1. Warm-Up Find the mistakes!
1. During the 1940s and 1950s, scientists began using radar on moving ships to map large areas of the ocean floor in detail.
2. The youngest rocks are found far from the mid-ocean ridges.
3. The scientist Harry Henry Hess invented echo-sounding devices for mapping the ocean floor.
4. As the seafloor spreads apart, hot saltwater moves upward and flows from the cracks.
5. Rocks on the seafloor are much older than many continental rocks.

2. PLATE TECTONICS

3. Theory of Plate Tectonics
Earth’s crust and part of the upper mantle are broken into sections.
These sections are called plates.
Plates move on the asthenosphere: a plastic-like layer of the mantle.

4. Earth’s Structure

5. Earth’s Crust & Mantle
Plates are made up of the crust and a part of the upper mantle:
Lithosphere- Rigid. Made up of crust and upper mantle km thick.
Asthenosphere- The plastic-like layer that lies below the lithosphere.
The plates of the lithosphere float on the asthenosphere.

6. Divergent Plates are moving apart from each other
Creates new seafloor and expanding oceans

7. As continental plates separate, they create a rift valley
As oceanic plates separate and magma rises, ridges form

8. Mid Ocean Ridge Eurasian Plate North American Plate
South American Plate
African Plate

9. Convergent Plates move together
There are two things that can happen at a convergent plate boundary…

10. Oceanic - Continental
At sites where oceanic and continental plates collide, subduction zones form.
At subduction zones, the more dense plate (oceanic) sinks beneath the less dense plate (continental).
The sinking plate melts and forms magma that rises to the surface through a volcano.
Mountains and deep sea trenches are also found at subduction zones.

11. The Andes Mountain Range is found in Chile.
The volcanism of the Andes Range is a result of the subduction of the Nazca Plate underneath the South American Plate.

12. Continental - Continental
As continental plates collide, mountain ranges are created.

13. The Himalayas are still forming as the Eurasian and Indian Plates collide.

14. Transform Plates slide past each other
As one plate slips past another suddenly, earthquakes occur.

15. San Andreas Fault Located in California
The Pacific Plate is sliding past the North American Plate

16. On the split screen Notes
Draw a picture of the Earth’s Layer- Label and explain a convection current

17. Why Do The Plates Move?
The transfer of heat inside the Earth provides the energy to move plates and, subsequently, many of Earth’s surface features.
Convection currents inside the mantle causes the movement of the plates

18. Convection Currents
The Earth’s hot, inner core heats the liquid mantle.
The magma closest to the core heats up, becomes less dense, and rises.
The magma at the top of the mantle cools, becomes more dense, and sinks.

19. Graphic organizer Create a three flap flip chart
In the front of each flap write the name of a type of boundary: Transform, Divergent, Convergent boundaries
Draw and color the boundaries on the inside of the front flap
Use your book and notes to write the following information under each flap:
What happens at this type of boundary
What types of geographic formations does it create
Where in the world can this boundary be found