F. Geomorphic Processes

• The endogenic and exogenic forces causing physical stresses and chemical actions on earth materials and bringing about changes in the configuration of the surface of the earth are known as geomorphic processes.
• Diastrophism and volcanism are endogenic geomorphic processes.
• Weathering, mass wasting, erosion and deposition are exogenic geomorphic processes.
• Any exogenic element of nature (like water, ice, wind, etc.,) capable of acquiring and transporting earth materials can be called a geomorphic agent.
• When these elements of nature become mobile due to gradients, they remove the materials and transport them over slopes and deposit them at lower level.
• Geomorphic processes and geomorphic agents especially exogenic, unless stated separately, are one and the same.
• Gravity besides being a directional force activating all down slope movements of matter also causes stresses on the earth’s materials. Indirect gravitational stresses activate wave and tide induced currents and winds.
• Without gravity and gradients there would be no mobility and hence no erosion, transportation and deposition are possible.
• So, gravitational stresses are as important as the other geomorphic processes.
• Gravity is the force that is keeping us in contact with the surface and it is the force that switches on the movement of all surface material on earth.
• All the movements either within the earth or on the surface of the earth occur due to gradients— from higher levels to lower levels, from high pressure to low pressure areas etc
• The external forces are known as exogenic forces and the internal forces are known as endogenic forces.
• The actions of exogenic forces result in wearing down (degradation) of relief/elevations and filling up (aggradation) of basins/ depressions, on the earth’s surface.
• The phenomenon of wearing down of relief variations of the surface of the earth through erosion is known as gradation.

The endogenic forces continuously elevate or build up parts of the earth’s surface and hence the exogenic processes fail to even out the relief variations of the surface of the earth