Magazine article Geographical

The Frozen Kingdom

Magazine article Geographical

The Frozen Kingdom

Article excerpt

On the edge of a frozen world, polar seas provide an unlikely sanctuary. Rich in nutrients, these cold, deep waters harbour a surprising array of creatures. During the short summer, the sunfilled days trigger an explosion of life but in winter the regions become a frozen kingdom

The Arctic north is an unforgiving world of snow and ice. Much of the landscape is a biological desert where few things can grow and even fewer animals can survive. To the animals who inhabit this region, it is a harsh and inhospitable environment.

One of the few animals to have adapted to the environment is the polar bear. Its wide, bushy paws provide a sure footing on the ice, and its hollow hairs conduct and retain heat from the sun's faint rays. Polar bears are so well insulated that they are rarely bothered by temperatures that may drop to 50 [degrees] Celsius below zero.

Polar bears are capable of sleeping for five months over the winter, the cubs relying on their mother's milk for nourishment. By early spring, the mother has expended all of her fat reserves and is forced out of her den in search of food. During the winter hibernation she has lost nearly half her body weight and will need to catch a seal every four to five day's if her family is to survive. She :is well equipped to hunt seals with her hollow hairs providing buoyancy and webbed paws allowing her to swim competently.

Despite seals being one of the most abundant mammals of the Arctic, polar bears have only a five per cent success rate in hunting them. Seals have learnt to be elusive and, like the polar bear, are well adapted to the harsh conditions, creating their habitat from the pack-ice, which protects them from predators while allowing them easy access to both land and sea. Short claws on the end of their flippers allow them to keep a good grip on the ice, though they are extremely awkward on land. Their web-like forelimbs are short forcing them to wriggle on the ice to move about. Once in the water, however, their torpedo-shaped bodies are able to glide effortlessly, diving to depths of nearly 500 metres, where they can remain for up to 28 minutes.

Looming above the world of the seal, glaciers reach the end of their long journey to the sea. From their mountain origins, rivers of ice carve huge valleys into the landscape below. The weight of centuries of compacted snow allows gravity to do most of the work. Glaciers cover 10 per cent of the Earth's surface and contain about 75 per cent of its freshwater. Water carves tunnels and caves into the ice sometimes many hundreds of metres deep. Here the ice is so densely packed that it only reflects the colour blue.

Deep beneath the glacier's frozen surface, life makes a surprising display. Ice worms thrive where most animals would freeze to death. At about half a centimetre long, they are small enough to travel in the nooks and crannies within the ice. Feeding on microscopic algae, they move slowly to seek places where the ice is softer. They stay below the surface, since the sun's rays would kill them.

The vast region from the Bering Sea to the Gulf of Alaska is one of the richest marine habitats in the world. In the winter, walruses find their way here to escape the cold of the north. Like seals, walruses are built for the sea -- their skin is five centimetres thick. Weighing up to 1,360 kilograms, they have a hard time moving on land. Their tusks are used in displays of dominance; those with the largest tend to win territory and females. …

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