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USA is located in North America, bordering both the North Atlantic Ocean and the North Pacific Ocean, between Canada and Mexico. Area comparatively about one-half the size of Russia; about three-tenths the size of Africa; about one-half the size of South America (or slightly larger than Brazil); slightly larger than China; about two and one-half times the size of Western Europe.
Total land boundary is 12,248 km, border countries are Canada 8,893 km (including 2,477 km with Alaska), Cuba 29 km (US Naval Base at Guantanamo Bay), Mexico 3,326 km
note: Guantanamo Naval Base is leased by the US and thus remains part of Cuba.
Climate is mostly temperate, but tropical in Hawaii and Florida and arctic in Alaska, semiarid in the great plains west of the Mississippi River and arid in the Great Basin of the southwest; low winter temperatures in the northwest are ameliorated occasionally in January and February by warm chinook winds from the eastern slopes of the Rocky Mountains. Terrain consists of vast central plain, mountains in west, hills and low mountains in east; rugged mountains and broad river valleys in Alaska; rugged, volcanic topography in Hawaii. Elevation extreme has the lowest point in Death Valley -86 m and highest point in Mount McKinley 6,194 m. Natural resources are coal, copper, lead, molybdenum, phosphates, uranium, bauxite, gold, iron, mercury, nickel, potash, silver, tungsten, zinc, petroleum, natural gas, timber. Land use: arable land: 19%, permanent crops: 0%, permanent pastures: 25%, forests and woodland: 30%, other: 26% (1993 est.). Irrigated land: 207,000 sq km (1993 est.). Natural hazards are tsunamis, volcanoes, and earthquake activity around Pacific Basin; hurricanes along the Atlantic coast; tornadoes in the midwest; mud slides in California; forest fires in the west; flooding; permafrost in northern Alaska is a major impediment to development.
Environment—current issues: air pollution resulting in acid rain in both the US and Canada; the US is the largest single emitter of carbon dioxide from the burning of fossil fuels; water pollution from runoff of pesticides and fertilizers; very limited natural fresh water resources in much of the western part of the country require careful management; desertification.
Geography—note: world's third-largest country (after Russia and Canada).
อ้างอิง Anonymous, 1999 |