1. Plate Boundaries

2. Types of Crust Continental Crust Less dense granite Oceanic Crust More dense basalt

3. Divergent Boundaries Two plates move apart (diverge from each other). New crust is formed from magma.

4. Underwater Mid ocean ridges. Seafloor Spreading. EX: Mid Atlantic Ridge On Land Rift Valleys. EX: African Rift Valley, New Madrid Fault System

5. Mid Ocean Ridge

6. Mid Atlantic Ridge

7. Rift Valley

9. Convergent Plate Boundaries Plates come together (converge) The denser plate (Oceanic Crust) sinks while the less dense plate (Continental Crust) rises. 3 types of collisions….

10. Continental colliding with oceanic. A Zone of Subduction occurs, the denser plate is forced underneath the less dense plate and melts. Volcanoes and Trenches. Possible earthquakes and tsunamis. EX: Mt. St. Hellens

12. Oceanic/Continental Convergence

13. Oceanic colliding with oceanic. Subduction Volcanoes, trenches, and island arcs. EX: Mariana Trench and Alaskan islands Possible earthquakes and tsunamis

15. Oceanic/Oceanic Convergence

16. Continental plates colliding with continental plates. Mountain range EX: Himalayan Mountains

18. Continental/Continental Convergence

19. Transform Boundaries Two plates move past each other in opposite directions. Faults lines and earthquakes. EX: San Andreas Fault

20. Transform Boundary

22. Hot Spots Volcanic activity that does not occur on plate boundaries occurs at hot spots. Magma shoots up through the lithosphere. Hot Spots are in fixed locations, as the lithospheric plates move over them. EX Yellow Stone National Park and Hawaii

24. Tsunami A series of long waves that travel across the oceans at very fast speeds. Caused by Earthquakes which vertically move the sea floor (zones of subduction).

25. Geysers and Ocean Vents A geyser is a vent on Earth’s surface that periodically shoots out hot water. An ocean vent is a vent underwater which releases heat, warming the water around it. Both are caused by volcanoes!