1. Chapter Introduction Lesson 1 Earth’s Moving Surface Lesson 2 Shaping Earth’s Surface Lesson 3Changing Earth’s Surface Chapter Wrap-Up Chapter Menu

2. What processes change Earth’s surface? Chapter Introduction

3. What do you think? Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements. Chapter Introduction

4. 1. Earth’s surface is made up of tectonic plates. 2. Tectonic plate motion is too slow to measure. 3. Most earthquakes occur near tectonic plate boundaries. 4. Volcanoes can erupt anywhere. Do you agree or disagree? Chapter Introduction

5. 5. Wind erosion only occurs in the desert. 6. Rivers are the only cause of erosion. Do you agree or disagree? Chapter Introduction

6. Earth’s Moving Surface • What is the theory of plate tectonics? • What are the differences between divergent, convergent, and transform plate boundaries? • What causes tectonic plates to move on Earth’s surface? Lesson 1 Reading Guide - KC

7. Earth’s Moving Surface • convergent boundary • subduction • transform boundary • convection • plate tectonics • lithosphere • asthenosphere • divergent boundary Lesson 1 Reading Guide - Vocab

8. Plate Tectonics • The theory of plate tectonics states that Earth’s surface is broken into large, rigid pieces that move with respect to each other. • These pieces, or tectonic plates, move slowly over Earth’s surface. Lesson 1-1

9. Tectonic plate motion and other processes have affected North America. The western United States has tall mountains, while the central region is flat. Lesson 1-1

10. Plate Tectonics (cont.) What is the theory of plate tectonics? Lesson 1-1

11. Plate Tectonics (cont.) tectonic from Greek tekton, means “builder” Lesson 1-1

12. Plate Tectonics (cont.) • The Earth’s crust and uppermost part of the mantle make up the lithosphere. • The lithosphere forms a rigid shell on the outside of Earth which is broken into tectonic plates. Lesson 1-1

13. Scientists have identified 15 large tectonic plates. Lesson 1-1

14. Plate Tectonics (cont.) • The partially melted portion of the mantle below the lithosphere is the asthenosphere. • The asthenosphere is hotter than the lithosphere and can bend more easily. Lesson 1-1

15. Plate Boundaries • Scientists describe the movement of tectonic plates, in terms of relative motion—how it moves in relation to another plate. • As plates move relative to each other, they form different types of boundaries. • The type of boundary depends on the relative motion of the plates. Lesson 1-2

16. Plate Boundaries(cont.) • A boundary where two plates move away from each other is called a divergent boundary. • As plates at a divergent boundary move apart, new crust forms between them. Lesson 1-2

17. Plate Boundaries(cont.) • A boundary where two plates move toward each other is a convergent boundary. • In some convergent boundary locations, one plate is pushed under the other plate and down into the mantle where it melts and becomes part of the mantle. Lesson 1-2

18. Plate Boundaries(cont.) Subduction is the process that occurs when one tectonic plate moves under another tectonic plate. Lesson 1-2

19. Plate Boundaries(cont.) Two plates slide past each other at atransform boundary. Lesson 1-2

20. Plate Boundaries(cont.) What are the differences between divergent, convergent, and transform plate boundaries? Lesson 1-2

21. Measuring Plate Movement • Tectonic plates move horizontally over Earth's surface. • During the 1970s, scientists and engineers developed new technologies that enabled them to measure how fast tectonic plates move. • The position of any point on Earth’s surface can be accurately measured using the network of satellites known as the Global Positioning System (GPS). Lesson 1-3

22. North America and Europe once were part of a large continent called Pangaea. Over time, tectonic plate motion broke apart the supercontinent Pangaea. Lesson 1-3

23. Measuring Plate Movement(cont.) • A divergent boundary formed between North America and Europe about 200 million years ago. • The plates moved apart, and the Atlantic Ocean formed. • North America is separating from Europe at an average rate of just 2.5 cm per year. Lesson 1-3

24. Why do tectonic plates move? • The circulation within fluids caused by differences in density and thermal energy is called convection. • Convection occurs in Earth’s asthenosphere, just below the lithosphere. Lesson 1-4

25. Why do tectonic plates move?(cont.) Convection in the mantle can drag plates over Earth’s surface. Lesson 1-4

26. Why do tectonic plates move?(cont.) • Another process that causes plate movement is subduction. • When two plates collide, one can subduct or sink into the hotter, less-dense mantle. • When this happens, the rest of plate is pulled along behind the sinking part of the plate. Lesson 1-4

27. Why do tectonic plates move?(cont.) What causes tectonic plates to move? Lesson 1-5

28. Earth’s lithosphere is broken into pieces called plates. These plates move on Earth’s surface and interact in three different ways. Lesson 1 - VS

29. GPS can be used to measure and track plate movement. Lesson 1 - VS

30. Convection in the mantle causes tectonic plates to move across Earth’s surface. Lesson 1 - VS

31. Which term refers to a location where two plates slide past each other? A. asthenosphere B. lithosphere C. divergent boundary D. transform boundary Lesson 1 – LR1

32. At about what rate is North America separating from Europe? A. 2.5 centimeters per day B. 2.5 centimeters per year C. 2.5 meters per year D. 2.5 miles per year Lesson 1 – LR2

33. Which is the partially melted portion of the mantle below the lithosphere? A. divergent boundary B. transform boundary C. tectonic plate D. asthenosphere Lesson 1 – LR3

34. 1. Earth’s surface is made up of tectonic plates. 2. Tectonic plate motion is too slow to measure. Do you agree or disagree? Lesson 1 - Now

35. Shaping Earth’s Surface • Where do most earthquakes occur? • How are landforms related to plate tectonics? • Where do most volcanoes form? • How does plate movement form mountains? Lesson 2 Reading Guide - KC

36. Shaping Earth’s Surface • volcano • mid-ocean ridge • earthquake • fault • magma • lava Lesson 2 Reading Guide - Vocab

37. Earthquakes An earthquakeis the vibrations caused by the rupture and sudden movement of rocks along a break or a crack in Earth’s crust. Lesson 2-1

38. The strong shaking of Earth’s surface can damage both natural features and human-made structures. USGS photo by Walter D. Mooney USGS Lesson 2-1

39. Earthquakes occur at faults. • A faultis a crack or a fracture in Earth’s crust along which movement occurs. • Convection currents beneath tectonic plates force the rocks on either side of the fault to move. Photograph by N.J. Silberling, USGS Photo Library, Denver, CO Lesson 2-1

40. Earthquakes(cont.) fault Science Use a fracture in the crust of a planet Common Use responsibility for wrongdoing or failure Lesson 2-1

41. The magnitude of an earthquake refers to how much energy is released during an earthquake. Lesson 2-1

42. Earthquakes(cont.) • Most earthquakes occur at plate boundaries. • A plate boundary is made up of more than one fault and covers a large region. • Faults are largest where one plate subducts into the mantle, and the strongest earthquakes occur at these locations. Lesson 2-1

43. The convergent boundary between the Indian Plate and the Burma Plate (part of the Eurasian Plate) ruptured in 2004. The area of the rupture is indicated in green on the map. Smaller earthquakes have occurred in the purple areas. Lesson 2-1

44. Earthquakes(cont.) Where do most earthquakes occur? Lesson 2-1

45. Different types of movement occur at the three types of plate boundaries. • At a transform boundary, blocks of crust move horizontally past each other. • Features that cross the fault, such as streams, are shifted both by plate movement and by earthquakes. Lesson 2-1

46. At divergent boundaries between oceanic plates, mid-ocean ridges form. • Between continental plates, one side of the fault moves down relative to the other side of the fault. • Normal faults form valleys at these boundaries. Lesson 2-1

47. At subduction zones of convergent boundaries, the plate that does not subduct deforms and crumples as the two plates push toward each other. • As the mantle near the subducted plate melts, magma rises and forms a volcanic arc on the plate that does not subduct. Lesson 2-1

48. At convergent boundaries with no subduction, the edges of both tectonic plates become crumpled and deformed. • Because neither plate subducts, blocks of crust slide upward along a complex series of faults called reversefaults. • This results in the formation of tall mountains. Lesson 2-1

49. Earthquakes(cont.) How are landforms related to plate tectonics? Lesson 2-1

50. Volcanoes Volcanoes are vents in Earth’s crust through which molten rock flows. Lesson 2-2