Реферат: Geography of USA
The vast and varied expanse of the United States of America stretches from the heavily industrialized, metropolitan Atlantic seaboard, across the rich flat farms of the central plains, over the majestic Rocky Mountains to the fertile, densely populated west coast, then halfway across the Pacific to the semi-tropical island-state of Hawaii. Without Hawaii and Alaska the continental U.S. measures 4,505 kilometers from its Atlantic to Pacific coasts, 2,574 kilometers from Canada to Mexico; it covers 9,372,614 square kilometers. In area, it is the fourth largest nation in the world (behind the Soviet Union, Canada and China).
The sparsely settled far-northern state of Alaska, is the largest of America's 50 states with a land mass of 1,477,887 square kilometers. Alaska is nearly 400 times the size of Rhode Island, which is the smallest state; but Alaska, with 521,000 people, has half the population of Rhode Island.
Airlines service 817 cities throughout the country. A flight from New York to San Francisco takes five-and-a-half hours. Train service is also available: The most frequent service is between Washington, D.C., New York and Boston in the East; St. Louis, Chicago and Milwaukee in the Midwest; and San Diego, Los Angeles and San Francisco in the West. A coast-to-coast trip by train takes three days. The major means of intercity transportation is by automobile. Motorists can travel over an interstate highway system of 88,641 kilometers, which feeds into another 6,365,590 kilometers of roads and highways connecting virtually every city and town in the United States. A trip by automobile from coast to coast takes five to six days.
America is a land of physical contrasts, including the weather. The southern parts of Florida, Texas, California, and the entire state of Hawaii, have warm temperatures year round; most of the United States is in the temperate zone, with four distinct seasons and varying numbers of hot and cold days each season, while the northern tier of states and Alaska have extremely cold winters. The land varies from heavy forests covering 2,104 million hectares, to barren deserts, from high-peaked mountains (McKinley in Alaska rises to 6193.5 meters), to deep canyons (Death Valley in California is 1,064 meters below sea level).
The United States is also a land of bountiful rivers and lakes. The northern state of Minnesota, for example, is known as the land jf 10,000 lakes. The broad Mississippi River system, of great historic and economic importance to the U.S., runs 5,969 kilometers from Canada into the Gulf of Mexico—the world's third longest river after the Nile and the Amazon. A canal south of Chicago joins one of the tributaries of the Mississippi to the five Great Lakes—making it the world's largest inland water transportation route and the biggest body of fresh water in the world. ThЕ St. Lawrence Seaway, which the U.S. shares with Canada, connects the Great Lakes with the Atlantic Ocean, allowing seagoing vessels to travel 3,861 kilometers inland, as far as Duluth, Minnesota, during the spring, summer and fall shipping season.
America's early settlers were attracted by le fertile land along the Atlantic coast in the southeast and inland beyond the eastern Appalachian mountains. As America expanded westward, so did its farmers and ranchers, cultivating the grasslands of the Great Plains, and finally the fertile valleys of the Pacific Coast. Today, with 1,214 million hectares under cultivation, American fanners plant spring wheat on the cold western plains; raise corn, wheat and fine beef cattle in the Midwest, and rice in the damp heat of Louisiana. Florida and California are famous for their vegetable and fruit production, and the cool, rainy northwestern states are known for apples, pears, berries and vegetables.
Underground, a wealth of minerals provides a solid base for American industry. History has glamorized the gold rushes to California and Alaska and the silver finds in Nevada. Yet America's yearly production of gold ($2,831,000,000) is far exceeded by the value of its petroleum, natural gas, clays, phosphates, lead and iron, even its output of sand, cement and stone for construction. Production value of crude oil alone is about 4.2 thousand million annually, pumped from petroleum reserves that range from the Gulf of Mexico to Alaska's North Slope.