What's the difference between weathering and erosion?

Weathering 

Weathering refers to the various mechanical and chemical processes that cause exposed rock to decompose. Weathering involves two processes: 

• chemical weathering and 
• mechanical weathering 

Both processes occur in place. No movement is involved in weathering. 

Chemical weathering 

Chemical weathering involves a chemical change in at least some of the minerals within a rock. 

Mechanical weathering

Mechanical weathering involves physically breaking rocks into fragments without changing the chemical make-up of the minerals within it. 

Erosion

As soon as a rock particle (loosened by one of the two weathering processes) moves, we call it erosion. We call it erosion if the rock particle is moved by some flowing agent such as air, water or ice.

wind erosion

water erosion

ice erosion

Erosion

Erosion is the process of natural forces moving rocks and soil. Rocks and soil can be referred to as earth materials.

The natural forces that make erosion happen are:

water	water	Happens when water moves the pieces of rock or soil downhill and carries small pieces of material with it.
	waves	Carry away small pieces of material. A wave can wash up onto the surface of rock or soil and then carry away pieces of material as it flows back into the ocean or lake.
Wind		Occurs when wind moves pieces of earth materials. Wind erosion is one of the weakest kinds of erosion. Small pieces of earth material can be rolled along the ground surface by wind. Very small pieces can be picked up and carried by the wind. Occasionally, wind can carry small pieces of earth materials over large distances.
Ice		Usually happens when a glacier moves downhill. As the ice of the glacier moves downhill, it pushes and pulls earth materials along with it. Ice erosion is one of the strongest kinds of erosion because glaciers can move very large rocks.
Gravity		Is the simplest kind of erosion. Gravity simply pulls loose earth materials downhill. Landslides are dramatic examples of gravity erosion).

Erosion is a geological process. Geology is the study of the structure of the earth and the processes that change the earth. Erosion occurs only at the earth's surface.

Most of the energy that makes erosion happen is provided by the sun. The sun's energy causes the movement of water and ice in the water cycle and the movement of air to create wind. If the sun did not provide energy for erosion, only gravity erosion would still occur.

Erosion can cause problems that affect humans. Erosion can also cause problems for humans by removing rocks or soil that support buildings.

Erosion

The process known as weathering breaks up rocks so that they can be carried away by the process known as erosion. Water, wind, ice, and waves are the agents of erosion that wear away at the surface of the earth.


Erosion by water

VIDEO: Erosion by water