Transcript Chap7Sect3 review

Chapter 7
Plate Tectonics:
Open your IAN for
today’s notes.
Chap 7, Sec 3 Review
Objectives:
1. Review subduction. (yes, again!)
2. What ocean features does it create?
3. What continental crust features are
created by tectonic boundaries?
4. Brainpop Plate Tectonics
• 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 _____________.
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.
New Evidence
to support Wegner’s claims?
• Cooling & Shrinking of the
Earth’s Crust
• Sea Floor Spreading
• Molten Material and
Magnetic Stripes
• Convection Currents
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
What are Three Possible Driving
Forces of Plate Tectonics?
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
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).
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!