1. Plate Tectonics: Open your IAN for today’s notes.
Chapter 7
Plate Tectonics:
Open your IAN for today’s notes.

2. Chap 7, Sec 3 Review Objectives: Review subduction. (yes, again!)
What ocean features does it create?
What continental crust features are created by tectonic boundaries?
Brainpop Plate Tectonics

3. Let’s take a closer look
Sea-floor spreading and subduction can change ______________________ of the oceans.
The Pacific Ocean, aka__________ ______________, has lots of subduction zones, thus it is getting ______________.
The Atlantic Ocean is _____________.
Let’s take a closer look

4. NEW
Sea-floor spreading is the process by which _________ ____________________ forms as magma rises toward the surface and solidifies. As the tectonic plates move away from each other, the sea floor spreads apart and magma fills in the gap.
Oceanic Lithosphere

5. New Evidence to support Wegner’s claims?
Cooling & Shrinking of the Earth’s Crust
Sea Floor Spreading
Molten Material and Magnetic Stripes
Convection Currents

6. NEW Evidence of CD And Sea-Floor Spreading?
Magnetic reversals in oceanic crust are shown as bands of light blue and dark blue oceanic crust. Light blue bands indicate normal polarity, and dark blue bands indicate reverse polarity

7. Convection Currents:
The world wants to
be balanced!

8. What are Three Possible Driving Forces of Plate Tectonics?

9. So what will happen as these plates in the ocean floor continue to spread?
Earth 100 Million Years from now
Convection Currents in the Earth. One more time, a different way!
Plate tectonics on a cocoa earth - YouTube

10. 1. ______________ – when the ocean floor sinks beneath a deep ocean trench and gets swallowed by the mantle.
2. __________________– this feature forms from subduction (the oceanic crust bends downward forming a deep underwater canyon on the ocean floor).

12. 3 Types of Boundaries have different effects. What are they?
3 types of Boundaries in Review
With your hands, show me the 3 types of boundaries! Stand and Do!
Now let’s illustrate it!
HW: Flashcards!