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: 19.13%
permanent crops: 0.22%
other: 80.65% (2001)
Irrigated land:
214,000 sq km (1998 est.)
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