United States: Geography Note

LAND MASS TOTAL Total: 9,826,675 sq km Land: 9,161,966 sq km Water: 664,709 sq km Note: includes only the 50 states and District of Columbia LAND 9,161,923 sq km (3,537,438 sq mi)  Barns built at the turn of the century dot America's rural landscapes. WATER  664,707 sq km (256,645 sq mi) 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 CLAIM Territorial sea: 12 nm Contiguous zone: 24 nm Exclusive economic zone: 200 nm Continental shelf: not specified CLIMATE/WEATHER 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 Note: the peak of Mauna Kea (4,207 m above sea level) on the island of Hawaii rises about 10,200 m above the Pacific Ocean floor; by this measurement, it is the world's tallest mountain - higher than Mount Everest, which is recognized as the tallest mountain above sea level NATURAL RESOURCES Natural resources Coal, copper, lead, molybdenum, phosphates, uranium, bauxite, gold, iron, mercury, nickel, potash, silver, tungsten, zinc, petroleum, natural gas, timber Note: the US has the world's largest coal reserves with 491 billion short tons accounting for 27% of the world's total LAND USE Arable land: 18.01% Permanent crops: 0.21% Other: 81.78% (2005) NATURAL HAZARDS Tsunamis; volcanoes; 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 Volcanism: volcanic activity in the Hawaiian Islands, Western Alaska, the Pacific Northwest, and in the Northern Mariana Islands; both Mauna Loa (elev. 4,170 m) in Hawaii and Mount Rainier (elev. 4,392 m) in Washington have been deemed "Decade Volcanoes" by the International Association of Volcanology and Chemistry of the Earth's Interior, worthy of study due to their explosive history and close proximity to human populations; Pavlof (elev. 2,519 m) is the most active volcano in Alaska's Aleutian Arc and poses a significant threat to air travel since the area constitutes a major flight path between North America and East Asia; St. Helens (elev. 2,549 m, famous for the devastating 1980 eruption, remains active today; numerous other historically active volcanoes exist, mostly concentrated in the Aleutian arc and Hawaii; they include: in Alaska: Aniakchak, Augustine, Chiginagak, Fourpeaked, Iliamna, Katmai, Kupreanof, Martin, Novarupta, Redoubt, Spurr, Wrangell; in Hawaii: Trident, Ugashik-Peulik, Ukinrek Maars, Veniaminof; in the Northern Mariana Islands: Anatahan; and in the Pacific Northwest: Mount Baker, Mount Hood 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 freshwater resources in much of the western part of the country require careful management; desertification 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