A continental divide is a ridge or natural boundary of elevated terrain that separates the drainage basins of a continent. Each drainage basin contributes its water to river systems, which in turn flow into distinct larger bodies of water, such as oceans. The main continental divide in Canada follows the ridge of the Rocky Mountains.
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.
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.
Badlands are dramatic landforms characterized by a network of deep, narrow and winding gullies, along with occasional hoodoo rocks. Their steep, barren slopes provide striking evidence of the force of erosion by wind and water — a source of continual change in their terrain. Badlands are found in several places in Canada, most notably in southern Alberta. While those of Writing-on-Stone archeological site have great spiritual significance to the Siksika (Blackfoot) people, European explorers found badlands unfamiliar and difficult to navigate, which is the source of their current name.
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.
The Rocky Mountain Trench is a long and deep valley extending approximately 1,500 km from the Bitterroot Valley in northwest Montana through British Columbia to the Liard Plain just south of the Yukon Territory. Its predominantly flat floor is 3–20 km wide and ranges in elevation between 600 m and 1,000 m above sea level. With walls made of sedimentary, volcanic and igneous rock, the Trench is sometimes referred to as the “Valley of a Thousand Peaks” because of the towering mountain ranges on either side: the Rocky Mountains to the east and the Columbia, Omineca and Cassiar mountains to the west. Humans have relied on the rich resources provided by this distinctive landscape from pre-colonial times to the present.
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.
Ellesmere Island, at 196 236 km2, is the third-largest island in Canada, the 10th-largest island in the world and the most northerly island in the Arctic Archipelago. It is located in Nunavut and is separated from Greenland by Kane Basin and Kennedy Channel, and from Devon Island to the south by Jones Sound.