Major Landforms of the Earth
A landform is a physical feature of the surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography.
Landforms are created as a result of various forces of nature such as wind, water, ice, and movement of tectonic plates. Some landforms are created in a matter of few hours, while others take millions of years to appear.
There are many types of landforms on the earth’s surface. Mountains/Hills, Plateaus, and Plains are the three major types of landforms. Minor landforms include Buttes, Canyons, Valleys, and Basins.
The highest landform on Earth is Mount Everest mountain on the crest of the Great Himalayas of southern Asia that lies on the border between Nepal and the Tibet. It measures 8,850 meters (29,035 feet) above sea level. The Mariana Trench, in the South Pacific Ocean, is the deepest (at 11,034 meters at its deepest) landform on Earth.
Major Landforms
I. Mountains & Hills
An uplifted portion of the Earth’s surface is called a hill or a mountain.
A hill is a land surface that rises higher than the surrounding area. Generally, a steep hill with an elevation of more than 600 metres is termed as a mountain.
Mountains are classified into following four types:
1. Fold Mountains
These are formed by the folding of the earth’s crust by compressive forces.
Examples: The Himalayas in Asia, the Andes Mountains in South America and the Alps Mountains in Europe.
2. Block Mountains
When great blocks of the Earth’s crust are raised or lowered during the last stage of mountain building, block mountains are formed.
Examples: Vosges in France, Black Forest mountains in Germany.
3. Volcanic Mountains
These are formed by the matter thrown out from the volcanoes, and are also known as mountains of accumulation.
Examples: Mt Mauna Loa in Hawaii, Mt Popa in Myanmar.
4. Residual or Dissected Mountains
They are known as relict mountains or mountains of circumdenudation. They owe their present form to erosion by different agents.
Examples in India include: the Aravalli Range, the Nilgiri Mountains in Tamilnadu, the Rajmahal Hills, and the Eastern and Western Ghats
II. Plateaus
A plateau is an elevated flat land. It is a flat-topped table land standing above the surrounding area. A plateau may have one or more sides with steep slopes. The height of plateaus often varies from few hundred metres to several thousand metres.
The Tibetan plateau is the highest plateau in the world with an average elevation of around 4,500 meters above the mean sea level. It is often referred to as “The Roof of the World”.
Plateaus are very useful because they are rich in mineral deposits. As a result, many of the mining areas in the world are located in the plateau areas. African plateau is famous for gold and diamond mining. In India huge reserves of iron, coal and manganese are found in the Chota Nagpur Plateau.
III. Plains
Plains are large stretches of flat land. They are, generally, not more than 200 metres above mean sea level. Most of the plains are formed by rivers and their tributaries. The rivers flow down the slopes of mountains and erode them. They carry forward the eroded material. Then they deposit their load consisting of stones, sand and silt along their courses and in their valleys. It is from these deposits that plains are formed. Generally, plains are very fertile and are the most useful areas for human habitation.
The Indo-Gangetic plains, the Mississippi plain and the Yang-tze plain are some of the famous plains of the world.
