1 / 31

Chapter Menu

Chapter Introduction Lesson 1 Plate Tectonics Lesson 2 Earthquakes and Volcanoes Lesson 3 Weathering, Erosion, and Deposition Chapter Wrap-Up. Chapter Menu. 1. Continents do not move. 2. Earth ’ s mantle is liquid.

keira
Download Presentation

Chapter Menu

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter Introduction Lesson 1 Plate Tectonics Lesson 2 Earthquakes and Volcanoes Lesson 3Weathering, Erosion, and Deposition Chapter Wrap-Up Chapter Menu

  2. 1. Continents do not move. 2. Earth’s mantle is liquid. 3. Earthquakes occur and volcanoes erupt only near plate boundaries. • Volcanoes erupt melted rock. 5. Rocks cannot change. 6. Sediment can be transported by water, wind, and ice. Do you agree or disagree? Chapter Introduction

  3. Plate Tectonics • What is the theory of plate tectonics? • What evidence do scientists use to support the theory of plate tectonics? • How do the forces created by plate motion change Earth’s surface? Lesson 1 Reading Guide - KC

  4. Plate Tectonics • transform boundary • subduction zone • compression • tension • shear • plate tectonics • continental drift • convergent boundary • divergent boundary Lesson 1 Reading Guide - Vocab

  5. Plate Motion • The theory of plate tectonics states that Earth’s crust is broken into rigid plates that move slowly over Earth’s surface. • The rigid plates are called tectonic plates. • North America is part of the North American Plate. Lesson 1-1

  6. Plate Motion(cont.) • The movement of one plate is described as either moving away from or toward another plate, or sliding past another plate. • Plates move at speeds of only a few centimeters per year. • At this rate, it takes moving plates millions of years to make new continents, new mountain ranges, or other landforms. Lesson 1-1

  7. Plate Motion(cont.) Long before geologists proposed the theory of plate tectonics, they discovered evidence of continental movement. Photo by G.K. Gilbert, U.S. Geological Survey Lesson 1-1

  8. Plate Motion(cont.) • In 1912, Alfred Wegener developed the hypothesis that continents move, called continental drift. Lesson 1-1

  9. Plate Motion(cont.) • One piece of evidence is the shape of Earth’s continents. • The outlines of South America and Africa match up like pieces of a puzzle. Lesson 1-1

  10. Wegener used different types evidence to back up his hypothesis: • Geological evidence • Fossil evidence

  11. Plate Motion(cont.) • Fossil and rock evidence from the Gondwana continents also supports the hypothesis of continental drift. Lesson 1-1

  12. Geologists have discovered the same types of fossils on continents that are now separated by vast oceans. Lesson 1-1

  13. Plate Motion(cont.) • Scientists have also found geological evidence. • Rocks that are made of similar substances and mountains that formed at similar times are present on continents that are now far apart. Lesson 1-1

  14. Plate Motion(cont.) • Wegener’s hypothesis of continental drift was not accepted for more than 50 years after it was proposed. • The main reason for this was because he could not explain how the continents could move. Lesson 1-1

  15. Plate Motion(cont.) • Convection is the circulation of particles within a material caused by differences in thermal energy and density • Convection affects the mantle underneath tectonic plates. • Hotter mantle rises toward Earth’s surface and cooler mantle sinks deeper into the mantle. Lesson 1-1

  16. Plate Motion(cont.) As the Earth’s mantle moves, it pushes and pulls tectonic plates over Earth’s surface. Lesson 1-1

  17. Tectonic Plate Boundaries • The edges of tectonic plates are called plate boundaries. • A convergent boundary is where two plates move toward each other. • A divergentboundary is where two plates move apart from each other. • A transformboundary is where plates slide horizontally past each other. Lesson 1-2

  18. Convergent Boundaries • When two plates come together, the denser oceanic plate usually is forced down into the mantle and the less dense continental plate remains on Earth’s surface. • The area where one plate slides under another is called a subduction zone. Lesson 1-2

  19. Convergent Boundaries • When two continents collide at a plate boundary, both continents remain on the surface. • As two continents push together, the crust rises up and large mountains form. Lesson 1-2

  20. Divergent Boundaries • When plates move apart at divergent boundaries, a rift forms between the two plates. • A rift can form within continents when continental crust moves in opposite directions. Lesson 1-2

  21. Divergent Boundaries • A rift also can form at divergent boundaries on the ocean floor. • As plates separate, molten rock can erupt from the rift. • As the molten rock cools, it forms new crust. Lesson 1-2

  22. Transform Boundaries • Tectonic plates slide past each other at transform boundaries. • The two sides of the boundary move in opposite directions. • This can deform or break features such as fences, railways, or roads that cross the boundary. Lesson 1-2

  23. Forces Changing Earth’s Surface • Forces within Earth cause plates to move. • The three types of plate boundaries experience different types of forces. Lesson 1-3

  24. The squeezing force at a convergent boundary is calledcompression. • The pulling force at a divergent boundary is called tension. • The side-by-side dragging force at transform boundaries is called shear. Lesson 1-3

  25. Forces Changing Earth’s Surface(cont.) • Even though plates move slowly, the forces at plate boundaries are strong enough to form huge mountains and powerful earthquakes. • Tensional forces pull the land apart and form rift valleys and mid-ocean ridges. • Compressional forces form mountains. Lesson 1-3

  26. Evidence of continental drift includes fossils, mountain ranges, rock types, and the shapes of continents. • Earth’s crust is broken into pieces called tectonic plates. Convection currents in the mantle cause the plates to move. Lesson 1 - VS

  27. There are three types of tectonic plate boundaries. Movement occurs at all three boundaries. Lesson 1 - VS

  28. Which boundary is between two plates moving toward each other? A. convergent B. divergent C. subduction D. transform Lesson 1 – LR1

  29. Which zone describes the boundary where one plate slides under another plate? A. convergent B. divergent C. subduction D. transform Lesson 1 – LR2

  30. Which is the side-by-side dragging force at transform boundaries? A. shear B. tension C. compression D. continental drift Lesson 1 – LR3

  31. 1. Continents do not move. 2. Earth’s mantle is liquid. Do you agree or disagree? Lesson 1 - Now

More Related