Investigation Sequence

Title

Erosion

Written by:

Angie Rief and Todd Ariens                 Date

 

Focus Questions

 

Concepts

Content: Earth, Physical, & Life

Earth: Landforms are a result of a combination of constructive and destructive forces. Constructive forces include crust deformation, volcanic eruption and deposition of sediments. Destructive forces include weathering and erosion. The surface of the earth changes slowly and rapidly. Surface changes slowly through erosion and weathering and rapidly through landslides, volcanic eruptions and earthquakes.

Physical: Objects in motion continue in a straight line unless acted upon or a change in force will change the speed or direction

Cross cutting concepts

Evolution/ Equilibrium: Present condition such as the salt in the oceans, continental drift, erosion of landforms, and changes in organism can be explained as gradual and sporadic. They are a series of changes that account for the present.

Evidence is collected through observation

Change in properties can happen over time or abruptly.

Careful observation can help us notice changes we sometimes overlook

Observations are used to collect evidence to explain why certain events happen.

Science Practice

Cite evidence to support conclusion
Good explanations and based on evidence from scientific investigations
Listen to and respect the explanations proposed be others
Scientist use different kind of investigations depending on the question they are trying to answer

Personal, Social, Technology, Nature of Science, History

Personal/Social: Changes in the environment can be natural or influenced by humans.

Background information

The following activities will demonstrate to students various types of erosion. The purpose of these activities id to increase student’s awareness to the point where they can make intelligent decisions on responsible land use. Erosion represents a significant force in the creation of landscapes. Learning about erosion will help children not only identify one factor that sculpts the earth’s surface, but also enable them to strategize means to preserve our natural treasure.

Activity Sequence

1. Model of a Land Form
2. Water Erosion
3. Water Weight Erosion
4. Wind Erosion
5. Glacier Erosion
6. Temperature Erosion
7. Chemical Erosion
8. Landslides
9. Formation of a Canyon
10. Mountain Building - Assessmen
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Activity Descriptions

Activity 1. Model of a Land Form
Materials: Plastic cup, damp sand, foil pan, pebbles, dropper and water.
Procedure
1. Ask the students what happens when it rains on a mountain.
2. Tell the students they are going to make a model of a mountain out of the damp sand on one side of the pan. Then they should cover the mountain with pebbles. Pat them gently so that they will stay in place. Place a book under the end of the pan that has the mountain.
3. Then they should make and record predictions of what would happen if they dropped a single drop of water, five drops of water, and slowly poured water on the mountain.
4. Have the students experiment and then return for a class discussion.
5. Ask the following questions.
6. How did one drop of water affect the sand and pebbles?
7. How did five drops of water affect the sand and pebbles?
8. How did the poured water affect the sand and pebbles?
9. Ask them to explain how much of a difference there was and how the different amounts changed the results.
10. How can moving water affect landforms?
11. How do different amounts cause different changes?
12. Why is this information important?
13. When and for whom is this information important?
14. Based on your observations how does water cause erosion?
15. How long would it take a grain of sand to move down a mountain?
16. How do scientists explain changes like this?

Activity 2. Water Erosion
Materials: Non-oily Clay (non modeling clay), tray or pan, outdoor water hose, pebbles, coins, plastic chips, pencil, paper, science journal
Procedure
1. Before class form a mound of non-oily clay into a level mass about 5 – 10 centimeters across and place it into a tray or large pan.
2. Press pebbles, coins and plastic chips into the top surface of the clay.
3. Take the entire class outside and spray water lightly over the clay from the top.
4. Students should note how the spray washes away the clay and how the pebbles, coins, and chips interact with the clay, water, and each other.

Questions:
What caused the clay to run off?
What evidence do you have to support your answer?
What happened to the pebbles, coins, and chips?
What other materials might have protected the clay?
What other examples of water erosion can you think of?
How do different amounts cause different changes?
Why is this information important?
When and for whom is this information important?
Based on your observations how does water cause erosion? Were your observations easy to make? What did you learn about making observations? How would you observe differently the next time?
How does the time it takes to erode a grain of sand from the clay compare to the sand in activity one?
How do scientists explain changes like this?


Activity 3. Water Weight Erosion
Materials: cup, water, spot of bare dry earth
Procedure
1. Find a spot of bare dry earth
2. Pour a cupful of water on it.
3. Record your observations
4. Repeat steps 1 and 2 on the same spot, but this time hold the cup as high as possible from the ground.
5. Record your observation.

Questions
How does the weight of water affect the earth?
How did the earth change when you poured the first cupful of water?
Was the water soaked up?
Where did the water go?
How did it change when you poured the second cupful from the greater height?
Can you relate this to change caused by the weight of water in various places around the earth?
Would grass, rocks or other objects on the ground make a difference when pouring the water?
What would eventually happen if you kept pouring water in one spot?


Activity 4. Wind Erosion
Materials: Cardboard box with top and one side removed, sand, pencil, paper, water, plastic chips, pebbles, coins, science journals, goggles, straw or tube optional.
Procedure
1. Give every group of students a box and have them form a pile of sand in the center.
2. Have the student’s blow lightly over the sand from the open side of the box, may want to have student blow through a straw or tube. Have students wear goggles to protect eyes from sand.
3. Have student record their results
4. Have students reform the pile of sand and give of choice of materials (water, pebbles, coins, or chips) to try and prevent the sand from moving.
5. Have students again blow the sand from the side of the box and record their observation

Questions:
What happened to the sand as you blew?
Could you make the whole pile move if you blew long enough?
What material did you choose to add to your pile and why did you choose this material?
What effect did the material you chose have on the pile of sand the second time you blew?
Can you think of any examples of wind erosion in nature?

Activity 5 Glacier Activity
Materials: Ice cubes, sand, modeling clay, paper towel, pencil, paper, science journal
Procedure
1. Have students press an ice cube against the flat surface of modeling clay and move it back and forth several time and record observations.
2. Have student them place a small pile of sand on the clay. The ice cube should be placed on top of the sand and left for one minute.
3. Have student then pick up the ice cube and observe the surface of the cube that was touching the sand and again record their observation.
4. The same side of the ice cube should then be placed on the sandy part of the clay and moved back and forth several times.
5. The ice cube should be removed, the sand should be wiped away from the surface of the clay and the clay surface texture should be recorded.

Questions
What happened to the clay the first time you wiped the cube against it?
What happened to the ice cube after it sat on the sand?
What did the surface of the clay look like after you rubbed the cube against it the second time?
Does glacial erosion still occur today or is it just an ice age phenomenon?

Activity 6. Temperature Erosion
Materials: Hot plate, matches, stand, pyrex beakers, marbles, cups of ice, cups of water, non-metal tongs, goggles, science journal
Procedure
1. Safety rules will be thoroughly reviewed before this lesson. Teacher will turn on the hot plate, have student wear goggles, warnings against touching the hot plate or standing to close will be given by the teacher.
2. Students should set up a stand holding a pyrex beaker. Their marble should be placed in the beaker and they should have a cup of water and ice nearby.
3. Students will monitor the hot plate and marble for five minutes.
4. After 5 minutes one of the students will use tongs to place the marble in a glass of water and then into the jar full of ice. Another student will be responsible for simultaneously turning of the hot plate.


Questions
What happened to the marble while on the hot plate?
What happened to the marble when it was placed in the cup of ice?
What do you think caused the marble to crack?
How does this relate to erosion?
What objects in the environment may react like the marble when heated or cooled?
Can you give examples of temperature erosion?


Activity 7. Chemical Erosion
Materials: Plastic tray, eye dropper, chalk, vinegar, goggles, science journals, pencil, paper
1. Make prediction about what will happen to the chalk when vinegar is dropped on it.
2. Conduct the experiment. Place the chalk into the plastic container.
3. Slowly add drops of vinegar using the eyedropper.
4. Record your observations.
5. Make a hypothesis why such a reaction occurred.

Questions
What happened when you dropped vinegar on the chalk?
What happened after first drop of vinegar?
How or Does the reaction change if you continue to drop vinegar on the chalk?
Why do you think this happened?
How can chemicals affect landforms?
What are some examples of chemical erosion?
How can we lessen the affects of chemical erosion?


Activity 8. Landslides
Materials: sand, water, and bucket
Procedure
1. Build a firmly shaped sand castle.
2. Slowly pour water onto the sand castle. Be sure to do it slowly to allow the sand to soak up all the water.
3. Continue to pour water until the sand cannot absorb any more. Record your observations.

Questions
Why do hills and mountains that seen very solid in dry weather develop major landslides after prolonged rain?
How can you compare what happened to the sand castle to rainfall and the mountains?
What was the first thing to happen to the sand castle?
How much water did the sand absorb before it fell?
What if there would have been rocks or chips in the sand castle, would it have made a difference?
What finally happened?
What are forms of landslides?
What causes landslides?
How are landslides related to erosion?

Activity 9. Formation of a Canyon
Material: salt block, fish tank water pump, and tub large enough to hold salt block and water
Procedure
1. Place salt block into tub. Have one end of the block propped up.
2. Put enough water into tub to allow fish tank pump to run.
3. Position pump so that water runs from elevated end of salt block to lower end.
4. Students will make predictions about what they think will happen.
5. Let the water run over salt block for five days.
6. Each day students will write down changes that have occurred.
7. At the end of five days, the students will discuss what has happened and check their predictions.


Questions
What affect did the water have on the salt block?
How many days did it take to make noticeable changes?
What were these changes?
What type of erosion caused that to happen?
What happened to the salt that was eroded away?
How can running water affect landforms?
What are some examples of this event in nature?
How does this type of erosion affect our water supply?

Activity 10. Mountain Building - Assessment
Materials: Dishpans, potting soil, rocks, plastic chips, ice cubes, sand, water, watering can, and science journal
Procedure
1. Have groups of students build a mountain, which they believe will best hold up to a watering can full of water being poured over the structure. One group will be assigned sand, one with rocks and sand, one group will use soil and other groups can use a combination. All groups will have to access a certain number of plastic chips, pebbles and ice cubes.
2. The group will devise and plan writing down all suggestions. Have student write down their final decision and why they think it is the best structure to withstand the water.
3. Have students observe all the groups completed structure and make predictions.
4. Teacher will empty one water can of water onto each mountain.
5. Have student record results and explain why they think the outcome occurred and any improvements that may be beneficial it their mountains.


Questions
What materials did you select to make your mountain?
Why did you select these materials?
Why did the material you selected work or didn’t work?
Did you mountain hold up to the water?
What type or erosion occurred to your mountain?
Was the erosion gradual or sporadic?
What would you change or do differently if you were to do this project again?
How does the amount of water effect the type of erosion?
Why is this information important to scientist?
How does this activity relate to erosion in nature?

Dr. Robert Sweetland's notes