Wind Erosion Activity

Transcription

1 Wind Erosion Activity Activity Description: Students will be able to witness the effects of wind on our Earth s surface from a bird s eye view by utilizing a model that mimics wind erosion in a container. Students are encouraged in this activity to discover on their own patterns and concepts related to air pressure, obstructions, the role of plants, and the role of human activity on wind erosion by constructing their own experiments that focus on testing different variables that could influence wind erosion. Estimated Lesson Time: * 1 Class Period Standards: Michigan High School: HS-ESS2.A (HS-ESS2-1) - Earth s Materials and Systems HS-ESS3.C (HS-ESS3-3) - Human Impacts on Earth Systems Michigan Middle School: MS-ESS3.B (MS-ESS3-3) - Human Impacts on Earth Systems Focus Question(s): * What is wind erosion? * How might water, plants, or buildings impact wind erosion? Objectives: * Students will observe the effects of wind on our Earth s surface from multiple perspectives. * Students will understand how wind causes the shoreline to change. * Students will explore how plants and humans can impact the results of wind erosion. Student Misconceptions we aim to challenge: * All sand moves across the ground it does not get in the air. * Wind erosion is not strong enough to have an effect on landforms let alone create landforms. Knowledge Needed: * Students will need a basic understanding of erosion. Vocabulary: Wind Erosion: the transportation and deposition of sand by the wind Creep: occurs when larger particles are moved across the ground by rolling and impacting other particles Saltation: the transportation of wind-blown sediment through a series of leaps and bounces Suspension: occurs when fine particles are lifted and carried by flowing air and water

2 Pattern: consistent and recurring characteristics or traits that help in the identification of a phenomenon Materials for the Teacher Demo: * Large box (preferably made from wood or plastic) * Hair Dryer * Sand * Objects (fake grass, dune grass, rocks, etc.) * Large screen * Broom and dustpan Materials for the Student Activity: * Shoe box (or something similar) * Straws * Sand * Samples of marram grass * Small rocks * Small models of houses (from the monopoly board game) * Scissors * Tape * Objects to be placed in the box (fake or live grass, rocks, etc.) * Broom and Dustpan Procedure: * In Class: Introduce the different types of ways that sand can be transported by wind: saltation, surface creep, and suspension. Large volumes of sand bounce along within a meter of the ground in a process called saltation. Saltation is responsible for most of the sand movement on dunes. Coarse sand is too large to be readily moved by the wind and its movement consists of short distance, called surface creep, resulting from collisions with moving fine and medium sand particles. Finer silt and clay sized particles are carried by suspension and can be transported for hundreds of miles.

3 * Teacher Demo: The instructor will have a larger scale model for this activity using a hairdryer, a large box or container, and a larger sample of sand. He or she will set up the materials as shown below in the image to create a wind erosion demonstration box. A clear cover will be placed on top of the box or container. The instructor will insert the hair dryer into a pre-cut hole in the box or container. Then the students will be asked to make observations as the hair dryer is turned on. What is happening? How is the sand reacting to the moving air?how does this reflect what happens on our shorelines? * Then propose to students: How might water, plants, walls, or buildings impact wind erosion? Allow time for students to come up with their own hypotheses to answer this question. Then allow students to test their hypotheses with their own smaller-scale models. * This activity is best done in groups of 3-10 students each. If you have multiple erosion boxes, assign each group to a prepared table. If you only have one erosion box, you may need to provide an alternate activity for the groups to do while they wait for their turn with the erosion box. * Encourage students to manipulate different variables and observe how erosion patterns change. Encourage students to come up with their own experiment. Also, remember to encourage students to practice good use of science by manipulating only one variable at a time. * Instruct students to add objects like large rocks and blocks to simulate man-made structures. How do walls or buildings impact the wind flow and erosion patterns? * Encourage students to try the same experiment many times to uncover patterns that happen by chance from the predictable patterns of erosion. * If time allows, encourage students to use the wind erosion box to discover how various land formations are created, for example: canyons, arches, and sand dunes. What conditions must be present for each of these to form?

4 * Have students to write, sketch, and share what they have observed or noticed about wind erosion.what are techniques that they discovered, questions that they have, or what innovative ways have they found to alter to surface of the earth? References: *"Wind Erosion in a Box." The Leonardo Education, n.d. Web. 28 June < Student Handout Wind Erosion Today s Questions: What is wind erosion? How might water, plants, and buildings impact wind erosion? Draw a diagram of your wind erosion box before you begin the experiment:

5 Form your own hypothesis on what might happen if you place objects in your box and then continues the experiment. Draw a diagram of you wind erosion box after you have completed the experiment:

6 How has the sand in the box changed? Did this surprise you at all? Why or why not? As you observed your wind erosion box what was the most prominent type of wind erosion that you saw? Creep, saltation, suspension or all three? How did placing different objects in the box affect the movement and final location of the sand? What patterns did you observe? Explain. Today s Questions: Student Handout Answer Key Wind Erosion

7 What is wind erosion? How might water, plants, and buildings impact wind erosion? Draw a diagram of your wind erosion box before you begin the experiment: Form your own hypothesis on what might happen if you place objects in your box and then continues the experiment. * Students answers will vary. Draw a diagram of you wind erosion box after you have completed the experiment:

8 How has the sand in the box changed? Did this surprise you at all? Why or why not? * Answers will vary. The sand has blown up against the objects and has accumulated in front of the items. The amount of sand behind the objects has decreased dramatically As you observed your wind erosion box what was the most prominent type of wind erosion that you saw? Creep, saltation, suspension or all three? * The students will see a variety of wind erosion depending on how much air they blow through the straws and how fast. How did placing different objects in the box affect the movement and final location of the sand? What patterns did you observe? Explain. * By placing objects in the box the sand is deflected around the objects in some cases and also slowed or stopped ( deposition ) by the objects. This pattern occurs almost every time with varying results depending on the size and stability of the object.