A delta is a deposit of sediment at the mouth of a river that accumulates as the river flows into a standing body of water such as a lake or ocean. Because sediment tends to be rich in nutrients, deltas become fertile wetlands inhabited by diverse wildlife. Among the largest deltas in Canada are those of the Mackenzie and Saskatchewan rivers, as well as the Peace-Athabasca Delta (where the Peace, Athabasca and Birch rivers meet). Certain deltas offer advantageous access to natural resources and maritime transportation, but development projects are often controversial due to the ecological importance of these environments.
A glacier is a large mass of ice, formed at least in part on land, that shows evidence of present or past movement. It is formed by the compaction and recrystallization of snow into ice crystals and commonly also contains air, water and rock debris. With approximately 200,000 km2 of glacier coverage in the Arctic and the West, Canada is home to a significant percentage of the world’s glaciers. By 2100, however, scientists predict that those in Alberta and British Columbia will have lost 70 per cent of their 2005 volume due to climate change.
British Columbia is Canada's most westerly province, and is a mountainous area whose population is mainly clustered in its southwestern corner. BC is Canada’s third-largest province after Québec and Ontario, making up 10 per cent of Canada’s land surface. British Columbia is a land of diversity and contrast within small areas. Coastal landscapes, characterized by high, snow-covered mountains rising above narrow fjords and inlets, contrast with the broad forested upland of the central interior and the plains of the northeast. The intense "Britishness" of earlier times is referred to in the province's name, which originated with Queen Victoria and was officially proclaimed in 1858.1
Tundra, which comes from a Sami word meaning “barren land,” refers to a treeless arctic region characterized by permafrost. Canada’s tundra is known for its freezing temperatures, lack of trees, low-growing vegetation and abundant rock outcrops. The southern boundary of tundra in Canada extends from the Mackenzie River delta to the southern reaches of Hudson Bay and northeast to the Labrador Peninsula. The term “alpine tundra” is often used to describe any area above the treeline in mountainous areas. But “alpine tundra” and “arctic tundra” are not interchangeable. (While the two regions share some similarities, the differences are significant.)
The Aroostook War was a confrontation between British and Maine authorities in disputed territory known as Madawaska. During the Napoleonic Wars, Britain was in dire need of wood and the region’s pine forests became an important commodity. Claimed by both Maine and New Brunswick, Madawaska became fertile ground for confrontations between the two. The war peaked in 1838‒39 when the governor of Maine, John Fairfield, sent a group, led by Rufus McIntyre, to stop “provincials” from entering territory that Fairfield believed was Maine’s. McIntyre was captured and accused of invading the colony. The conflict ended in 1842 with the Webster-Ashburton Treaty, which divided the territory along the Saint John River.
The Arctic Circle is a parallel or line of latitude at approximately 66°33’ N that marks the border of the Arctic, the northernmost region of Earth. The geographic point at the centre of Arctic Circle is the North Pole. In Canada, communities located close to this cartographic boundary include Old Crow in the Yukon, Fort McPherson in the Northwest Territories, and Repulse Bay and Qikiqtarjuaq in Nunavut. The latitude of the Arctic Circle shifts slightly depending on the tilt of the Earth’s rotational axis.