Endogenic and exogenic forces
Also called: Endogenic and exogenic processes · Topic: Geomorphic Processes: Weathering, Mass Movement, Erosion and Soil Formation · NCERT: Class 11, Ch 2 "Structure and Physiography"
Meaning
Endogenic and exogenic forces are the two groups of forces that shape the earth's surface. Endogenic forces come from inside the earth and build land up through folding, faulting and volcanism. Exogenic forces act at the surface and are driven mainly by the sun's energy. They wear land down through weathering, mass wasting (rock and soil sliding downhill), erosion and deposition. Endogenic forces keep raising land, so exogenic forces never make the surface flat. For this reason, Class 11 calls the earth "a playfield for two opposing groups of geomorphic processes".
Example
In India, endogenic forces folded up the Himalayas. Exogenic forces, mainly rivers such as the Ganga, wear the mountains down and lay the eroded silt across the Indo-Gangetic plains.
Don't confuse with
- Geomorphic agent: an agent is the moving medium that does the work, such as a river or a glacier. Endogenic and exogenic forces are the groups of forces.