Purpose: To help visualize how the crustal plates move in relation to one another. This lab will also show how mountain ranges form and how seafloor spreading occurs.

Materials:
- One square of wax paper to cover desk area
-Two whole graham crackers
- One very flat cracker, (thinner than graham crackers)
- Cake frosting
- Plastic knife
-Writing instrument

Procedure:
1.) Break one graham cracker along the midline.
2.) Then break the two "half" crackers along their midlines. One whole cracker will yield four small rectangular crackers.
3.) Spread about 3 mm of frosting on an area of the wax paper.
4.) Place two graham crackers on the frosting and firmly but gently press down on the crackers.
5.) Move the crackers away from one another.
6.) Place the graham crackers on the frosting and move it towards a thinner cracker that has been placed on the frosting.
7.) Move the graham crackers back and forth so they slide past one another. Slowly increase the pressure. If the cracker breaks, don’t worry about it.
8.) Place two other graham crackers on the frosting. Move the graham crackers towards one another. Two different types of movement could occur.
9.) Move the crackers towards one another again to demonstrate subduction.
10.) For each type of plate movement, make a drawing of what is happening. Show what is happening at the crustal boundary. Color the crust (lithosphere) brown, the mantle (asthenosphere) red, and the ocean blue. Make your drawings on a separate sheet of paper. Identify the type of boundary and what happens at that boundary on your diagram sheet.


Think About It! ·


What do the graham crackers represent?
The graham crackers in the model represent plates in the Earth.

What does the frosting underneath the graham crackers represent?
The frosting underneath the crackers represents the mantle of the Earth. ·

What kind of features might occur when the plates move towards on another?
During this action, the process of subduction may occur. ·

What kind of motion is in process of two plates moving past each other? This motion is known as transform boundaries. ·

Why do you suppose that the cracker broke? How is it similar to what happens on the earth’s crust?
The cracker broke because of the immense pressure on the plates, and it resembles older plate crust falling off. ·

Where in the U.S. do we find a boundary like this? In the United States, a boundary such as this one can be found in the state of California or the Western Coast of the United States.
What features or events may occur in step 8 according to the diagram that you have drawn? This process may cause mountains to form or undersea bulges.
In subduction, the lower plate is forced downward towards the mantle and this causes what?
The lower plate of a convergent boundary is forced downwards towards the mantle and causes what?
When the lower plate is forced down into the crust towards the mantle, it causes the old crust to break off and to be disbursed during sea floor spreading.


Two continental plates meet and collide making what?
When two continental plates collide, the plates either crumble or mountain ranges are formed.

When plates moves apart from eachother and a new crust is formed from the magma coming out of the earth that pushes the plates apart. This is typically found at the mid-ocean ridge as what?
New crust that is formed from magma is usually found at the Mid- Ocean Ridge as Divergent Boundaries.
The slip plate boundary is where two plates slip past eachother horizontally. This causes what?
Transform Boundaries of plates cause the breaking of old crust and earthquakes. Conclusion Recent events have made the study of the Earth’s crustal plates important to our lives. What has happened recently concerning the Earth’s plates? What type of movement occurred and what did that movement cause to happen? What lithospheric plate was involved in the event?
The event that has recently happened was the tsunami in the Indonesian region. A Transform Boundary caused the lithosphere to rupture and cause it to move. This earthquake was measured a magnitude of 9.0 and was caused by the interface of the India and Burma plates. Citizens of the Eastern Coast of the United States can rest easy though. This type of natural disaster would in all probability not happen. The East Coast is not situated on a plate or boundary, but plates shifting and an earthquake caused the Tsunami in Asia.
The East Coast is stable and firm land, more stable than the West Coast.




Observations

What happens to the frosting when you move the crackers away from one another? A for of chocolate was created, a demonstration of a divergent boundary.
What happens when the crackers move towards one another? The smaller cracker went under the graham cracker.
Diagram and explain what occurs in step 8. They move upward forming a mountainous landform.