Weathering and Erosion Unit
By Sarah M. Davis
Science Subject Area/Grade:
Earth Science/ 4th Grade
Rationale:
Although many children have an appreciation for the outdoors, few understand the forces of nature that shape Earth’s surface. Erosion and weathering impact Earth’s many varied landscapes. This unit will help the students better understand how landforms are eroded and weathered to sculpt the surface of the earth in ever evolving ways.
Affective Unit Objective:
Students will appreciate the evolving nature of Earth’s landscape and the different forces that shape Earth’s surface.
Day 1
Lesson: Mechanical Weathering
Objectives
o The student will be able to predict how physical agitation will affect rocks. (Cognitive)
o The student will be able to define mechanical weathering. (Cognitive)
Sunshine State Standard
SC.4.E.6.4 Describe the basic differences between physical weathering (breaking down of rock by wind, water, ice, temperature change, and plants) and erosion (movement of rock by gravity, wind, water, and ice).
Materials
o Jars
o Sugar cubes
o Gravel
o Coffee cans
o Paper
o Rocks
Process skills employed this lesson:
o Observing
o Predicting
Key Concepts
o Rocks can be broken apart by physical forces.
o When rocks are broken apart by mechanical or physical weathering, there is no change to the mineral composition of the rock.
o Many forces can cause mechanical weathering.
Key Vocabulary
o Weathering: the break down of rocks and minerals on Earth.
o Mechanical Weathering: the change in rocks caused by a physical process, with no change to the mineral composition.
Procedure
Exploration (5 minutes)
1. The teacher will split the class up in to pairs and give each pair a jar containing sugar cubes and gravel.
2. The teacher will tell the students to shake their jar and record their observations.
Explanation (15 minutes)
1. In a whole-class discussion, students will report what they found. The teacher will list student observations on the board.
2. The teacher will prompt the discussion by asking:
o How did the sugar cubes change? (How & Why Productive Question)
o Did you notice the color of the sugar cubes changing? (Attention-focusing Productive Question)
o Did you notice the shape of the sugar cube changing? (Attention-focusing Productive Question)
o What do you think made the sugar cubes change? (How & Why Productive Question)
3. The teacher will assist students in defining the key concepts and key terms.
The teacher will give some examples of mechanical weathering (wind, smashing a rock until it breaks apart, etc.)
Application (15 minutes)
1. The teacher will split the class up into groups of 3-4 to complete an activity.
2. The teacher will explain the activity and have students predict what they believe will happen for each.
3. After students complete the activity, students will record what they observed. They will write whether or not their prediction was correct.
Activity: Each group will have a coffee can (with a lid), white paper, and some rocks. Students will take turns shaking the rocks in the can for a total of 500 shakes. Pour out the rocks on the paper and record what happened.
Assessments
o Before the application activity, the students will write a response to this prompt: How will physical agitation, or shaking, affect the rocks in the can?
o The students will complete a “ticket-out” in which they define mechanical weathering (See attached).
Citations
o Website: Illinois State Museum, Geology Online. (2003). Weathering and Erosion.
o Website: Capella, The University Online. Weathering and Erosion
Day 2
Lesson: Chemical Weathering
Objectives
o The students will be able to explain how carbonated water affects a rock (limestone) differently than tap water after observing the two different interactions. (Psychomotor)
o The student will be able to identify examples of mechanical and chemical weathering. (Cognitive)
Sunshine State Standard
SC.4.E.6.4 Describe the basic differences between physical weathering (breaking down of rock by wind, water, ice, temperature change, and plants) and erosion (movement of rock by gravity, wind, water, and ice).
Materials
o Pennies
o Jars
o Vinegar
o Limestone rocks
o Carbonated water
o Tap water
Process skills employed this lesson:
o Observing
o Formulating and testing hypotheses
Key Concepts
o Chemical reactions cause changes in rocks, most often breaking these rocks into smaller and smaller pieces.
o Chemical weathering is most common in places with lots of water, because water is a key factor in many chemical reactions.
Key Vocabulary
o Chemical Weathering: the change in rocks is caused by a chemical process.
o Oxidation: when oxygen combines with other elements to cause a change in a rock, which usually softens the rock.
o Hydrolysis: when water combines with other elements to cause a change in a rock, which usually softens the rock.
o Solution Weathering: a type of chemical weathering in which acidic solutions break down a rock; an example of solution weathering is called carbonation.
o Carbonation: when carbon dioxide reacts chemically with a rock, breaking it down; an example of the carbonation process is how acid rain affects limestone.
Procedure
Exploration (10 minutes)
1. The teacher will split the class up into pairs and pass out the first three materials to the pairs.
2. Students will place pennies (copper) in a jar of vinegar (acid rain).
3. Students will record what happens initially and then after five minutes. (chemical weathering)
Explanation (15 minutes)
1. In a whole-class discussion, students will report what they found. The teacher will list student observations on the board.
2. The teacher will prompt the discussion by asking:
o How did the pennies change? (How and Why Productive Question)
o Did you notice the shape of the pennies changing? (Attention-focusing Productive Question)
o Did you notice the color of the pennies changing? (Attention-focusing Productive Question)
o Why do you think the pennies changed like they did? (How and Why Productive Question)
3. The teacher will assist students in defining the key concepts and key terms.
4. In the explaining chemical weathering, the teacher will show pictures of the Marianna Caverns, showing how the acid in the underground water has caused changes in the limestone. The teacher will also explain how the Grand Canyon was carved by chemical weathering caused by the Colorado River for millions of years; this explanation will be supplemented by a Google Earth tour of the Grand Canyon.
NOTE: Visually impaired students will be moved to the front of the class to watch the tour of the Grand Canyon.
Application (20 minutes)
Activity: Students will have rock samples, a jar of carbonated water and a jar of tap water. Students will place rocks in each jar. The students will complete the lab worksheet while completing the lab, which includes productive questions (Action, Comparison, and How & Why) and employs process skills (Observing, Formulating & Testing Hypotheses, and Identifying Variables). Students will record initial observations and observations after 20 minutes. (While the students are waiting the 20 minutes for the second observation, they will read the page in the textbook on chemical weathering.) Students will keep the jars in an area designated by the teacher with group labels, and record observations the next day as well.
Assessment
o Chemical weathering lab worksheet (see attached).
o The teacher will tear up a piece of paper towel and ask students to write down if they think it is an example of mechanical or chemical weathering. Next, the teacher will dip the paper towel in water and ask the students to write down if they think it is mechanical or chemical weathering. Briefly discuss answers if students did not answer correctly.
Citations
o Textbook: Cooney, T. (2005) Scott Foresman Science: Seeing Science in a Whole New Light. Glenview, IL: Pearson Scott Foresman.
ISBN-13: 978-0328100040
o Website: Visit Florida Website. Marianna Caverns State Park http://floridians.visitflorida.com/getaways/g/park_yourself_in_marianna.php
o Software: Google Earth. Tour of Grand Canyon.
Free download of Google Earth available at http://earth.google.com.
Day 3
Lesson: Water Erosion
Objectives
o The student will be able to describe how different-sized particles are affected differently by water erosion after observing the phenomena. (Psychomotor)
o The student will be able to define water erosion. (Cognitive)
Sunshine State Standard
SC.4.E.6.4 Describe the basic differences between physical weathering (breaking down of rock by wind, water, ice, temperature change, and plants) and erosion (movement of rock by gravity, wind, water, and ice).
Materials
o Ice cubes
o Cups
o Dishpans
o Dirt
o Heat lamp
o Mixture of sand, dirt, gravel and rocks
o Water
o Lab reports
o Pencils
Process skills employed in this lesson:
o Observation
o Formulating and Testing Hypotheses
o Identifying Variables
Key Concepts
o After rocks have been broken in to smaller rocks through the weathering process, these smaller rocks and matter are carried away to a different location. This process is called erosion.
o Water is the most influential force in erosion. Water has the ability to move materials all over the surface of the Earth because so much of the Earth is covered by water.
o The cumulative effect of all of the water on Earth moving materials to different locations results in many different landforms.
Key Vocabulary
o Deposition: the process where by sediment is laid down on the Earth’s surface.
o Erosion: the movement of soil and rock due to forces produced by water, wind, glaciers, gravity, and other influences.
o Landform: any natural formation of rock and dirt, found on Earth.
o Sediment: matter deposited by some natural process.
o Water Erosion: the movement of broken down of materials caused by the water.
Procedure
Exploration (7 minutes)
1. The teacher will arrange the students in groups of 3-4, and give each group a dishpan with a mound of warm dirt and a cup of ice. (Prior to the beginning of the lesson, the dirt should be kept in a bucket with a heat lamp over it.)
2. The teacher will instruct the students to carefully place the ice cubes on the mound of dirt.
3. The students observe the mounds as the ice melts.
Explanation (25 minutes)
1. In a whole-class discussion, students will report what they found. The teacher will list student observations on the board.
2. The teacher will prompt the discussion by asking:
o What did you notice happened when the ice melted into water? (Attention-focusing Productive Question)
o How did the mound of dirt change? (How & Why Productive Question)
o Why do you think the dirt moved from the mound to flatten out? (How & Why Productive Question)
3. The teacher will assist students in defining the key concepts and key terms.
4. In explaining water erosion, the teacher will show pictures of Cape San Blas, FL and have a representative of the Save the Cape foundation come briefly discuss the efforts to control water erosion at Cape San Blas, FL.
Application (15 minutes)
Activity: The teacher will have the students get back into their groups of 3-4 and ask 1 student from each group to come empty the tray of wet dirt outside (or in a yard bag if the classroom does not have quick access to the outside). The students will have a pile of the sand, dirt, gravel and rock mixture, placed by the teacher on one end of the dishpan. The students will also be given a cup of and observe/report the ways in which the different particles are affected by water erosion. The students will complete the lab worksheet while completing the lab, which includes productive questions (Action, Comparison, and How & Why) and employs process skills (Observing, Formulating & Testing Hypotheses, and Identifying Variables).
Assessment
o Both objectives assessed on Water Erosion Lab Worksheet (see attached).
Citations
o Website, Science Clarified. http://www.scienceclarified.com/everyday/Real-Life-Earth-Science-Vol-2/Erosion-Key-terms.html
o Website, Geology Online, Illinois State Museum Society. http://geologyonline.museum.state.il.us/tools/lessons/6.3/lesson.html.
o Guest Speaker. For images and information on the beach restoration efforts in Port St Joe, go to the website: http://www.savethecape.com/.
ESOL Adaptations
Instructional adaptations could be made to accommodate English language learners in this lesson in the following ways.
o Early Production* Stage of Second Language Acquisition: During the explanation phase of the lesson, the teacher would give the ELL flash cards with images and the term for each of the key vocabulary words (images available at http://www.kidsgeo.com/geology-for-kids). The teacher would use clear, simple language to explain key concepts. The teacher would avoid using idioms. The teacher would have a communication system with the child in which he or she could express confusion discreetly. This could be a peace sign hand gesture. The ELL would complete the lab activity and the assessments (verbally if needed) with the support of an ESOL teacher, paraprofessional or the classroom teacher. Assessments would gauge meeting of objectives, not language skills. Any confusion over a response in an assessment would be discussed directly with the child.
o Speech Emergence* Stage of Second Language Acquisition: In the explanation phase of the lesson, the teacher would post on the board images to accompany verbal and written definitions of key terms (images available at http://www.kidsgeo.com/geology-for-kids). The teacher would use clear, simple language to explain key concepts. The teacher would avoid using idioms. The teacher would have a communication system with the child in which he or she could express confusion discreetly. This could be a peace sign hand gesture. The ELL would be grouped with students he or she is comfortable working with. The ELL would complete the assessments with the support of his or her group members.
*Stages of Speech Acquisition from the book Classroom Instruction That Works with English Language Learners by Jane D. Hill and Kathleen M. Flynn (2006).
Day 4
Lesson: Wind Erosion
Objectives
o The student will be able to define wind erosion. (Cognitive)
o The student will be able to describe how wind erosion affects particles differently, dependent on the size of the particle. (Cognitive)
Sunshine State Standard
SC.4.E.6.4 Describe the basic differences between physical weathering (breaking down of rock by wind, water, ice, temperature change, and plants) and erosion (movement of rock by gravity, wind, water, and ice).
Materials
o 3-sided shoe boxes
o Sand
o Water
o Plastic chips
o Pebbles
o Coins
Process skills employed in this lesson:
o Observation
o Formulating and testing hypotheses
o Identifying and controlling variables
Key Concepts
o Although water erosion is the most powerful force on Earth, wind also causes the movement of sand, rocks, topsoil, etc.
o Wind erosion is a powerful agent shaping arid landscapes.
Key Vocabulary
o Wind Erosion: the movement of broken down of materials caused by the wind.
Procedures
Exploration (5 minutes)
1. The teacher will split the class up into groups of 3-4; every group will be given a box with its top and one side removed. A pile of sand will then be formed in the center of the box bottom.
2. (SAFETY PRECAUTION) The teacher will go over the lab safety rules and warn of the consequences for endangering themselves or their classmates. The teacher will then instruct the class to blow lightly over the sand from the open side of the box.
3. Students will record their results.
Explanation (25 minutes)
1. The teacher will read the trade book Cracking Up: A Story About Erosion by J. Bailey (2006).
2. After reading the book, the teacher will discuss the findings the students had in their exploration, asking, “Did you notice how the sand traveled from end of the box to the other?” (Attention-focusing Productive Question) and assist the students in defining the key concepts and key terms.
3. The teacher will then show pictures from the National Geographic website of the most dramatic landscapes that have been affected by wind erosion:
4. *The teacher will then play a short video on wind erosion and the Dust Bowl. (Three minutes in length, found at http://www.youtube.com/watch?v=x2CiDaUYr90)
NOTE:
-Hearing impaired students will sit near the teacher while he or she reads the trade book and have access to the book after the teacher has read it.
-Visually impaired students will be moved to the front of the class to see the images of wind erosion and the video on the Dust Bowl.
Application (10 minutes)
1. Students will then reform their sand piles.
2. Next the teacher will ask, “Can you think of a way you could prevent wind (your blowing) from moving the sand?” (Problem Solving Productive Question)
3. The students will be given a choice of materials (water, plastic chips, pebbles, coins) to choose from to try and prevent the sand from moving.
2. Students will again be instructed to blow and record their observations.
3. As a class, we will compare the piles each group constructed. The teacher will ask, “Which sand pile was the most resilient to wind erosion?” (Comparison Productive Question)
Assessment
o The students will complete a “ticket-out” on wind erosion after completing the application (see attached). Both objectives are assessed on the worksheet.
Citations
o Trade book. Bailey, J. (2006) Cracking Up: A Story About Erosion. Minneapolis: Picture Window Books.
ISBN-13: 978-1-4048-1996-7
*Integration Across Content Areas: Social Studies: during explanation, the video on wind erosion shows how the Dust Bowl was caused.
Day 5
Lesson: Mountain Building
Objectives
o The student will be able to describe the differences between mechanical weathering and erosion. (Cognitive)
o The student will be able to construct a model of a landform. (Psychomotor)
o The student will be able to explain why a landform is susceptible to mechanical weathering and water erosion. (Cognitive)
Sunshine State Standard
SC.4.E.6.4 Describe the basic differences between physical weathering (breaking down of rock by wind, water, ice, temperature change, and plants) and erosion (movement of rock by gravity, wind, water, and ice).
Materials
o Large plastic box lids
o Sand
o Rocks
o Soil
o Watering Can
Process skills employed in this lesson:
o Observing
o Identifying and Controlling Variables
o Formulating and Testing Hypotheses
Key Concepts
o Weathering breaks material down, whereas erosion moves materials to a different location.
o Landforms can be more or less susceptible to weathering and erosion, depending on the composition of the landform and the intensity of environmental factors the landform is exposed to.
Key Vocabulary (Review of week’s vocabulary)
o Weathering: the break down of rocks and minerals on Earth.
o Mechanical Weathering: the change in rocks caused by a physical process, with no change to the mineral composition.
o Chemical Weathering: the change in rocks is caused by a chemical process.
o Oxidation: when oxygen combines with other elements to cause a change in a rock, which usually softens the rock.
o Hydrolysis: when water combines with other elements to cause a change in a rock, which usually softens the rock.
o Solution Weathering: a type of chemical weathering in which acidic solutions break down a rock; an example of solution weathering is called carbonation.
o Carbonation: when carbon dioxide reacts chemically with a rock, breaking it down; an example of the carbonation process is how acid rain affects limestone.
o Deposition: the process where by sediment is laid down on the Earth’s surface.
o Erosion: the movement of soil and rock due to forces produced by water, wind, glaciers, gravity, and other influences.
o Landform: any natural formation of rock and dirt, found on Earth.
o Sediment: matter deposited by some natural process.
o Water Erosion: the movement of broken down of materials caused by the water.
o Wind Erosion: the movement of broken down of materials caused by the wind.
Procedures
Exploration (5 minutes)
1. The teacher will have all of the students gather around his or her desk. The teacher will have a small model of a mountain made out of sand and pebbles in the center of a large box lid. The teacher will have the students jot down observations while he or she does the following events: (1) shakes the box lid gently from side to side and (2) pours water over the pile with a watering can.
2. The students will go back to their seats and share their observations with their table groups (5 groups in all).
Explanation (20 minutes)
1. The teacher will read excerpts from the trade book The Disappearing Mountain and Other Earth Mysteries by Spilsbury, L., Spilsbury, R., & Lingard, D. (2006).
2. After reading, the teacher will start a discussion in which the students will report what they observed during the explanation. The teacher will list student observations on the board.
3. The teacher will prompt the discussion by asking:
o What did you notice happened when the mountain was shaken? How about when the water was poured on the mountain? (Attention-focusing Productive Questions)
o Why did those outcomes occur? (How & Why Productive Question)
o How might a landform be more resistant to physical or mechanical weathering and water erosion? (How & Why Productive Question)
4. The teacher will assist students in defining the key concepts and reviewing the key terms.
Application (20 minutes)
1. The five table groups will be asked to build a model of a mountain which they believe will best hold up to water being poured over their structure. One group will be assigned to build their mountain out of sand, one group will use rocks and a small amount of sand, one group will use soil, and two groups will be able to use any combination. All groups will have access to a certain number of plastic chips, pebbles, ice cubes.
3. The groups must write down a “building plan”, writing down all suggestions made by group members. After deciding on a plan, the groups must also write why they think their plan is the best to withstand the shaking and water.
3. Students will observe all groups' completed structures and make predictions which the teacher will record on the board.
4. The students should then build their mountains, after which I will shake the box lids gently and empty a watering can of water onto them.
5. Students must record the results and explain why they think such an outcome occurred. Then students must suggest improvements to their structure and explain why they think such improvements will be beneficial.
Assessment
o As a “ticket-out”, the students will (1) have to describe the differences between mechanical weathering and erosion and (2) explain why a landform is susceptible to mechanical weathering and water erosion
o The teacher will check each group’s model for completion.
Citations
o Trade book. Spilsbury, L., Spilsbury, R., & Lingard, D. (2006). The Disappearing Mountain and Other Earth Mysteries. Chicago: Raintree
Resources
Websites
Textbook
o Cooney, T. (2005) Scott Foresman Science: Seeing Science in a Whole New Light. Glenview, IL: Pearson Scott Foresman.
ISBN-13: 978-0328100040
Children’s Trade Books
o Bailey, J. (2006) Cracking Up: A Story About Erosion. Minneapolis: Picture Window Books.
o Spilsbury, L., Spilsbury, R., & Lingard, D. (2006). The Disappearing Mountain and Other Earth Mysteries. Chicago: Raintree.
ESOL Accommodation Information
o Hill, J. D. & Flynn, K. M. (2006) Classroom Instruction That Works with English Language Learners. Alexandria, VA: Association for Supervision & Curriculum Development.
Software
o Google Earth
Guest Speaker
o A representative from the Save the Cape Foundation. For information, go to the website: http://www.savethecape.com/.
Field Trip Site
o Marianna Caverns State Park. For information, go to website:
Audio-Visuals
o Images of Marianna Caverns found at www.floridians.visitflorida.com.
o Images of different affects of erosion and weathering found at www.science.nationalgeographic.com.
o Wind erosion video found at http://www.youtube.com/watch?v=OH6xatDSu00.
TICKET OUT: Mechanical Weathering (Day 1)
1. Define mechanical weathering:
TICKET OUT: Wind Erosion (Day 4)
1. Define wind erosion.
2. Describe how wind erosion affects particles differently, dependent on the size of the particle.
TICKET OUT (Day 5)
1. What is the major difference between erosion and mechanical weathering?
2. What factors make a landform susceptible to water erosion and mechanical weathering?
CHEMICAL WEATHERING LAB WORKSHEET (Day 2)
1. Collect from the teacher 2 rocks, a jar of carbonated water and a jar of tap water.
o What do you think would happen to a rock if you put it in the carbonated water?
o What do you think would happen to a rock if you put it in the tap water?
2. Place one rock in the carbonated water, and place the other in the tap water.
o In this experiment, what is the one factor that is different in the two jars that may affect the outcome?
o State your hypothesis for how the rocks will be affected in the two jars (Will the rocks affected the same way, differently or at all? Why or Why not):
3. Record your initial observations:
4. After 20 minutes, compare the two jars.
o Has the rock in the carbonated water been affected differently than the rock in the tap water? If so, how?
o Why do you think those outcomes occurred?
BONUS:
What do you think would happen if a stream ran over one of these rocks for many, many years?
WATER EROSION LAB WORKSHEET (Day 3)
1. Define water erosion:
2. Receive lab materials from the teacher.
o What do you think will happen if you were to pour the water carefully over the side of the pan with the pile of sand, dirt, gravel and rocks?
o In the experiment described above, what is a factor that may affect how the different materials would be affected by the water?
o State your hypothesis for how the different sizes of the materials would be affected differently by the stream of water.
2. Carefully and slowly pour the water over the pile of materials in the pan.
o Record your observations:
3. Was you hypothesis correct? Why or why not?
BONUS:
What are some real world challenges presented by water erosion?