Layers of the Earth Grade Level: 3 5 Teacher Guidelines page 1 Instructional Pages pages 2 4 Review Page page 5 Crossword Puzzle page 6 Answer Key pages 7 8
Classroom Procedure: 1. Without comment the teacher will be wearing 4-6 layers of shirts, jackets, etc. as students walk into the classroom, or will add the clothing while beginning the lesson. 2. The teacher will then ask the students: Why do you think I am wearing a number of layers of clothing? 3. Allow for responses: May include protection, warmth, etc. (The point is to get students thinking about layers, leading to the main topic: The Layers of the Earth.) 4. Introduce students to the topic: The Layers of the Earth 5. Tell students they will discover the meaning of each of the displayed numbers 6. Distribute the reading content: The Layers of the Earth 7. Have students read the information page independently or read aloud as a class. 8. After reading, ask for student volunteers to go to each of the displayed Number pages and write the meaning of the number. 9. Once completed, distribute Handout #1: Review Page 10. Allow students time to complete the handout independently 11. Review and discuss the students responses to the handout, correcting errors, and checking for understanding 12. Have a final discussion, review the names of the layers of the Earth, answer students questions, and encourage students to research some of the additional resources on their own 13. Distribute the Crossword Puzzle for homework 14. The next day, collect homework or review the answers for students to check Approximate Grade Levels: 3-5 Objectives: The students will be able to identify the four main layers of the Earth and identify some characteristics of each layer. Class Sessions (45-60 minutes): One Teaching Materials/Worksheets: Layers of the Earth content page, review page, crossword puzzle, and answer keys. Number pages for display in the classroom with answer key. Student Supplies: None, except handouts Prepare Ahead of Time: Display the Number pages throughout the classroom. Have extra articles of shirts, coats, etc. Additional Resources: http://www.learner.org/interactives/dynamicearth/str ucture.html http://volcano.oregonstate.edu/earthslayers-lesson-1 http://www.enchantedlearning.com/subjects/astrono my/planets/earth/inside.shtml (useful for advanced students and with many more details) Options for Lesson: Instead of the layers of clothing opening, have different types of balls split in half showing layers. Use half pieces of fruit for each student they can then eat. Switch in-class work to the puzzle and the review sheet for homework. To save time do not display the Number pages. 1
Layers of the Earth The Earth is not simply a giant ball made up of dirt, rocks, or minerals. The Earth is much more than what meets the eye as you walk on top of the surface. There are four main layers that make up the Earth: crust, mantle, outer core, and inner core. 2
Layers of the Earth Crust The first layer you are quite familiar with because you walk on it every day, or maybe dig holes into it. It is the Earth s crust. The Earth s crust is the outer layer of the Earth and is about 5 to 25 miles thick depending on its location. It is the thinnest layer, only about 3-5 miles thick under the oceans which is called the oceanic crust. Under the continents it is about 25 miles thick, which is called the continental crust. The temperatures of the Earth s crust can be anywhere between air temperature and 1600 F, which is hot enough to melt rocks. The thin layer of the crust is also broken into pieces called plates. The plates float on top of soft mantle below the crust and this movement can sometimes cause earthquakes to occur. Two other areas that are part of the next layer, the mantle and crust, are the lithosphere and the asthenosphere. These two areas are mostly composed of rock types called granite and basalt. Mantle The second main layer of the Earth is called the mantle. The mantle of the Earth is the largest layer and is about 1800 miles thick. It is made up of extremely hot, dense rock and flows like asphalt. The temperature at the top of the mantle is about 1600 F and at the bottom it is about 4000 F. Basically, the mantle is made up of melted rock which allows the plates of the Earth s crust to float on top of it. The melted rock that escapes to the Earth s surface is what leads to the volcanoes that occur in the world. 3
Inner Core & Outer Core The final layers of the Earth include the outer core and the inner core. The outer core is basically melted metals, nickel and iron, that move as a liquid. The outer core is located about 1800 miles below the Earth s surface and is about 1400 miles thick. The outer core has temperatures between 4000 F and 9000 F. The inner core is about 800 miles thick and the temperatures may be as high as 9000 F. There is so much pressure that the metals are squeezed so tightly together they are forced to vibrate as solids. The weight of the other layers of the Earth is basically pressing down onto the inner core of the Earth. In summary, the four main layers of the Earth include the crust, mantle, inner core, and outer core. Two additional areas located between the crust and mantle are the lithosphere and the asthenosphere. Earthquakes are caused by the movement of the pieces of the Earth s crust called plates, and when a volcano erupts the melted rock comes from the mantle of the Earth. Finally, the inner and outer core are the hottest and deepest of the layers and are under the most pressure. There are many other details to learn about the layers of the Earth, which can be found on the Internet or through many books available at your school or local library. 4
Review Page Name Label the Four Main Layers of the Earth: 1. 2. 3. 4. Fill in the blank 5. The thickest layer of the Earth is the. 6. The thinnest layer of the Earth is the. 7. The hottest layer of the Earth is the. 8. The two areas that are part of the mantle and the crust are called the and 9.. Answer the following questions 10. What are the two metals located in the outer core and why do they float? 11. Explain the cause of an earthquake: 12. Explain where the melted rock from a volcano comes from: 5
Homework Page Name Solve the crossword puzzle based on the information you learned about the layers of the Earth There are many other details to learn about the layers of the Earth, which can be found on the Internet or through many books available at your school or local library. 6
Review Page ANSWER KEY Name Label the Four Main Layers of the Earth: 1. Crust 2. Mantle 3. Inner core 4. Outer core Fill in the blank 5. The thickest layer of the Earth is the mantle. 6. The thinnest layer of the Earth is the crust. 7. The hottest layer of the Earth is the core or inner core. 8. The two areas that are part of the mantle and the crust are called the lithosphere and 9. asthenosphere. Answer the following questions 9. What are the two metals located in the outer core and why do they float? The two metals located in the outer core are iron and nickel. They float because the temperature is so hot metals melt into a liquid. 10. Explain the cause of an earthquake: An earthquake is caused by the movement of the Earth s crust which is made up of several pieces called plates. The plates float on top of soft mantle below the crust and this movement can sometimes cause earthquakes to occur. 11. Explain where the melted rock from a volcano comes from: The melted rock from a volcano comes from the melted rock that is located in the mantle of the Earth. 7
Homework Page ANSWER KEY Name Solve the crossword puzzle based on the information you learned about the layers of the Earth 8