Download Snack Tectonics

Snack Tectonics
Abstract: Learn about how the plates move by using edible food!
Grade Level: 3-8
Time Needed: 30 minutes
Materials:
 One large graham cracker broken in half (i.e., two square graham crackers)
 Two 3-inch squares (approx.) of fruit roll up
 Cup of water
 Frosting
 Sheet of wax paper
 Plastic knife or spoon
Preparations before program:
Procedure:
1. Each student will receive some wax paper and a large spoonful of frosting. Have the students to
spread frosting into a thin layer on the wax paper.
a. The layer of the earth which plates are located on is called the asthenosphere. This is
what the frosting represents.
b. The plates in graham crackers (continental crust which is thick but less dense).
2. Have students to put two squares of fruit roll up onto the frosting right next to each other.
a. The fruit roll ups represent the thin and dense oceanic crust.
b. Push apart the fruit roll ups by a half cm. As you do this, slowly pressing down on them
as this layer will sink a little in the asthenosphere.
c. The frosting will come up a little where the plates separate. This represents how magma
is pushed towards the surface at divergent plate boundaries. When divergent plates pull
apart, rift valleys are made, like the Great Rift Valley in Africa, which can become the
bottom of the sea floor if the plates continue to pull apart.
3. Next, remove one of the fruit roll ups.
a. Place one graham cracker half lightly onto the frosting next to the fruit roll up.
b. The continental crust is thicker and less dense than oceanic crust. This is represented by
the graham cracker, which doesn’t push down on the frosting (asthenosphere).
c. Push the graham cracker towards the fruit roll up until the graham cracker is on top. The
oceanic plate is sub ducted below the continental one.
4. Now the students will see what happens when two continents collide. Remove both the cracker
and fruit roll up from the frosting.
a. Place one edge of both crackers into the glass of water for just a few seconds.
b. Place the crackers onto the frosting with wet edges next to each other. Slowly push the
graham crackers towards each other.
c. What happens to the edges? This is similar to how mountains are made at convergent
plate boundaries.
5. Take crackers off the frosting and turn them around so that two dry edges are touching.
a. Push one cracker past the other. This mimics a transform plate boundary like the San
Andreas Fault.
Terminology and Definitions:
Plate tectonics: Theory that the earth is divided into plates that move and shape the earth over time.
References: http://www.windows.ucar.edu/tour/link=/teacher_resources/teach_snacktectonics.html
Additional Information:
How to Simplify:
How to extend:
Additional/Background information:
Lithosphere
 Rigid rock outer layer of the Earth made of plates that fit together like a jigsaw puzzle.
 The plates float on top of the denser asthenosphere.
 Plates made of continental crust are thicker but less dense than plates made of ocean crust,
which are denser but thinner.
Divergent plate boundaries
 Plates coming apart
 Rift valleys and spreading ridges form as plates pull away from each other.
Convergent plate boundaries
 Plates are coming together
 When an oceanic plate and a continental plate collide, it forms a subduction zone
 Mountains build when two continental plates collide
 Large faults form when plates slide past each other making the Earth tremble with earthquakes