Grade Level: 3rd – 5th grades
Duration: One regular class period
Location: Laboratory setting or in outdoor learning area
Vocabulary: karst, sinkhole, bedrock, sedimentary rock, sinking stream, springs, limestone, erosion, weathering
Living with Sinkholes
Introduction:
In Central and Western Kentucky, much of the beautiful and diverse landscape is due to karst formations that have
formed in areas where the bedrock is limestone or similar sedimentary rock. These karst landscapes have caves,
sinkholes, sinking streams, and springs. Homes, businesses and schools built in areas with sinkholes are susceptible
to structural damage as the fill material is transported out of the sinkhole by water causing the sinkhole to collapse.
Engage:
Introduce students to the topic of karst landscapes. Explain that sinkholes form as water flowing through cracks in
limestone or other soft sedimentary rock gradually erode or dissolve the limestone causing the cracks to become
larger over time. This commonly results in a gentle slumping of the soil over the crack. Less often, the flowing water
enlarges the cracks causing caves to form. If the bedrock roof of the cave is too thin to support the soil and rock
above it, the cave roof will collapse forming a sinkhole.
Communities that build structures in active karst areas may suffer adverse consequences. Buildings and roads may
develop structural damage over time as the limestone is eroded or dissolved and the rock and soil layers slump into
the space created in the bedrock layers.
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Materials:
• One plastic shoe box sized container per group
• Sand to fill each shoe box
• One oblong balloon per group
• Sugar cubes (4 or 5 per group)
• Modeling clay
• Spray bottle
• Cup of water
• Enough small rocks to cover the bottom of the shoe box container
• An item to represent a building for each group
• One straight pin per group
Explore:
Part I. Simulation of sinkhole formation when a cave roof collapses.
1. Distribute materials to each group.
2. Explain to the students that they are going to simulate a sinkhole and how a building can move or collapse into the ground when built over a sinkhole.
3. Cover the bottom of the shoe box with a layer of rocks.
4. Have each group cover the rock layer with approximately two inches of sand.
5. One student will blow up and tie the balloon.
6. Place the balloon in the center of the box on top of the sand.
7. Fill the shoe box with enough sand to cover the balloon and lightly pat the sand into place around the balloon.
8. Place the building on top of the sand over the balloon.
9. Use a straight pin to pop the balloon.
Part II. Simulation of sinkhole formation due to erosion and weathering.
1. Take the clear shoe box and cover the bottom with small rocks.
2. Cover the rocks with sand.
3. Stack the sugar cubes on top of the sand and gently add enough sand to cover the sugar cubes.
4. Pack the sand firmly around the sugar cubes.
5. Flatten a small piece of clay and make a road across the sand covering the sugar cubes.
6. Slowly add water to the top of the sand until you can see the water collecting in the rock layer.
7. Observe any changes in the road.
Explain:
1.
2.
3.
4.
5.
Have the students move around the room to look at each group’s simulations.
Compare and contrast the effects on the buildings from the collapse of the cave to form a sinkhole.
Compare and contrast the effects on the road from the erosion and weathering simulation.
What would happen to a truck loaded with heavy materials if it drove across the sinkhole formed in Part II?
Which process caused the most damage to the built structures? Why?
Extension/Elaborate:
If the students have not completed the activity “Dupree – It’s Settled,” have them complete the activity and answer
the questions, using the sinkhole simulation data in planning the community.
Evaluate:
Have students make posters or dioramas illustrating the two types of sinkhole formation and their effects on
manmade structures.
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KENTUCKY CORE ACADEMIC STANDARDS ALIGNMENT
Science
• 3-5-ETS1.1: Defining a simple design problem.
• 3-5-ETS1.2: Generate and compare multiple solutions to a problem.
• 4-ESS3-2: Generate and compare multiple solutions to reduce the impacts of natural Earth processes on
humans.
Social Studies
• SS-P-G-U-3: Students will understand that people depend on, adapt to, and/or modify the environment to
meet basic needs. Human actions modify the physical environment and in turn, the physical environment limits
and/or promotes human activities.
• SS-EP-4.4.1: Students will describe ways people adapt to/modify the physical environment to meet their
basic needs (food, shelter, clothing).
• SS-EP-4.4.2: Students will describe how the physical environment can both promote and restrict human
activities.
Suggested Reading/Resources
1. PBS Learning Media http://ket.pbslearningmedia.org/search/?q=caves+and+karst
2. Sinkhole by S. Boydston
3. Sinkholes by Sandra Friend
4. Sinkholes by Megan Kopp
5. A Drop Around the World by Barbara S. McKinney
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