Chapter 13, Introduction and Lesson 1.

Materials:

• Worksheet, 13-01 "Movement of the Earth's Crust."

Objective:

• Students will Identify the earth's layers.
• Students will explain continental drift, sea-floor spreading, and plate tectonics.

Anticipatory Set:* Set up a baking dish with water in it. Put some small pieces of aluminum foil in the dish and send them floating around. As they move about rubbing into each other and floating around. The discussion of ways the surface of the earth resembles this demonstration. Keep records of students' responses and refer back to them as you proceed through the chapter.

Show the picture on Page 306. Discuss what is happening in the picture. Ask the student to suggest why a volcano erupts.

Show the students the Organize Your Thoughts diagram from Page 307. Go through how the chapter is organized.

Go through the goals for the chapter on Page 307.

Teacher Input:* Discuss the picture on Page 308 of the earth's layers. Show the students a more detailed picture which includes movement of the mantle as it heats up at the core and then cools at the surface. Show the students a third picture which discusses the fact that we still don't know what is under our feet. Discuss the two ideas of this poster.

Show a picture of the earth and suggest similarities between the rocks and fossils of Brazil and the rocks and fossils of West Africa. Discuss other similarities between Fossils and rocks of East Africa and Western Australia. There are also similar rocks found in North Carolina and Northwest Africa. What does this suggest? Explain the idea of Continental drift and how the continents may have broken apart over time.

During world war II scientists figured out ways to detect Submarines under the oceans surface. These methods were used after that to map the ocean floor. Scientists were amazed to find that is was not nearly as flat as they had thought. Show this picture of the ocean surface and discuss the features of the ocean floor. Explain sea-floor spreading.

• There are rift valleys.
• 8 times more heat is found at these rift valleys.
• Magma rises through these cracks and forms new rock.
• The age of there rock on the ocean floor increases with distance from the ridge.

These ideas of continental drift and sea-floor spreading lead to a bigger idea of Plate Tectonics. Even though this movement is very slow about the speed that your hair grows, we can feel the effects. How? (Earthquakes) Discuss this diagram and how it can be used to tell us where the edges of the plates are. On page 310 discuss the movement of plate and what is happening at the zone where the plates meet. Ask the students to predict what they would see at the different edges. Define plate tectonics and Plate.

Remind the students of the convection currents in the Mantle. Show this picture and explain how the convection currents in the mantle affect the direction the plates are moving.

Guided Practice:* Each site will be assigned one of the questions from page 312. Students will then take turns answering the questions in class.

Independent Practice:* Students will complete the worksheet, "Movement of the Earth's Crust."

Check for Understanding:* Students will take a quiz on 13-01, "Movement of the Earth's Crust"

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).

Alaska Content Standards Addressed in this lesson:

• SCI A-1 Students will understand models describing the nature of molecules, atoms, and sub-atomic particles and the relation of the models to the structure and behavior of matter (Structure of Matter);
• SCI A-3 Students will understand models describing the composition, age, and size of our universe, galaxy, and solar system and understand that the universe is constantly moving and changing (Universe);
• SCI A-4 Students will understand observable natural events such as tides, weather, seasons, and moon phases in terms of the structure and motion of the earth (Earth);
• SCI A-6 Students will understand that forces of nature cause different types of motion and describe the relationship between these forces and motion (Motion);
• SCI A-7 Students will understand how the earth changes because of plate tectonics, earthquakes, volcanoes, erosion and deposition, and living things (Processes that Shape the Earth);

• SCI A-15 Students will use science to understand and describe the local environment (Local Knowledge); and: