PhET:  Plate Tectonics                                                        

Go to the PhET website

Select the Plate Tectonics Simulation

Spend a few minutes exploring the simulation.  Don’t worry, you can’t break it.

Select the “Crust” tab at the top of the simulation.  Under view select “Both”.

1)   What are the 3 variables that can be changed in this simulation?  (Scale or zoom is a nice feature, but not a variable.)

          1.composition

2.  thickness

3.     temperature

2)   Try to duplicate the continental crust as accurately as possible. How did you set 

temperature: 2.7 markings

composition: 7.7 markings

thickness: 45 km

3)  Try to duplicate the oceanic crust as accurately as possible.  How did you set 

temperature: 4 markings

composition: 9.6 markings

thickness: 6 km

4)  In terms of the three variables you have investigated, describe how continental crust differs from oceanic crust.  Continental crust is much thicker than oceanic crust, this means it is much warmer and has a thicker composition (more iron).

Select the “Plate Motion” tab at the top of the screen.  Under view select “Both”.

8)   Investigate convergent boundaries (green arrows).  Report your findings in the following table:

Left Side Crust	Right Side Crust	Which Crust is Denser?	Which Crust Subducts?	Do non-volcanic Mountains Form?	Does a Trench Form?	On Which Crust Do Volcanoes Form?
Continental	Continental	same	neither	yes	no	no
Continental	Old Ocean	continental	old	no	yes	yes
Old Ocean	Continental	continental	old	no	yes	yes
Continental	Young Ocean	continental	young	no	yes	yes
Young Ocean	Continental	continental	young	no	yes	yes
Old Ocean	Young Ocean	old	old	no	yes	young
Young Ocean	Old Ocean	old	old	no	yes	young

9)  Describe the relative motion of the plates at ALL convergent plate boundaries.  

Mountains are formed between two continental crusts, subducts and volcanoes are formed between oceanic crusts and continental crusts.

10)  Three times you used the same two types of crust, but switched left and right sides.  What do you observe about the results?  Is the side the crust is placed on important?
 No, it most certainly is not, whatever "side" of the circular earth the different types of crust are on, the outcomes will be the same when they come together.

11)          Look for patterns in density, subduction, and volcanoes in the table.  When volcanoes form, on which plate do they always form?  
 The volcanoes always form on the side that is less dense, even if it is thicker.

12)          Explore how a continental-young oceanic crust collision differs from a continental-old oceanic crust collision.

  Describe the difference in the angle of subduction between old and new plates.

The old oceanic crust subducted at a much steeper angle than the younger oceanic crust.

  How does the distance between the volcanoes and the plate boundary differ between old and new plates?  
The distance between the plate boundaries and the volcanoes is greater in the young oceanic crust than the older oceanic crust.

13)          Investigate divergent boundaries (red arrows).  Click show labels.  Describe the relative motion of ALL plates at divergent boundaries.  

When two crusts diverge they form a young oceanic plate between them.  Oceanic crusts do as well.

14)          What is generated at ALL divergent plate boundaries?  

Young oceanic crusts are always formed at divergent plate boundaries.

15)          Investigate transform fault boundaries (blue arrows).  Describe the relative motion of ALL plates at transform fault boundaries.  They move side to side from each other, but do not create any new things.