4. The asthenosphere consists of solid rock that is flowing. But it’s not all flowing in the same direction.

5. Theory of Plate Tectonics Theory that pieces of lithosphere move around on top of the asthenosphere

6. Plate Boundaries The edges of different pieces of The lithosphere meet at lines called plate boundaries

7. Plate Boundaries Plate Videos

8. So the plates move. Now What? As the plates move, they produce changes in Earth’s surface, including volcanoes, earthquakes, mountain ranges, and deep- ocean trenches.

9. 3 Types of Plate Boundaries Divergent Convergent Transform Divergent Transform

10. 3 Types of Boundaries Divergent boundary= two plates move apart Magma rises and creates new crust or seafloor Causes: mid- ocean ridges, rift valleys, new crust, volcanoes

11. Divergent Boundaries © All Rights Reserved. Diverging Africa

12. Diverging Iceland

13. 3 Types of Boundaries Convergent= when two tectonic plates push into one another.

14. Convergent Boundaries Continental vs. Continental Continental vs. Oceanic Oceanic vs. Oceanic

15. Continental vs. Continental When two continental crustal plates collide, the continents buckle upward and form mountains. Himalayas- Asia

17. Oceanic vs. Continental The oceanic plate slides under the continental plate. The continental crust crumbles and forms new mountains.

18. Oceanic vs. Continental Ex: Andes mtn in S. America Cascade Mtns. in N. America- Mt. St. HelensMt. St. Helens

19. Oceanic vs. Oceanic Two oceanic plates collide, one of the oceanic plates slides under the other. oceanic plates slides also called a subduction zone subduction zone

20. Hawaiian Islands Oceanic vs. Oceanic

21. Transform boundary When two tectonic plates slide past each other horizontally Produces? Earthquakes

22. San Andreas Fault

23. New Madrid Fault

24. Examples of Convection Convection exampleConvection example Convection in a roomConvection in a room DOS

27. How do the plates move? CONVECTION CURRENTS Hot material rises while cooler material near the surface sinks

28. How do the plates move? CONVECTION CURRENTS Hot material from deep within the Earth rises while cooler material near the surface sinks http://education.sdsc.edu/optiputer/flash/convection.htm

30. Convection currents

32. How do we know? Sea-floor spreading =new ocean floor is created as two lithospheric plates pull away from one another. Sea-floor spreading

33. Seafloor spreading

34. The Plates Move… So what now? Which way? 50 million years