The Western Arctic stretches from the Richardson Mountains in the west to Tuktut Nogait National Park in the east. The region includes the Mackenzie Delta, one of the largest freshwater deltas in the world, several mighty rivers, bird sanctuaries, the northern limit of trees, parts of the Arctic Ocean, the Northwest Passage, and parts of Canada's Arctic Islands stretching up to the North Pole.
The treeline, or the northern limit of trees, cuts a line from Inuvik southeast to the Nunavut border near Great Slave Lake. In the Mackenzie Delta region, the trees, mostly black and white spruce, fight to stay upright due to slumping soil overlying frozen ground. East and north to the Arctic coast, this drunken forest or "Land of Little Sticks" gives way quite suddenly to tundra with its carpet of small willow, berry bushes and tiny flowering plants.
The tundra, or barrenland stretching north and east from the treeline is far from barren. Some 1700 different plants have been identified, creating a dense carpet of low shrubs, reindeer moss, grasses, sedges and about 400 species of flowering plants. Natural features of the barrenland include low relief, sandy eskers, muskeg and thousands of lakes and ponds.
The Mackenzie Delta
Canada's longest river, the Mackenzie (1800 km) empties into the Beaufort Sea from the Mackenzie Delta. The delta is some 13,500 sq km of braided streams, islands and ponds laid over permafrost. Each year the Mackenzie drops a huge load of soil and trees swept from southern Canada, causing continuous changes to the delta landscape. The delta freezes each winter and floods every spring. At peak spring flow some 30,000 metres per second rushes toward the frozen ocean, creating new channels and islands.
Dwarfed by the Mackenzie, the Arctic Red, the Peel, the Anderson, the Horton and the Hornaday rivers are nevertheless major waterways in the Western Arctic, challenging canoeists and kayakers. On Banks Island, the Thomson River flows north to McClure Strait through Aulavik National Park. This river, too, is navigable by experienced canoeists.
Permafrost is short for permanently frozen ground. It occurs when rock and soil temperatures remain below freezing continuously for several years. The Western Arctic is largely in the area of continous permafrost, which can be hundreds of metres thick. Permafrost regions are susceptible to shearing, heaving and subsiding. If the surface cover is disturbed, these areas can continue melting for many years. To prevent disturbance, roads are constructed on protective berms, and in communities like Inuvik, larger buildings are raised on stilts to prevent heat from the building melting the permafrost below.
Pingos, the conical hills surrounding Tuktoyaktuk, grow in a permafrost environment. They develop in shallow or drained lakes, and are believed to grow as a result of permafrost penetrating the thawed lake basin. Some 1350 surround Tuktoyaktuk peninsula, with Ibyuk pingo rated the second highest in the world, at 49 metres high.