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

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)

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

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

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

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