Landforms
There are many types of landforms, for example :
How are landforms so different and how are they formed ?
To explore this, let’s look at:
How are such different landforms formed ?
There are 2 processes involved
2. Exogenic process - external process which take place on the earth
Some important words in this chapter
What is weathering ?
Weathering is the process of breaking down of rocks into smaller rocks .
What is erosion ?
Erosion involves moving the particles or rocks ( sediments) from one place to another .
Weathering VS Erosion
Landforms shaped by water
How does a river bend?
Why do you think rivers bend more in the plains and less in the mountains?
A tributary is a stream or a lake that joins a main river .
A distributary is a stream that comes from the main river .
Deltas and levees
Please pause the video in between if needed
Deltas contain deposits that the river has carried all the way through its course!
...What kind of soil do you think deltas have?
...What benefits result from delta soil?
The Ganga-Bhramaputra Delta in India
Sometimes, running water erodes the ground and creates a narrow valley. This is called a ‘ V - shaped valley ‘
Coastal landforms
Sea cliffs - rock faces formed when sea waves continuously hit against them
Over a period of time, cracks are formed in the rock, hollowing out caves. These are called
Sea caves .
As sea caves become larger and larger because of the waves sometimes only the roof is left. They are then called sea arches .
When the roof also breaks due to erosion only the wall is left and that's called a sea stack.
The coastline always changes because of continuous erosion and deposition of sand .
Sea coast: where the land meets the sea
Sea water deposits sand and gravel along the shore forming a beach.
Here is a picture of gravel and sand you may find in a beach !
What are some thing you like to do at the beach?
Lagoon - a stretch of water separated from the sea .
Landforms shaped by ice
The work of glaciers
A glacier is a large body of ice moving slowly down a slope
Continental glacier when the glacier covers surface of land with thin ice sheets
e.g.- Antarctica
Mountain glacier
It is a stream of ice flowing along a valley . It usually follows a rivers course.
Criques are mountain valley heads which have been shaped into deep hollows by the erosion of small glaciers.
When the ice melts the cirque gets filled with water and they become lakes called tarn lakes .
Landforms shaped by wind
How do you explain the shapes of land in areas like deserts where there is very little water/ice?s like deserts where there is very little water/ice?
Inselbergs -
When winds erode the lower portion of rocks more than the upper sections , the rocks have a narrow bottom but a big top.
When the wind blows over empty desert, it easily picks up sand and deposits it on a low hill forming a sand dune
Crescent shaped sand dunes are called barchans.
Questions & Activity