1. Plate Tectonics and the Structure of the Earth
Welcome!
Cracking Up:
Plate Tectonics and the Structure of the Earth

2. An Assessment: Think Pair Share
Best procedures: read quietly to yourself (so you don’t give any subconscious clues)
As the instructor, we read it too, for timing, then ask if anyone needs more time
If not, it’s time to vote simultaneously—use your fingers, right in front of your chest so others don’t see (anonymous)

3. What is a scientific theory?
Theories are educated guesses.
Theories that are proven become laws.
Theories have been tested many times.
Theories never change.
Theories relate to a narrow set of phenomena.
A and B are true
C and D are true
Only C is true
A, B, and E are true
C, D, and E are true

4. The North American continent is
a part of a larger tectonic plate that floats on the asthenosphere
floating on top of the oceanic crust
a tectonic plate separate from the Pacific and Atlantic oceanic plates
very thick and sinking into the asthenosphere
stationary relative to the Pacific and Atlantic oceanic plates

5. Scientists use earthquakes to
Measure the age of the crust
Study the Earth’s internal structure
Measure the mass of the Earth
Support the theory of plate tectonics
A and B are true
B and D are true
A and C are true
A, B, and C are true
A, B, C, and D are true

6. Which features are likely to be found at a convergent boundary formed by two oceanic plates?
An ocean ridge
An ocean trench
A continent
Volcanic islands
Just A
B and D
A and C
Just D