Erosion

The erosion is the wearing away of a rock by the action of external agents and the subsequent detachment. After the detachment, there is a transport: that is what differentiates it from weathering. 

Factors that affect the degree of the erosion:

• Slope: By increasing the degree of slope, erosion increases, because the materials are more unstable, and the minimum force applied make them fall. 

• Weight of the materials: The more weight you have the more materials will be the degree of erosion because it will drag more materials.

• Cohesion: Is the internal join of the particles that form the material. The materials can be more or less cohesive. The more cohesion, more difficult is the erosion.  The cohesion will depend on:

• Presence of plastic.

• Level of fracture.

• Material hardness.

• If the surface is smooth or soaked. 

• The absence of vegetation: If there are many roots, the make a support for the ground. They stop the rain when it rains, and it strains little by little; like this, it protects from erosion. 

• Climatic factors: The climate will be an important factor for the formation of some reliefs. 

Main form of erosion:

• Detachment: They are sudden falls of loose rocks. This happens, apart from erosion, because of the gravity. 

• Avalanche:  They are like detachments, but of greater magnitude. They can be of land and of snow. When they are of snow, the are called snow-slides.

• Land: 
  

• Snow: 
  

• Landslides: It arise when a land slides on off surface breaking off with the forces of cohesion. The landslide is accentuated with the slope, presence of water and plastic layers. 
  

• Flows and lava flows: They are rivers made of mud, that flows without a sliding plane. The materials move faster if they are placed at the top, because they have more space to pick up speed. 
  

• Creep: The floor is moving down. The trees are twisted above it, and when they try to stretch to go to the light, the ground moves. It is a very slow process, and plastic materials are needed.
  

• Gully: They are channels formed on slopes that have soft materials because of the torrential water. 
  

• Earth pyramids: 
  

• Fairy chimneys: