Mini-Landslide
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highlights Critical Zone Observatories U.S. NSF National Program EDUCATION & OUTREACH QUICK LOOK Modified with Grade Level: 5 (3-5) permission from: https://www.teac Mini-Landslide Time Required: 45 minutes Group Size: 8-10 Links: Subject Areas: Earth science, This with extensions: http://bcczo.colorado.edu/eno/agi-czo.pdf geology, physics, science and Video: https://youtu.be/9oCWkElPK_4 technology, critical zone science Houses: http://bcczo.colorado.edu/eno/agi-houses-czo.pdf Work Sheet: http://bcczo.colorado.edu/eno/agi-landslide-worksheet.pdf Educational Standards: NGSS: Next Generation Science In the week of September 9th, 2013 Standards - cience A stalled cold front over Colorado collided with warm air from the south, causing persistent, heavy rain. By September More about Educational standards met: 15th, rainfall totaled 17 inches (430 mm) in Boulder County, http://bcczo.colorado.edu/eno/ more than 1000 landslides occurred, and many roads agi-czo.pdf were damaged. One question is why landslides occurred in some locations and not others. ACTIVITY SUMMARY INTRODUCTION: Students explore how different materials Not all hills and mountains (sand, gravel, lava rock) with different water are made of the same contents on different slopes result in materials. There are landslides of different severity. They measure different types of rock, the severity by how far the landslide debris sand and soil found extends into model houses and roads placed in everywhere. Have you the flood plain. This activity is a small-scale played with sand before? model of a debris chute used by scientists to How about modeling clay? study landslide characteristics. If you made a castle out of Fourmile Canyon Creek near Lee Hill Drive in NW each of these materials, Boulder destroyed the road, carrying a van downstream, which created a dam for timber and which one would be more sediment (photo credit Frederick Blume). likely to fall down? (Answer: The one made from sand.) Each group needs: One hillside covered with a certain material may be more stable than • Model House Template and 1 sheet of cardstock (for construction of model houses) another of the same size and shape. Also, when you add water to • Transparent tape, scissors, markers, colored different materials, it is hard to predict what might happen. Material pencils, or crayons (to decorate houses) properties matter to how well a hillslope holds up or how strong it is. • 2 small paper cups; one for water, one for test Landslides are the result of gravity and friction acting on these different material types of earth materials (rock, soil, sand, gravel, etc.). • Mini-Landslide Worksheet, one per student Today, we are going to have some fun and learning aboutlandslides by https://www.teachengineering.org/content/cub_/activ creating our own landslides. We are going to build houses, and see if ities/cub_natdis/cub_natdis_lesson05_activity1_wor they get wiped out by the landslides. Not all hills and mountains are ksheet.pdf made of the same materials, we are going to test different situations. To share with the entire class: Scientists and engineers perform these same experiments to • 2 ft (.6 m) section of plastic downspout (~$5) understand how real-life landslides work—let's give it a try! • 1 bag small bag of each: sand (~$20), pea gravel (~$4), and volcanic (lava) potting rock (~$6) LEARNING OBJECTIVES • 1 large, shallow, plastic waterproof tub (8-in x After this activity, students should be able to: 14-in x 30-in, clear plastic is best but not necessary) • Define landslides as the result of gravity and friction acting on (-$10-$20) different types of earth (rock, soil, sand, gravel, etc.). • Duct tape, scissors (to cut downspout plastic), • Relate that different types of materials that create different landslide ruler dynamics. • Stack of books, stool or chair, to support • Explain how adding water weight to landslide materials reduces downspout friction, increasing landslide dangers. • Plastic scoop (optional, or use small paper cup) • • Describe how studying landslides allows scientists to determine where Plastic bins to hold, wet and store the sand, and when there are risks to buildings and people from landslides. gravel and volcanic potting rock (optional) Visit us at Twitter: Supported by the CriticalZone.org @CriticalZoneOrg National Science Foundation highlights Critical Zone Observatories U.S. NSF National Program EDUCATION & OUTREACH PRE-REQ STUDENT KNOWLEDGE original location, or worse) during each landslide trial? Have It is helpful for students to have a basic understanding of students record their prediction on the worksheets. gravity and friction which are critical to understanding landslides. In addition it is helpful to have a familiarity with TRIAL 1: EARTHQUAKE geological events (volcanic eruptions, earthquakes and 6. Make sure the chute is at tsunamis) to better understand landslide causes and effects. the shallowest angle allowed by the bin (see PROCEDURE Figure 3). Using a small Before the Activity paper cup, place a one cup • Set up the mini-landslide of sand at the top of the model activity in advance by chute (Figure 3). The first cutting the downspout material should not slide in half so you have two equal Figure 3. Placing material in the down the chute at this landslide chute. sections. Tip: Cut through shallow angle. the narrow sides of the 7. Next, increase the angle of the slope until material is on downspout to create the Figure 1. Pre-activity setup. the verge of sliding. Simulate an earthquake, a common widest chutes. trigger for landslides, by shaking the chute. The material is • Duct tape one downspout not expected to go very far on this trial. It may not even chute section to the bottom of the plastic tub, in the middle make it out of the chute. of the tub, to create a shallow angle (Figure 1). 9.Secure the chute at this angle by placing books (or a stool • Support the top end of the downspout by taping it to a or chair, as necessary) under stack of books, stool or chair. it and taping it in place. WITH THE STUDENTS TRIAL 2: FLOOD Note: It is best if the three materials and chute are damp 10. This time, place the when performing the trials. The materials react differently material in the chute and when wet. Damp materials produce greater uniformity in have a student bring you a spreading. paper cup one-quarter full 1. Divide the class into three teams (approximately 8-10 of water. Pour the water students per team). into hute above the 2. Have each team use the Model House Template to material. Observe what Figure 4. Houses after trial using ¼ paper cup of water. construct three houses per team with the cardboard stock . happens (Figure 4). Have 3.Assign each team to test the properties of one of the students record their observations on their worksheets. following materials: sand, gravel or lava rock. Each group performs three trials, assisted by the instructor, while the TRIAL 3: 100 YEAR FLOOD rest of the teams watch and record measurements on their 11. The third trial is similar to the second, except with more worksheets. water. Use a paper cup half full of water. Pour the water into 4. Clean off the flood plain the chute and watch what happens. Have students record (tub) and having students their observations on their worksheets. place their houses in three 12. Repeat the procedure with the other two teams for the locations relative to the other two materials. debris chute. During the RESULTS: experiment trials, students Conclude with a class discussion comparing results. How will predict whether certain good were student predictions? What did you observe? How locations are safe from the did the steepness of the chute make a difference in the landslide. Suggested Figure 2. Placement of houses. damage caused by the landslides? How did the addition of locations: 1) Two inches in water make a difference in the severity of the landslide front of and two inches to side of the chute path, 2) four damage? Which material caused the worst landslides? Which inches in front of and two inches to the other side of the landslide scenario caused the most damage? What if we chute path, 3) six inches directly in front of chute path (see combined the materials? What were the best locations in the Figure 2). Label houses: 1, 2, 3 with the numbers on the trials? Where would the safest location be on the flood plain? rooftops. 5. Ask students to predict whether each model house will be How can a mini-landslide model like this help us understand damaged or moved during each trial in the activity, and the many different conditions and results from real record their predictions on their worksheets. Which of the landslides? How would students apply what they've learned model buildings will be "damaged" (moved from their to real-world landslide situations? Visit us at Twitter: Supported by the CriticalZone.org @CriticalZoneOrg National Science Foundation highlights Critical Zone Observatories U.S. NSF National Program EDUCATION & OUTREACH Modified withhttps://www.teachengineering.org/activi permission from: Mini-Landslide ties/view/cub_natdis_lesson05_activity1 Activity Extensions the challenge and requirements: Have students re-design and place their own new buildings • Make your mountain as tall as possible. (This keeps to survive a landslide. Give them some limited supplies and a groups from settling for small mounds that won’t building size constraint, perhaps about one cubic inch (2.5 cm2). erode.) Each landslide material made a different pattern after it • The mountain may not be anchored by the sides of the came down the chute. Have the students investigate more plastic bin: it must be free-standing. about the patterns made by the different materials.