Part 4. Relief

About half the United States’ territory is covered by plateaus and mountains.

The eastern part of the country is occupied by the Applachian Moiuntains, which in the north come close to the Atlantic coast and in the south are separated from it by the Atlantic Lowland.

West of the Appalachians stretch the Central Plains, the Great Plains, and the Mexican Lowland.

The Central Plains are 500-400 m high and have a hilly moraine relief in the north and a more gentle erosional relief in the middle and southern parts.

The Great Plains (west of west longitudes 97-98º) are a deeply cut plateau with the heights of 500 m in the east to 1600 m at the Cordillera foothills.

The flat Mexican Lowland, with the height of up to 150 m, is swampy along the Gulf coast and fringed by a strip of marsches.

The western part of the country (including almost the whole of Alaska) is made up of high mountain ranges, tablelands and plateaus of the Cordillera system.

The Cordilleras consist of rows of mountain ranges with the heights of up to 3000-5000 m and a broad strip of intermountain tablelands and plateaus. In Alaska the mountain ranges stretch in the west-east direction and include the Brooks Range, the Yukon Tableland, the Aleutian range with Mount McKinley, 6193 m – the highest peak of the USA and the whole of North America.

On the territory of the USA proper the mountain ranges stretch in the north-south direction. The first from the east are the Rocky Mountains, reaching up to nearly 4400 m. West of the Rockies lie vast plateaus and tablelands: the volcanic Columbia Plateau, the Great Basin – a desert tableland with deep depressions (the largest is the Death Valley, containing the lowest point in the western hemisphere – 86 m below sea level), the Colorado Plateau. Typical for this area is the alternation of tablelands situated at the height of about 2000 m and mountain ranges reaching up to 3000-5000 m, with numerous deep river canyons.

Further west is a narrow belt of the Cascade Mountains, and the Sierra Nevada Range (over 4400 m). Still further west lies an area of valleys (Willamette, the California Valley).

The Pacific coast is formed by the deeply cut Coastal Ranges with the height of up to 2400 m.

QUESTIONS.

1) Where are Appalachian Mountains?

2) What is the relief of the United States like to the west of the Appalachian Mountains?

3) What is the relief of the Great Plains like?

4) What is the Mexican Lowland like?

5) What kind of relief does the western part of the country have?

6) What does the Cordillera mountain system consist of?

7) In what direction do the Cordillera mountain ranges stretch?

8) What is the highest peak of the Cordilleras? Where is it?

9) Where are the Rocky Mountains?

10) What is the Great Basin? Which is the largest depression of the Great Basin? What is it called?

11) What is typical of the relief of the Great Basin?

12) Where are the Cascade Mountains and the Sierra Nevada?

13) What is the Pacific coast of the USA like?