United States
The United States is located in North America, bordering both the
North Atlantic Ocean and the North Pacific Ocean, between Canada and
Mexico.
The world's third-largest country by size (after Russia and Canada)
and by population (after China and India), 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. Mt.
McKinley is highest point in North America and Death Valley the
lowest point on the continent.
There is a vast central plain, mountains in the west, hills and low
mountains in the east, rugged mountains and broad river valleys in
Alaska, and rugged, volcanic topography in Hawaii.
The climate is 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.
Natural hazards include tsunamis, volcanoes, and earthquake activity
around the 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 is a major impediment to development.
Current environmental issues include 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.
The United States is a stable, highly developed
constitution-based federal republic with a strong
democratic tradition and a modern economy. Tourist
facilities are widely available. |
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