• The lithosphere is broken down into a number of plates known as the Lithospheric plates.
• The movement of these plates causes changes on the surface of the earth. The molten magma inside the earth moves in a circular manner. The forces that act in the interior of the earth are called endogenic forces, while the forces that work on the surface of the earth are called exogenic forces.
• Sudden movements like earthquake and volcanoes cause mass destruction over the surface of the earth.
• A volcano is a vent (opening) in the earth’s crust through which molten material erupts suddenly.
• The vibration in the plates of earth is called a earthquake.
• The place in the crust where the movement starts is called the focus.
• The place on the surface above the focus is called the epicentre. Vibrations travel outwards from the epicentre as waves. Greatest damage is usually closest to the epicentre and the strength of the earthquake decreases away from the centre.
• Although earthquakes cannot be predicted, the impact can certainly be minimized. Some common earthquake prediction methods adopted locally by people include studying animal
behaviour.
• Major Landforms:
(i) The landscapes are continuously worn away by two forces, weathering and erosion.
(ii) Weathering is the breaking down of the rocks on the earth’s surface.
(iii) Erosion is the wearing away of the landscape by different agents like water, wind and ice.
(iv) The eroded material is carried away or transported by water, wind, etc. and eventually
deposited. This processes of erosion and deposition create different landforms on the surface of the earth.
• Work of a River:
(i) When the river tumbles at a steep angle over hard rocks or down a steep valley side, it forms a waterfall.
(ii) As the river enters the plain, it twists and turns, forming large bends known as meanders.
(iii) At this point of time, the meander loop cuts off from the river and forms a cut-off called ox-bow lake.
(iv) During flooding, the river deposits layers of fine soil and other materials called sediments along its banks. This leads to the formation of a flat fertile plain called floodplain.
(v) The raised banks along the river are called levees.
(vi) As the river approaches the sea, the speed of the river begins to break up into a number of streams called distributaries. The river becomes so slow that it begins to deposit its load.
Each distributary forms its own mouth and flowing water decreases. The collection of sediments from all the mouths forms a delta.
• Work of Sea Waves:
(i) The erosion and deposition of the sea waves gives rise to coastal landforms.
(ii) Due to seawaves, hollow-like caves and formed on the rocks. They are called sea caves.
(iii) As cavities become bigger in size, only the roof of the caves remain, thus forming sea arches.
(iv) The erosion further breaks the roof and only walls are left. These wall-like features are called stacks.
(v) The steep rocky coast rising almost vertically above sea water is called sea cliff.
(vi) The sea waves deposit sediments along the shores forming beaches.
• Work of Ice:
(i) Glaciers are rivers of ice which erode the landscape by bulldozing soil and stones to expose the solid rocks below.
(ii) The material carried by the glaciers, such as big and small rocks, sand and silt gets deposited. These deposits form glacial moraines.
• Work of Winds:
(i) An active agent of erosion and deposition in the deserts is wind. It makes rocks in shape of a mushroom, called mushroom rocks. Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top.
(ii) When the wind stops blowing, the sand falls and get deposited in low hill like structures. These are called sand dunes.
(iii) When the grains of sand are very fine and light, the wind can carry it over long distances. When such sand is deposited in large areas, it is called loess.
For More :-
CBSE
Class–VII | CHAPTER – 1 Integers | NMMS
Revision Notes à Click
Here
Tracing
Changes Through a Thousand Years | NMMS Revision Notes | Class 7 | Social à Click
Here
New
Kings and Kingdoms | NMMS Revision Notes | Class 7 | Social à Click Here
The
Delhi Sultanate | NMMS Revision Notes | Class 7 Social à Click
Here
The
Mughal Empire | NMMS Revision Notes | Class 7 Social à Click Here
Tribes
Nomads and Settled Communities | NMMS Revision Notes | Class 7 Social à Click
Here
Devotional
Paths to the Divine | NMMS Revision Notes | Class 7 Social à Click
Here
The
Making of Regional Cultures | NMMS Revision Notes | Class 7 Social à Click
Here
Eighteenth
Century Political Formations | NMMS Revision Notes | Class 7 Social à Click
Here
Environment
| NMMS Revision Notes | Class 7 Social à Click
Here
Inside
Our Earth | NMMS Revision Notes | Class 7 Social à Click Here
Our
Changing Earth | NMMS Revision Notes | Class 7 Social à Click Here
Air |
NMMS Revision Notes | Class 7 Social à Click Here
Water
| NMMS Revision Notes | Class 7 Social à Click Here
Human
Environment Interactions the Tropical | NMMS Revison Notes | Class 7 Social à Click
Here
Life
in the Deserts | NMMS Revision Notes | Class 7 Social à Click Here
On
Equality | NMMS Revision Notes | Class 7 Social à Click Here
How
the State Government Works | NMMS Revision Notes | Class 7 Social à Click
Here
Role
of the Government in Health | NMMS Revision Notes | Class 7 Social à Click
Here
Growing
up as Boys and Girls | NMMS Revision Notes | Class 7 Social à Click
Here
Women
Change the World | NMMS Revision Notes | Class 7 Social à Click Here
Understanding
Media | NMMS Revision Notes | Class 7 Social à Click Here
Markets
Around Us | NMMS Revision Notes | Class 7 Social à Click Here
A
Shirt in the Market | NMMS Revision Notes | Class 7 Social à Click Here
Nutrition
in Plants | NMMS Revision Notes | Class 7 Science à Click Here
Nutrition
in Animals | NMMS Revision Notes | Class 7 Science à Click Here
Heat |
NMMS Revision Notes | Class 7 Science à Click
Here
Acids
Bases And Salts | NMMS Revision Notes | Class 7 Science à Click Here
Physical
And Chemical Changes | NMMS Revision Notes | Class 7 Science à Click
Here
Respiration
In Organisms | NMMS Revision Notes | Class 7 Science à Click Here
Transportation
in Animals and Plants | NMMS Revision Notes | Class 7 Science à Click
Here
Force
and Pressure | NMMS Quick Revision Notes
| Class: 8 Physics à
Click Here
Reproduction
In Plants | NMMS Revision Notes | Class 7 Science à Click Here
Motion
And Time | NMMS Revision Notes | Class 7 Science à Click Here
Electric
Current and its Effects | NMMS Revision Notes | Class 7 Science à Click
Here
Light
| NMMS Revision Notes | Class 7 Science à Click Here
Waste
Water Story | NMMS Revision Notes | Class 7 Science à Click Here
How
When and Where | NMMS Revision Notes | Class 8 Social à Click
Here
From
Trade to Territory | NMMS Revision Notes | Class 8 Social à Click Here
Ruling
the Countryside | NMMS Revision Notes | Class 8 Social à Click Here
Tribals
Dikus and Vision of Golden Age | NMMS Revision Notes | Class 8 Social à Click
Here
When
People Rebel | NMMS Revision Notes | Class 8 Social à Click Here
Weavers
Iron Smelters and Factory Owners | NMMS Revision Notes | Class 8 Social à Click
Here
Civilising
the Native Educating the Nation | NMMS Revision Notes | Class 8 Social à Click
Here
Women
Caste and Reform | NMMS Revision Notes | Class 8 Social à Click Here
