1. LESSON Essential Questions 7.3 The Theory of Plate Tectonics What is the theory of plate tectonics? What are the three types of plate boundaries? What results from interactions of tectonic plates?

2. The Theory of Plate Tectonics Vocabulary plate tectonics divergent plate boundary transform plate boundary convergent plate boundary subduction convection

3. Theory that suggests that the Earth’s surface is divided into large plates of rigid rock that move over the Earth’s hot and semi-plastic mantle. plate tectonics

4. divergent plate boundary Places on the Earth’s crust that move apart as a result of pulling forces (tension) that act in opposite directions on each plate. New Lithosphere is created at this boundaries. Creates mid-ocean ridges and rift valleys

5. transform plate boundary Plates that slide past each other at different speed and or direction. Causes: earthquakes and tsunamis

6. convergent plate boundary When plates move toward each other, they collide, the outcome of the collision depends on the density of the plates involved. See below.

7. subduction When and oceanic plate collides with an oceanic plate or with a continental plate, the denser plate sinks under the less dense one and forms a deep trench. The subducting plate sinks into the mantle and melts. This is why the Earth doesn’t grow larger. It destroys crust by melting it into the mantle. Creates volcanic island chains, trenches and volcanoes.

8. convection Heat transfer in fluids caused by differences in temperature and density. The hot molecules separate becoming less dense and rise, when they cool they get closer together become heavier and fall to the bottom to start the cycle over again.

9. LESSON 7.3 The Theory of Plate Tectonics Earth’s crust is made of 14 tectonic plates that interact at their boundaries in various ways. Lesson Main Idea

10. The arrows indicate whether the plates are convergent, divergent or transforming

11. LESSON Texas Essential Knowledge And Skills 7.3 The Theory of Plate Tectonics 6.10(C) Identify the major tectonic plates, including Eurasian, African, Indo- Australian, Pacific, North American, and South American.

12. LESSON Texas Essential Knowledge And Skills Eurasian Plate North American Plate Pacific Plate South American Plate African Plate Indo-Australian Plate Antartic Plate

13. LESSON Texas Essential Knowledge And Skills 7.3 The Theory of Plate Tectonics 6.10(D) Describe how plate tectonics causes major geological events such as ocean basins, earthquakes, volcanic eruptions, and mountain building.