1 / 14

Our Changing Earth

Our Changing Earth. What is a Theory?. In science, it’s almost the same as a fact Must be some sort of evidence to support a theory Even with evidence there is still debate about how true it is. Continental Drift Theory.

kailani
Download Presentation

Our Changing Earth

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. Our Changing Earth

  2. What is a Theory? • In science, it’s almost the same as a fact • Must be some sort of evidence to support a theory • Even with evidence there is still debate about how true it is

  3. Continental Drift Theory • Alfred Wegener said the world used to be one large land mass millions of years ago • The land was called Pangaea • Pangaea kept moving apart a few centimeters each year • After millions of years it became the world we see today

  4. Continental Drift Theory Evidence for Continental Drift includes includes includes includes Continental Edges Rock Structures Same Fossils Climate fit like showed seen in evidence from found Mountains with similar features Puzzle Pieces Continental ice sheets On different continents

  5. Plate Tectonics • Plate Tectonics – a more advanced theory about how the continents move • Explains that there are loose plates in the earth that shift causing: • Oceanic Trenches • Mountains • Volcanoes • Earthquakes.

  6. How Do the Plates Move? http://library.thinkquest.org/17457/english.html

  7. So… • Continental Drift – theory that says continents drift around on plates • Plate Tectonics – theory that explains WHY scientists believe the continental drift theory is true

  8. Now it’s time for a… REVIEW

  9. What is Continental Drift? Theory that says the continents are moving on plates

  10. What is Plate Tectonics? Theory that explains WHY scientists think continental drift occurs It tells us how the earth’s plates move

  11. Divergent Boundaries • This is when the plates move apart • It happens mostly between oceanic plates • The rising magma causes volcanoes and underwater mountains to be formed

  12. Convergent Boundary • When the two plates are in the OCEAN they collide and form deep trenches. • When the two plates are on the CONTINENTS they collide to form mountains.

  13. Transform (Sliding) Boundaries • This is when the plates slide past each other or move horizontally • The sliding is what causes earthquakes • This type of boundary is found in California

More Related