Naturalists at Large: Plate tectonics

1,793 views
1,739 views

Published on

Naturalists at Large Plate Tectonics Slide Show

Published in: Education, Automotive, Technology
0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,793
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
119
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide

Naturalists at Large: Plate tectonics

  1. 1. Theory of Plate Tectonics Plate Tectonics Plate Boundaries Causes of Plate Tectonics
  2. 2. Plate Tectonics
  3. 3. What is Plate Tectonics• The Earth’s crust and upper mantle are broken into sections called plates• Plates move around on top of the mantle like rafts
  4. 4. What is the Lithosphere?• The crust and part of the upper mantle = lithosphere –100 km thick –Less dense than the material below it so it “floats”
  5. 5. What is the Asthenoshere?• The plastic layer below the lithosphere = asthenosphere• The plates of the lithosphere float on the asthenosphere
  6. 6. 2 Types of Plates• Ocean plates - plates below the oceans• Continental plates - plates below the continents
  7. 7. Plate Boundaries
  8. 8. Divergent Boundaries• Boundary between two plates that are moving apart or rifting • RIFTING causes SEAFLOOR SPREADING
  9. 9. Features of Divergent Boundaries• Mid-ocean ridges• rift valleys• fissure volcanoes
  10. 10. Convergent Boundaries• Boundaries between two plates that are colliding  • There are 3 types…
  11. 11. Type 1• Ocean plate colliding with a less dense continental plate• Subduction Zone: where the less dense plate slides under the more dense plate• VOLCANOES occur at subduction zones
  12. 12. Andes Mountains, South America
  13. 13. Type 2• Ocean plate colliding with another ocean plate• The less dense plate slides under the more dense plate creating a subduction zone called a TRENCH
  14. 14. Aleutian Islands, Alaska
  15. 15. Type 3• A continental plate colliding with another continental plate• Have Collision Zones: –a place where folded and thrust faulted mountains form.
  16. 16. Transform Fault Boundaries• Boundary between two plates that are sliding past each other• EARTHQUAKES along faults
  17. 17. San Andreas Fault, CA
  18. 18. Causes of Plate Tectonics
  19. 19. Convection Currents• Hot magma in the Earth moves toward the surface, cools, then sinks again.• Creates convection currents beneath the plates that cause the plates to move.

×