In:Weathering and erosion go hand in hand. We know that weathering is the breaking down of rocks and land. So what is erosion?

I will be able to determine the effects of water erosion by participating in a lab.

• Erosion is the moving of the small broken rocks and land.
• Erosion has helped form mountains, valleys, coastlines and other landforms.

Grand Canyon Video

Water erosion

Water is one of the main causes of erosion. Even though it does not seem super powerful, water is one of the greatest forces on Earth. Let's look at some ways that water can change the land.

When rain hits the ground, it can cause erosion. This is called splash erosion. Rain can also cause erosion when it forms little streams that flow along the land.

rivers

Rivers are one of the largest sources of erosion. As water flows down the river, it breaks up particles of the land along the river floor and carries it downstream.

The Grand Canyon was actually formed by the Colorado River flowing through the middle and eroding the land.

• Water erosion over a long period of time creates different types of landforms.
• Canyons form when water carves away rock.

Motlatse Canyon often called Blyde River Canyon, South Africa

Waves

Waves are so strong that as they hit the coastline, they break off small rocks and pieces of the land and carry them away. Over time, the coastline changes.

waves

Waves can also erode our beaches. The water pulls sand away from the beaches and into the ocean. Have you ever noticed a beach getting smaller year after year? Have you ever seen big barges pumping sand back onto the beach from the ocean?

Coastal Erosion

When erosion occurs along the coast, it is called coastal erosion.

Build your mountains:

1. LEADER: Fill one of the plastic cups with the wet sand. Use the bottom of the other cup to push the sand down and pack it into the cup (This will help make your mountain stand up.)

2. Turn the cup with the sand upside down on the plate and lift if away so you have a sand mountain.

3. TIMER KEEPER: Fill one of the plastic cups with the wet dirt. Use the bottom of the other cup to push the dirt down and pack it into the cup (This will help make your mountain stand up.)

4. Turn the cup with the sand upside down on the plate and lift if away so you have a dirt mountain.

Test your mountains:

1. RECORDER: Use the spray bottle to spray the mountains and test which one will erode less. Hold the bottle about 1 foot about the mountains.

2. Spray only 8 times! Then wait and watch for 1 minute.

3. MATERIAL MANAGER: After 1 minute, spray 8 more times. Then wait and watch for another minute.

4. TECHNICIAN: Continue to spray 8 times and wait in between until you notice the rain start to run down your mountains. ***Waiting between each time will give the rain more time soak into the mountains and you will have time to observe what is happening to each mountain.

Directions: Answer the questions while completing the erosion testing.

1. Predict. Which mountain do you think will survive better against erosion during the rain? Explain why you think so.

2. Observe. As you make rain, write down what you observe happening to your mountains.

3. Explain. Which mountain survived the rain better? Why do you think this material does better against erosion?

4. Reflect. What did you learn about erosion?

5. Plan. What could you build around the mountain to stop it from eroding?

Out:

Objective Reflection

1: I need help.

2: I understand but I need more practice.

3: I understand and can explain this objective.

4: I can teach this objective.

1. Using the “objective reflection” rate how you feel about this objective. (I will be able to determine the effects of water erosion by participating in a lab.)

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