Geography of North America- 1 - Geography for UPSC CSE

• North America is the third largest continent after Asia and Africa. It covers an area of nearly 24 million square kilometers.
• From south to north, it extends from 7°N to 85°N latitude and east to west from 20°W to 179° W.
• In other words, its northern boundary is only about 500 kilometers away from the North Pole and its western boundary only 10 kilometers away from the International Date Line.
• There are five time zones in North America.
• The Tropic of Cancer and the Arctic Circle passes through the continent and the 100°W longitude cuts through the center of the continent.

North-America-Time-zone

US-Timezone

• This huge landmass includes three large countries – Canada, the United States of America and Mexico, seven small states of Central America, and the islands of the West Indies.
• The Atlantic, Pacific, and Arctic oceans surround North America in the east, west, and north respectively.
• In the north-west, the Bering Strait separates it from Asia and in the south-east, the Isthmus of Panama joins it to South America. North America has a smooth coastline except for the existing in the north-west.

Region-wise North America can be classified into the following parts which are listed below:
Western Region

• Great Plains
• Canadian Shield
• Eastern Region

Western Region
Young mountains rise in the west. The most familiar of these mountains are probably the Rockies, North America’s largest chain. They stretch from the province of British Columbia, Canada, to the U.S. state of New Mexico.

Great Plains
In the middle of the continent lies the Great Plain. Deep, rich soil blankets are large areas of the plains in Canada and the United States. Grain is grown in this region called the “Breadbasket of North America,” feeds a large part of the world. The Great Plains are also home to rich deposits of oil and natural gas.

Canadian Shield
The Canadian Shield is a raised but relatively flat plateau. It extends over eastern, central, and northwestern Canada. The Canadian Shield is characterized by a rocky landscape pocked by an astounding number of lakes.

Eastern Region
This varied region includes the Appalachian Mountains and the Atlantic coastal plain. North America’s older mountain ranges, including the Appalachians, rise near the east coast of the United States and Canada. These areas have been mined for rich deposits of coal and other minerals for hundreds of years.

• The Western Cordilleras
• The Central Lowlands
• The Eastern Highlands

The Western Cordilleras

• The parallel ranges of young fold mountains run from Alaska and extend into South America as the Andes.
• As they resemble twisted cords they are known as Cordilleras.
• Fold mountains are formed when tectonic plates push the Earth’s crust and force it to form ridges and valleys.
• Volcanic rocks from the base of fold mountains.
• The Cordilleras are part of the Pacific Ring of Fire. Mount St. Helena is in the USA.
• The snow-covered Cordilleras act as a barrier to moisture-laden winds and cause relief rainfall.
• Some of the rivers flow westwards and some eastwards with the Cordilleras acting as the water divide between them.
• Rocky Mountains, Alaska Range, Cascades, Sierra Nevada, and the Sierra Madre are the chief ranges of the Western Cordilleras
• The Grand Canyon is a network of deep narrow valley cuts into the dry Colorado Plateau.
• The Old Faithful” is a natural geyser (a hot waterspout). Once in every 90 minutes, the water from the geyser comes out roaring up to 60 meters high. It is found in Yellowstone National Park.

The Central Lowlands

• These stretch from around the Arctic Shores and Hudson Bay to the Gulf of Mexico.
• They are hemmed in by the Cordilleras in the west and the highlands in the east.
• In the west, they are known as high plains because of the greater altitudes.
• In the north, they form the Canadian Shield.
• The Canadian Shield is a peneplain with a number of lakes. They are large enough to be called seas. They are the five Great lakes – Superior, Michigan, Huron, Erie, and Ontario.
• Lake Winnipeg, Great Bear Lake, and Lake Athabaska are also on the Canadian Shield.
• South of the Canadian Shield, the Central Lowlands are covered with layers of sediment brought by glaciers and rivers. It is a very fertile region.

Importance of great lakes region

• Glacial lakes
• The largest freshwater system
• Together – they hold 1/5 th of the earth surface’s freshwater
• Source of drinking water, irrigation, transport, sulfide and iron mining in the periphery

The Eastern Highlands

• They are old fold mountains that stretch from the valley of River St. Lawrence to Southern USA.
• They are not high or as continuous as the Cordilleras.
• The highlands are also known as the Laurentian highlands in Canada and the Appalachians in the USA and are less than 2,000 meters in height.
• Their eastern slopes facing the Atlantic Ocean are very steep causing waterfalls in the streams that flow to the coast.

Canadian Shield
The Canadian Shield is a raised but relatively flat plateau. It extends over eastern, central, and northwestern Canada. The Canadian Shield is characterized by a rocky landscape pocked by an astounding number of lakes.