Landforms are the natural features and shapes existent on the surface of the earth. They are basically the geographical features that control the ecosystem, climate, weather and the essence of life on earth. Landforms possess many different physical characteristics and are spread out throughout the planet. An area of one-fourth of the Earth’s surface is covered by land or landforms.
This article explains,
1. How are Landforms Created?
2. What are the Major Landforms of the Earth?
3. What are some other Common Landforms?
How are Landforms Created
The various landforms that exist on earth today have occurred due to various natural processes such as erosion, wind, rain, ice, frost and various chemical actions. Natural events and disasters such as earthquakes (the tectonic plates) and eruption of volcanoes also contribute to the creation of the various shapes of landforms like sink holes, mountains and faults. The largest landforms on earth took hundreds to billions of years to be what they are now according to scientific evidence.
Such created landforms together make a given terrain and their arrangement in the landscape is known as topography. Terrain (or relief) is, therefore, the third or the vertical dimension of the land surface, and topography is the study of terrain.
Landforms are physical attributes such as elevation, slope, orientation, stratification, rock exposure, and soil type. They also include intuitive elements such as berms, mounds, cliffs, hills, ridges, valleys, peninsulas, rivers, and numerous other elements including various types of inland and oceanic water bodies and sub-surface features.
What are the Major Landforms of the Earth
Mountains are the highest landforms on the surface of the earth. They are often seen in a conical shape with steep sides, and a pointed tip called a peak. Mountains could be steep and snow covered, or they could have gentle slopes and rounded tops. Mountain formation results from the forces of erosion, volcanism, or uplifts in the earth’s crust. The Himalayas is the highest mountain range in the world. Some mountains found under the sea can be even taller than the Mount Everest, which is the highest mountain peak in the world.
There are 4 types of Mountains.
- Volcanic Mountains
These mountains are formed through volcanic activity. Examples of volcanic mountains include Mount Vesuvius in Italy, Mount Fuji in Japan, Mount Erebus in Antarctica, and Mount Saint Helens in the United States. The majority of volcanic mountains have summit craters that still expel debris and steam.
- Fold Mountains
Fold mountains are formed primarily by the effects of folding on layers within the upper part of the Earth’s crust. The Himalayan mountain range is an example of fold mountains.
- Block Mountains
Block mountains are formed by natural faults in the earth’s crust. Black Forest Mountain is an example of a fold mountain.
- Residual Mountains
Residual or relict mountains have are actually remnants of the older mountain ranges, which have been worn down by the various factors such as erosion and denudation.
Plains are broad flat areas on the earth’s surface. Plains are lower than the land that surrounds them; plains can be found both inland and along the coast. Plains that meet the oceans or seas are called coastal plains. They rise from the sea level up to the point they meet raised landforms such as plateaus or mountains. Example: Atlantic Coastal plain. On the other hand, inland plains are generally found at high altitudes. Some plains are formed by the action of rivers; these are called river plains. Example: Indian Northern Gangetic Plain. Thick forests normally flourish on plains in humid climates. A fairly large portion of plains are covered by grasslands, for example, we can consider the Great Plains in the United States. Floodplains are also in this category, and they are formed as a result of the continuous accumulation of sand, silt, and mud when rivers overflow its banks. Human populations prefer settling on plains because of the soil and the terrain which is good for farming and building settlements such as cities, residential areas, and transportation networks.
A plateau is a flat-topped highland with steep sides. Since plateaus also look like a table, they are also called tablelands. They are basically areas of high flat land. There are three types of mountain plateaus named as intermontane, piedmont and continental. Plateaus cover wide land areas, and together with their enclosed basins, they cover approximately 45% of the entire earth’s land surface. They are formed when magma pushes up towards the surface of the earth’s crust. This magma does not break through, but it raises a portion of the crust, creating a plateau. For instance, the Columbia Plateau of the United States and the Deccan of India are basaltic and were created due to lava flows spreading to thousands of square kilometres, building fairly flat land surfaces.
Plateaus are also formed as a result of upward folding and erosion of the nearby land that leaves them elevated. Since plateaus are elevated, they are subject to erosion. Most of the world’s high plateaus are deserts. Some typical examples of plateaus include Plateau of Tibet, the Bolivian plateau in South America, the Colorado Plateau of the United States, the Laurentian Plateau and the plateaus of Iran, Arabia, and Anatolia.
Glaciers are the perennial ice sheets on the planet. These are huge masses of ice that move over the land surface, predominant in high mountains and the cold Polar Regions. The temperature of these regions are very low, and this feature enables the buildup of snow and densification into ice at depths of 15 meters or even more. Most glaciers have density thickness in the ranges of 91 to 3000 meters.
When the compaction is so dense, it moves under the pressure of its weight. It is estimated that more than 75% of the world’s fresh water is currently locked away in these frozen reservoirs. Example for glaciers includes the Greenland Ice Sheet and the Antarctic Ice Sheet. The Antarctic Ice sheets outlet glaciers comprise of the steep and extensively long and narrow depression Beordmore Glacier, which is one of the longest outlets in the world. The gradual rise in continental temperatures has seen the glacial density grow smaller owing to melting.
Deserts are large, dry areas of land which receive little or no rainfall throughout the year. Deserts constitute approximately 20% of the earth’s total land cover.The deserts are divided into four major categories including the semi-arid deserts, the hot and dry deserts, the cold deserts, and the coastal deserts.
Cold Deserts are the large areas of land covered with snow. They receive snowfall during the winters but receive little or no rainfall. Animals such as penguins, fur seals and whales can survive in the cold deserts.
Hot Deserts are vast areas of land covered with sand and dust. These areas receive little or no rainfall and are very dry. Animals such as camels, snakes, lizards and rats can survive in hot deserts.
These deserts are located in different areas of the world. Deserts experience very high temperatures, less cloud cover, low humidity, low atmospheric pressure, and very little rain, which makes them have very little vegetation cover. The soil cover is also rocky and shallow, and with very little organic matter and as such, it only supports a few plants adapted to the conditions.
Apart from these major types of landforms, one can find other landforms like valleys, hills, loess, Peninsula, cape and Isthmus.
Valleys are natural troughs bounded by mountains or hills on the surface of the earth sloping down to lakes, oceans or streams, which are created because of water or ice erosion. Example: Indus Valley.
Hills are raised areas on the surface of the earth with distinctive summits but are not as high as mountains. Hills are created as a result of the accumulation of rock debris or sand deposited by wind and glaciers. They can also be created by faulting when the faults go slightly upwards.
Loesses are sedimentary deposits of clay and silt mineral particles which accumulate on land. Therefore, Loess is a fine-grained unstratified accumulation of clay and silt deposited by the wind.
Peninsulas are land that is surrounded by water from three sides. India is a peninsula; the southern part of India is surrounded by the Bay of Bengal, Arabian sea, and the Indian ocean and is joined to land on the fourth side.
Cape is a part of land extending into a water body.
Isthmus is a narrow stretch of land which joins to large land masses. Isthmus of Panama is an example.
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