Students will be able to describe erosion. They will also be able to list at least three causes of erosion.
Start the lesson by asking students to tell you what erosion is. Erosion is the displacement of solids (soil, mud, rock and other particles) by the agents of wind, water, ice, or living organisms, or by down-slope movement in response to gravity. (New World Encyclopedia)
Show students the short video of an Alaskan coastal area eroding at: http://dotearth.blogs.nytimes.com/2008/09/25/video-alaskas-eroding-arctic-coast/. Ask them what is happening and why.
If time permits, take the students to the library or computer lab to research different causes of erosion and to find images of Alaskan coastal villages that have been affected by erosion. You may want to assign different topics to different students (groups) and then have them share (present) they findings to the rest of the class.
Emphasize to them that erosion is the wearing away of a substance. It can happen over a long period of time or it can be quick. The soil around a river is susceptible to gradual erosion. When it storms or blows, then erosion may happen in a quicker fashion. Highlight the fact that erosion can be caused by wind, rain, water, ice and sea. Tell them that today they are going to perform an experiment to evaluate how much the Earth can erode.
The Effect of Wind
The Effect of Water
Ask the students if they can think of other conditions that could affect the rate of erosion. You may test other variables such as the slope of the pan, different speeds of wind (fan), and dry versus wet soil.
Have the students answer the following questions on their observation sheets: