Major Landforms of the Earth

Boating, water skiing, swimming, fishing, surfing, sun bathing and canoeing. In Kerala, snake boat races are held in connection with Onam, the harvest festival in August/September.

Lava plateaus are formed by highly fluid (runny) basaltic lava during numerous successive eruptions through numerous vents without violent explosions (quiet eruptions). These eruptions are quiet because of low viscosity of lava and contains small amount of trapped gases. Multiple successive and extensive lava flows cover the original landscape to eventually form a plateau, which may contain lava fields, cinder cones, shield volcanoes and other volcanic landform.

The two processes that lead to the formation of landforms are:
1. Internal Process: This process leads to the upliftment and sinking of the earth’s surface at several places. Example: block mountains
2. External Process: The external process is the continuous wearing down and rebuilding of the land surface. Examples: Barchans

Volcanic mountains are formed due to volcanic activity that is due to solidification of lava. Mt.Kilimanjaro in Africa and Mt. Fujiyama in Japan are examples of such mountains.

We should do following practices: (1) We should not construct buildings on the fertile land. (2) We should not throw garbage on the land or in water and make them dirty. (3) We should avoid using important gifts of nature in a careless manner.

Deposition, also known as sedimentation, is the geological process whereby material is added to a landform. This is the process by which wind, water or ice transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited another geographical location.

Mountains are very useful to man in the following ways:

• Mountains are storehouses of water.
• Many rivers have their source in the glaciers.
• Water from mountains is also used for irrigation and generation of hydroelectricity.
• Mountains have a rich variety of flora and fauna.
• Forests are found on mountains also.
• Mountains provide an idyllic site for tourists.
• Several sports are popular in mountains.

Plains are formed by the rivers. The rivers erode the slopes of mountains and carry forward the eroded material. They then deposit their load consisting of stones and sand along their courses and in valleys. In this way the plains are formed.

The river plains are thickly populated due to following reasons:

• River plains are very fertile due to the presence of alluvial soil and thus proved to be very useful for agriculture
• Construction of transport network is easy
• Its climate is suitable for human habitation
• More flat land is available for building houses and cultivation

The mountains are thinly populated because

• Harsh climate is found in mountaneous area that is not suitable for people.
• The mountain slopes are steep making it difficult to construct buildings.
• Less land is available for farming.

Block Mountains are formed when large areas of bedrock are widely broken up by faults creating large vertical displacements of continental crust. Vertical motion of the resulting blocks, sometimes accompanied by tilting, can then lead to high escarpments. These mountains are formed by the Earth's crust being stretched and extended by tensional forces. Fault block mountains commonly accompany rifting, another indicator of tensional tectonic forces. The uplifted blocks are called block mountains or horsts. The intervening dropped blocks are termed as graben. These can be small or form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges, the Basin and Range province of Western North America, in south-central New England and the Rhine valley. These areas often occur when the regional stress is extensional and the crust is thinned

A volcano is an opening on the surface of the Earth from which magma, associated gases and ash erupt. Volcano has a magma chamber that is a huge bottomless pot of molten rock. The main channel through which magma moves towards the surface is the central vent. A crater sits at the top of a volcano and it is from here that much of the lava, gas, rock fragments and ash are ejected from. Volcanic cones arethe result of eruptions that erupt are mostly small pieces of rocks that build up cone around the vent.

• They are rich in mineral deposits
• Most of the India's mining area are located in plateau
• Plateau areas have plenty of waterfalls, scenic spots and are great attraction for tourist
• The lava plateaus are rich in black soil that is good and fertile for cultivation

Due to harsh climatic conditions, number of people living in mountain areas is less. Generally two types of housing pattern can be seen on mountains. One in which the houses are generally scattered mud houses with low roofs and have a lot of distance between houses. Second is clustered type, where all the houses are situated on a particular slope. The houses are generally wooden houses and may be joined wall to wall with each other.

1. The Black Forest: Block mountain
2. The Nilgiris: Residual mountain
3. The Fujiyama: Volcanic mountain

Mountainous areas have lower temperatures. They serve as climatic divide between two adjoining regions. The Himalaya for example forms a barrier to the movement of cold winds from Central Asia towards the Indian subcontinent. They also force the South West Monsoons to ascend and cause rainfall on their southern slopes.

The two processes that lead to the formation of landforms are:
1. Internal Processes: These processes lead to the upliftment and sinking of the earth’s surface at several places.
2. External Processes: The external process is the continuous wearing down and rebuilding of the land surface.