Lesson 15: Investigating Plate Movement

Lesson 15: Investigating Plate Movement Lesson 16: Convection in the Mantle

6-8 ES2F: (1) Describe that convection in the upper mantle causes crustal plate movement. (2) Describe what may happen when plate boundaries meet (earthquakes, volcanoes, tsunamis, faults, mountain building).

6-8 PS3B: (1) Describe that thermal (heat) energy transfers from warmer objects to cooler ones until the objects reach the same temperature. (2) Describe energy transfer by convection in a given system.

Focus Question 1: How does plate movement cause earthquakes, volcanoes, mountains, and trenches? (Write this in your lab book) Focus Question 2: How does convection in the mantle cause the plates to move?

Demonstration: Look at the three models which will be used for Stations 1, 2, and 3, what type of plate boundary you think you will model with each one? Discuss with your partner and the class why and how models will be used for each station. Now look at the fourth model. How could this model be used to show convection in the mantle?

What you will do: You will test all three of the models. You will start with one station and not move to the next station until you are told to do so (the whole class will move together).

Station 1: Inquiry 15.1-Simple Model of Plate Movement (put this in your lab book

Directions: 1. Read and follow the procedure steps 1-9 on pages 172-174 of the student guide. 2. Conduct the lab following steps A, B, C, and D.

Observations: In your journal tell what happened for each of the following tests.

A- Pulled on the pad from opposite ends B- Pushed on the pad at opposite ends C- Side two pads past each other D- Collided two pads by pushing them together

Clean Up your station and then….

Read: “Colliding, Sliding, and Separating Plates” on pages 174- 175 and answer the following questions in your lab book

Questions: 1. Which pad do you think represents the colder, denser, thinner Oceanic plates? Which pad represents the thicker, less dense Continental plate? 2. How did the density of the pads affect the way they behaved when you made them collide? 3. When do colliding plates on the earth form mountains? 4. When do colliding plates on the earth form trenches? 5. How do you think colliding plates on the earth cause earthquakes? 6. The place where plates meet is called a ______?

If you have extra time, then work on 15.1-Plotting Earthquakes by Depth.

Station 2: Inquiry 15.2 – Using the Moving Plates Model

Directions:

1. Read procedure steps 1-9 on pages 176-177. Next, set up your Moving Plates model as shown in figure 15.4. Make certain the belts on top of the lid are black, with red just about to emerge from the slit in the center. 2. Practice moving the belts. Try moving the knobs in opposite directions at the same time. Very slowly turn the knobs so that both belts move away from the slit in the center. 3. Flatten out the clay. Make it as thin as possible. Place the continent stencil on top of the flattened dough. Outline each continent- North America, Africa, and South America-in the clay using a toothpick. 4. Reset the belts again like in #1.

Test One: Place South America and Africa together like puzzle pieces over the center slit on the black belts (see figure 15.5). Slowly turn the knobs so that the continents move away from one another (about 8cm). This represents movement of the continents over millions of years. Look at the globe. What ocean has formed between these two continents as a result of their moving apart? How do you think the Atlantic Ocean formed? In your lab book, write your observations and answer these questions.

Test Two: Place North America and Africa on the outer ends of the belts (see figure 15.6). Pinch the outer edges of the continents onto the belt to secure them. Now you will go back in geological history. Turn the knobs so that the continents move inward, toward the center slit. What happens when the continents collide? Write your observations in your lab book

Clean Up: Remove any clay that may be stuck to the belts of the Moving Plates Model. Roll the clay back into a ball.

Questions: Use the globe and what you learned in this lab to answer the following questions. 1. Where on earth do you see evidence that plates collided in the past? 2. Where on the globe do you think plates are separating? Find evidence of this both within continents and under the ocean? 3. Find Japan and the Japan Trench. Feel those areas on the globe. What do you observe about this area? 4. Find the middle of the Atlantic Ocean, called the Mid-Atlantic Ridge. Feel this ridge on the globe. What do you observe about this landform? 5. How do you think the Moving Plates Model shows what happens on the earth when two plates separate?

If you have extra time, then work on 15.1- Plotting Earthquakes by Depth Station 3: Inquiry 15.3- Investigating Faults with Models

Directions: 1. Read procedures steps 8-15 on pages 181- 184. Make sure to also, read “Earthquake and Faults”. 2. Set up the materials as shown in figure 15.8 on page 181. 3. Conduct the lab following steps for three trials.

Data Collection: Draw the following table in your lab book Frictional Resistance Force (N) Force (N) Force (N) Force (N) Number of strips of Trial 1 Trial 2 Trial 3 Average Velcro 0 1 2 3

Questions: 1. How did the amount of friction along the fault affect the amount of force needed to rupture the fault? 2. Under what conditions did the blocks rupture more abruptly? 3. Under what conditions did the block slip (move slowly) but not rupture?

If you have extra time, then work on 15.1-Plotting Earthquakes by Depth.

Station 4: Inquiry 16.1-Modeling Convection in the Mantle Directions: 1. Read procedure steps 5- 10 on pages 192-193. Don’t worry about #9 as you do not have the worksheet. 2. Set up the materials as shown in figure 16.1. 3. Conduct the lab, making sure you look at figure 16.2 4. Draw a picture in your lab book of the set-up and show how the fluid moves (make sure you give it several minutes to warm up before you take your observations. 5. READ: “The Earth’s Moving Plates” on pages 186-187.

Questions: 1. What happened to the fluid near the upper surface of the jar (parallel to the table)? 2. Think back to lesson 5 and 7, what causes convection currents in a gas or liquid? 3. On the basis of what you have seen in the jar, what effect do you think convection in the hot mantle might have on the earth’s plates? What observations of the fluid inside the jar support your explanation? 4. What evidence did Alfred Wegener use for his Theory of Continental Drift? 5. What evidence finally proved the Theory of Continental Drift?