A vital zone between North America's and Russia's northernmost frontiers consists of the Arctic regions. Once only explorers, traders, and Inuit, or Eskimo, hunters were interested in the vast, icy area at the “top” of the world. Today, because of its strategic location and its value to scientists, the Arctic is the scene of much activity.

Arctic Ocean and Arctic Land

The greater part of the 8,000,000 square miles (21,000,000 square kilometers) within the Arctic Circle is occupied by the Arctic Ocean (5,440,200 square miles, or 14,090,050 square kilometers). Around the pole, the ocean is about 13,800 feet deep (4,200 meters). Islands dot the southern two thirds of the ocean. Then comes a rim of land provided by the northern continents.

The most important islands north of America are Baffin, Victoria, and Ellesmere, belonging to Canada. Svalbard, a Norwegian group, and Franz Josef Land and Novaya Zemlya, belonging to Russia, are the largest islands north of Europe.

North of Asia, near Siberia, lie Severnaya Zemlya and the New Siberian Islands. Other islands in the Arctic regions are Wrangel, Prince Patrick, Devon, and Banks islands, and the Parry Islands. Alaska and northern Canada form the Arctic lands of North America. Farther east is the world's largest island, Greenland. It is part of the Danish kingdom. At Dundas, Greenland, the United States has a large air base.

In Northern Europe, the Laplands of Norway, Sweden, Finland, and western Russia jut into the Arctic. Eastward stretches the Russian territory of Siberia. (See also Alaska; Canada; Siberia.)

The Greatest Cold Is Not at the Pole

The most extreme winter cold and summer heat in the Arctic are not at the pole because the Arctic Ocean prevents extremes. The water absorbs heat during the summer and gives it out in the winter.

Greater extremes occur near the Arctic Circle because the land there is less effective than water in storing heat. Alaska has had a winter temperature of –80° F ( 62° C). In summer the temperature has reached 100° F (38° C). The coldest weather in the Arctic regions occurs near Verkhoyansk in Siberia. The January temperature there can reach –90° F (–68° C). The Arctic is warmer than Antarctica (see Antarctica).

Within the Arctic Circle winter cold is bearable because there is little wind (see Wind). Blizzards and gales occur only when the air is flowing strongly outward across the Arctic Circle or where a break in the land level disturbs the circulation. The winter air is very dry. Most of the moisture in the region is frozen. Snowfall totals less than in Chicago or New York City.

The Cause of Arctic Climate

The Arctic climate is determined by the amount of heat and light received from the sun. The slant of the Earth in relation to the sun prevents the sun's rays from reaching the Arctic regions for part of each year. The North Pole has no direct sunlight for six months. In summer the Arctic has long hours of sunlight. The sun's rays strike at a great slant, however, and do not give as much heat as they do farther south (see Earth).

More than half the Arctic Ocean is covered with a layer of ice all the time. Much of it stays in place as a jumbled mass called pack ice.

Animal and Plant Life

Many animals live in the Arctic wilderness. Although not as numerous as in other oceans, countless microscopic plants called diatoms live in the polar sea. They furnish food for shrimps and other crustaceans. These, in turn, are eaten by fishes. Both the crustaceans and the fishes are eaten by seals, walruses, and the few whales that still live in the sea.

Much of the land in the Arctic region is covered with a treeless grassy carpet called tundra. In summer flowers and grasses spring up in some places. Caribou, reindeer, and musk oxen eat the tundra. In winter they paw away the snow to get moss and lichens. Polar bears, wolves, and foxes prey on these larger animals and the sea animals. Smaller meat eaters live mainly on sea life.

During the long cold season fox, ermine, muskrat, beaver, marten, mink, and other animals grow thick, rich furs. In the lengthy days of summer many species of migrating land birds, such as the redpoll, snowbird, pipit, and rock ptarmigan, fatten on the swarming insects. Seabirds eat the abundant fish. The snowy owl and the raven often winter here.

People of the Arctic

The Arctic plains have only a sparse and scattered native population. These people manage to live comfortably, however, by making use of everything the bleak surroundings afford. The Inuit who dwell in Arctic America and Greenland depend upon hunting and fishing (see Inuit). They have no fruits or vegetables. They make clothing and tents of animal skins. Snug igloos are built of snow and ice for temporary shelter on winter hunting trips. For more permanent homes the Inuit use sod, stones, and driftwood.

The Lapps of Northern Europe rove about the tundra with their grazing herds of reindeer. These animals supply milk, meat, and skins for clothing and tents (see Lapland). Reindeer-herding tribes also live in Siberia. Other Mongoloid people of the Asian Arctic hunt and fish in summer and trap fur-bearing animals in winter.

Growing Importance of the Region

Many attempts to explore the Arctic ended in tragedy. Growing appreciation of the region's importance, however, has stimulated experiments in Arctic living. The Soviets began setting up weather stations on Arctic islands in the 1930s. In 1944 scientists from the United States and Canada founded the Arctic Institute of North America for polar research.

World War II brought weather stations to Arctic America and Greenland. In 1958 the submarine Nautilus, sailing beneath the icecap, made the first undersea crossing of the North Pole (see Polar Exploration).

A Radar Picket Fence

Along the extreme north rim of North America stretches the Distant Early Warning (DEW) line, built in the 1950s. This series of radar outposts would signal the alarm should enemy planes attack via the polar route. Stations of the Ballistic Missile Early Warning System (BMEWS) were added in the early 1960s in Greenland and Alaska (see Greenland). South of the DEW line is the Mid-Canada line. Roughly along the United States–Canada border is the Pinetree System. All these warning systems are connected with the combined North American Air Defense Command (NORAD) headquarters at Ent Air Force Base in Colorado.

Along the western flank of the United States Arctic defenses is a web of air, land, and sea bases. The bases are kept constantly in touch by a communications system called White Alice. The system speaks across hundreds of miles in Alaska with signals that are deflected from the troposphere, a layer of air up to 7 miles (11 kilometers) above the Earth's surface.

The Permafrost

In much of the Arctic, earth, ice, and rock are frozen solid permanently. The solid mass is called permafrost. It is covered with a layer of ice and snow which melts in summer. In winter the Earth's crust in the Arctic is a solid frozen mass as deep as 1,000 feet (300 meters) in some places. In summer, however, the surface thaws to a depth of 2 to 6 feet (0.6 to 2 meters). The surface then becomes swampy. The water cannot drain off or be absorbed because the earth beneath is frozen.

Great care must be taken that buildings erected in the Arctic do not thaw the permafrost layer and sink. The top cover of earth was removed in building the runways at the United States Thule Air Base near Dundas (formerly called Thule, which is now the name of a town to the north). A rock pad was then laid down in layers to form a base over the permafrost. This was covered with further layers of compacted materials and then paved with asphalt. Buildings at the air base were made to sink slowly.

Scientific Arctic Investigation

During the International Geophysical Year (IGY), from July 1957 to December 1959, scientists studied weather and ice in the Arctic. Teams stationed on floes, or ice islands, found that their chief problem was summer thawing. Giant cracks appeared in one island, and the campsite broke away from the main part of the floe. Men and equipment had to be airlifted to another island.

Four such drifting ice stations (two Soviet, two American) were set up in the Arctic during the IGY. Driven by wind and current, they traveled as far as 4,000 miles (6,400 kilometers). Soundings made daily from one of the American stations revealed the existence of an unsuspected submerged mountain ridge.

Another floe team took the first photographs of the ocean bottom in the central polar region. This team collected samples of sediment and measured ocean depths, the Earth's magnetic field, temperatures, and ice movements. Studies made on McCall Glacier during the IGY indicate that glaciers swell rather than shrink as the weather becomes warmer.

The United States Navy's nuclear-powered submarines Sargo and Sea Dragon reached the North Pole in 1960. An ice island 12 feet (4 meters) high was found about 150 miles (240 kilometers) north of Point Barrow, Alaska, in May 1961. It probably was part of a glacier that broke off and drifted away. As the island melted, glacial debris was exposed. This floe became the United States Navy's Arctic Research Laboratory Ice Station II (ARLIS II). Weather and oceanographic studies were carried on there.

The United States Army Corps of Engineers has studied the properties of ice and problems of construction and living in the Arctic in two subsurface camps on the Greenland ice cap. At Camp Century, 138 miles (222 kilometers) from Thule Air Base, engineers built tunnels and insulated buildings beneath the snow for their activities. The tunnels are deep trenches cut with a rotary snowplow. As the plow moved downward, the cuts were widened. The narrow top was roofed over. At Camp Tuto, occupied in January 1962, tunnels were constructed through solid ice.

In addition to an extensive scientific research program, Canada is encouraging a widespread search for significant mineral deposits in its Far North. It holds 28 percent of the Earth's Arctic land surface. Only Russia has more—40 percent. Mineral riches have been under development in the Canadian subarctic. In the late 1960s huge reserves of natural gas were found on Melville and other Canadian Arctic islands, and in 1970 oil was discovered near the mouth of the Mackenzie River. Oil and gas were found in the shallow waters of the Beaufort Sea. Extensive reserves of oil were discovered at Prudhoe Bay on Alaska's North Slope in 1968. Construction of an 800-mile (1,290-kilometer) crude-oil pipeline from Prudhoe Bay to the ice-free port of Valdez was completed in 1977.

The Arctic lands of Russia are known to contain rich reserves of minerals, including cobalt, nickel, coal, and iron. The gold and diamond mines of eastern Siberia place Russia high among world producers of these minerals. Natural gas and oil have been found in several places. The first nuclear power station in the Arctic was opened by the Soviet Union on the Kola Peninsula in 1974. In 1977 the Soviet nuclear icebreaker Arktika became the first ship to break its way through to the North Pole.

The discovery phase of Arctic exploration is over; there is no longer any possibility of finding new lands. Photo surveys have provided accurate maps, and improved aircraft and base facilities are making the once formidable region increasingly accessible. The emphasis now is on studying the area's geology and ecology. The bed of the Arctic Ocean has also been the subject of increasingly intensive studies. (See also Polar Exploration.)