1. Plate Tectonics and Boundaries
8-3.6 Explain how the theory of plate tectonics accounts for the motion of the lithospheric plates, the geologic activities at the plate boundaries, and the changes in the landform areas over geologic time.

2. Layers of the Earth Recap

3. Cause & Effect
Before
After

4. What do all of these colored regions represent?

5. Each region = Tectonic Plate aka Lithospheric Plate

6. How do the Tectonic Plates Move?
Lithospheric (Tectonic) Plates float on top of the upper part of the mantle (asthenosphere)

7. Why do the Tectonic Plates Move?
Convection currents in the mantle cause the asthenosphere to flow slowly
Causing the lithosphere to “float” on top of the slowly moving asthenosphere

8. What is the Effect of Tectonic Plate Movement?
Changes the
sizes
shapes
positions
of Earth’s continents and oceans

9. http://teachertube. com/viewVideo. php

11. Theory of Plate Tectonics
Explains why and how large sections of Earth’s crust (lithospheric plates) move.
Explains how Earth features formed.

12. What is continental drift?

13. Continental Drift Hypothesis
Developed before present theory of plate tectonics.
Based on:
continent shape
fossil evidence
rock and climate clues
This hypothesis later led to the theory of plate tectonics when evidence was found as to why the plates move.

15. How do Landforms Change Over Geologic Time?
Plates move at very slow rates-
about 1-10 centimeters per year.
Before: continents were joined together in one large landmass
called Pangaea.
After: As the plates continued to move and split apart:
oceans were formed
landmasses collided and split apart
until the Earth’s landmasses became where they are now.

17. How do we know there was a Pangaea?
Evidence of these landmass collisions and splits comes from:
fossils
landform shape and features
rock structures
climate change

18. Plate Tectonic Video (5:00 min)

19. BrainPop: Plates Tectonics