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1. What are the 5 layers of the Earth
a. Crust, Lithosphere, asthenosphere, mantle, outer core, inner core
2. Which layer of the Earth is liquid?
a. Outer core
3. What makes up the lithosphere?
a. The crust and the very upper portion of the mantle
4. Where is the asthenosphere located?
a. Just below the lithosphere
5. Why is the asthenosphere so important?
a. Because the asthenosphere convects slowly moving the lithospheric plates around
6. What happen to temperature as you go deeper into the Earth?
a. It gets hotter
7. What happens to pressure as you go deeper into the Earth?
a. It increases
8. What is the core made up of?
a. Iron and nickel
9. How does the core create a magnetic field around the Earth?
a. The solid inner core spins inside the liquid outer core creating a strong magnetic field that surrounds the
Earth far out into space
10. Who proposed the theory of continental drift?
a. Alfred Wegener
11. What is the theory of continental drift?
a. The theory is that 225 million years ago there was a great supercontinent called Pangaea. It broke apart
and the continents floated to their present locations
12. What was Wegener’s theory missing?
a. How the continents were able to move
13. What was the evidence for his theory?
a. Fossil: Glossopteris fossils (fern plants with huge seeds) and Mesosaur (fresh water dinosaurs) fossils
lined up on different continents separated by an ocean
b. Landform: Mountain ranges on different continents seem to line up when you put the continents
together the way Wegener did
c. Climate: Glacier scratches (striations) lined up on different continents and coal deposits were found in
strange places like Antarctica which is currently too cold for ferns
d. Fit: The continents seem to fit together
14. What technology was used in the 40s and 50s to revive the theory of continental drift and update it?
a. Sonar
15. What is sea floor spreading?
a. Sea floor spreading is when oceanic plates diverge from each other at a mid-ocean ridge creating new
sea floor
16. Where does sea floor spreading take place?
a. At oceanic divergent boundaries (divergent boundaries on the sea floor)
17. Who revived Wegener’s theory?
a. Dr. Harry Hess
18. What evidence was gathered to explain the movements of the continents?
a. The age of the sea floor gets older as you move away from the mid ocean ridge at divergent boundaries.
The age of the floor gets older at the same rate on either side of the mid-ocean ridge
b. The temperature and density of the sea floor gets colder and denser as you move away from the midocean ridge, it gets colder and denser at the exact same rate on either side of the mid-ocean ridge
c. The magnetic polarity that is locked in the basalt (rock) of the ocean floor reverses as you move away
from the mid-ocean ridge. It switches back and forth from “normal” polarity (the magnetic polarity that
we currently have) to reverse polarity as you move away from the mid ocean ridge and it is the same
pattern on either side of the mid-ocean ridge
19. What is subduction?
a. Subduction is the process in which a dense, cold, old oceanic plate gets pulled into the mantle of the
earth at deep sea trenches
20. Where does subduction take place?
a. At convergent plate boundaries on the ocean floor. Subduction causes deep sea trenches to occur
21. What is a lithospheric plate?
a. A piece of the earth that floats on the asthenosphere. It is composed of the crust and the very upper
portion of the mantle
22. What is the theory of plate tectonics?
a. The theory of plate tectonics is that pieces of the Earth’s lithosphere are in constant slow motion that
are moved around by convection currents in Earth’s lithosphere
23. What are three main types of plate boundaries?
a. Convergent (plates move towards each other)
b. Divergent (plates move away from each other)
c. Transform (two plates scrape past each other in opposite directions)