Snack Tectonics

Students use graham crackers and frosting to learn about the different aspects of plate tectonics. They manipulate the graham crackers in various ways to model divergent plate boundaries, convergent plate boundaries - continental and oceanic, convergent plate boundaries - continental, and lateral plate boundaries. Students observe what happens to the graham crackers and frosting and discuss their findings.

Below is a description of the activity from http://www.mbmg.mtech.edu/kids/shakin.htm

A crack in the earth's crust is called a fault.  The large crack where two huge earth plates move against each other is a fault line. Fault lines are where the action happens.

 

What you'll need:
bulletGraham crackers
bulletWaxed paper spread with a thick layer of frosting or peanut butter.
bulletMilk (To drink with the crackers after finishing the experiments.)
Put two graham crackers side by side, and slide one up away from you and the other one down toward you.

When plates move past each other like this, things don't exactly go smoothly. In fact, the plates usually get stuck on each other and then give a lurch and move on, sending waves of vibrations through the earth's interior (much like the circular waves that ripple out when you drop a pebble in the water). These vibrations are so powerful the we have a special name for themó earthquake!

 

Whose fault is this?

What if you went outside after an earthquake and found the  raspberries your family planted in the front yard were growing in front of your next door neighbor's house ( and in your yard were the roses from the next house)? This is what happened in San Francisco along one of the most famous fault lines in the worldó the San Andreas Fault in California, a 600 -mile boundary where the American and Pacific Plates meet. In 1906, there was an earthquake along this fault line and the earth moved about 20 feet in less than a minute! Wonder who got to eat the ripe berries?

These two delicious and fun projects and many more can be found in GEOLOGY ROCKS!, a Williamson Publishing book by Cindy Blombaum

Put two graham crackers very close to each other on the wax paper and slowly push them together.

You've made a rift, or big crack in the ocean floor. As the plates separate, magma oozes up from below and makes new ocean floor or creates underwater mountain ranges.

 

Push two crackers toward each other, make one slide underneath the other.

When this happens on earth, watch out! The bottom plate starts to melt from the intense heat and pressure. It becomes new magma that floats up between two plates, building up and up over many years until it finally causes a volcano blast! That plate action caused Mt. St. Helens in Washington State to blow its top!

Put two graham crackers side by side on the wax paper (wet the edge of one graham cracker in milk first), and slowly push them together.

The ridge of pushed -up cracker is just like many mountain ranges around the earth that were formed as two plates slowly crumbled together over millions of years. The Himalayas ( the mountain range that includes Mount Everest) were formed when India crashed into Asia.

 

 A similar, but more complete, lesson is given in Windows to the Universe.  The materials needed are:

For each student:

bulletOne large graham crackers broken in half (i.e., two square graham crackers)
bulletTwo 3-inch squares (approx.) of fruit roll up
bulletCup of water
bulletFrosting
bulletAbout one square foot of wax paper with a large dollop of frosting. ( Instruct students to spread frosting into a layer about half a cm thick.)
bulletPlastic knife or spoon

Activity:
http://www.windows.ucar.edu/tour/link=/teacher_resources/teach_snacktectonics.html

Directions overheads http://www.windows.ucar.edu/tour/link=/teacher_resources/snack_tect_overheads.html