Cuernos Del Paine, Andes Mountains Gabriel Callaghan

2. Cuernos Del Paine, Andes Mountains Gabriel Callaghan

3. Examples of divergent boundaries

4. So, we’re making new crust?

5. Convergent plate boundaries 2 types of crust = 3 possible combinations • Oceanic lithosphere meets oceanic lithosphere • Oceanic lithosphere meets continental lithosphere • Continental lithosphere meets continental lithosphere

6. Convergent boundaries involving oceanic lithosphere • At convergent boundaries oceanic plates are subducted. • Subduction is the recycling of oceanic crust into the mantle

7. Play convection animation

8. Subduction zonesare characterized by two things: • Deep trench • Long chain of volcanoes Volcanic arc Trench

9. Where is this subduction zone?

10. At oceanic-oceanic convergent boundaries, volcanoes form chains of islands called island arcs. The Aleutian Islands in Alaska

11. At continental-oceanic convergent boundaries, volcanoes form long mountain chains such as the Cascade Mountains. Mt. Saint Helens

12. Subduction zones cause the largest Earthquakes known. • The 2004 Tsunami in the Indian Ocean was caused by an earthquake at a subduction zone.

13. Continent-continent convergent boundaries • Neither lithospheric plate can be fully subducted. • Instead, the plates pile up to form huge mountain ranges

14. Where is this continent-continent collision?

15. You are here

16. Play plate motions animation

17. Transform plate boundaries • Relatively few volcanoes • Lots of earthquakes, though not so large as at subduction zones

18. Where is this transform boundary?

20. Mid-ocean ridge transforms

21. Hot Spots

23. Hot Spots of the World

24. Divergent boundaries

25. Begin with rifting—upwelling of hot mantle starts to break the crust apart

26. Faults form rift valleys • Decompression causes melting and volcanism

27. New oceanic crust begins to form. The plate boundary is now a mid-ocean ridge.

28. The Theory of Plate Tectonics Active Rift Aulacogen Mantle Plume