Landforms on the earth are:
They are of two types: Block Mountains and Fold mountains.
Mountain Building Process:
Fold Mountains are also called true mountains and are the youngest mountains of the earth. They are formed due to compressive force of the plates. They can be either of continental – continental convergence origin or continental – oceanic convergence origin. Therefore only compression is the force that creates Fold Mountains.They are the most widespread and most important. These are associated with volcanic activity and mineral wealth. They are called mountains of elevation. The compressive forces push the layers of the earth upwards and these are formed into mountains.
Characteristics of Fold Mountains:
Fig 2: Block mountains
Volcanic mountains: These are formed when materials ejected from the earth’s crust erupts from the vent of the mountain. This material accumulates around the vent of the mountain. Therefore volcanic mountains are called mountains of accumulation.
Residual mountains: These are mountains formed from the effects of denudation agents like rivers, air, breeze etc.
This is raised land higher than surrounding areas. It is formed during mountain building process. It is raised land due to erosion of mountain from glaciers or deposition from winds or lava.
These are flat areas with low heights. These are the most populated areas of the world. They are most fit for human habitation.
The depositional plains are formed due to rivers or sea. Erosion plains are formed due to erosions of plateau.
There may also be low hills that form a rolling topography.
The main types of lava are:
In some volcanoes the top of the cone collapses into the vent or is blown off. This orifice gets widened forming a caldera. Sometimes a lake may form in this depression and is called a Caldera lake.
The greatest concentration of volcanoes is along the Cir-cum Pacific region which is also known as the “Pacific Ring of Fire” which has 2/3rds of the world’s volcanoes. It is also the region that sees the highest concentration of earthquakes as nearly 70% of the earthquakes are seen in this reg
Most of the lakes in the world are fresh water lakes and a few that have limited source of water and face high evaporation are salt water lakes. Lakes are however only temporary land-forms and shall be erased due to siltation and evaporation.
Factors responsible for lake formation:
Apart from these there are also lakes formed by erosion or deposition or formed from activities of man, animals and ornamental lakes.
Tourist industry has become the National occupation in Switzerland due to the presence of lakes in the Alps.
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Q1:True mountains or the youngest mountains on the earth are
Q2:The uplifted portion of the block mountains is called
Q3:These are the most populated areas of the world?
Q4:highest and most common type of volcano
Q5:Lake formed in the vent of a volcano is called