Plate Tectonics PhET Lab (1)

Plate Tectonics Simulator Directions: 1. Go to the following website and click on “Run Now” http://phet.colorado.edu/en/simulation/plate-tectonics 2. On the bottom right-hand corner of the simulator click on “Both and “Show Labels”. 3. Place the density dial so that it points to the middle plate. Part A: Oceanic vs. Continental Crust 1. Observe the Oceanic Crust on your left and the continental crust on your right. Which type of crust is thicker? The continental crust is thicker. 2. You can change the crust in the middle of the simulator by adjusting the temperature, composition and thickness. Adjust each of the variables ONE AT A TIME by sliding the dials. Describe what happens to the plate when you adjust each variable. Variable Less More Temperature I notice that with less temperature, the crust becomes lighter I notice that with more temperature, the crust becomes darker Composition I notice that with less composition, the crust sinks I notice that with more composition, the crust rises Thickness I notice that with less thickness, the crust sinks and becomes thin I notice that with more thickness, the crust rises and becomes thick 3. Use the information you just collected in the table above to answer the following questions: Which type of crust has a higher temperature? the continental crust Which type of crust has a higher composition of silica? the continental crust Which type of crust has a higher composition of iron? the oceanic crust

Which type of crust is thicker? the continental crust Which type of crust has a lower temperature? the oceanic crust 4. What do you think causes the difference in temperature between the 2 types of crust? The convection in the mantle. 5. Why type of crust do geologists most typically drill when trying to reach the mantle? Why do you think they do this? I think they drill in the oceanic crust because it is thinner and smaller compared to the continetal crust. 6. On the top right corner of your screen, drag the Zoom bar all the way to the bottom. Drag the Density dial into each layer of the Earth to see how dense that layer is. Drag the dial into each layer and fill out the table below. Name of Layer How does this layer’s density compare to the layer above it? Why do you think this is? Mantle • Greater Than • Less Than • Equal to greater the crust Convection currents Lower Mantle • Greater Than • Less Than • Equal to Greater the mantle Other convection currents Outer Core • Greater Than • Less Than • Equal to Less than the lower mantle To trap the heat Inner Core • Greater Than • Less Than To trap the heat

Two Types of Plates Type of Boundary (highlight the type of boundary that applies) Describe what happens! What surface features are formed? Time Elapsed Continental vs. Young Oceanic ● Convergent ● Divergent ● Transform Continental vs. Old Oceanic ● Convergent ● Divergent ● Transform 7. Reset the simulator again with one young oceanic plate and one old oceanic plate. Drag the knob over the old oceanic crust towards the middle to create a convergent boundary. a. Hold the knob in place for as long as the simulation will allow. b. Describe what happens in Table C below. 8. Reset the simulator and create a divergent boundary between the 2 types of oceanic plates by pulling the plates away from each other. a. Record your observations in Table C below. 9. Finally, reset the simulator one last time and pull the knob over the old oceanic plate toward you to create a transform fault. a. Record your observations in Table C below. Table C: Old Oceanic vs. Young Oceanic Plate Boundaries Two Types of Plates Type of Boundary (highlight the type of boundary that applies) Describe what happens! What surface features are formed? Time Elapsed Old Oceanic vs. Young Oceanic ● Convergent ● Divergent ● Transform Old Oceanic vs. Young Oceanic ● Convergent ● Divergent ● Transform Old Oceanic vs. Young Oceanic ● Convergent ● Divergent ● Transform Extension: Click “Automatic Mode”. Create as many plate boundaries and timelines as you wish! Record any interesting observations here: Conclusion Questions:

1. Based on your observations, what is the difference between convergent, divergent, and transform boundaries? 2. Why does the oceanic crust subduct (sink) under the continental crust? 3. Why does old oceanic crust subduct (sink) under young oceanic crust? 4. When looking at the interactions between 2 continental plates, why didn’t either plate subduct (sink) beneath the other? 5. In each of these interactions, where does “new crust” come from? Where does “old crust”go? 6. Why do you think you aren’t able to create a divergent oceanic/continental boundary? 7. Some tectonic plate interactions are described as “folding” interactions, where 2 plates push up against each other and parts of the Earth’s crust “fold” on top of one another. Based on your observations in this simulation, would these folding interactions happen at convergent, divergent or transform boundaries? What types of landforms or events could be produced by “folding” interactions? 8. Some tectonic plate interactions are described as “faulting” interactions, where a gap forms between 2 plates and parts of the Earth’s crust break apart. Based on your observations in this simulation, would these “faulting” interactions happen at convergent, divergent or transform boundaries? What types of landforms or events could be produced by “faulting” interactions?