Our Changing Earth

Our changing earth consists of a lithosphere that is broken into various plates known as the Lithospheric plates. These plates move around at their leisure because of the development of the liquid magma in a roundabout way inside the Earth. These plates move at a certain pace which causes changes on the surface of the Earth. The Earth’s movements are the result of various forces acting on the plates.

Various forces inside Our Changing Earth: 

• The forces which act on the inside of the Earth are called Endogenic forces 
• The forces that work on the outer layer of the Earth are called Exogenic forces

Endogenic Forces:

• Endogenic geomorphic processes are driven mostly by energy emitted from deep below the earth. Diastrophism and abrupt movements are the two basic forms of earth tremors

• Under diastrophism are processes that shift or build up the earth’s crust. There are a variety of orogenic processes to consider, such as mountain construction by extreme folding of the Earth’s crust. Plate tectonics is an example of how they work in a tangential manner to the Earth’s surface

• Fissures are the result of tension (force acting away from a point in two directions) and Folds resulting from compression (force acting towards a point) are forms of orogenic processes 

• Epeirogenic processes include the lifting or warping of significant portions of the earth’s crust, making them a type of continental construction. They are also known as radial movements since they take place along the Earth’s axis

• Subsidence occurs when movement is in a downward direction. When it’s in the centre, it lifts you up. For example: elevated wave-cut terraces, sea caves, and other forms of elevated beach

• It is possible to have both earthquakes and volcanoes in a short period of time, and both can produce significant deformation

Examples of Endogenic Forces:

Volcano:

• A vent (opening) in the crust of Earth, through which molten material erupts suddenly, can be referred to as a volcano

Earthquakes:

• The vibrations on the surface of Earth due to the movement of Lithospheric plates are called earthquakes
• Focus is the exact place where the movement starts in the crust
• The location on the surface above the focus is called the epicentre

Exogenic Forces

• Because of the sun’s heat, exogenic forces are created when earth materials are subjected to stress. It is possible that they will be subjected to shear stresses that break rocks and other earth materials, or molecular stresses induced by temperature variations
• In terms of exogenous geomorphic processes, denudation encompasses all of them. Denudation includes weathering, mass wasting/movements, erosion, and transportation

Examples of Exogenic Forces

Major Landforms and their Evolution:

Multiple landforms on the surface of the Earth form due to two significant occurrences: weathering and erosion.

• The breaking up of rocks present on the Earth’s surface can be referred to as Weathering
• When any landscape wears away due to different agents like water, wind, and Ice is called Erosion 

Landforms formed by Rivers:

• Meanders: Once the river enters the plain, it automatically twists and turns to form large bends known as meanders
• Ox-bow Lake: Meander loop cuts off from the river and forms a cut-off lake, called an ox-bow lake
• Floodplains: Sometimes, the river overflows its banks which leads to the flooding of the neighbouring areas. As it floods, it deposits multiple layers of fine soil and other material called residue along its banks. This prompts the development of a level fruitful floodplain
• Levees: These are raised banks
• Distributaries: As the river approaches the sea, the speed of the flowing water decreases, and the river starts to separate into various streams called distributaries. These distributaries help in expanding the delta
• Waterfall: Rivers and other water bodies often have a waterfall because of their rapid descents and subsequent plunges into a pool below. Cascades are another name for waterfalls

Coastal landforms:

The deposition combined with constant erosion of the sea waves gives rise to coastal landforms.

• Sea caves: Hollow-like caves formed on the rocks are known as Sea caves
• Sea arches: As the holes become greater and greater, just the top of the caverns remains, shaping ocean curves 
• Stacks: Further, disintegration breaks the rooftop, and just dividers are left. These dividers, like highlights, are called stacks
• Sea cliffs: The steep rocky coast rising almost vertically above seawater is called a sea cliff 

Landforms formed by Ice:

• Glaciers are “waterways of ice”
• Glaciers cut out profound hollows there. As the ice dissolves, they get topped off with water and become beautiful lakes
• The material conveyed by the glacial mass, such as shakes of all shapes and sizes, gets saved by sand and residue. These stores structure frosty moraines

Landforms formed by Winds:

An active agent of erosion and deposition in the deserts is wind. 

• In deserts, various rocks in the shape of a mushroom, commonly called mushroom rocks, are found
• Dunes: These are formed by the deposition of sand by the wind in low hills–like structures.
• When such sand is deposited in large areas, it is called loess
• Large deposits of loess are found in China

Conclusion

Our Earth is a dynamic body which is constantly changing. Earth’s lithosphere is broken into various plates known as tectonic plates. The movement of these plates causes changes on the earth surface. Changes on the earth’s surface are the result of mainly two kinds of force: Endogenic force and Exogenic force. Endogenetic forces give rise to the major structure of the world like mountains, volcanic eruption, earthquake, upwarping and downwarping. Forces acting on the outer surface of earth are exogenic forces like wind, water, waves. This force takes the form of weathering, erosion, wearing and tearing. Endogenic force is a constructive force while exogenic force is a destructive force. Some of the prominent landforms found on the earth’s surface are mountains, gorges, rivers, sand dunes, sea cliffs, caves, oxbow lakes etc.