Colored modeling clay
A map showing the plates of the earth, cut into pieces on the plate lines and placed in envelopes (I used the map from this packet since it’s what I already had from a previous unit, but you could use any plate tectonics map, just Google it)
Red marker to make dots
Mr. Shaefer’s Graham Cracker handout (You could do one for each kid, but I chose to have a single copy and we discussed the process together instead of having each kid responsible for writing their answers so it was more interactive.)
Play dough, frosting, or red Jell-O
Lesson Outline: Introduction to Plate Tectonics
- Warm Up: Challenge your children to a rock stacking competition. How many rocks can they each stack? How many rocks can you stack together? Is there a secret to rock stacking?
- Relate: Where do rocks come from? All rocks come from the Earth. Use a hardboiled egg to demonstrate that the Earth has a core (yolk), mantle (egg white), and crust. Explain that the core is comprised of hot iron ore, the mantle is a combination of hot igneous rock (the lower mantle’s rock moves in slow motion), and the crust is what we see around us (rocks, dirt, ocean floor). The crust is broken into plates that can push against each other, move, and overlap, just as the shell of an egg.
- Break the concept down even further by making a model of the Earth. Be sure they know that the earth is a sphere – not a circle – even though it’s not a perfect sphere because of gravity. Use a red-hot for the inner core, red clay for the outer core, yellow for the lower mantle, orange for the upper mantle, and green clay for Earth’s crust. Some interesting things to note:
- Note how far the distance is from your city to the inner core. From where I am in California, we learned that the distance was like driving from here to Costa Rica!
- Explain the differences in the inner and outer cores. The inner core is so hot that it most likely is white in color, but it doesn’t liquefy because of all the pressure being placed on it. The outer core is liquefied iron and nickel and holds the Earth’s magnetic field. What are some things held to the Earth by gravity? (we are, the moon is)
- Note the temperatures of the different layers and connect that to how hot it gets in your area…as well as how hot you normally cook food in your oven!
- Discuss how far of a drive it would be to go the depth of the oceanic crust layers or the continental crust layers. Based on mileage, some might be a 45 minute drive, while others might be a 4 hour drive. Relate these to common landmarks.
- Demonstrate the different layers using maps found online so they can “see” the layers.
- Have the kids use the plastic knives to cut away a quarter of the sphere to reveal the red hot in the center and all the layers. Challenge them to use flat toothpicks to label each layer.
- Learn about the plates of the Earth: Provide each child with an envelope containing puzzle pieces you have cut from a map showing the plates of the world. Have them assemble the puzzle on the red construction paper and glue down, coloring the land areas blue or green. The red between the cracks is the molten igneous rock under the plates! Next, explain to them the major plates of your area, noting any interesting sites (for us, we discussed the Pacific and North American plates, the Ring of Fire, and the mid-Atlantic rise – the tallest mountains in the world and they’re under water!). We looked at maps and placed red dots around any areas with extreme activity.
- Demonstrate the movement of the plates: I used Mr. Schaefer’s graham cracker activity but substituted and homemade play dough for the frosting and a square of foam instead of the Rice Crispy treat. I related the plate movement to landforms near our geographical area, so students could make connections to features they see every day. For another great explanation, refer to this video that demonstrates plate movement using 2x4s.
- Closing: If your children have access to a computer, here’s a fun little game to see if they can figure out how different landforms were created over time.
Next week we’ll be reinforcing the concept of plates and plate boundaries with some drawing, and using our geologist skills to make topographical maps of play dough mountains. Hope to see you back here next Wednesday!
For more information on this series and to check out the posts on teaching an enrichment geology class to younger kids, check out my original post by clicking the image below.