the rest of the world.
The Arctic is also the shortest way (Great circle route) for airlines to fly between some cities on different continents. The flight from London to Tokyo, for example, is 1,400 miles shorter if flown across the top of the world instead of the old route south across Europe and Asia. The polar route from San Francisco to Norway is several hours shorter than the same flight going across the United States and the Pacific Ocean.
Thus, man is making use of the Arctic in various ways even though it is a hard place to live.
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