1 / 32

Plate Tectonics

Plate Tectonics. Looking at the world map, what do you notice about the shape of the continents?. The thing is…the world didn’t always look like this! It used to look like this:. How is this possible?!?!?. Plate Tectonics Theory.

flower
Télécharger la présentation

Plate Tectonics

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. Plate Tectonics

  2. Looking at the world map, what do you notice about the shape of the continents?

  3. The thing is…the world didn’t always look like this! It used to look like this:

  4. How is this possible?!?!?

  5. Plate Tectonics Theory • The earth is divided into a number of large and small plates and the plates are floating on the mantle

  6. Can you see the direction of movement?

  7. What about the tectonic map, see anything sneaky? What major physical features does this map show?

  8. Plate Boundaries In some places of the world, plates move away from each other. This is because magma from the mantle spreads open the ocean floor.

  9. Divergent boundary:

  10. This is an area of Iceland where two pieces of land are getting further from each other.

  11. Some plates are moving toward each other and are colliding

  12. When Ocean Plates collide with Contintental Plates • Can Create near coast volcanoes • Can create earthquakes

  13. When a continental plate collides with another continental plate • Mountainranges are created (example: Himalayan Mountains)

  14. Himalayan Mountains

  15. Sometimes plates are neither moving toward nor away from each other, they are moving past one another.

  16. Transform Fault Boundary • The plates may move in opposite directions or in the same directions but at different rates and frequent earthquakes are created (example: San Andreas Fault)

  17. San Andreas Fault

  18. So is the Earth getting bigger? • No • Plates are destroyed as fast as they are created (2 ways) • Plates may be subducted and melted or may push be pushed upward to form mountains

  19. What causes this? Convection currents within the mantle

  20. Speed of Spreading • Atlantic Ocean – 2-3 cm/year • South Pacific Ocean – 15-18 cm/year

  21. Continental Drift Theory The continents have shifted their position over geologic time

  22. At one time all land masses were connected into one piece called Pangaea

More Related