1 / 12

PLATE TECTONICS

PLATE TECTONICS. If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle. So how do convection currents cause plate movements? . As semi-molten rock in the mantle is heated it becomes less dense than its surroundings and rises.

ingrid
Download Presentation

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 If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

  2. So how do convection currents cause plate movements? As semi-molten rock in the mantle is heated it becomes less dense than its surroundings and rises. As it reaches the crust above, it spreads out carrying the plates above with it. As the semi-molten rock then cools, it gradually sinks back down to be re-heated.

  3. The Earth’s crust is divided into 8major plates which are moved in various directions.

  4. What are tectonic plates made of? • Plates are made of rigid lithosphere. The lithosphere is made up of the crust and the upper part of the mantle.

  5. Continental Drift Alfred Wegener 1900’s continents were once a single land mass that drifted apart atop a liquid core.

  6. Evidence of Pangea

  7. What was the problem with continental drift theory?

  8. Sea Floor Spreading

  9. Sea Floor Spreading • Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins • Magma rises to the surface and solidifies and new crust forms • Older Crust is pushed farther away from the ridge

  10. Oceanic crust is more densethan Continental crust

  11. Lithosphere is broken into tectonic plates

  12. But why do tectonic plates move?

More Related