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THE ARCTIC

The most northerly constellation of stars, Arktos, or the Great Bear, gives its name to the icy ocean beneath it, which surrounds the North Pole. One of the coldest places on Earth, the Arctic Ocean is bordered by the northernmost parts of Europe, Asia, and North America, including Greenland, the world’s largest island. Most of the Arctic Ocean is covered by ice, although warmer currents from the Atlantic and Pacific flow northward into it, warming the sea and air and clearing ice from the coasts in summer. Few people live in the Arctic, although the region is rich in minerals and wildlife.
CLIMATE During the long winter months, the Sun never rises over the horizon, and temperatures drop as low as -94°F (-70°C). In the summer, the Sun never sets, bathing the region in constant daylight and raising temperatures considerably. This is because the Earth rotates at an angle to the Sun, plunging the Arctic from total light to total darkness as the North Pole moves toward and away from the Sun. The dark polar skies are lit by the Aurora, wispy curtains of red and green light caused by electricity in the upper atmosphere.
    NATURAL RESOURCES The lands that surround the Arctic Ocean are rich in minerals. Vast oil and gas reserves lie under Alaska,
while Norwegian and Russian companies are mining coal on the island of Svalbard.
Smaller quantities of gold, iron, silver, tin, and other minerals are found throughout the region. Extracting these resources is expensive, but as supplies elsewhere begin to run out, oil and mining companies are turning their attention to the untapped wealth of the Arctic region.
ARCTIC WILDLIFE The Arctic Ocean teems with wildlife. Seals, walrus, and many species of whales thrive in the icy water, protected from the cold by layers of thick blubber beneath their skins. On land, reindeer, musk ox, hares, foxes, and wolves scavenge for food, migrating south to avoid the worst of the winter. In the brief summer hardy plants bloom, providing food for millions of insects.
 
Birds such as the Arctic tern and Brent goose take advantage of this insect food supply to breed and raise their young.
Arctic terns breed in large colonies during the Arctic summer. When winter comes, they fly halfway around the world to take advantage of the daylight and rich food supply of the Antarctic summer.
The polar bear is well adapted to Arctic life. It has acute senses, runs fast, swims well, and is camouflaged against the snow and ice by its white fur. Polar bears feed on seals and other animals, ranging far across the ice in search of prey.
TRAVEL IN THE ARCTIC Travel on land has always been difficult in the Arctic. In the winter, thick snow covers the ground, while the summer thaw turns much of the land into a boggy marsh. Snowshoes and skis stop people from sinking into the soft snow, while boots with rough or spiky soles grip well on icy ground. In the past, teams of huskies pulled sleds with supplies over great distances, but now the dogs have largely been replaced by snowmobiles. These small, motorized sleds on skis are easy to maneuver and can pull very heavy loads.
ICE BREAKERS The Arctic sea ice is usually about 6 ft (2 m) thick. Ships called ice breakers are specially constructed with reinforced hulls and bows shaped for plowing through this icy obstacle. Their powerful engines push the bow on top of the ice until the weight of the ship breaks it, clearing a passage for other sea vessels.  
ARCTIC EXPLORATION In the 16th century, European sailors first explored the Arctic seas in search of a new trade route to Asia. English sailors began to map the northwest passage around the top of Canada, while the Dutch explored the northeast passage around Siberia. By 1906, both routes had been successfully navigated. Three years later, an American, Robert Peary, claimed to have reached the North Pole itself. However, the speed of his journey has led some explorers to doubt his achievement.
CROSS-SECTION THROUGH THE ARCTIC For centuries, some Arctic explorers believed that the polar ice lay on top of a vast continent. In 1958, an American atomic-powered submarine, the USS Nautilus, demonstrated that this was untrue by sailing from Alaska to Svalbard underneath the ice. Subsequent exploration beneath the ice has revealed the ridges and basins of the seabed below.
                               

 




Date: 2015-04-20; view: 273


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