Geography of United States
Location: | North America, bordering both the North Atlantic Ocean and the North Pacific Ocean, between Canada and Mexico |
Geographic coordinates: | 38 00 N, 97 00 W |
Map references: | North America |
Area: | total: 9,826,630 sq km land: 9,161,923 sq km water: 664,707 sq km note: includes only the 50 states and District of Columbia |
Area - comparative: | about half the size of Russia; about three-tenths the size of Africa; about half the size of South America (or slightly larger than Brazil); slightly larger than China; more than twice the size of the European Union |
Land boundaries: | total: 12,034 km border countries: Canada 8,893 km (including 2,477 km with Alaska), Mexico 3,141 km note: US Naval Base at Guantanamo Bay, Cuba is leased by the US and is part of Cuba; the base boundary is 28 km |
Coastline: | 19,924 km |
Maritime claims: | territorial sea: 12 nm contiguous zone: 24 nm exclusive economic zone: 200 nm continental shelf: not specified |
Climate: | mostly temperate, but tropical in Hawaii and Florida, 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: | 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 extremes: | lowest point: Death Valley -86 m highest point: Mount McKinley 6,194 m |
Natural resources: | coal, copper, lead, molybdenum, phosphates, uranium, bauxite, gold, iron, mercury, nickel, potash, silver, tungsten, zinc, petroleum, natural gas, timber |
Land use: | arable land: 18.01% permanent crops: 0.21% other: 81.78% (2005) |
Irrigated land: | 223,850 sq km (2003) |
Natural hazards: | tsunamis, volcanoes, and earthquake activity around Pacific Basin; hurricanes along the Atlantic and Gulf of Mexico coasts; tornadoes in the midwest and southeast; mud slides in California; forest fires in the west; flooding; permafrost in northern Alaska, 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; limited natural fresh water resources in much of the western part of the country require careful management; desertification |
Environment - international agreements: | party to: Air Pollution, Air Pollution-Nitrogen Oxides, Antarctic-Environmental Protocol, Antarctic-Marine Living Resources, Antarctic Seals, Antarctic Treaty, Climate Change, Desertification, Endangered Species, Environmental Modification, Marine Dumping, Marine Life Conservation, Ozone Layer Protection, Ship Pollution, Tropical Timber 83, Tropical Timber 94, Wetlands, Whaling signed, but not ratified: Air Pollution-Persistent Organic Pollutants, Air Pollution-Volatile Organic Compounds, Biodiversity, Climate Change-Kyoto Protocol, Hazardous Wastes |
Geography - note: | world's third-largest country by size (after Russia and Canada) and by population (after China and India); Mt. McKinley is highest point in North America and Death Valley the lowest point on the continent |