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Utah has some of the most beautiful scenery around. We can thank both weathering and erosion for this beauty!
Observe a stream or river after a rainstorm. What color is the water? If you notice it is no longer clear or blue but dirty looking, you are correct. What causes the dirty color?
Weathering is a process that breaks rocks down to smaller pieces. Wind can break down rocks as it blows other rock particles against them. Water also helps break the rocks apart. If water gets into a hole, it will expand when it freezes - making the hole larger than it was before. The rocks break to allow the hole to get bigger. Animals help this process when they dig holes in the ground. When tree roots grow down and push against a rock, they can make a hole for water to enter as well. Just look at the tree on the left.


Erosion is a science term that means soil or rocks are moved away from their original location. Water erodes soil or rocks very well. Wind is also a common cause of erosion. Can you think of any other methods which move soil or rocks?
Gravity working with water caused erosion. The eruption of the Mt. St. Helens volcano destroyed all the plants and trees living around it. When the snow on the mountain melted, the water quickly eroded paths causing soil and rock to be displaced.

You Decide!

Pick two of the images below (one showing erosion and one showing weathering). Write a paragraph explaining how erosion or weathering played a part in each images' creation.


Download the plug-ins: Get Adobe Acrobat Reader , and Get Quicktime Player. (The QuickTime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

  1. The title of the activity
  2. The URL (Internet address)
  3. Your name.

Remember that no pictures can be used that show student faces or student names on it. 

Teachers should view the Teacher Site Map to relate Sci-ber text and the USOE 4th grade science core.

Updated October 24, 2008 by: Glen Westbroek

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