Earthquake chapter
1. Imagine a seismic wave is passing from material 1 to material 2. The densities for
the materials are given below. You must decide whether the wave will speed up,
slow down or stay at the same velocity.
a. Low density material to high density material
b. High rigidity material to medium rigidity material
c. Medium density material to medium density material
d. Medium density material to low density material
2. Given the following information:
a. Average wave speed = average distance (cm) divided by average travel
time (s) which is: V=d/t
b. The average wave speed = 33.7 cm/s
i. How long would it take the waves to travel using t = d/V
1. 50 cm
2. 100 cm
3. 200 cm
3. Suppose you dropped your pebble into a material through which the waves move
twice as fast as through water.
How does this change in material change the average travel time of the
wave?
4. What is the difference between P waves and S waves?
5. How do earthquakes produce seismic waves?
6. Describe wave refraction in your own words.
7. What is the FOCUS of an earthquake?
8. How are earthquake waves detected on the surface of the earth?
9. How do scientists know that the mantle of the earth is made of solid rock?
10. How do scientists know that the earth has a core?
11. The direction of wave motion (wave) and the direction that a wave travels
(medium) are not necessarily the same such as for longitudinal and transverse
waves. How are these two types of waves different from one another? Explain!
12. Why do seismic waves follow a curved path through earth?
13. How do scientists know that the Earth’s core is made of a different material than
that of the mantle?
14. Let’s say an earthquake occurred below the ocean floor. How might this
earthquake affect the hydrosphere?
15. Give an example of how we used models in the various waves demonstrations and
experiments.
16. Summarize in your lab notebook what you have learnt about the Geosphere.