3. This is a model of sea floor spreading at a divergent boundary called a mid ocean ridge .

4. Did you know that the Earth’s longest mountain range is underwater and is called the mid-ocean ridge? : www.ocean.udel.edu The Mid-Ocean Ridge system, shown above snaking its way between the continents, is more than 56,000 kilometers (35,000 mi) long. It circles the earth like the stitching on a baseball!

7. There are three conbinations of how earth's crust can come together. Continental crust to continental Continental crust to oceanic Oceanic crust to oceanic

8. from: http://www.geo.lsa.umich.edu/~crlb/COURSES/270 Continental crust to continental crust collision India-Asia (Himalayas) Before collision After collision

9. This is how the Himalaya Mountains formed Also the way the Appalachian Mountains formed!

10. Because one plate gets pushed under another, it is called subduction . This is where volcanoes form! Oceanic crust colliding with oceanic crust Oceanic crust colliding with continental crust all from: http://www.geo.lsa.umich.edu/~crlb/COURSES/270

11. The process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle is called subduction

12. Plate tectonics video clip Here is an great link for seeing where each type of boundary is located. Click here for a great hyperlink! Make sure you click on each type of boundary in the key!

13. Worldwide Earthquake patterns help us know where the edges of plates are located

14. The Earth’s Plates

15. Here you see the two slides together. What do you see?

16. http://www.livescience.com/images/pangea_animation_03.gif