Erosion
All loose material at the surface of the earth moves down hill under force of gravity to a lower energy state

This can be caused by:
- gravity alone
- material lubricated by water + gravity
These processes are grouped under the general category of MASS WASTING
- the action of a transportation agent that itself is moved by gravity

After humans, ice is the most efficient due to its high viscosity and thus greater strength.

However the most effective agent of erosion is running water. More of Earth's surface is affected by running water. Even in deserts, where running water is scarce, water is a very effective erosion agent because there is not vegetation to hold down the soil.

The action of erosion can be visualized by tracing its effects on features whose shapes prior to erosion are known. A good example of this is a volcano. Volcanoes are mountains built on the surface of the earth by transport of liquid rock to the surface.

Many volcanoes have a classical cone shape. A good examply is Mt. Fuji in Japan. Click on Best Live photos for a variety of views. To return to this page, click the back button on the menu bar.

A volcano eroded by ice: View of Mount Rainier

The pictures below illustrate the changes due to erosion on the ancient volcano once at Shiprock, New Mexico.

View of Shiprock close up

View of Shiprock far off view

View of Shiprock reconstructed before erosion

Erosion leads to transport of sediments. Again rivers are the most effective agents.

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