Weathering and Erosion

Transcription

1 Weathering and Erosion Grade 4 Unit: 04 Lesson: 02 Suggested Duration: 10 days Lesson Synopsis: This lesson will contribute to the student s ability to observe and identify the slow changes to Earth s surface caused by weathering, erosion, and deposition from wind, water, and ice. TEKS: 4.7 Earth and space. The students know that Earth consists of useful resources and its surface is constantly changing. The student is expected to: 4.7B Observe and identify slow changes to the Earth s surface caused by weathering, erosion, and deposition from water, wind, and ice. Scientific Process TEKS: 4.1 Scientific investigation and reasoning. The student conducts classroom and outdoor investigations, following home and school safety procedures and environmentally appropriate and ethical practices. The student is expected to: 4.1A Demonstrate safe practices and the use of safety equipment as described in the Texas Safety Standards during classroom and outdoor investigations. 4.3 Scientific Investigation and Reasoning. The student uses critical thinking and scientific problem solving to make informed decisions. The student is expected to: 4.3C Represent the natural world using models such as rivers, stream tables, or fossils and identify their limitations, including accuracy and size. 4.4 Scientific investigation and reasoning. The student knows how to use a variety of tools, materials, equipment, and models to conduct science inquiry. The student is expected to: 4.4A Collect, record, and analyze information using tools, including calculators, microscopes, cameras, computers, hand lenses, metric rulers, Celsius thermometers, mirrors, spring scales, pan balances, triple beam balances, graduated cylinders, beakers, hot plates, meter sticks, compasses, magnets, collecting nets, and notebooks; timing devices, including clocks and stopwatches; and materials to support observation of habitats of organisms such as terrariums and aquariums. 4.4B Use safety equipment as appropriate, including safety goggles and gloves. GETTING READY FOR INSTRUCTION Performance Indicator(s): Draw a three-part illustration that clearly demonstrates the difference between weathering, erosion, and deposition. Write a description for each. (4.2F; 4.7B) 1C; 5G Key Understandings and Guiding Questions: Weathering is the process of breaking rocks down into smaller pieces called sediment. What natural agents contribute to weathering? Erosion is the process which changes the Earth s surface by moving earth material. What natural agents contribute to erosion? Deposition is the process which changes the Earth s surface by depositing sediment in a new location. What kinds of factors contribute to deposition? Weathering, erosion, and deposition can be caused by water, ice, wind, and temperature. How does water cause weathering, erosion, and deposition? 1 of 11

2 How does ice cause weathering, erosion, and deposition? How does wind cause weathering, erosion, and deposition? Vocabulary of Instruction: weathering erosion deposition wind water glacier ice u-shaped valleys fjords canyons caves deltas sand dunes beaches rock arches pinnacles hoodoos Refer to section for materials. Handout: Changes to Earth s Surface (1 per student) Teacher Resource: PowerPoint: Slow Changes to Earth s Surface KEY Teacher Resource: PowerPoint Script KEY Optional Handout: Weathering, Erosion, and Deposition by Ice: U-Valley Formation by a Glacier Valley (1 per student) Handout: Slow Changes to the Earth s Surface from Water and Ice (1 per student) Handout: Identifying Landforms (1 per pair) Teacher Resource: Performance Indicator Instructions KEY Advance Preparation: 1. Prepare glaciers: Each group will need a glacier model. Pour ¼ cup water into each bathroom cup. Add about 6 8 pebbles and about 1 tablespoon each of sand, gravel, and soil. Stir and freeze. 2. Prepare the play-dough: For each group, you will need flour (1 cup), water (warm, 1 cup), salt (1/2 cup), and vegetable oil (1 tablespoon per. Mix all dry ingredients. Add oil and water. Cook over medium heat, stirring constantly until reaching the consistency of mashed potatoes. Let mixture cool. (Alternatively, purchased play-dough could be used.) 3. Prepare the Earth s surface for the canyon formation model. Pack the sand (damp, about 3 cups per, pebbles (about ¼ cup per, and gravel (about ½ cup per into the top shallow portion of the paint tray, coming down about five inches. Level the surface. 4. Prepare attachment(s) as necessary. Background Information: This lesson bundles SEs that address identifying changes to the Earth s surface. During this lesson, students will also be making observations about and identifying how slow changes to Earth s surface can be caused by weathering, erosion, and deposition from water, wind, and ice. Prior to this, students had been limited to investigating only rapid changes to the Earth. The content in this lesson is very critical to student success because it contains concepts that directly provide foundation for Readiness Standards in Grade 5. Although standard 4.7B is not a Supporting Standard, its content is crucial to making the connection to Readiness Standard 5.7B. It is important to note that students 2 of 11

3 have never previously investigated the slow changes to Earth s surface, so it is expected that this may be an underdeveloped concept. It will be critical to make connections to the instruction of the previous year so that students can fully understand that changes to Earth s surface can occur both slow and rapidly. GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to address the needs of learners. The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus Document for this unit. Instructors are encouraged to create original lessons using the Content Creator in the Tools Tab located at the top of the page. All originally authored lessons can be saved in the My CSCOPE Tab within the My Content area. INSTRUCTIONAL PROCEDURES ENGAGE Weathering and Erosion: An Introduction 1. Divide the class into groups of 3 4 students. Distribute a pair of safety goggles to each student. 2. Instruct students to create one chart in their science notebook to record their observations. It should have a space for the students to record a drawing and description of the rock surface after weathering, drawing and description of the grain particles, and description of the quantity of particles when the rocks were rubbed together gently and then rubbed together vigorously. 3. Distribute two sandstone-type rocks and a plain piece of paper to each group. In addition, each student should have a hand lens. 4. Say: Hold the two pieces of rock above the paper. Rub the two rocks together gently, and then rub the two rocks together vigorously. Observe what happens. 5. Allow a few minutes for the students to weather the rocks. They should look at the eroded surfaces of the two rock pieces as well as the particles that have collected on the paper. 6. Choose a student from each group to describe the surface of the weathered rocks. Choose a different student from each group to describe the particles. 7. Choose another student from each group to describe the difference in the quantity of particles produced (or if there was a difference) between gentle and vigorous rubbing. 8. Instruct groups to choose one member of their group to GENTLY blow on the particles. Students should observe what happens to the particles. 9. NOTE: 1 Day = 50 minutes Suggested Day 1 rocks (sandstone-type or bricks, 2 pieces per paper (plain, 1 sheet per hand lens (1 per student) safety goggles (1 pair per student) water (about 2 cups per class) container (large enough to hold the 2 cups of water and the rocks, 1 per class) resealable plastic bag (to hold rocks that have been soaked in water, 1 per class) Safety Notes: Remind students to wear safety goggles during this investigation. They should also be told NOT to blow the rock particles unless instructed to do so. Instructional Notes: Students were introduced to weathering in Grade 3. If students do not recall learning this concept, the Grade 3 Teacher Resource: Power Point: Weathering You Break Me Up would be an informative review. Show after students complete the investigation in the Engage. Misconceptions: Students may think all changes to 3 of 11

4 What happens to the particles when there is air movement? The particles are eroded (move) and deposited in a new location. the Earth occur rapidly. Students may think all changes to the Earth occur slowly. 10. Collect the sandstone, and place it in a container of water. Facilitate a discussion: In what ways will the sandstone change when soaking in the water? Students should recall that the rocks will change color and change mass (because they will absorb some of the water). Students may come up with other suggestions. After soaking for an hour or so, I will put the rocks in a plastic bag and place them in the freezer. You will then have a chance to observe the rocks for other physical changes. ENGAGE/EXPLORE Weathering, Erosion, and Deposition by Ice Suggested Days 2 and 3 1. Distribute the Handout: Changes to Earth s Surface to each student. Instruct students to add information to each section (ice, wind, water, wind and water) as they progress through the lesson. Students should be encouraged to use both words and pictures to describe the landforms and the processes that change the Earth s surface. 2. Project the Teacher Resource: PowerPoint: Slow Changes to Earth s Surface KEY. As you project each picture, you may use the Teacher Resource: PowerPoint Script KEY for information to assist students in completing their handout. Students should have their Handout: Changes to Earth s Surface out in order to write and draw information during the presentation of the information on the PowerPoint. 3. You may wish to distribute the Optional Handout: Weathering, Erosion and Deposition by Ice U-Valley Formation by a Glacier so students have a visual when discussing glacier formation during the PowerPoint presentation. 4. Distribute the Handout: Slow Changes to the Earth s Surface from Water and Ice to each student prior to showing slide 5: Glaciers: Fjords. Students could use this as a guide for creating their definition for glacier and visual for the section on ice that they will complete on the Handout: Changes to Earth s Surface. 5. After the conclusion of the PowerPoint, divide class into groups of 3 4 students. 6. Distribute a frozen rock to each of the groups. Instruct students to observe the rocks for physical changes. A hand lens will be useful for a more detailed observation. In what ways did the rock change after freezing? Answers may vary, but students should see hairline cracks in the sandstone play-dough (see Advance Preparation for recipe, 1 cup per flour (1 cup per water (warm, 1 cup per salt (1/2 cup per vegetable oil (1 tablespoon per glacier (see Advance Preparation) bathroom cup (1 per water (1/4 cup per pebbles (6 8 per gravel (1 tablespoon per sand (1 tablespoon per soil (1 tablespoon per frozen rock (from previous activity) Handout: Changes to Earth s Surface (1 per student) Teacher Resource: PowerPoint: Slow Changes to Earth s Surface KEY Teacher Resource: PowerPoint Script KEY Optional Handout: Weathering, 4 of 11

5 where the water expanded during freezing. What natural agent contributed to weathering? (Ice) 7. Inform students that you will be providing each group with some playdough and a glacier. Prior to receiving the materials, each group will design a model for demonstrating how a glacier causes slow changes to the Earth s surface from water and ice. 8. Provide students the opportunity to design a model with which they will demonstrate how ice causes slow changes to the Earth s surface through weathering, erosion, and deposition. 9. On the Handout: Slow Changes to the Earth s Surface from Water and Ice, each student is responsible for completing his/her own handout; however, groups should collaborate on the design, building, and demonstration of the glacier model. 10. Instruct students to answer the question: How does ice cause weathering, erosion, and deposition? On the handout. Erosion and Deposition by Ice U- Valley Formation by a Glacier Handout: Slow Changes to the Earth s Surface from Water and Ice (1 per student) Instructional Notes: When introducing the terms weathering, erosion, and deposition, encourage students to visualize an action to remember each word. For example, for erosion, they might think of a person rowing in water since erosion can be movement by water. [Please note that this particular visualization will not necessarily work with the Spanish language translation.] (Very basic definition) Glacier: a large section of moving ice that stays frozen all year. Misconception: Students may think weathering and erosion are the same. EXPLORE/EXPLAIN Weathering, Erosion, and Deposition by Water Suggested Days 4 and 5 1. Divide the class into groups. (The availability of materials may determine group size.) 2. Provide a paint tray filled with damp sand, gravel, and pebbles to each group. 3. Instruct students to divide a page in their science notebook into thirds. In the top third, they should draw the set-up shown above and label it as before weathering, erosion, and deposition by water. The middle third should be a drawing of their prediction of what will happen when a steady stream of water is applied to the surface of the Earth. canyon model (see Advance Preparation) paint tray (aluminum, 1 per sand (damp, about 3 cups per pebbles (about ¼ cup per gravel (about ½ cup per cup (bathroom-size, with 5 6 holes in the bottom, 1 per container (to hold water, such as a 16-ounce cup, 1 per water (16 ounces, per salt brick (1 per class) Optional stream table (paint tray may be 5 of 11

6 4. Distribute a cup with 5 6 holes in the bottom and container with at least 16 ounces of water in it. 5. Model (without actually pouring any water) how to hold the cup over the same location on the Earth's surface, and then pour the water into the cup to allow it to rain on the land. 6. Students should carefully observe and record what happens. Their observations will be drawn and labeled in the bottom third of the page and titled after weathering, erosion, and deposition by water. substituted, 1 per class) Optional Teacher Resource: PowerPoint: Slow Changes to Earth s Surface (from previous activity) Instructional Notes: Paint trays are an inexpensive substitute for stream tables. In addition, they already have a deep and shallow end built in. The sand, gravel, and pebble mixture can be dried, sifted, and saved for another activity. This reinforces student responsibility to conserve our natural resources for future generations. (4.7C) 7. Allow students the time to complete the investigation, draw and label their observations, and clean up their materials. 8. Say: Running water is an extremely powerful force. Running water is powerful enough to move large amounts of soil and sediment from one location to another. Water that continually runs over rock, causes it to weather and erode, creates canyons over time. 9. Facilitate a discussion about the process of canyon formation. Some guiding questions to use include: What natural agents contribute to weathering? What natural agents contribute to erosion? How does water cause weathering, erosion, and deposition? 10. Show slide 7 on the Teacher Resource: PowerPoint: Slow Changes to Earth s Surface. Inform students that these are two different canyons. The first picture is of Government Canyon, located northwest of San Antonio, Texas. The second picture was taken in 1872 of the Grand Canyon. In what ways are they similar? In what ways are they different? Which one is probably older, and how do you know? Check for Understanding: As students complete their Handout: Changes to Earth s Surface for changes caused by water, this can be used as a formative assessment of student understanding. Notebooks: Instruct students to divide a page in their science notebook into thirds. In the top third, they should draw the set-up and label it as before weathering, erosion, and deposition by water. The middle third should be a drawing of their prediction of what will happen when a steady stream of water is applied to the surface of the Earth. Their observations will be drawn and labeled in the bottom third of the page and titled after weathering, erosion, and deposition by water. 6 of 11

7 11. (Optional activity) Set up a stream table in a location where it will be visible to all students. Place a salt brick at one end of the stream table, elevating one end of the brick slightly. Set up a water bottle with a sipping top above one end of the brick, and allow the drip of water to hit the same area for several hours. (The bottle can be attached to a ring stand, if available, or taped to the leg of a chair.) Set-up After several hours of a slow drip of water 12. Use the Teacher Resource: PowerPoint: Slow Changes to Earth s Surface, slides 8 11, to show images of caves and deltas and to facilitate a discussion about the formation of these landforms. Remind students to review the drawing they created of the canyon formation. Did any students observe a delta where the sediments washed away? What natural agents contribute to erosion? What natural agents contribute to weathering? How does water cause weathering, erosion, and deposition? What kinds of factors contribute to deposition? 13. Instruct students to complete the section on their Handout: Changes to Earth s Surface for changes caused by water. EXPLORE/EXPLAIN Weathering, Erosion, and Deposition by Wind Suggested Day 6 1. Introduce students to weathering, erosion and deposition by wind by showing the Teacher Resource: PowerPoint: Slow Changes to Earth s Surface, slides Slide 12 shows a picture of sand dunes in Port Aransas. How do you think sand dunes are formed? Allow several students to share their thinking. 3. Show slide 13. This provides a brief explanation about sand dune paper (plain, 1 sheet per student) Teacher Resource: PowerPoint: Slow Changes to Earth s Surface (from previous activity) Handout: Changes to Earth s Surface (from previous activity) 7 of 11

8 formation. 4. Slide 14 shows images of Hoodoos and Pinnacles. These are landforms caused by the weathering and erosion of rock by wind. What could you predict about the type of rock that is shown in these formations? Students may not know the exact type of rock, but they should be able to predict that the rock is softer and is able to be worn down (like the rocks in the Engage activity). Why is the rock weathered and eroded in different places? The formation may be composed of different types, or hardness, of rocks. Softer rocks will wear away faster than harder ones. 5. Slide 15 shows weathering and erosion by wind: formation of an arch. Instruct students to Think-Pair-Share about how they believe this landform was created. 6. Allow students the opportunity to share their thinking. 7. Slide 16 provides one explanation for arch formation. 8. Display slide 17. This is Boquillas Canyon. Distribute a piece of paper to each student. Instruct students to think about how the cave was formed and to write the sequence of events that happened for this landform to be created. Students could create a storyboard to show the sequence of events. 9. Provide students the opportunity to share their claims and evidence. Instructional Notes: Formation of Boquillas Canyon caves: students should be able to apply their knowledge of weathering, erosion, and deposition to determine the processes that occurred in the formation of the caves. Wind and water weathered the canyon walls. Wind and water deposited the rock particles and the shore by the river. Strong winds blew the sand particles against the canyon wall, eventually digging out the cave. The eroded and deposited sand continues to blow and weather rocks, creating slow changes to the Earth s surface. Notebooks: Students should affix their description of how the cave in Boquillas Canyon was formed into the science notebook. 10. Instruct students to complete the section on their Handout: Changes to Earth s Surface for changes caused by wind. To assist students, you may wish to project slides one more time. EXPLORE/EXPLAIN Weathering, Erosion, and Deposition by Wind and Water Suggested Days 7 and 8 1. How many of you have been to the beach (shore or coast)? Answers will vary. How would you describe the beach to someone who has never seen it? Answers will vary, but should include a description of the shoreline, including the sand, water, and waves, animals, and plants. What processes do you think it took to create a beach? Students are not answering this question at this time, but should be encouraged to think about it. Students may want to write their thinking down in their science notebooks. 2. Divide the class into groups of 3 4 students. paint tray (aluminum, 1 per sand (damp, about three cups per pebbles (about ¼ cup per gravel (about ½ cup per container (to hold water, about 12 ounces, 1 per water (about 12 ounces per plate (paper, 1 per 8 of 11

9 3. Instruct students to label the next clean page in their science notebook as weathering, erosion, and deposition by water and wind. The page should have two sections: gentle wave action and more vigorous wave action. 4. Distribute the materials to investigate weathering, erosion and deposition by wind and water to each group. (paint tray, sand, pebbles and gravel, container of water, and paper plate folded in half) 5. Distribute safety goggles, and instruct students to wear them. safety goggles (1 pair per student) Teacher Resource: PowerPoint: Slow Changes to Earth s Surface (from previous activity) Handout: Changes to Earth s Surface (from previous activity) 6. Instruct students to set up the sand in the same way as for the canyon model investigation. They may arrange the gravel and the pebbles in a way that their group agrees upon. 7. Explain that they will be pouring the water into the deep part of the paint tray. Then, using the paper plate, they will create gentle waves. After each student in the group has had the chance to create 2 3 gentle waves on the shoreline, students should stop and draw/label the results of gentle wave action on the beach. After students have completed the gentle wave action, then each student in the group should have the opportunity to create 2 3 slightly more vigorous waves. Students should then draw/label the results in the lower section of the page. 8. After students have completed their two drawings and cleaned up the materials, show the Teacher Resource: PowerPoint: Slow Changes to Earth s Surface slides 18 and As slide 19 is projected, instruct students to visualize each of the steps. Clarify any sections that students do not understand. There may be some new vocabulary terms that need clarification (currents, suspended). 10. Show slides 20 (Barrier Islands) and 21 (Sea Caves). What natural agents contribute to erosion? Water and wind 9 of 11

10 What natural agents contribute to weathering? Water and wind How does water cause weathering, erosion, and deposition? The waves wear down the rock and then carry the rock particles away. The waves also cause deposition by depositing the sediments back onto the land. How does wind cause weathering, erosion, and deposition? The wind wears down the rock and then carries the rock particles away. The wind also deposits the sediments back onto the land. What kinds of factors contribute to deposition? Water and wind 11. Instruct students to complete the section on their Handout: Changes to Earth s Surface for changes caused by wind and water. To assist students you may wish to project slides one more time. ELABORATE Putting it All Together - A Literature Connection Suggested Day 9 1. During this part of the lesson a literature connection is used to ensure students can identify the slow changes to the Earth s surface caused by weathering, erosion, and deposition from water, wind, and ice. 2. Provide students with a selection of books or other resources on weathering, erosion, and deposition. 3. Allow students the opportunity to use the additional resources to complete any unfinished sections on their Handout: Changes to Earth s Surface. If the glossary has not been completed, provide students the opportunity to complete this section as well. 4. Distribute the Handout: Identifying Landforms to each pair of students. Instruct students to carefully cut out the pictures. 5. Say: Place the pictures between you and your partner face down in a single pile. Decide who will go first. The first person will draw a card from the pile. They are to identify the landform and then describe the processes by which it was formed. Listen to make sure your partner uses the terms weathering, erosion, or deposition and justifies whether the process is from water, wind, or ice. Continue choosing cards until you make it through each of the pictures. 6. Instruct students to clip the set of pictures with a paperclip and return the materials to you. books (about weathering, erosion, and deposition, per teacher) scissors (1 per pair of students) paperclip (1 per pair of students) Handout: Changes to Earth s Surface (from previous activity) Handout: Identifying Landforms (1 per pair) Instructional Note: Clarify any questions students may still have on identifying landforms. 10 of 11

11 EVALUATE Performance Indicator Suggested Day 10 Performance Indicator Draw a three-part illustration that clearly demonstrates the difference between weathering, erosion, and deposition. Write a description for each. (4.2F; 4.7B) 1C; 5G paper (plain, 1 piece per student) 1. Refer to the Teacher Resource: Performance Indicator Instructions KEY for information on administering the assessment. Teacher Resource: Performance indicator Instructions KEY 11 of 11