Fourth Grade - Science - Geology - Lesson 7

Earth layers model activity adapted from Make It Work! Earth by Wendy Backer and Andrew Haslam

Cornstarch mantle activity adapted from How the Earth Works by John Farndon


Describe the characteristics of the layers of the Earth--crust, mantle, outer and inner cores.

Make a model of the Earth's layers to show their relative thicknesses.

Simulate the plasticity of the Earth's mantle layer.


Earth's layers diagram for transparency (see attached)

For A groups of five: modeling clay or modeling dough in four colors, plastic knife, toothpicks and paper slips for labels, paper plate and wax paper (to protect desks and display model)

For B groups of five: Two small cups (one containing 1 Tbsp. of water, the other 1 Tbsp. of cornstarch ), eye dropper, spoon, paper plate, worksheet (see attached)

For optional activity: Slip of paper for each student. Write heavy on some of the slips and light on the others

Suggested Books

Baker, Wendy and Andrew Haslam. Make It Work! Earth. New York: Macmillan, 1992. Explores the earth sciences: geology, meterology and geography. Contains many activities--model making, experiments, mapmaking and games--and color photos of how to do them.

Clifford, Nick. Incredible Earth. New York: Dorling Kindersley, 1996. Elaborate models illustrate how pressure at fault lines results in earthquakes, how geysers form, glacier movement and more. Also includes cut-aways of different types of volcanoes.

Farndon, John. How the Earth Works. Pleasantville, NY: Reader's Digest, 1992. Contains many experiments and projects on various aspects of the Earth's structure including mountain building, volcanic eruptions and weathering.

Gibbons, Gail. Planet Earth/Inside Out. New York: Morrow, 1995. Gibbons presents a very simple explanation of the formation of the Earth and its layers. The information and illustrations of earthquakes, tsunamis and volcano island-building are outstanding.

Markle, Sandra. Earth Alive! New York: Lothrop, 1991. Beginning with the dramatic story of a 400-foot-wide sinkhole in Winter Park, Florida, Markle turns our attention to what is happening under our feet. Color photos of land forms are expecially beautiful.

McNulty, Faith. How to Dig a Hole to the Other Side of the World. New York: Harper, 1979. A child makes an imaginary trip, a la Jules Verne, to the center of the Earth. Includes evocative descriptions of the crust, mantle and core of the Earth plus wonderful illustrations by Marc Simont.

Parker, Steve. Science Project Book of the Earth. New York: Marshall Cavendish, 1986.

Robbins, Ken. Earth: The Elements. New York: Henry Holt, 1995. An extremely beautiful book with hand-tinted photos and lyrical descriptions of volcanoes, mountain forming, erosion, accumulation of soil, fossils forming and more. "Ashes to ashes and dust to dust. Wood decays and iron rusts. Everything changes because everything must."

Sattler, Helen Roney. Our Patchwork Planet: The Story of Plate Tectonics. New York: Lothrop, 1995. While the text is written for middle schoolers, Sattler's style is lucid and her analogies are wonderful: "Scientists think that our present continents may have been built Fourth Grade - Science - Geology - Lesson 7

from island arcs that were swept together at subduction zones, like floating toys in a

bathtub after the drain plug has been pulled."

Sipiera, Paul. I Can Be a Geologist. Chicago: Childrens Press, 1986. Simple text describes various specialties within the field.

Taylor, Barbara. Earth Explained: A Beginner's Guide to Our Planet. New York: Henry Holt, 1997. Contains an excellent overview of how heat energy from outside and inside the Earth, cause movement and change. "The heat inside the Earth is the driving force behind the movement of rocks on the surface. It makes continents move around the globe, pushes up mountains and volcanoes, and causes earthquakes to happen." The section on volcanoes is especially well-written.

Background Information

Geology is the study of the Earth's origin, history and structure. Geo is from the Greek word gaia, meaning Earth. Geologists study the structural form, arrangement and internal structures of rocks. They also study the causes and processes of geological change and the chronology of those changes. When the Earth was formed four and a half billion years ago, gravity pulled materials together. As the planet's density increased, heavy elements sank to the center and lighter elements floated to the top. The heavier ones, iron and nickel, formed the planet's inner and outer cores. The outer core is molten iron while the inner core, even at 11,000 degrees Fahrenheit, is solid because of the incredible pressure exerted upon it from the Earth pressing down. Scientists believe it may be a moon-sized (1,500 miles across), single giant crystal. Although theorized for more than a decade, only recently was there evidence to indicate that the inner core is spinning freely, like "a planet within a planet," at a rate of one rotation every 100-400 years. Magnetic fields caused by moving molten iron in the Earth's outer core may cause the inner core to spin. The interaction of this solid iron and the molten outer core may create the Earth's magnetic field and cause the needle of a compass to point north. The outer core is about 1,300 miles thick.

The mantle of the Earth is a 1,800-mile-thick layer that surrounds the outer core. This layer is so hot that much of it is melted rock called magma. Magma's consistency has been compared to gooey asphalt, hot jam, and Silly Putty. Depending on its make-up and temperature, it flows at different rates. Just as differences in temperature in the atmosphere cause air to move causing wind, scientists believe heat convection currents in the mantle probably cause the magma to move. The movement of magma is what causes movement of rocks on the surface of the Earth. The very thin layer on the outside of the Earth, the layer that we walk on, is called the crust. The crust is about three miles thick under the oceans and about 22 miles thick under the continents. An apple is often used as an Earth model with the apple's skin representing the relative thinness of the Earth's crust to the thick mantle. The Earth's crust and upper mantle are broken into pieces or plates that float on the molten mantle like "vanilla wafers on chocolate pudding" writes Helen Roney Sattler. These plates "pull apart, collide, grind past, or dive underneath one another the way luggage does on a conveyor belt at an airport," she says. The study of the movement of plates is called plate tectonics. Where plates meet, faults, such as the San Andreas fault in California, occur. While they move rather slowly, 2.5 miles in all the time humans have been on Earth, Ms. Sattler reports, it is the movement of the plates that produces earthquakes, volcanoes, mountain building and ocean trenches.

The deepest hole ever dug is in Russia. It is eight miles deep and barely scratches the crust.

Fourth Grade - Science - Geology - Lesson 7


Draw a dot at one end of the blackboard. From the dot, draw a line that extends all the way across the board to the other end. Measure with a ruler one-quarter inch from that end of the line and draw a dot. Tell the students that the long line represents the time the Earth has been in existence, four and a half billion years. (Write Earth's history and 4,500,000,000 on the board.) Tell the students that the tiny piece on the end of the line represents four million years (4,000,000), the time that humans or human-like ancestors have been in existence. Point out the expanse of the long line and tell the students that over the next few months, this is what they will be studying--the history of the Earth, changes that have occurred since it formed and changes that are happening now.

Ask: How can we know anything about what happened over billions of years of Earth's history if humans weren't here? (Accept all answers.) Tell the students that the history of our planet is written in its rocks. Geology is the study of Earth's beginnings, its structure and its changes. Geologists unlock the secrets of rocks so they tell us something about how the Earth was formed and what forces have shaped it.

Point to the beginning of the line and tell the students that scientists think four and half billion years ago, a spinning cloud of gases and dust began to clump together. Matter or star debris stuck to the clump, pulled in by its gravity. As more and more matter was pulled in, the Earth slowly grew and became denser. Heavy matter, such as iron and nickel, sank to the center of the clump. Lighter matter floated to the top. This created layers in the Earth. Remind the students that they learned about layers in the atmosphere. Tell them there are four layers of Earth beneath their feet. (An optional activity to demonstrate the formation of the planet. Distribute slips of paper of two colors to the students, one color indicating heavy and the other indicating light. Have two students stand in an open area. Have other students walk by one or two at a time and join the two. As the group grows, have them crowd closer together. Ask the students carrying the slips of paper with heavier on them to move toward the center of the crowd and those carrying slips with lighter to move toward the edges of the crowd.)

Divide the students into two groups. Show the students the transparency of Earth's layers. Ask the students in one group to make notes about the depths of each layer because they will be making models of Earth and its layers in clay or dough. Ask: Which layer is the thinnest layer? (crust) Tell the students that this is the layer that we live on. Ask: How thick is the crust? (3-22 miles) Tell the students that crust under the ocean tends to be thinner than crust under the continents. Tell them that the deepest hole ever dug is in Russia. The idea was to drill a hole through the crust to the Earth's next layer, the mantle. The Russian scientists drilled a hole 8 miles deep, but still didn't break through the crust. Tell the students that the Earth's crust is not one solid covering like chocolate coating on a candy. It is broken into seven big pieces called plates. Write this word on the board.

Have a student come up and identify the mantle on the transparency. Ask: How thick is the mantle layer? (1,800 miles thick) Tell the students that the temperatures in the mantle are so hot that much of this layer is melted rock called magma. Write this word on the board. Ask: What do you think melted rock or magma is like? (Accept all answers.) Tell the students that geologists have compared magma to the consistency of gooey asphalt, hot jam or Silly Putty. Depending on its make up and its temperature, magma in the mantle can flow like shampoo, uncooked egg white or like sticky syrup or molasses. A solid that is able to flow like a thick liquid has plasticity. Write this word on the board. Tell the students in the second group that they will be simulating the plasticity of the Earth's mantle by making some make-pretend magma.

Remind the students that they learned in their study of weather how differences in temperatures of air masses make them move and cause wind. Tell the students that many scientists believe differences in temperature in the mantle cause magma to move around just like the air masses. Since the plates of the crust are floating on the magma, they move around, too. One author wrote that the plates float on the molten mantle like "vanilla wafers on chocolate pudding." Ask: What do you think happens when the plates move around? (They bump together or spread apart.) Tell the students that sometimes they slide under each other. Tell them that the movement of the plates causes earthquakes and volcanoes. It also causes mountains to be pushed up and deep ocean trenches to form. The study of the movement of plates is called plate tectonics. Write this on the board. Tell the students that they will be learning more about earthquakes, volcanoes and plate movements.

Point out on the transparency the layer beneath the mantle, the outer core. Tell the students that this layer is 1,300 miles thick. It is so hot that the iron and nickel that make up the outer core are liquid. Inside the outer core is the inner core. Even though the temperature at the center of the Earth is 11,000 degrees Fahrenheit, certainly hot enough to melt iron, the inner core is solid. This is because the great weight of the Earth on top of it pushes against it and keeps it from melting. Point out that the inner core is nearly the size of the moon, about 1,500 miles across. Tell the students that next time they will be learning more about the inner and outer cores of the Earth.

Tell the members of A groups that they are to use clay or dough to build models showing the Earth's layers. The models can be cross sections (the view one would get from cutting an apple in half). They can also be views that show slices or three-quarter views of the Earth with one quarter cut away. Ask them to label each layer. Remind them that they have notes on the thickness of each layer.

Tell the members of B groups to follow directions on the worksheets they will receive to create a substance that has the plasticity of the Earth's mantle. Distribute materials to the groups.

Possible Homework

Ask the students to make a list of things in their homes that were made from earth materials: rocks and minerals. ( Examples: Flower pots are made from clay. Cat litter is made from clay and stone products. Frying pans are made of metals such as iron. Front steps are sometimes made of marble. Cans are made of metal.) Remind the students that there is a material made from sand that is everywhere in their homes (glass).

If the Earth has existed for 4.5 billion years (4,500,000,000) and humans have existed for 4 million years (4,000,000), how many years did Earth exist before the appearance of humans?

How to Make Simulated Plastic Rock

One cup contains cornstarch. The other cup contains water. Use the eyedropper to add water to the cornstarch, one drop at a time. Stir the mixture between drops. Observe how the mixture behaves.

Answer the following questions.

1. Before you added water, was the cornstarch a solid, liquid or gas?

2. After you added the water, was the mixture a solid, liquid or gas?

3. Tilt the cup. Does the mixture move? Does it move like a liquid or solid?

4. Drag the spoon slowly through the mixture. Does the mixture act like a solid or liquid?

5. Stir the mixture quickly or strike it with the spoon. What happens to the mixture?

6. How do you think the mixture is like the Earth's mantle? Do you think the Earth's plates could slide on plastic rock?

Fourth Grade - Science - Geology - Lesson 8


Calculate the distance traveled on a trip to the center of the Earth.

Recognize the theory that movements in the Earth's core generate electricity and create magnetic fields.

Demonstrate how the Earth's magnetic fields affect a bar magnet and a compass needle.

Describe a theory and ways evidence might be gained to prove it.


Bar magnet, 2-3 feet of thread, a glove or mitten, small red sticker


Suggested Books

Curtis, Neil and Micheal Allaby. Planet Earth. New York: Kingfisher, 1993.While the text is informative, the strength of this book is the interesting viewpoint displayed in the cutaway diagrams of the Earth. Includes a sidebar on magnetic fields and homing pigeons.

Farndon, John. How the Earth Works. Pleasantville, NY: Reader's Digest, 1992. Includes a compass-making project and an activity that displays magnetic fields using iron filings and a representation of Earth.


After sharing and discussing the homework assignment(s) and the Earth layer models from the last lesson, show the transparency of the Earth's layers again. Have a student come up, point out and name the four layers. Ask: Which layer takes up the most room in the Earth? (mantle) Ask: What layer do you think takes up the least amount of room? (crust) Tell the students that because the crust and mantle interact so much, (remember that plates in the crust float on the mantle like vanilla wafers on pudding), scientists often call the crust and upper part of the mantle by one name: the lithosphere. Write this word on the board.

Point out the outer core and remind the students that the temperature in the outer core is so great that the heavy metals there, iron and nickel, have melted. The outer core is liquid metal. Point out the inner core. Tell the students that the inner core is even hotter. It may be as hot as the surface of the sun. At that temperature, heavy metals would definitely melt but the tremendous pressure of the other Earth layers pushing in on it causes the inner core to remain solid.

Ask: If you were to take a trip from Baltimore to the center of the Earth, what would be the distance you would have to travel? Ask a volunteer to come up and help set up the problem on the board. If necessary, point out that the thicknesses of each layer are on the transparency. Also, if the students do not recognize this, point out that the center of the inner core is one half the width on the transparency or 750 miles. Use 22 miles as the crust thickness. Help the student to add the figures to find the distance of a trip from Baltimore to the center of the Earth (3,872 miles). Ask: Is this a very long trip? Point out that this distance is the same distance one would travel on a trip from Baltimore to Utah and back. Ask: Do you think we will ever by able to make a trip to the center of the Earth? Why or why not? (too hot, great pressure. Some students may think that in the future technology may overcome these forces.)

Tell the students that very recently geologists discovered something amazing about the inner core of the Earth. They found evidence that the inner core is spinning inside the Earth just like a planet within a planet. They have a lot more data to collect, but they estimate that the inner core rotates once every 100 to 400 years. Some geologists think the inner core, the center of the Earth, might be one giant spinning, vibrating crystal the size of the moon. Geologists are very excited about this new evidence.

Tell the students that for the last twenty years geologists had a theory. Ask: Who can tell me what the word theory means? (an explanation of how or why something happens that has not yet been proved true) For years, geologists theorized that movement in the inner and outer cores was making electricity. Now they have evidence that the inner core is moving. They theorize that all the iron and all the movement in the center of the Earth is generating electricity. That electricity is creating magnetic fields and making the Earth a giant magnet with a north pole and a south pole. All the little bitty magnets on refrigerator doors around the world are affected by the giant Earth magnet's poles.

Ask: What information can a person get from a compass? (which direction is north) Tell the students that it is because of the Earth's magnetic fields that a compass works. Show the students a compass and how the magnetized needle always points north. Ask: In what circumstances would a compass come in handy? (finding your way in a strange place, following a map or directions)

Show the students the bar magnet. Ask: Do you think the Earth's magnetic field will affect this magnet? Tie the thread around the middle of the magnet. Have four students come to the front of the class. Ask one student to suspend the magnet on the thread, holding his or her hand very still, so the magnet may rotate freely. When the magnet has stopped spinning, have the second student stand pointing in the two directions in which the magnet ends are pointing. Ask the third to use the compass to determine which of the two directions is North. (Make sure the compass is not close to the bar magnet or it will be affected by it.) Have student four put a red sticker on the north-pointing pole of the magnet and a glove or mitten on the north-pointing hand of the second student. Point out that now students one and two have a compass, too. They have all they need to use the Earth's magnetic fields to find out which way is north and which is south. Have students one and two move to another location, facing a different direction and test their compass. Have students three and four verify north. Remind the students that because electricity is being made in the center of the Earth, magnets line up pointing north and south.

Remind the students that geologists had a theory about the movement of the inner core of the Earth. Then they looked for evidence to prove the theory. Write theory and evidence to prove on the board. Ask: Do you think the geologists went to the center of the Earth to find the evidence? (no) If they could not visit the center of the Earth and see it, how do you think they were able to get evidence to prove it was moving? (Accept all answers.) Ask the students to close their eyes. Ask: With your eyes closed, do you still know I am here? Point to where you think I am. Walk to the other side of the room. Ask: With your eyes closed, point to where you think I am now. Have the students open their eyes. Ask: How did you know where I was if you could not see me? How did you know I had moved across the room? (listened and heard you) Ask: Did you feel the floor vibrate a little as I walked across it? Tell the students that geologists did the same thing when they were looking for evidence to prove their theory. They could not see the inside of the Earth, so they traveled all over the outside layer of the planet and they listened to the echoes of earthquakes. Tell the students that next time they will learn how geologists listen to earthquake echoes.

Possible Homework

Suppose you are given a box and there is something going on inside it. You want to open it up and look, but that is forbidden. Based on a sound you hear coming from the box, you have a theory about what is going on inside. Write a paragraph stating your theory and how you might go about getting evidence to prove it without opening the box.

Fourth Grade - Science - Geology - Lesson 9


Recognize the damage earthquakes can cause.

Recognize the frequency of earthquake occurrence.

Describe how earthquake magnitude is measured.

Describe how seismic energy travels in S and P waves.


Descriptions of earthquake experiences (see attached)

Pictures of earthquake damage and of a siesmograph from Suggested Books

A jumprope

Suggested Books

Asimov, Isaac. About Earthquakes. New York: Walker, 1978. This little book is for older children but Asimov's explanations of how geological discoveries were made are so clear that younger students will appreciate them, too.

Dudman, John. Earthquake. New York: Thomson Learning, 1992. Contains several pictures of earthquake damage and a very good close-up photo of a seismograph.

Ganeri, Ann. Earth Science. New York: Dillon, 1993. Has a good spread on What Makes Earthquakes Happen.

Lambert, David. Earthquakes and Volcanoes. New York: Bookwright, 1986.

Levine, Ellen. If You Lived at the Time of the Great San Francisco Earthquake. New York: Scholastic, 1996. The story of the earthquake as seen through the eyes of a child who was there April 18th, 1906.

Sattler, Helen Roney. Our Patchwork Planet: The Story of Plate Tectonics. New York: Lothrop, 1995. Contains some pictures of earthquake damage and an actual seismographic reading from the Northridge, California earthquake of 1994.

Simon, Seymour. Earthquakes. New York: Morrow, 1991. Great pictures of earthquakes, seismograph and maps of earthquake zones in the U.S. and a world map showing all the crustal plates.

Teacher Note

To save time, you may want to write these theories on a corner of the board before class: 1. Earth formed from dust and gas that clumped together. Gravity pulled in more and more material.

2. Gravity pulled heavy metals to the center of the Earth.

3. The outer core is liquid and the inner core is solid.

4. Movement in the Earth's core generates electricity and creates the Earth's magnetic fields.

5. The Earth's crust is broken into plates that float on the soft mantle.


Ask: What is a theory? (an explanation of how or why something happens that has not yet been proved true) Have some students read aloud their homework assignments about boxes, theories and finding evidence. Write Theories of What Is Going On In the Box on the board and under it some of the students' theories. Point out how the students went about getting evidence to prove their theories.

Remind the students that they have learned about several geological theories. Ask: What are some of the geological theories we have learned about? Review the list of theories on the board. Remind the students that evidence was found to support one theory about movement of the Earth's inner core--the planet within a planet. This evidence was found by listening to the echoes of earthquakes.

Ask: What does quake mean? (tremble or shake) Tell the students that an earthquake suddenly and violently shakes the ground. Depending on how strong an earthquake is, it can knock down buildings, bridges, tear up roads, cause avalanches, and open up giant crevases in the ground. Tell the students that when a mild earthquake happened in Washington State recently, there was a survey of elementary school students in the area. The students were asked what they were doing at the time of the earthquake, what they observed happening and how they responded to the earthquake. Read aloud a selection of the students' descriptions (see attached).

Tell the students that severe earthquakes have killed many people and done enormous damage. Show the students pictures of earthquake damage from Suggested Books. Tell the students that one of the most violent earthquakes happened in 1906 and literally destroyed the city of San Francisco, California. That earthquake was so strong that people felt the earth shaking in neighboring states. Three thousand people died, crushed by falling buildings or trapped in fires that started when the gas mains broke. Read the description of the earthquake by Eva Atkins Cambell (see attached).

Ask: Do you think earthquakes happen very often? Tell the students that earthquakes happen someplace in the world every thirty seconds. Most of them are so mild that people are not even aware of them. We know they have happened because shock waves from the earthquakes travel through the ground. These energy waves can be picked up by sensitive recording instruments called seismographs. Write seismograph on the board. Show the students a picture of a seismograph from Suggested Books. Tell the students that energy from earthquake tremors causes the base of the seismograph to vibrate. A pen that is suspended above the base then makes a wavy line on paper. Bigger vibrations make taller waves. Tell the students that the strength of an earthquake is measured on a scale from 1 to 10 called a Richter scale. Write Richter Scale on the board. Each number up from 1 is thirty times more powerful than the number before it. An earthquake measured at a 10 would be the most violent earthquake of all. Tell the students that the most powerful earthquake ever measured was nearly 9 on the Richter scale. That is equal to the power of an explosion of 200 million tons of dynamite.

Tell the students that all earthquakes produce energy waves. Energy waves move through the ground. The power of the wave decreases as one gets further away from the earthquake event. Ask the students to imagine dropping a pebble in a pool and watching the ripples move outward away from the center. Tell them this is how the waves of earthquake energy travel through the ground. Have a student come up and take one end of a jumprope. Take the other end and make the rope snake up and down. Point out to the students that the energy is moving down the rope and making it ripple. People who have witnessed earthquakes say they can see the waves moving the ground up and down like waves in water.

Tell the students that there are different kinds of energy waves produced by an earthquake. Some energy waves called P waves (write this on the board) can travel through solid rock and through liquid. They travel most quickly through very dense rock. Another kind of energy waves called S waves (write this on the board) can only travel through solids. When S waves reach liquid, they stop. Seismographs measure both kinds of energy waves. Ask: Can you see how earthquake energy waves going through the Earth might give clues about what is inside? What do you think happens to S waves when they get to the liquid outer core? (They stop.) What happens to P waves when they reach very dense rock of the lower mantle? (They move faster.) Tell the students that by setting up seismographs all over the planet, in very deep holes, on mountaintops, in deserts, and in underground caves, geologists can measure and track the many earthquake energy waves moving through the Earth and learn something about what is beneath the crust.

Remind the students that the Earth's crust is broken into plates. Earthquakes usually happen at the edges of these plates. Tell them that next time they will find out how these floating plates move around, where the plate edges are and what causes an earthquake.

Possible Field Trips

Contact a geology department of a nearby university and ask if they have a working seismograph or find out if there is a seismograph station in the area. Visit and watch the seismograph in action. If there is a geologist available, ask him or her to show how the P and S waves are read.

Student Earthquake Survey Responses

Mark Twain Elementary, Kirkland, WA

--When the earthquake started, I was leaning on my bed reading. I was nervous enough as it was because I knew I should be getting ready for bed. At first I thought it was thunder hitting the side of the house (not very logical!) Really loud thunder. Then I thought it was my dad pounding up the stairs to get me. Then I thought it was my sister jumping off her bed and making the chandelier shake downstairs. I was about to yell, "Hey, stop it, Haley," and then I knew. I was so terrified! I ran (actually jumped) down the stairs shouting, "Mom! Dad! I don't know what to do!" I have been in three tornadoes and remained perfectly calm but with an earthquake I blew it. My mom had opened the garage and we were standing in the doorway to the garage. My dad had run upstairs and was dragging my sleepy little sister, Haley, downstairs with her head under his looped arm. As I look back on the experience, it all was very funny. But I learned I just have to not panic and be more prepared (and not panic!).

--I saw plants shake and books fly across the room and my house felt like it was starting to collapse (we live in an old house). I heard a really loud rumbling sound. It scared the pajamas off me (and I wasn't in my pajamas!) I saw great flashes in the sky and then the lights went out. I tried to call my grandma, but the phone was dead. I didn't like it!

Ardmore Elementary, Bellevue, WA

--I saw my T.V. rumbling and sliding across the dresser and it almost fell off and I heard a huge rumble sound and it was sort of scary but not too scary. I just layed there very surprised and I started to bounce on my bed. I started moving up and down and up and down and I was thrown off my bed but not hurt.

--I saw the entire house shake and thought I heard thunder. At first it felt like the Earth was bouncing up and down and then it felt like my house was built on water and there were small waves going under it.

Wellington Elementary, Bothell, WA

--I was in my house on the couch watching T.V., when there was this rumbling sound that sounded like a really strong wind. Then when the house started to move, I ran to my dogs. They were out on the back porch and I thought that the first thing that was going to happen was that the back porch was going to fall so I ran and got them. The quake lasted about 20 seconds where I live because I am between 12 to 20 miles away from the center. It hit pretty hard! It was the first earthquake I have ever been in.

--I looked around my room and everything was shaking and all of the pictures on my dresser were upright before but now were falling over. I also was able to hear my house shaking and I could feel it, too. But after the whole thing was over, nothing was broken and I was happy!

--When the earthquake happened, I was washing my hair in the sink. Then the floor started shaking and then I thought it was Diane putting her radio up too loud so I stomped on the ground and kept washing my hair. Then Christine came out of her room and said, "EARTHQUAKE!" My dad was watching the Mariners game downstairs like nothing was going on. Then he got up and came upstairs and told Christine and me to go downstairs. That was the first earthquake I ever felt. By accident, I almost got underneath a glass table. Then the earthquake was over. Cool, huh?

--I was at my house, sitting at the kitchen table watching my sister make a seaweed poster. She was coloring it in when the table started to shake. I told her to stop and she did. As soon as she stopped coloring, the whole room was shaking. My dad was listening to the Mariners game on the radio. He said, "It's an earthquake." Sarah, my sister said, "Ashley, duck and cover." As soon as we got under the table it stopped. My brother Johnny came downstairs reading and was very shocked. Jennifer, my other sister, was on the phone when it happened. That night I couldn't sleep. I thought there was going to be an after shock.

--I saw my house move. It sounded like a rumbling bomb or like I was where an airplane was landing. I was in my room on my couch playing Monopoly with my two chameleons, Skittle and Snickers. Skittle was just about to move when the earthquake scared him to death. I saw my poor lizards being tossed around and around the Monopoly board. I felt the ground shaking and paper money all over my legs.

An account from the San Francisco earthquake 1906

"The moment I felt the house tremble...I leaped out of bed and rushed out to the front door...I felt sure the house would fall before I got out. It rocked like a ship on a rough sea. Streams of people...poured into the streets...a mourning, groaning, sobbing, wailing, weeping crowd. The deathly air was very oppressive...quiver after quiver followed...until it seemed as if the very heart of this old earth was broken and was throbbing and dying away slowly and gently."

(Eva Atkins Campbell)

Fourth Grade - Science - Geology - Lesson 10

Convection demonstration adapted from How the Earth Works by John Farndon


Locate on a map of the world's crustal plates, the North American and Pacific Plates and the San Andreas Fault.

Simulate the movement of plates at collision/subduction, spreading and transform boundaries.

Describe how convection moves the material in the Earth's mantle and causes the plates to move.

Identify heat energy in the Earth's interior as the source of earthquakes and volcanoes.

Describe how a tsunami is formed.


Crustal plates map for transparency (attached)

Two dry kitchen sponges

Small heatproof glass bowl, food coloring, votive candle, matches, cooking oil, two blocks of equal height


Tectonic Jigsaw Puzzle (attached)

Suggested Books

Bonnet, Robert and G. Daniel Keen. Earth Science: 49 Science Fair Projects. New York: Tab, 1990. While many of these projects require extensive lists of materials, some are more manageable such as the pudding plates experiment simulating the Earth's crust.

Buck, Pearl S. The Big Wave. New York: HarperCollins, 1947. This classic story tells how a tsunami affected the lives of Kino and Jiya, two Japanese boys.

Souza, D.M. Powerful Waves. Minneapolis: Carolrhoda, 1992. Explains through text, diagrams and historical photos how volcanoes, earthquakes and avalanches cause the huge destructive waves called tsunamis.

Teacher Note

To set up the convection demonstration, choose two blocks of wood that are a few inches taller than the votive candle and place them side by side on a table. These will support the glass bowl. Put the candle (in a container or on a dish) in between them. Light the candle and place the bowl, half filled with vegetable oil, over the candle on the supports. This little stove will heat the oil in the bowl. Drop a few drops of red or blue food coloring in the oil. As the candle flame heats the oil, blobs of the colored oil will be carried in the convection current--a little like a homemade lava light! Blobs will cool and fall, be heated and rise to the surface, cool and drop again. Because it will take a few minutes for the oil to heat and the action to begin, you may want to set this up before class and light the candle a few minutes before the demonstration. When after a few minutes of activity the blobs become too small, add more drops of food coloring. If students have trouble seeing the movement from a distance, you might have them come up in small groups or file by the demonstration, being careful that no one touches the warm oil or the flame.

Teacher Resources

Two websites with information on tsunamis:

Fourth Grade - Science - Geology - Lesson 10


Remind the students that at the end of the last lesson you mentioned that earthquakes usually happen at the edges of plates. Show them the transparency of the world and the crustal plates (see attached). Remind them that the Earth's crust is not like a candy coating but more like a cracked egg shell. The pieces, or plates, slowly move around on the mantle. They move as much as four inches a year, about the distance across your knuckles. Ask: Does the Earth's crust remind you of a big jigsaw puzzle? What happens in a jigsaw puzzle when one of the pieces moves? (It affects the other pieces.) Remind the students that the theory that crustal plates move about and that new crust is constantly being created is the theory of plate tectonics. Write plate tectonics on the board.

Ask the students to recall the two earthquakes mentioned last time: the mild earthquake in Washington State and the one in San Francisco in 1906. Both these places are located near where two plates meet. Have a student locate Washington State and the city of San Francisco on the transparency. Ask: What plates meet near these two places? (North American Plate and the Pacific Plate) Ask him or her to show where these two plates meet. Ask: Is there a smaller plate wedged in between the North American and the Pacific Plates near Washington State? What is the name of that plate? (Juan di Fuca Plate) Tell the students that these places are located along the San Andreas Fault. A fault is a deep crack in the Earth that marks the boundary of two plates. A boundary is where one plate ends and the other begins. Write San Andreas Fault on the board. Have the student point out the San Andreas Fault on the transparency. Tell the students that there have been numerous earthquakes along the San Andreas Fault.

Ask the students to look at the directions of the arrows on the map that show which way plates are moving. Tell the students that looking at the map, there are three kinds of movement at plate boundaries. At some plate boundaries, plates pull away from each other. Draw two arrows on the board pointing out and label this spreading boundary. Tell them that there is a spreading boundary in the middle of the Atlantic Ocean where the plates are moving apart. Show them this boundary on the map. Tell them that according to the theory of plate tectonics, magma from the mantle is pushing up in the crack between these plates and building mountains of crust on the ocean floor. This ridge of tall mountains is called the Mid-Atlantic Ridge. The Atlantic Ocean floor is getting wider at this Mid-Atlantic Ridge.

Ask a student to find a plate boundary where the two plates are pushing against each other. Draw two arrows pointing in. Label this convergent or collision boundary. Tell the students that at these boundaries the plates bump and push each other. Sometimes at collision boundaries, one plate dives under the other one. Draw two arrows showing this and label this subduction. Point out that sub in subduction means below. One plate moves below the other one. Tell the students that the Pacific Plate is the plate that is probably moving the most of all the plates. It is turning counterclockwise at a speed of about two and a half inches a year. At the San Andreas Fault it is moving northwest. The North American plate is moving the other way, toward the southeast. Show this on the transparency. Draw two arrows on the board, indicating the plates sliding past each other. Label this transform boundary. This is the third type of plate boundary movement. Ask: What kind of boundary is the San Andreas Fault? (transform boundary). Review the different types of boundaries: spreading, collision/subduction, and transform. Hand the two kitchen sponges to various students and have them simulate the movement of the plates at the different types of plate boundaries.

Tell the students that this pushing, pulling and sliding causes stress and pressure to build up. The edges of plates are not smooth like sponges. They are crooked with rough spots that catch on each other. After years of stress and strain, the rocks suddenly snap or fracture causing an earthquake. The earthquake, which is has the power of an enormous explosion, sends seismic waves of energy rippling through the Earth. Ask: What kinds of seismic waves did we discuss last time? (P and S waves) How are these waves recorded? (with a seismograph) Tell the students that often after an earthquake there are aftershocks, smaller earth tremors as the two plates settle.

Ask the students to think back to their study of weather and of plants and animals and the food chain. They will remember that the sun is the source of energy that powers weather on Earth. The sun is also the source of energy plants use to make food and through the food chain, to feed all the inhabitants of the planet. Tell the students that in addition to the sun, the heat inside the Earth also supplies energy. The heat energy from within the Earth powers earthquakes and volcanoes. It melts the metal of the outer core and the rock of the mantle. It causes crustal plates to move, maybe only a matter of inches, but the movement leads to sudden violent change at the surface of the Earth.

Ask the students to imagine that the candle burning beneath the bowl is heat from the core of the Earth and the oil in the bowl is the Earth's mantle. Remind the students that air, water, oil and magma all rise when they are heated. Ask: As the hot magma in the mantle rises to the surface, away from the candle or core's heat, what do you think happens to it? (It cools.) Ask: What do you think happens as the magma cools? (It sinks.) Point out that this same circulating action is occurring in the bowl of oil. Tell the students that this movement by heat and cooling is called convection. Magma in the Earth's mantle is mixed up and circulated by convection. Molten rock from deep in the mantle rises up to the surface, cools off and sinks back down. This movement of the mantle is what makes the crustal plates floating on top move. That movement is what causes earthquakes and volcanoes. Write on the board heat energy from core with an arrow pointing to makes magma move with another arrow pointing to makes plates move with another arrow pointing to causes volcanoes and earthquakes.

Ask the students if they have ever heard of a tidal wave. Ask a student to describe a tidal wave. Tell the students that these enormous, destructive waves are not caused by tides. Ask: What do you think they are caused by? (earthquakes, volcanic eruptions and landslides under the ocean) Tidal waves are also called tsunamis (soo-NAM-ees). Tell the students that the tremedous energy released by earthquakes and volcanoes under the ocean pushes the water and a wave is formed. Ask the students to recall the energy moving through the jumprope in the last lesson. Have two students come up and demonstrate a little amount of energy going through the rope. Then have the students try to show earthquake energy going through the rope. Ask: Do the rope waves get bigger when more energy is behind them? (yes) Tell the students that a tsunami moves with the speed of a jet. As it approaches the shoreline it slows down to about 70 miles per hour. Because the water is much shallower, the wave grows taller, pushed by the energy behind it. It can grow to be 100 feet tall, as tall as a ten story building. When it crashes down on the shore, it can cause terrible destruction. Read aloud this description of a tsunami by three scientists perched in a safe lookout at Hilo, Hawaii in 1960. As the wave, caused by an earthquake near Chile, hit their island:

"A dull rumble like a distant train came from the darkness. Our eyes searched for the source of the noise. In the dim light we saw a pale wall of tumbling water. It grew higher as it moved steadily toward the heart of the city. A 20-foot-high wall of water churned past our lookout. Seconds later, brilliant blue-white flashes lit up the darkness as the wave washed over the town with crushing force, snapping off power poles, grinding buildings together, and flooding the city."

Show the students the transparency of the Earth's plates again and tell the students that the earthquake in Chile in 1960 caused tsunamis all around the edges of the Pacific Ocean. Point out Chile on the map and then California, Alaska, Hawaii, Japan, the Philippines and New Zealand. Tell the students that all these places around what we call the Pacific Rim were hit with tsunamis from the earthquake near Chile. Tell the students that next time they will learn why this area, the Pacific Rim, is called "The Ring of Fire."

Possible Homework

From a teacher's guide developed by Hawaii Natural History Association and available on the Internet at Volcano World:

Distribute the Tectonic Jigsaw Puzzle (see attached) and ask the students to cut out the crustal plates and reassemble the tectonic map. They may glue or tape them on a separate sheet.

Distribute copies of the crustal map and ask the students to find examples of the three kinds of plate boundaries: collision/subduction, spreading and transform.

Fourth Grade - Science - Geology - Lesson 11


Describe why volcanoes are called Earth's safety valves.

Locate the "Ring of Fire" and the Mid-Atlantic Ridge on Plate Tectonics map.

Describe how volcanoes build new crust.

Build a model of a volcano.


Transparency of tectonic plates from previous lesson

Diagram of Inside a Volcano for transparency (attached)

Pictures of volcanic eruptions from Suggested Books or, if available, a video showing eruptions

For each group of five students: a shallow-sided cardboard box at least 15" wide, modeling clay or Playdoh, enough to made a mountain at least 8" tall. (Trees and houses can be made of paper, pipe cleaners, pebbles, etc.)

Suggested Books

Branley, Franklyn. Volcanoes. New York: HarperCollins, 1985. While the text is for younger children, the concepts are clearly stated.

Lasky, Kathryn. Surtsey: The Newest Place on Earth. New York: Hyperion, 1992. Examines the creation of Surtsey, an island created by volcanic activity in 1963 off the coast of Iceland and explores over time, its emerging ecosystems. This is a fascinating book about an example of volcanic land building and of ecological succession with dramatic photos.

Lauber, Patricia. Volcano: The Eruption and Healing of Mount St. Helens. New York: Bradbury, 1986. This Newbery Honor book contains stunning photos of the rebirth of an area transformed into a landscape as lifeless as the surface of the moon by a volcanic eruption. Lauber is able to convey the extraordinary power of the volcano's blast as its "stone wind" stripped acres of trees bare in seconds. She is at her best when describing the "islands of survivors and colonizers" that link life together in reclaiming the wasteland.

Simon, Seymour. Volcanoes. New York: Morrow, 1988.

Van Rose, Susanna. Volcano & Earthquake. New York: Knopf, 1992. This Eyewitness series book highlights the effects of these natural phenomena on humans over the centuries.

Vogt, Gregory. Volcanoes. New York: Franklin Watts, 1993. While profiling various volcanoes and the destruction they have caused, this book reinforces again and again the idea that volcanoes are land builders and necessary to combat the forces of erosion and weathering. Contains a strong chapter on volcanologists and their research.

Teacher Resources

Websites with information, illustrations, videos of eruptions and lessons:

U.S. Geological Survey:

volcano world:

Videos with footage of erupting volcanoes:

Born of Fire. Washington, D.C.: National Geographic Society, 1983. Shows the eruption of Mount St. Helens and discusses the San Francisco earthquake.

Living Planet: The Building of the Earth. New York: Ambrose Video, 1988. Scenes of a volcano erupting in Iceland and the return of plants and wildlife to Mt. St. Helens.

Nature: The Volcano Watchers. New York: Public Broadcasting Service, 1990.

Planet Earth: The Living Machine. Wilmette, IL: Films, Inc., 1986. Footage of erupting Kilauea in Hawaii.

Volcano. Washington, D.C.: National Geographic Society, 1997.

Teacher Note

The erupting volcano project is a little messy. The cardboard box is suggested as a base because its sides can contain some of the mess. When it comes time for the volcanoes to erupt in the next lesson, it is suggested that the cardboard box bases be placed on a plastic sheet or garbage bag.


Remind the students that when they studied Roman mythology, they probably heard about Vulcan, the Roman god of fire and the blacksmith of the gods. Vulcan made swords, spears, shields and Jupiter's thunderbolts at his forges deep in the Earth. The Romans believed that Vulcan's workshops were hidden deep under smoking mountains. Ask: What would you call a "smoking mountain?" (volcano) Tell the students that volcanoes are mountains, but they are clearly not the same as other mountains. Volcanoes are formed a special way.

Ask: What happens when you squeeze the bottom of a toothpaste tube? (Toothpaste comes out the opening at the top.) Ask: What if you squeezed the tube but did not take off the cap so the toothpaste had nowhere to go? Would pressure build up inside the tube? (yes) Ask: What if you squeezed and squeezed and then suddenly took off the cap? (The toothpaste would squirt out quickly.) Ask: If you had a bottle of soda and shook it up, what would happen when you finally took off the cap? (The soda would squirt out quickly with lots of bubbles.)

Tell the students that pressure from magma and steam beneath the surface of the Earth builds up as it does inside the toothpaste tube and the soda bottle. To find a release, the magma moves upward, pushing through cracks and holes until it erupts through the surface, forming a volcano. Tell the students that volcanoes have been called Earth's safety valves, releasing built-up pressure from deep inside the Earth. Volcanoes erupt through weak spots in the Earth's surface, usually at plate boundaries.

Show the students the transparency of the plate map from last lesson. Point out the perimeter of the Pacific Plate again. Tell the students that all around the edges of the Pacific Plate there are many volcanoes and earthquakes. Because the Pacific Plate is moving so much, magma is under extra pressure and erupts through the crust in many places. Tell the students that this is why this area is called "The Ring of Fire."

Show the students the transparency of a volcano (see attached). Point out that the opening where the magma and gases shoot out of the ground is called a vent. Point out the main vent. Show the students that the magma has also pushed through side vents. Ask: Does anyone know what we call magma after it comes out the vent of a volcano? (lava) Tell the students that lava pours or shoots out of the vent, runs down the sides, cools, and hardens back into solid rock. After one or several eruptions, a mountain is formed. The lava becomes new land.

Show the students the map transparency again. Point out the Hawaiian Islands. Ask: Are the Hawaiian Islands at the edges of the Pacific Plate, in the "Ring of Fire?" (no) Tell the students that the Hawaiian Islands formed at a weak spot in the plate. At this weak spot in the ocean crust, magma pushed through and volcanoes erupted. Over many eruptions, mountains of lava grew and grew until they were tall enough to reach the surface of the ocean. More eruptions, more lava, and the islands rose up out of the sea. The Hawaiian Islands are volcanic islands made totally from lava. The volcanoes that built the islands are still erupting and adding more lava now.

Ask: Does anyone remember another ocean where there is new crust being made? (Atlantic at the Mid-Atlantic Ridge, a spreading boundary) Tell the students that in 1960 a volcano erupted off the coast of Iceland in the middle of the Atlantic Ocean. The volcano had erupted many times in the past few million years and had built a tall mountain, one of the mountains in the Mid-Atlantic Ridge of mountains. This time when it erupted in 1960, it rose above the surface of the ocean and pushed up new land. Now there is a new island, a volcanic island in the Atlantic Ocean. It is called Surtsey, named after the ancient Norse god of fire.

Show the students pictures of volcanic eruptions from Suggested Books or a video of eruptions (see Teacher Resources). Tell the students that some eruptions are fairly quiet with the lava flowing out of the vent and quickly down the sides of the volcano. Other eruptions can be more explosive with lava shooting skyward and cinders, ash and gases thrown miles into the air.

Tell the students that volcanoes are known as active, dormant or extinct. An active volcano is erupting or is expected to erupt sometime in future. The volcano that formed Surtsey and the volcanoes on the Hawaiian Islands are active. A dormant volcano is sleeping. It is inactive but no one is quite sure that it will never erupt again. An extinct volcano has not erupted in human history and is not expected to erupt again.

Tell the students that they are going to build volcanoes today and, as long as they don't build extinct volcanoes, they will try to make them erupt during the next lesson. These new mountains they will make from simulated lava (clay or Playdoh). Show the students the volcano transparency again and remind them that when they build volcanoes, they should be sure to include a vent, the Earth's safety valve to release pressure. Suggest that a vent can be made by pushing a pencil down the top of the volcano almost to the base, moving it round to make the vent wider, and then taking the pencil out to leave an opening. They may want to build in some side vents that meet the main vent. Magma will be added the day of the eruption. Tell the students that if they are making dormant volcanoes, they may want to add trees, roads and houses on the sides and around the volcanoes. Ask: Why do you think dormant volcanoes could have trees growing on them? (because they have not erupted in a long time)

Divide the class into groups of five and distribute the materials.

Fourth Grade - Science - Geology - Lesson 12


Describe the differences between types of volcanoes: lava, cinder cone and composite.

Identify two types of rock formed when lava cools.

Simulate a volcanic eruption using models created in the last lesson.


Pictures of three types of volcanoes: cinder cone, lava cones (steep-sided and shield or gently- sloping), and composite (both ash and lava) from Suggested Books

Samples of obsidian or pumice, if available, or pictures of obsidian and pumice from Suggested Books

Small pitcher, large box of baking soda, warm water, bottle of white vinegar, plastic sheet or garbage bag, liquid detergent, (red or orange food coloring is optional)

Volcano Facts worksheet (attached)

Suggested Books

Branley, Franklyn. Volcanoes. New York: HarperCollins, 1985. Has a description of the eruption of Mount St. Helens as well as information on Vesuvius.

Ganeri, Anita. Earth Science. New York: Dillon, 1993. On page 14 there are two cutaway diagrams, one of a composite volcano (formed of ash and lava) and one of a shield (lava formed) volcano.

Lauber, Patricia. Volcano: The Eruption and Healing of Mount St. Helens. New York: Bradbury, 1986. Facing page 1 is a color photo of Mount St. Helens before the eruption, a composite volcano.

Markle, Sandra. Earth Alive! New York: Lothrop, 1991. See page 12 for pictures of obsidian and pumice and a good explanation of their formations.

Simon, Seymour. Volcanoes. New York: Morrow, 1988. Includes large color photos of Mount Shasta and Mount Hood, composite volcanoes, and a group of cinder cone volcanoes in Guatemala.

Taylor, Barbara. Earth Explained. New York: Holt, 1997. Section called "Exploding Earth" on pages 26-27 has small pictures of pumice and obsidian.

Vogt, Gregory. Volcanoes. New York: Franklin Watts, 1993. On page 27 there are small color photos of four volcanoes, two lava (one shield and one dome), a composite and a cinder cone.

Teacher Note

The drama of this project makes it memorable and far outweighs the possible mess. Being frugal with baking soda and vinegar, however, will produce smaller eruptions, if that is a concern. If you have a suitable area and are willing to risk larger eruptions, increase the amounts. For a small eruption, mix a teaspoon of baking soda with a little warm water in a small pitcher until the baking soda dissolves. Add a few drops of liquid detergent and a few drops of red or orange food coloring, if desired. Pour this into the volcano vent. Follow it quickly with a "glug" of vinegar from the bottle. Stand back. The result will resemble pouring too much rootbeer in a short glass.


Remind the students that this is the day they will use the models they have made to simulate a volcanic eruption. As in a real volcanic eruption, it will probably be messy.

Remind the students that in some eruptions, lava flows quickly out of the vent. One might call this a quiet eruption. The eruptions of Hawaiian volcanoes are usually "quiet." The lava is thin and runny. It shoots out or oozes out of the vent and spreads quickly, cooling and hardening into rock. After a few eruptions, layers of hardened lava form a dome with gently-sloping sides. Volcanoes of this shape are called shield volcanoes because they look a little like a warrior's shield lying on the ground. Show the students a picture of a shield volcano, such as Mauna Loa in Hawaii, from Suggested Books. Draw a profile of a gently-sloping shield volcano on the board and label it. Ask: Do any of the model volcanoes you have made resemble a shield volcano? Ask: How fast do you think lava can flow? (Accept all answers.) Tell the students that thin, runny lava can move much faster than a person can run, much faster than a car or train can move. Lava flowing downhill has been clocked at 360 miles per hour.

Tell the students that lava can also build cone-shaped volcanic mountains with steep sides if the lava is a bit thicker, like molasses. Draw a profile of a cone-shaped volcano and label it lava cone. Ask: Do any of the model volcanoes resemble a lava cone?

Tell the students that some eruptions are not "quiet." When thick and sticky magma hardens and plugs up a vent, hot gases cannot escape. They build up pressure behind the plug. The pressure builds and builds until finally, the volcano explodes. The explosion shatters the plug into millions of pieces, causing ashes and cinders to fly up in the air and come raining down. The cinders and ashes cover the ground and build up on the sides of the volcano until it is cone shaped. These volcanoes are called cinder cones. Show the students pictures of cinder cone volcanoes such as El Misti or Paricutin in Mexico from Suggested Books. Draw a profile of a cinder cone on the board and label it.

Tell the students that the most common kind of volcano is called a composite volcano. Composite volcanoes have erupted many times, sometimes with lava flows and sometimes explosively with ashes and cinders. Composite volcanoes have layers of lava and layers of ashes and cinders. Show the students pictures of composite volcanoes such as Mount St. Helens, Kilimanjaro, Mount Hood, Vesuvius. Tell the students that composite volcanoes are usually taller than cinder cones. Draw a larger cone-shaped profile on the board and label it composite.

Review the three types of volcanoes on the board and how they are formed--shield and lava cone volcanoes are all lava, cinder cones are all cinders and ash, composite volcanoes are a combination of lava and cinders.

Ask: Has anyone heard of a volcano called Mount St. Helens? Where is it located? (Washington State) Tell the students that you are going to read them a description of the eruption of Mount St. Helens in 1980. Read aloud a description from Volcanoes by Seymour Simon, pages 7-9, Volcanoes by Franklyn Branley, pages 9-10 or the much longer and richer passage in Volcano by Patricia Lauber, page 1 paragraphs one and two and pages 9-15. Ask: Was the eruption of Mount St. Helens a "quiet" eruption or an explosive one? (explosive) Was it lava that caused the damage? (It was exploding steam, gas and ashes, the force of the rock thrown in the explosion, and mud that caused the damage.)

If available, show the students the samples of pumice and obsidian or show them pictures of the rocks from Suggested Books. If possible, have several students hold the samples and describe them, their colors, weights, textures. Tell the students that these two rocks are both hardened lava formed under different conditions. Obsidian looks like black glass. It is lava that has flowed and cooled very quickly. Pumice is light and full of holes like a sponge. Pumice is lava that was full of air bubbles when it quickly cooled. Pumice is so light, it will float on water.

Set up the eruption area with a plastic sheet or garbage bags. Have one group at a time bring its volcano model to the eruption area. Have each group decide whether theirs is a lava, cinder cone or composite volcano. Pour in the lava ingredients. Discuss each eruption. When each volcano has erupted, ask: How are these simulations like real eruptions? (Lava flows out of the vent. The lava is thin and runny and flows quickly down the sides of the volcano. The lava is bubbly and full of gas.) In what ways is the simulation not like a real eruption? (The lava is not hot and glowing. It does not cool and harden into rock. It does not shoot into the air. The simulated volcanoes do not make ash or cinders.)

Possible Homework

Have the students choose one of the volcanoes on the top of the worksheet (see attached). By doing research in Suggested Books, encyclopedias or on the Internet at Volcano World (see address in previous lesson), the students will find answers to the questions.


Volcano Facts

Choose one of the volcanoes in the following list.

Look in books, encyclopedias or on the Internet for answers to the questions below about the volcano you have chosen.

Draw a picture of the volcano in the empty space below the questions.

1. Vesuvius

2. Kilauea

3. Mount Saint Helens

4. Mount Fuji

5. Surtsey

6. Mount Pinatubo

7. Mauna Loa

8. Mount Etna

9. Mount Hood

10. Izalco

11. Kimanura

Is this volcano extinct, dormant or active?

What type of volcano is it: lava (shield or cone), cinder cone, composite?

In what country is the volcano located?

When did this volcano last erupt?

Was it a violent eruption or a "quiet" eruption?

Did you find out any other interesting facts about this volcano?

Fourth Grade - Science - Geology - Lesson 13

Lava viscosity project adapted from How the Earth Works by John Farndon


Describe ways volcanoes and lava have shaped the Earth.

Measure the viscosity (flow rate) of two "lavas."

Analyze and graph data from viscosity tests.

Design a way of tapping and using geothermal energy (optional)


Birthday candle and holder, matches

World map

For each group of five: Four small paper plates, three small drink cups--one with molasses, one with shampoo and one with sand--plastic spoon, newspaper on the desks, data sheet and graph paper (attached)

Picture of Old Faithful or another geyser from Suggested Books

Suggested Books

Asimov, Isaac. How Did We Find Out About Volcanoes? New York: Walker, 1981.

Clifford, Nick. Incredible Earth. New York: Dorling Kindersley, 1996. There is a wonderful photo of a model geyser and a small photo of Old Faithful on pages 18-19.

Farndon, John. How the Earth Works. Pleasantville, NY: Reader's Digest, 1992.

Ganeri, Anita. Earth Science. New York: Dillon, 1993. Points out that there are 10,000 geysers at Yellowstone. Color photo, however, is of a geyser in New Zealand.

Markle, Sandra. Earth Alive! New York: Lothrop, 1991. On page 22 is a picture of Old Faithful.

Taylor, Barbara. Earth Explained. New York: Holt, 1997. Section called "Volcanic Landscapes" on page 28 has a very small picture of the macaques in a hot spring. On the next page there is a picture of a rather unimaginative geothermal power plant.

Whitfield, Philip. Why Do Volcanoes Erupt? New York: Viking, 1990. On pages 50 and 51 there is a clear answer to the question: What makes a geyser, plus a photo of Castle Geyser, another geyser in Yellowstone.

Teacher Note

It is necessary to draw two concentric circles in the center of the paper plates: a 2" diameter circle within a 3" circle. The students will fill the 2" circle with test liquids and time how many seconds it takes for them to spread to the 3" finish line. If the classroom has a clock with a second hand, timing will be easy. If there is no clock, the "timekeeper" in each group can count "one-potato, two-potato" for the passing seconds.


As a teaser, tell the students that in this lesson they will learn about monkeys in hot tubs.

Have students share information they found about famous volcanoes. Remind them that volcanic activity creates new land. Remind them that the Hawaian Islands and the new island of Surtsey are examples of this land building. Lava brings minerals from deep within the Earth up to the surface. Volcanic eruptions spread these minerals around. Tell the students that when the Earth was forming billions of years ago, there were many, many more volcanoes than there are now. Volcanoes all over the Earth produced rivers of hot lava. They shot steam and gases from their vents. These gases--nitrogen, carbon dioxide, carbon monoxide and sulfur dioxide--created an atmosphere. As Earth cooled, the lava hardened into a rock crust. The steam from the volcanoes condensed into water. The water fell as rain, cooled the rock and filled the oceans. All this happened over the course of a few billion years. On the board write volcanoes = land, atmosphere, oceans. Point out that volcano power has helped shape the Earth and is still shaping it now.

Remind the students that there are different kinds of lava. Some lava is thin and runny. Other lava is thick and sticky. Ask: Which lava do you think spreads faster: thin or thick? (thin) Tell the students that how fast a liquid flows is called viscosity. Write this word on the board. Tell the students that viscosity of a liquid such as lava can be measured by timing how fast it moves from one place to another, just as one would time a runner in a race from the starting line to the finish line. Liquids with high viscosity are slow runners. Liquids with low viscosity are the fast runners. Ask: What do you think makes one lava stickier, or have higher viscosity, than another? (Cooler lava does not flow as fast as hot lava.)

Light a birthday candle and have the students observe the melted wax running down the sides of the candle. Point out that as the wax is heated up by the flame and melted, it gets thin and runny. Ask: Does the wax have high or low viscosity when it is melted and moves quickly? (low viscosity) Point out that as the wax cools in the dish or holder below, it gets stickier and finally hardens just as lava hardens as it cools. Ask: Does the cooling wax have high or low viscosity (high viscosity).

Tell the students that another thing besides temperature that changes the viscosity of lava is what kind of melted rocks are in it. Lava with a lot of silica or sand in it is stickier and has a higher viscosity. Tell the students that they are going to measure the viscosity of two liquids, with and without sand added, to see if it does affect the liquid's viscosity. Divide the class into groups of five. Choose a timer to count the seconds and a recorder to record data for each group. Tell the students that they will first test each liquid for viscosity by pouring a very small puddle just big enough to fill the center circle on a paper plate. The timer will begin counting the seconds as the others observe the liquid and tell the timer to stop when the liquid reaches the finish line: the outer circle. The recorder will write down the number of seconds on the data sheet for that liquid. When they are finished recording viscosity results for the two liquids, have the students add a half-spoonful of sand to each cup and stir. Repeat the tests and record results. When the results are recorded on data sheets, help students transfer the data to the bar graph sheets. Ask: What were the results of the viscosity tests? Did you find that sand did affect the viscosity of liquids? How? (Their viscosities increased when sand was added.)

Tell the students that in just a minute you will tell them about monkeys in hot tubs but first you would like them to imagine that they live in a place called Iceland, an island near the Arctic Circle. Locate Iceland on the world map. Remind the students that Iceland is an island created by the volcanic mountains in the Mid-Atlantic Ridge, the same volcanoes that created Surtsey. Tell them that winters in Iceland are harsh, long, and very cold. But what do people in Iceland do during the winter? They stay toasty warm thanks to volcano power. They take dips in their outdoor pools thanks to volcano power. They grow grapes and bananas in greenhouses heated by volcano power. Ask: How do you think they are able to use the power of volcanoes? (Accept all answers.) Tell the students that in Iceland and in other places where there are is a lot of volcanic activity, water seeps underground and is heated up by hot volcanic rocks. The hot water bubbles up to the surface in hot springs. In the middle of winter, people can bathe in the hot springs. They pipe the hot water into radiators in their houses to keep warm. They heat swimming pools and greenhouses with the water from the hot springs.

Tell the students that on the other side of the world in northern Japan, (locate Japan on the map) there are high volcanic mountains where it is also very cold. Here there are hot springs, too. Instead of people using the hot springs, monkeys do. Tell the students that macaque (ma-KACK) monkeys keep warm in winter by lounging and snoozing in steaming natural hot tubs. Hot volcanic rocks beneath the Earth's surface heat up water that bubbles up into ponds. The monkeys depend on the warmth of the ponds to survive very harsh winters.

Ask: Does anyone know what a geyser (GUY-zer) is? Tell the students that geysers are caused by volcano power, too. In areas where there has been a lot of volcanic activity, water collects in underground chambers. The water bubbles and boils until steam forces it up through cracks in the rock. There is so much steam pressure that water and steam shoot up out of the ground like a fountain. When water seeps back into the underground chamber, the geyser shoots up again and again. Show the students pictures of Old Faithful from Suggested Books. Tell them that Old Faithful is the name of a famous geyser in Yellowstone National Park in Wyoming. Tell the students that Old Faithful shoots steam and water into the air in a fountain 164 feet high every 70 minutes. Ask: Why do you think people named a geyser Old Faithful? (because they could count on it to erupt regularly or "faithfully")

Write the words geothermal energy on the board. Tell the students that as they already know, geo means the Earth. Thermal means caused by heat. Ask them to imagine that instead of burning fuels that pollute the atmosphere, people used heat from inside the Earth--volcano power or geothermal energy--to make electricity. Suppose power plants were built that reached down into the Earth's crust and collected the heat energy there. They would be using geothermal energy.

Possible Homework

Ask the students to design a power plant that uses geothermal energy. Draw a picture of the power plant and show how the Earth's heat would be collected and how it would be used to make power.

Fourth Grade - Science - Geology - Lesson 13

Data Sheet for Viscosity Tests Name







Number of Seconds


shampoo with sand


molasses with sand