We all know that one – fourth of the earth’s surface is covered by land. The portion which forms land on earth’s surface is not the same everywhere. At some places the land may be too high, at some places very low, some areas would be lush green and certain areas are dry and barren. Our planet earth is a beautiful collaboration of various physical features.
These different physical features are called the various landforms on the surface of the earth. These are geographical features that control the ecosystem, climate, weather and the essence of life on earth. In simple terms, we say that any shape on the earth’s surface is known as a landform. The various landforms that we have, came into existence due to natural processes such as erosion, wind, rain, weather conditions such as ice, frost and chemical actions. Natural events and disasters such as earthquakes (the tectonic plates) and eruption of volcanoes created the various shapes of the land that we see.
The different major landforms are mountains, hills, valleys, plateaus, plains and deserts.
Facts about Mountains
- A mountain is the highest landform on the surface of the earth. It is usually found to be conical in shape with steep sides and a pointed tip called a peak.
- As compared to their surroundings, mountains are high points on the surface of the earth.
- Mountain range is a series of mountains.
- Mountains could be steep and snow covered or they could be gently sloping having rounded tops.
- The highest mountain range in the world is the Himalayas. Some mountains are found under the sea and could be taller than the Mount Everest, which is the highest mountain peak in the world.
3 Types of Mountains
- Volcanic mountains
- Fold mountains
- Block mountains
- Mountains could be formed when molten rocks from deep within the earth rise to the surface, pouring out in the form of lava from volcanoes.
- Sometimes the tectonic plates on the earth’s crust move towards each other, the sediments deep below the earth’s surface are squeezed up to form mountain ranges.
- There are many mountains that remain covered with snow throughout the year. These mountains are very cold and hence there is not much vegetation or life found in these hills. Trees like pine and conifer are found in the lower ranges or foothills.
- Animals that have a thick fur coat can survive the extreme cold in the high mountain regions. The yak, the mountain puma, snow leopard or the male goat called the ibex are some of the animals found in the mountain areas.
- Houses in the mountains have sloping roofs to enable the snow slide off easily. The houses are made of wood so that they remain warm. People usually work in small industrial units, farming and animal rearing form their main occupations.
- Even besides harsh conditions, mountains are very useful to us as they act as shields for the country blocking the cold winds and also protect us from invading enemies.
- Trees provide us with commercial and medicinal value.
- Melting snow from the snow capped mountains fills the rivers and they are a source of water.
- They make beautiful tourist destinations.
Facts about Hills
- Hills are lower than mountains but are higher than their surrounding areas.
- Hills are lower in height than mountains, but they are higher than the surrounding areas. A number of hills together form a ‘range of hills’. Hills are usually covered with grass.
- The climate in the hills is more pleasant than the climate in high snow covered mountains. It is usually neither too hot nor too cold. They make perfect tourist destinations.
- The vegetation is thick, beautiful fruit orchards are found in the hills and it is good for crop cultivation like tea and coffee.
Facts about Valleys
- Valleys are the low-lying areas between two mountains or hills.
- When rivers flow down the mountainsides and hillsides, it wears off the rocks and soil. Over a period of time, the water carves out v- shaped grooves. These grooves get deeper and wider, finally forming low land areas called valleys.
- Valleys formed by glaciers are U- shaped valleys.
- Valleys formed due to the effect of erosion are V – shaped valleys.
- The valleys formed (that is V shaped or U shaped), depend upon the rate at which deepening and widening takes place.
- Narrow valleys are called canyons.
- The climate in the valleys is pleasant and favourable for living, hence many civilizations in ancient times were found in valleys where there were rivers flowing making water available for the people.
- For example The Indus Valley Civilization that came up near the River Indus.
- Due to ample water that is provided by the rivers and fertile soil, the vegetation is thick and valleys look green and beautiful.
- They make great tourist destinations as well.
- In young Mountain areas the valleys found are steep sided.
Facts about Plateaus
- A plateau is a flat topped highland with steep sides. Since it looks like a table, it is also called a tableland. They are basically areas of high flat land.
- Plateaus are usually surrounded by steep rock faces called cliffs.
- Some plateaus like the Plateau of Tibet lies between mountain ranges.
- Plateaus are usually good for growing certain crops.
- Plateaus 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 up creating a plateau.
- There are certain kinds of plateaus like the butte and the mesa. These are special kinds of plateaus.
Facts about Plains
- Plains as you all are familiar with are areas of flat land.
- The plains usually meet the oceans or seas, these are called coastal plains.
- In India, we have the Eastern Coastal Plains and the Western Coastal Plains.
- Some plains are formed by the action of rivers, these are called river plains.
- In India the Northern Gangetic Plain is a river plain.
- River plains are very fertile and good for growing crops.
- You will find most big cities are located in plains. This is because it is easier to build houses, buildings, roads and other structures in the plains. Hence they are heavily populated.
Facts about Islands
- An island is a piece of land surrounded by water on all sides.
- The continent of Australia is an island.
- Islands are formed due to volcanic activity or due to hot spots in the lithosphere.
- Coral islands are formed when the skeletal material of the corals piles up over a long period of time. These look beautiful.
- A large group of islands close to each other together form an archipelago. The Lakshadweep islands are an example of an archipelago. The largest archipelago in the world is Indonesia.
Deserts : Facts and Types
- Deserts are large, dry and hot areas of land which receive little or no rainfall throughout the year. The vegetation is scanty due to the shortage of water. Deserts are covered with sand.
- Sand dunes are formed in deserts. Sand dunes are huge hills of sand formed by the winds.
- Deserts have extreme weather conditions, days could be very hot and nights very cold. This is because the sand absorbs heat fast during the day and gives off heat quickly at night.
- The main vegetation found in the deserts are the cacti and the baobab trees.
- The baobab tree can store nearly up to 1000 litres of water in its trunk which enables it to survive the harsh conditions.
There are two types of deserts – Hot Deserts and Cold Deserts.
- As the name suggests, hot deserts are vast areas of land that are covered with sand and dust. These areas receive little or no rainfall and are very dry.
- The animals found in the hot deserts are camels, snakes, lizards and rats.
- Thar Desert in India is a hot desert.
- The cold deserts are large areas of land covered with snow. These deserts receive little or no rainfall. They receive snowfall during the winters. Animals such as penguins, whales and fur seals survive in the cold deserts.
- The Antarctica is the world’s biggest cold desert.
- Life in these cold deserts is impossible.
- There are some rocky deserts like the Gobi desert in Asia.
Some other Landforms
- A peninsula is a piece of land that is surrounded by water from three sides. For example the southern part of India is a peninsula as it is surrounded by the Arabian sea, Bay of Bengal and the Indian ocean and is joined to land on the fourth side.
- Another example is the State of Florida.
- A cape is a part of land extending in to a water body
- An isthmus is a narrow stretch of land which joins to large land masses.
- Example the Isthmus of Panama.
5 Interesting Facts
- Camels are called the ship of the desert as they carry people and their loads from one place to another.
- An oasis is a place in the desert where a pool of water is found, surrounded by trees.
- A huge mass of snow that suddenly breaks loose and crashes down a mountain is called an avalanche.
- Mountain animals have sharp hooves that help them climb mountains.
- The Deccan Plateau in India is good for growing cotton because of the black soil present.
What are Landforms?
Landforms are the natural features and shapes existent on the face of the earth. Landforms possess many different physical characteristics and are spread out throughout the planet. Together, landforms constitute a specific terrain and their physical arrangement in the landscape forms what is termed as topography. The physical features of landforms include slope, elevation, rock exposure, stratification and rock type.Oceans and continents illustrate the largest grouping of landforms. They are they further subcategorized into many different landforms based on their physical features and shapes. Examples of distinctive landforms include mountains, valleys, plateaus, glaciers, hills, loess, deserts, shorelines, and plains. Features such as volcanoes, lakes, rivers, mid-ocean ridges, and the great ocean basins are also part of landform features.
Wikipedia define Landform as,
“A landform is a natural feature of the solid 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. Typical landforms include hills, mountains, plateaus, canyons, valleys, as well as sho
reline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great ocean basins.”
Different Major Landforms on Earth
Major types of landforms on earth include mountains, valleys, plateaus, glaciers, hills, loess, plains and desserts.
Mountains are lands physical features protruding high beyond the hills and very high up the land surface with steep top commonly shaped up to a peak. They are created through the action of incredible forces in the earth such as volcanic eruptions. Often, mountains occur in the ocean compared to land and some are seen as mountain islands as their peaks protrude out of the water. Mountain formation result from the forces of erosion, volcanism, or uplifts in the earth’s crust.
The forces of heat and pressure within the earth’s interior are the main influencing factors to these forces as stated by geologists. These forces can be summed up as the plate tectonic movements – theoretically defined as the division of the earth’s outmost layer into several plates which are in constant motion. Hence, the uplifts are cause by collision or pulling apart of the plates that also triggers other various geologic activities such as the ejection of magma onto the surface or volcanic eruptions.
The movements also contribute to horizontal compression that is the deformation of crustal strata which gives rise to folds. The Himalayas and the Europe’s Jura and Alps mountains are examples of mountains formed as a result of horizontal compression. Some mountain ranges are also formed as a result of wind, water, and ice erosion. Other mountains are created from volcanism.
Examples of volcanic mountains include Mount Fuji in Japan, Mount Vesuvius in Italy, Mount Erebus in Antarctica, and Mount Saint Helens in the United States. Majority of volcanic mountains have summit craters that still expel debris and steam.
A valley is a lowland area or surface depression of the earth between higher lands such as mountains or hills. In simple terms, it can be defined as a natural trough bounded by mountains or hills on the surface of the earth sloping down to the lake, ocean or stream, which is created because of water or ice erosion. On this basis, the rivers or streams flowing through the valley empty the land’s precipitation into the oceans.
The lowest parts of the valleys are very fertile and make very good farmlands. Majority of the valleys on land are made up of running streams and rivers and nearly all their floors slope downstream. Valleys within the mountains normally have narrow floors. The sides of a valley are termed as valley slopes or valley walls and the section of floor along riverbanks are referred to as flood plains.
Valleys physical features include U-shaped and V-shaped caused through the forces of erosion by the flowing masses that persistently widens and deepens the valley. The flowing masses are either water or glacier that carries away huge amounts of debris. Very narrow and deep valleys are known as canyons.
Plateaus are fairly flat areas higher than the land surrounding it. The surrounding areas may have very steep slopes. Some plateaus such as the Tibet are situated between mountain ranges. Plateaus cover wide land areas and together with their enclosed basins they cover approximately 45% of the entire earth’s land surface.
Some plateaus, for instance the Columbia Plateau of the United States and the Deccan of India are basaltic and were created because of lava flows spreading to thousands of square kilometers thereby building up the fairly flat land surfaces. Other plateaus form as a result of upward folding while some are due to the erosion of the nearby land that leaves them elevated. Because plateaus are elevated, they are subject to erosion.
Low plateaus make up good farming regions whereas high plateaus are considered great for grazing livestock. Most of the world’s high plateaus are deserts. Other typical examples of plateaus include 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. They are huge masses of ice that slowly move over the land surface, predominant in high mountains and the cold Polar Regions. The very low temperatures in the regions are the enabling factor for 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.
The movements begin when the compaction is so dense that 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. The glaciers include the Greenland Ice Sheet and the Antarctic Ice Sheet. The Antarctic Ice sheets outlet glaciers comprise the steep and extensively long and narrow depression Beordmore Glacier, which is one of the longest outlets in the world. The gradual rice in continental temperatures has seen the glacial density grow smaller owing to melting.
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 accumulation of rock debris or sand deposited by wind and glaciers. They can also be created by faulting when the faults go slightly upwards. Hills are generally present in low mountain valleys and plains.
The Black Hills are the most known. Deep erosions of areas previously raised by the earth’s crust disturbances carry most of the soil away leaving behind a hill. Human activities may also create hill when soils are dug and piled giant masses. Volcanic eruptions as well create hills after the eruption when the molten materials or lava cools and hardens in a pile.
Loess is a fine-grained unstratified accumulation of clay and silt deposited by the wind. It appears brown or yellowish in color and is brought about by past glacial activity in an area. In precise, it is sedimentary deposits of clay and silt mineral particles which take place on land in some parts of the world. The thickness of loess deposits are just a few meters and one of their basic feature is known as the ‘cat steps’.
It’s held together by few clay particles and is mostly composed of quartz crystals which readily slide against each other. This property makes it highly susceptible to erosion which leads to the ‘cat steps’ feature. Loess formed after the ice age when the glaciers covering a relatively large portion of the earth melted and was carried away, exposing the vast plains of mud.
Upon drying of the mud, the forces of wind blew away the mud and exposed sediments and eventually deposited them as silt in stacks on top of each other to create bold steep banks. Regions made of loess are witnessed in eastern China and the northwestern region of the United States.
Plains are broad flat areas on the earth’s surface stretching over a wide area. Plains are lower than the land in their surrounding and can be found both inland and along the coast. Coastal plains rise from the seal level up to the point they meet raised landforms such as plateaus or mountains. The Atlantic Coastal plain is a prime example of a substantially populated and fertile coastal plain.
On the other hand, inland plains are generally found at high altitudes. Thick forests normally flourish on plains in humid climates. A fairly large portion of plains are covered by grasslands, for instance, the Great Plains in the United States. 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. Flood plains are also in this category and they are formed as a result of continuous accumulation of sand, silt, and mud when rivers overflow its banks.
Deserts are the hot and dry areas of the world. They are the arid and semi-arid lands with little or no vegetation. Deserts constitute approximately 20% of the earth’s total land cover and are distinguished by little or no rainfall. 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.
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.
Plants such as cacti and short shrubs are the ones adapted to the desert conditions because they can conserve water and tolerate the high temperatures. Animals in the deserts include insects, small carnivores, snakes, lizards, and birds adapted to survive with very little water. These animals hide during the day till nightfall to avoid the heat. An example of a desert is the Sahara of North Africa.
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