3. Formation of landforms
•Landforms are produced by the earth’s natural
forces of erosion, deposition and tectonic forces.
•The scientific study of the processes that shape
landforms is called geomorphology.
4. Forces on the earth
•Endogenic or internal forces
•Exogenic or external forces
5. Endogenic or internal force
•They are responsible for the formation
of various landforms, hence they are
called as constructive forces.
Folding and faulting are internal forces.
6.
7. Exogenic or external forces
•They have the tendency to convert the
surface of the earth into a plain surface by
removing irregularities. Thus, these forces
are called destructive forces.
e.g., wind, water, glaciation, etc. These are
also called as agents of erosion.
8. Endogenic forces
•They are forces acting beneath the earth
surface and they are also called as
tectonic movements.
•They are further divided into:
•1. Diastropic forces.
•2. Sudden forces.
12. Vertical movements:
•Vertical movements cause rise and
fall of portion of earth.
•The part which rises above the
surrounding portion is known as
Uplift and the part sinks downward
is called Subsidence.
16. •Compressional forces lead to crumbling
and folding of rocks.
•Tensional forces lead to fractures, cracks
and faulting of rocks.
17. Sudden forces
•Movements caused by sudden
endogenic forces coming from deep
within the earth cause sudden and
rapid events that cause massive
destructions at and below the earth
surface.
18.
19.
20. B. Exogenic forces
•The different agents of erosion and weathering
like running water, wind, waves, glaciers etc.
act on the earth surface and erode the existing
features. This is degradation.
21.
22. •The broken material is deposited in
depression, raising the level of the land. This
process is called Aggradation.
23.
24. Difference between endogenic and exogenic
forces.
• Endogenic forces acts
beneath the earth surface.
• They are constructive forces.
• Eg. Folding and faulting.
• Exogenic forces act on the
surface of the earth.
• These are destructive forces.
• Eg. Includes agents of
erosion such as wind, water
and glaciers.
