Correct Option
The correct option isErosion
Explanation
The Earth's surface is continuously modified by geomorphic processes, which are broadly classified into endogenic (internal) and exogenic (external) forces. Exogenic processes, driven by solar energy and gravity, are responsible for gradation, which includes both the wearing down (degradation) and filling up (aggradation) of the land surface.
Option Analysis
- Deposition (Incorrect): Deposition is a process of aggradation. It occurs when the velocity of an erosional agent (like wind or water) decreases, causing transported material to settle. This process builds up the surface rather than wearing it away.
- Erosion (Correct): Erosion is the process of degradation. It involves the acquisition and transportation of rock debris by geomorphic agents such as running water, wind, glaciers, and waves. It is directly responsible for the wearing away of the Earth's surface.
- Upliftment (Incorrect): Upliftment is an endogenic process caused by diastrophism or tectonic activity. It results in the elevation of the Earth's crust, opposing the process of wearing away.
- Subduction (Incorrect): Subduction is a specific tectonic process occurring at convergent plate boundaries where one lithospheric plate sinks beneath another. While it destroys crust, it is a large-scale internal mechanism, not the general surface process described as "wearing away."
Key Takeaway
Erosion refers specifically to the wearing down of relief (degradation), while deposition refers to the building up of relief (aggradation).