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Second largest country in the world in area (after Russia ) but one of the most sparsely populated. Canada occupies roughly two-fifths of the North American continent. Its total area, including the Canadian share of the Great Lakes, is 3,849,674 square miles (9,970,610 square km), of which 291,576 square miles (755,180 square km) are inland water; also included are its adjacent islands, except Greenland .
In general terms, the landform structure of Canada can be considered as a vast basin more than 3,220 miles in diameter. The Cordillera in the west, the Appalachians in the southeast, the mountains of northern Labrador and of Baffin Island in the northeast, and the Innuitian Mountains in the north form its high rim, while Hudson Bay , set close to the centre of the enormous platform .
By far the largest of Canada 's physiographic regions, the Canadian Shield occupies about half of the total area of the country and is centered about Hudson Bay . It consists of ancient rocks folded by mountain-building movements and cut down by erosion until the area was reduced almost to a plain. It was warped and folded in places so that parts of it now stand much higher
Surrounding the Canadian Shield is a number of extensive lowlands underlain by sedimentary rocks: the Arctic lowlands to the north, the Great LakesSt. Lawrence lowlands to the south and southeast, and the interior, or western, plains to the west. The most extensive of these are the interior plains , which extend from the Arctic Ocean in the north to the United States .
The Great LakesSt. Lawrence region comprises the peninsula of southern Ontario bounded by the Canadian Shield and Lakes Huron , Erie , and Ontario . It extends along the St. Lawrence River to the Atlantic Ocean . This is a much smaller region, but it is important for its high agricultural productivity and its intensive industrialization.
The Appalachian region extends from the eastern townships of Quebec (south of the St. Lawrence valley) northeastward to the Gaspe Peninsula and the Maritime Provinces , and on to the island of Newfoundland . The region consists of very old folded rock formations that have been eroded into low, rounded mountains dissected by valleys and interrupted by lowland areas.
The Cordilleran region comprises a series of mountain belts some 500 miles wide that flanks the Pacific coast of Canada . The great heights and angularity of the peaks (many of which rise to more than 10,000 feet) indicate that these are much younger mountains than the Appalachians . Signs of alpine glaciations are widely evident.
The Arctic Archipelago is composed of thousands of islands north of the Canadian mainland. The southeastern islands are an extension of the Canadian Shield . The balance consists of two distinctive landform regions: the Arctic lowlands to the south and the Innuitian Mountains to the north.
With just 1 percent of the world's population, Canada has some 9 percent of the world's supply of fresh water. Much of this water is stored in lakes and wetlands that cover about 20 percent of Canada 's total area. About three-quarters of Canada 's land area is drained by rivers flowing into the Arctic Ocean and the Hudson and James bays.
Because of its great latitudinal extent, Canada has a wide variety of climates. The Pacific coast, like that of the U.S. Northwest coast, has a climate similar to that of England , with heavy precipitation and moderate winter and summer temperatures. The northern two-thirds of the country has a climate similar to that of northern Scandinavia .
Those parts of the country farthest from open water are the coldest, so that in the interior plains and in the North the winters are extremely cold. The lowest temperature ever recorded was ?81 F (?63 C) at Snag in the Yukon . In July those parts of Canada farthest from open water are the warmest. Thus, west-coast Vancouver has an average January temperature of 37 F (3 C) and an average July 26 C.
Humid air masses from the Pacific cause enormous quantities of orographic (mountain-caused) rain to fall on the coast and mountain areas. Several sites along the British Columbia coast receive annual precipitation in excess of 100 inches (2,540 millimetres). But British Columbia also receives much less precipitation in summer than in winter because low-pressure systems.
Canada 's snowfall does not follow the same pattern as rainfall. In the North and the interior plains, snowfall is light because cold air is very dry. The snow is hard and dry, falls in small amounts, and is packed down by the constant wind. The east and west coasts are areas of lighter snowfall because the ocean usually makes the air too warm for large quantities of snow.
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