Wegener1880-1930                   earthobservatory.nasa.gov            Alfred Wegener first proposed the            theo...
 Continental drift was Wegener’s theory  that all continents had once been joined  together in a single landmass and have...
Fit of ContinentsAcross the AtlanticMountain ranges inSouth America line up exactly with those in Africa!
http://evolution.berkeley.edu/evolibrary/images/history/fossils3.gifNotice how fossils lined up across continents!
Amazing Facts: Did you know......that India was once in the Southern Hemisphereconnected to Antarctica?...that North Ameri...
An example of the proof for changing climate:                                              At one time,                   ...
He could not find the force that was causing the continents to drift. Because of this, he could not convince anyone that c...
Discovery of Sea-Floor Spreading Sea floor spreading video clip
Sea-FloorSpreading              m.y.              means              million              years ago            Notice this...
http://platetectonics.pwnet.org/img/blocks.gifAs the sea floor spreads, the lava cools according to themagnetic poles at t...
What causes sea floor spreading?     Convection currents!
Click here for a hyperlink to an animation of convection         Be sure to click the play button!
Animation of sea floor spreadingCan you explain this diagram!?
The place where two plates moveapart or diverge is called a divergentboundary.
This is a model of sea floor spreading at a divergentboundary called a mid ocean ridge.
: www.ocean.udel.eduDid you know that the Earth’s longest mountain range isunderwater and is called the mid-ocean ridge? T...
Continental crust diverging from continental
A convergent boundary is where two platescome together, or converge. The result of theplates hitting together is called a...
A transform boundary is a place wheretwo plates slip past each other, moving inopposite directions.
San Andreas Fault in California
en ta l                           on tin                            oc                    ru st t             t al c      ...
Continental crust to continental crustcollision              Before collision      India-Asia (Himalayas)                 ...
Because one plate gets pushed under  another, it is called subduction. This  is where volcanoes form!                     ...
The process bywhich the oceanfloor sinksbeneath a deep-ocean trenchand back intothe mantle iscalled
Here is an great link for seeing where each type of  boundary is located.  Click here for a great hyperlink! Make sure you...
Worldwide Earthquake patterns help usknow where the edges of plates are located
The Earth’s Plates
Here you seethe two slidestogether.What do yousee?
http://www.livescience.com/images/pangea_animation_03.gif
Continental drift presentation
Continental drift presentation
Continental drift presentation
Continental drift presentation
Continental drift presentation
Continental drift presentation
Continental drift presentation
Continental drift presentation
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Continental drift presentation

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Continental drift presentation

  1. 1. Wegener1880-1930 earthobservatory.nasa.gov Alfred Wegener first proposed the theory of continental drift.
  2. 2.  Continental drift was Wegener’s theory that all continents had once been joined together in a single landmass and have drifted apart since. Wegener named this supercontinent Pangaea. Wegener’s theory was rejected by scientists because he could not explain what force pushes or pulls continents. Continental drift video clip
  3. 3. Fit of ContinentsAcross the AtlanticMountain ranges inSouth America line up exactly with those in Africa!
  4. 4. http://evolution.berkeley.edu/evolibrary/images/history/fossils3.gifNotice how fossils lined up across continents!
  5. 5. Amazing Facts: Did you know......that India was once in the Southern Hemisphereconnected to Antarctica?...that North America was once surrounded by warm,tropical seas?...that Africa was once covered by glaciers, which werekilometers in thickness?...that the Sahara desert was once a tropical rain forest?
  6. 6. An example of the proof for changing climate: At one time, the area that is New Mexico (and the rest of the USA was below the equator!As North America has drifted to different latitudes,changing climates were experienced. This shows thechanges in the state of New Mexico.
  7. 7. He could not find the force that was causing the continents to drift. Because of this, he could not convince anyone that continents could move. He died in Greenland on an expedition. At the time of his death, no one believed his hypothesis!Technology developed during the 1940’schanged all that!
  8. 8. Discovery of Sea-Floor Spreading Sea floor spreading video clip
  9. 9. Sea-FloorSpreading m.y. means million years ago Notice this compass. It is important for the next slide
  10. 10. http://platetectonics.pwnet.org/img/blocks.gifAs the sea floor spreads, the lava cools according to themagnetic poles at the time. The rocks on the oceanfloor have proved that the earth’s magnetic fieldsometimes reverses. The inner core flips and so thenorth pole moves to the southern hemisphere! Theearth itself does not flip.
  11. 11. What causes sea floor spreading? Convection currents!
  12. 12. Click here for a hyperlink to an animation of convection Be sure to click the play button!
  13. 13. Animation of sea floor spreadingCan you explain this diagram!?
  14. 14. The place where two plates moveapart or diverge is called a divergentboundary.
  15. 15. This is a model of sea floor spreading at a divergentboundary called a mid ocean ridge.
  16. 16. : www.ocean.udel.eduDid you know that the Earth’s longest mountain range isunderwater and is called the mid-ocean ridge? 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!
  17. 17. Continental crust diverging from continental
  18. 18. A convergent boundary is where two platescome together, or converge. The result of theplates hitting together is called a collision.
  19. 19. A transform boundary is a place wheretwo plates slip past each other, moving inopposite directions.
  20. 20. San Andreas Fault in California
  21. 21. en ta l on tin oc ru st t t al c Continen ta l c ru s t to n en o c e a n ic ntiCo Oceanic crust to oceanic
  22. 22. Continental crust to continental crustcollision Before collision India-Asia (Himalayas) After collision from: http://www.geo.lsa.umich.edu/~crlb/COURSES/270
  23. 23. Because one plate gets pushed under another, it is called subduction. This is where volcanoes form! Oceanic crustOceanic crust colliding colliding withwith continental crust oceanic crust all from: http://www.geo.lsa.umich.edu/~crlb/COURSES/270
  24. 24. The process bywhich the oceanfloor sinksbeneath a deep-ocean trenchand back intothe mantle iscalled
  25. 25. 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!Plate tectonics video clip
  26. 26. Worldwide Earthquake patterns help usknow where the edges of plates are located
  27. 27. The Earth’s Plates
  28. 28. Here you seethe two slidestogether.What do yousee?
  29. 29. http://www.livescience.com/images/pangea_animation_03.gif

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