By interacting with the models, students observe that although continental features appear stable, Earth's features are created by changes in plate movement.
Students extrapolate from small-scale models of plate movement to large-scale geologic events in order to better understand the dynamics of Earth's features.
Volcanic eruptions are common in Hawaiʻi (Fig. 1)!
Fig. 1. Lava flows on the island of Hawai'i. Image courtesy of GIPHY
Inquiry:
Where does lava come from?
Why do volcanic erruptions happen mostly on Hawai'i island?
How did the Hawaiian Islands form?
Guiding Questions:
What is the evidence that the land on earth is moving?
Where did the lava that formed the Hawaiian Island chain come from?
Activity:
Discover how geologic features form by modeling the slow movement of Earth's tectonic plates.
Note: This activity has Further Investigations below (an interactive game, crossword puzzle, and plate labeling sheets) to help solidify understanding of vocabulary.
Materials:
Part A. Model:
Deck of cards, or tangrams
Shaving cream
Small pebbles
Spatula or wooden spoon
Towels for clean up
Baking pan, tub, or wide bucket
Mesh mat or screen
Student Worksheet and Teacher Guide (attachment below)
Print the map of Earth's plates on clear acetate so that it can be placed over the world map, or
Print the map on plain paper and cut out each of the plates. Students can then try to connect the plates back together on top of the world map with seafloor features. (Note: You may also laminate the map of Earthʻs plates before cutting and then use the plates instead of cards or tangrams in the model portion of the activity.)
Procedure:
Part A. Prepare and Explore Your Model
Follow your worksheet to set up and conduct your trials.
Squirt a layer of shaving cream into the bottom of the pan or tub (Fig. 2).
Use your spoon to flatten the shaving cream so it's evenly distributed.
Gently place two of your plates on top of a pile of magma (shaving cream) so that they form a rectangle.
Conduct your trials.
Trial #1: Divergence
Before testing the plate movements, describe what you think will happen when you pull the plates apart.
Very slowly, push down and gently slide the two plates apart.
Record what happened on your worksheet.
Trial #2: Convergence
Clean your plates and place them back on top to form a rectangle.
Describe what you think will happen when you push one plate under the other.
This time, push one plate down and under the other plate.
Record what happened on your worksheet.
Trial #3: Transform Fault Movement
Clean your plates and place them back on top to form a rectangle, this time leave a small space between the plates.
Push down on the plates so a bit of magma comes up between.
Put a few small pebbles on the magma in between the plates.
Describe what you think will happen when you slide the plates in opposite directions along side each other.
Gently slide the plates in opposite directions along side each other.
Record what happened on your worksheet.
Trial #4: Island Chain Formation
Set aside the model of convergent and divergent plates to prepare a new model for island chain formation.
Using the mesh material (remember, this also represents one of Earth's plates), hold it flat and free from any surface.
With help from another partner, hold the can under the plate and point it upwards (Fig. 3).
Describe what you think will happen when magma (shaving cream) squirts upwards through the plate (mesh material).
Gently squirt a small amount of magma three times (stay still as you squirt the can!) and slowly move the plate after each squirt.
Record what happened on your worksheet.
Challenge: see if you can recreate the Hawaiian Island Chain!
Part B. Compare your model to a map of Earth's features
Using what you've learned in this experiment, take out the world map, clear acetate sheet, and map of Earth's plates overlay (printed on clear acetate).
Look at the world map and see if you can identify any plate boundaries where convergence, divergence, or transform movement may occur. (hint: start by looking in the middle of the Atlantic Ocean)
Place the clear acetate sheet on top of the map.
As best as you can, trace the plate boundary in the middle of the Atlantic ocean.
Continue tracing areas that you think are potential plate boundaries.
Place the map of Earth's plates overlay in between your trace layer and the map to compare what you've traced with the official plate boundaries.
Continue tracing plates, using the map and plate overlay as a guide.
Record your observations on your worksheet.
Activity Questions:
What did you see as the plates diverged, or moved apart?
What are the parts of a divergent zone? Fill in the diagrams on your worksheet.
What did you see when your plates converged, or slid underneath one another?
What are the parts of a convergent zone? Fill in the diagram on your worksheet.
What did you see when the plates moved along side each other?
What are the parts of a transform fault? Fill in the diagrams on your worksheet?
What did you see as you moved the plate over top of the spewing magma?
Where do earthquakes generally occur?
Why does Hawai'i have more volcanic activity than some other locations on Earth?
Further Investigations:
Interactive Plate Movement
Master your understanding of the different plate movements and hot spot formation with this interactive activity!
You may need to enable Flash or change browsers to view the interactive feature below.
Note: If you cannot view the entire interactive on your screen, press Ctrl-Minus (-) on a PC and Command-Option-Minus (-) on a Mac to zoom out.
Crossword Puzzle!
Click on the attachments below to complete the plate tectonics crossword puzzle!
Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.