1. Plate Tectonic Research ws
IT pages

2. 1 a: Define: tectonic plates
Ans: Pieces of the lithosphere that move around on top of the asthenosphere

3. 1b. Give the name of one tectonic plate that contains mostly oceanic lithosphere and one plate that contain mostly continental lithosphere.
Oceanic: ____Pacific__________ Continental: ____Eurasian______

4. 2a.Define seismic waves:
Ans: Vibrations created by earthquakes

5. 2b.Explain how scientists use seismic waves to study the interior of the Earth.
Ans: the speed of the seismic wave depends on the density and composition of the material through which is passes

6. 3a. What is continental drift
3a. What is continental drift? Give three pieces of evidence that support the idea of continental drift.
Ans: Continental drift is the theory that the continents were once together as a single large land mass. They broke apart and drifted to their current locations.
Evidence: fit together like a puzzle, fossils/plants, and rocks/mountain ranges

7. 3b. Why do South America and Africa seem to fit together?
Ans: The same type of rock and fossils have been found on each continent which indicates that at one time the continents were once joined together.
These organisms could not have traveled across the ocean so the continents had to be joined together.

8. 3c.How do fossils indicate that the continents have moved over time?
Ans: The same type of fossils have been found on two separate continents that are now far apart.

9. 3d.What is a mid-ocean ridge?
Ans: Mountain chains found on the bottom of the ocean floor.

10. 3e. Explain how seafloor spreading causes continents to move apart
3e. Explain how seafloor spreading causes continents to move apart. Also, provide a diagram to help with you explanation.
Ans: 1: At the mid-ocean ridge, melted rock rises through the cracks in the ocean floor.
2: The melted rock cools, hardens, and forms new crust.
3: The new crust pushes the older crust away from the mid-ocean ridge.

11. 3f. Does the oceanic lithosphere get older or younger as you move closer to the mid-ocean ridge?
Ans: younger

12. 3g: Why do you think old rocks are rare to find on the ocean floor?
Ans: Because newer rocks are being pushed up onto the ocean floor replacing the older rock.