What Causes Erosion?
demonstrationActivity Exercisesuggested grade levels: 4- 6
view Idaho achievement standards for this lesson

Overview:
Erosion is happening all around us. It is constantly changing our landscape and wearing down our mountains. Different things including wind, water, and ice can cause erosion. The following activity will expose students to these various types of erosion and they will observe how it can change the landscape.

Materials:
Fine sand Shallow pan
Soil Clay
Watering can Gravel
Small blocks of ice Large bucket

Procedure:
1. Expose students to the concept of erosion and the various types: wind, water, ice, etc. This activity could be incorporated into use with the glacier, geology, and hydrology sections of the Digital Atlas of Idaho. In particular, the Lake Bonneville Flood, Bruneau Sand Dunes, and Glacier sections.

2. Wind Erosion: Obtain a handful of fine sand and place it in a shallow pan or box. Blow on the sand and observe what happens. Ask the following questions for class discussion.
         a. Could you make the pile of sand change places if you blew long enough?
         b. What do you think would blow around faster, large particles or smaller particles?
         c. Does this process happen to the earth?

3. Water Erosion:  Put some soil into a shallow tray. Tilt the tray and slowly pour some water near the top edge. Let the water run over the soil and then drain into a large bucket.
         a. What happened to the soil where the water ran over?
         b. Is there any soil that the water carried off into the drainage bucket?
         c. Is this process similar to what a river does?

4. Ice/Glacier Erosion:  Flatten out a piece of clay and put some gravel on top of the clay. Take a small block of ice and rub it back and forth across the gravel that is on top of the clay.
         a. What happened to the surface of the clay?
         b. Could a glacier do the same thing to the surface of the earth on a larger scale?

5. Mudslides:  Pile up some dry soil in the middle of a tray. Slowly and gently poor some water on the soil and explain how the soil can absorb some water. Keep pouring the water until the soil is saturated and then observe how the mud will slide down.
         a. Can this same process occur on a hillside?
         b. How could vegetation on the soil slow down this process?

Related Lesson Topics:
Hydrology: Hydrology Topics

Lesson Plan by Vita Taube, 2000
Idaho Achievement Standards (as of 7/2001) met by completing this activity:
759.02.03.04
760.01
772.02.03.04
773.01
785.02.03.04
786.01