PLATES ON THE MOVE
Grades 3-5

In this lesson the children will gain a better understanding of the Earth, inside and out. Through this lesson and extended activities, children will come to realize that at this very moment, according to scientists, Africa appears to be tearing apart from Asia,a new mountain range is forming by the Earth's crust being shoved up in the Mediterranean, the Red Sea is getting larger and larger and may some day be called an ocean, while at the same time the Pacific Ocean appears to be shrinking. This is all happening so slowly that most of us, unless we become geologists, will not even notice that it is happening. In fact, geologists only a hundred years ago would not have believed that continents were moving and oceans were changing size. However, today most accept the theory that continents, as well as the entire crust of the Earth, are "on the move." We will examine the structure of the Earth and how forces inside the Earth help supply the source of energy needed to create the changes we see outside on the crust of the Earth.

Bill Nye the Science Guy: Crust of the Earth (KCTS/Seattle)
Bill Nye the Science Guy: Earthquakes (KCTS/Seattle)

Students will be able to:

• name the three main parts of the Earth;
• describe what the plates of the Earth are and the different ways that they move;
• identify three of the four major things that happen when the plates of the Earth move;
• practice mapping skills;
• be able to plot locations using longitude and latitude.

• scissors
• glue
• diagram of the three layers of the Earth for the overhead or one for each child
• a map of the world with longitude and latitude on it
• a map of the world showing the plates on the go (either one for each child or one for the overhead)
• sand
• shoe box

• core - the word scientists give for the center of the Earth which is made of hot, heavy metals (mostly iron and nickel) that sank due to gravity after the Earth formed. It is believed to have two layers, one molten and the other solid rock.
• earthquake - a shaking or sliding of a portion of the Earth's crust. It is caused by the sudden movement of masses of rock along a fault or by changes in the size and shape of masses of rock far beneath the Earth's surface.
• geysers - a hot spring from within the Earth that erupts intermittently in a column of steam and hot water.
• magma - hot, molten rock from deep in the Earth.
• lava - magma that has reached the Earth's surface.
• mantle - made of the same thing the Earth's crust is made of only a lot denser. The mantle has three zones: uppermost zone (lithosphere), the middle zone (asthenosphere), and the deep mantle.
• molten rock - rock that is so hot it is a very thick, slow-moving liquid.
• outer core - the first layer of the core that is molten and responsible for the gravitational pull of the Earth.
• plates - that part of the inside of the Earth that floats the crust and the uppermost layer of the mantel. Scientists feel that there are about 12 of them.
• stalagmite - a formation of lime, shaped like a cone, built up on the floor of a cave. It is formed by water dripping from a stalactite.
• stalactite - a formation of lime, shaped like an icicle, hanging from the roof of a cave. It is formed by dripping water that contains lime.
• subduct - where one plate goes under the other which forces molten rock up and out which will form an earthquake.
• plate tectonics - a new theory scientists put with the moving of the Earth's plates.
• volcano - a place where the Earth's crust opens up and spews lava.
• seismograph - an instrument used to measure the shock waves of an earthquake.
• epicenter - the center of an earthquake.

Vocabulary Activity
Have pictures mounted on cardboard or colored paper, or locate books with pictures to depict each of the vocabulary words. Make sure they are well labeled. Elicit discussion with each picture, soliciting from the children any experiences they have had with things around each picture. Display the pictures around the room and say, "These things all exist presently or have at one time. Some may even be frightening if you are caught in the middle of them, but they are all a part of science and we will spend time from a safe distance looking at why these things exist."

Tell the children that we are about to explore an area of science called geology. We will go over vocabulary words first so that when you come across them in the video or other activities, they will have a better understanding of the material.

To give students a specific responsibility while viewing, say, "You are now going to see parts of two videos that tell about the different parts of the Earth and how scientists think the land has formed over millions of years. We will also consider the idea that the Earth is still changing at this very minute.Watch the video to find out what scientists think is inside the Earth."

BEGIN tape Bill Nye the Science Guy: The Earth's Crust immediately following the opening credits. The video is Bill Nye outside squatting down by a rock saying, "See these little holes in this rock?" Watch the video long enough to allow the children to validate what is inside, under the Earth's crust. STOP this tape with the visual of Bill Nye giving a brief explanation of geysers. There are bubbles from the geysers being shown and Bill Nye is standing in the front right corner of the screen.

Discuss two things that can happen to the Earth's crust because of the heated energy from within. (earthquakes and geysers)

Note to the teacher: At this point you may skip the experiment that comes next and demonstrate how a geyser works. Show the diagram of the side view of the Earth where geysers are located or go back to the tape and show the experiment that comes immediately following Bill Nye standing by the geyser. You may also have children experiment with baking soda and vinegar by doing a demonstration of a volcano using one already made by you or by the children themselves.

Try to promote conversation using the vocabulary words relating to earthquakes and geysers to make sure that the children have a good handle on the subject. Bring back into play the pictures used in the beginning of this activity to demonstrate vocabulary words that go with earthquakes and geysers.

To give students a specific responsibility for viewing, say to the children, "You are now going to watch another Bill Nye video. Before I tell you its title to give it away, I want you to watch the first part of the film. Tell me what the third change is that can happen to the Earth's crust and how it happens."

FAST FORWARD the video Bill Nye The Science Guy: Earthquakes to start after the credits and after the beginning vocal logo for Bill Nye and the quake shake commercial. The scene is Bill Nye sitting at a desk with a model of the Earth and moon saying, "Do you realize that every year there are thousands of earthquakes all around the world?" The room starts shaking. Continue watching and then pause after Bill Nye has explained about the seismograph and seismometer by saying, "These are very delicate and accurate instruments and scientists can tell just exactly how the Earth's surface is moving at any time. They're fabulous!" Discuss what earthquakes are and how they work.

Note to the teacher: In this discussion, you may either show the "Try This" experiment using sand in a shoe box to demonstrate how faults in earthquakes are made as well as volcanoes, or you may rely strictly on the demonstration in the tape. Personally, the hands on, especially at this age, will give the children a better grasp of exactly how this works.

Sum up this segment of the lesson with the children by saying, "Now that you've learned about what causes volcanoes, geysers and earthquakes, are along with a few instruments that are used to test them, we will finish the tape. In this last section we will learn how to determine where earthquakes are happening and how scientists compare one earthquake to another.

RESUME video after the "Try This Experiment" using the sand in the shoe box to demonstrate what happens when plates of the Earth move and the word "Try It!" appears on a black and blue screen. Play the video to the end of the clip. STOP.

Begin this activity by reviewing what an earthquake is. Ask questions such as:
"How long do they last? Can earthquakes happen anywhere? Are they more likely to happen in one place than another?"

You want to make sure that everyone understands what an earthquake is, how long Earthquakes normally last, what the magnitude of an earthquake is, and how scientists measure an earthquake's magnitude.

Tell the children that they are going to plot some earthquakes on a world map. The earthquakes are actual earthquakes of magnitude 6.1 or greater that occurred during 1983, 1984 and 1985.

Divide the data you have copied among the children, giving each child some earthquakes to plot. You might want to review latitude and longitude with the children so that they know how to find the correct points on the map. Then pass out markers and maps and give them time to plot the quakes.

When the children are finished ask them if they see any pattern as to where the quakes have occurred. (After plotting the points, they should be able to see that most of the earthquakes occurred along plate boundaries in the Pacific Ocean.)

Review the parts of the inner Earth by using a picture of the diagram of the layers on a piece of acetate on the overhead. Break the mantle and core into further parts pointing out the names given to each part.

Sum up the lesson by reviewing with the children that almost all earthquakes are caused by the movement of rock along fractures in the Earth called faults. Then explain that the Earth's surface (the crust plus the top portion of the mantle) is believed to be divided into several large plates that slowly move. As the plates move, they pull apart, collide or slide past each other and this movement creates the stress that forces rocks to break along faults.

Have a geologist from the area or a geology teacher from a local college or high school come to visit the class to talk about rocks and minerals found in your area.

Visit a site where an earthquake, volcano or other significant history "Earth moving" event has happened in your area if there is one.

Art and Science: Make a model-size volcano to demonstrate what happens when a volcano erupts.

Art and Science: Make a model of the cross section of the Earth and label each section.


The People Earth

(This activity is best done before viewing the tape and is to be done in a large area inside or out.)

Materials:
Cut pieces of paper with the words:
inner core (1)
outer core (3)
deep mantle (6)
asthenosphere (8)
lithosphere (12)
(The numbers beside the words represent how many of each word would be given out for a group of 30. Adjust the numbers to fit the size of your group.)

First have each of the children pick a part to play by drawing a slip from the hat. (The names of what goes on which piece of paper are found in the materials.) Then, using the information provided, explain what each "part" does. Let the children practice any sounds or movements and then build the Earth from the inside out.

1. Have the child playing the part of the inner core flex his or her muscles (or pretend to lift weights) and stand in the center of the open area. Tell the kids that this represents the very dense and solid metal inner core.

2. Next have the outer core kids form a circle around the inner core. They should face in, toward the inner core. Then have them walk counterclockwise around the inner core while holding their arms out to the side and waving them up and down. Tell them this represents the fact that the outer core is liquid and is moving.

3. Have the children playing the deep mantle join hands to form a circle around the outer core. Have them chant, "hot rock, hot rock, hot rock."

4. Have the asthenosphere children surround the deep mantle. Have them slowly sway their bodies back and forth to represent the movement that occurs in this layer.

5. Finally, have the lithosphere children form a circle around the entire rest of the Earth. Have them face outward and slowly walk around the rest of the Earth. Have them chant, "moving plates, moving plates."

Master Teacher: Gail Roberts