Upliftment and sinking of the earth’s surface
Explanation
Geomorphic processes are broadly classified based on the source of energy behind them. Endogenic processes (internal forces) derive energy from within the Earth, while Exogenic processes (external forces) derive energy primarily from the sun and atmospheric gradients.- Continuous wearing down of the land surface is incorrect: The continuous wearing down of the land surface is referred to as degradation or denudation. This is the primary outcome of exogenic processes (such as weathering and erosion), which aim to level the Earth's surface.
- Upliftment and sinking of the earth’s surface is correct: Endogenic processes are constructive forces. They generate vertical and horizontal movements in the Earth's crust, leading to the upliftment (e.g., mountain formation) and sinking (subsidence) of the Earth's surface. These processes create relief and irregularities.
- Deposition of eroded materials is incorrect: Deposition is the consequence of exogenic agents (like rivers, wind, or glaciers) dropping the material they have eroded and transported. This process, known as aggradation, fills up depressions.
- Formation of glaciers is incorrect: The formation of glaciers is a climatic phenomenon. While glaciers act as powerful agents of exogenic change, their formation itself is not a direct outcome of the Earth's internal tectonic processes.
Key Takeaway: Endogenic forces are land-building forces that create relief through upliftment and subsidence, whereas Exogenic forces are land-wearing forces that level the surface through erosion and deposition.