1/21 Answers to Study Guide Earthquake

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NAME________________________________________D_________________P_____
Earthquake Review
1. Base your answers to this question on the map below. Seismic
stations are located at the four cities shown on the map.
Letter X represents the epicenter of an earthquake determined
from seismic waves recorded at all four cities.
Which map correctly shows how the location of the epicenter
was determined?
NAME________________________________________D_________________P_____
Earthquake Review
2. For seismic waves that travel through the Earth, the Travel-Time curves for P and S- waves
are curved (example on the right). Why do you think this is?
Curves because
the wave is
introduced to
new material/Layer causing it to change
direction and speed
3. Define reflected and refracted.
Reflection- seismic waves hit a
material/surface and they
bounce back
Refraction- seismic waves hit a
material and bend changes
speed and direction (velocity)
NAME________________________________________D_________________P_____
Earthquake Review
4. Decide on the diagrams below which one is reflected and refracted and explain how you
know.
Refraction –
bending
through layers
Station 1
Station 2
Earthquake
Station 4
Station 3
5. Which stations will record fewer waves than other? Explain how you know
NAME________________________________________D_________________P_____
Earthquake Review
Station 2 and 3 because S waves can not reach
those stations because they can not travel
through a liquid core.
6. What do the changing P-wave velocities mean?
Velocity- speed and direction (distance/ time
When a p wave changes speed and/or direction
we know that it has entered a new layer of the
Earth
7. Using the graphs below circle where P-wave changed velocity. Explain how you know.
NAME________________________________________D_________________P_____
Earthquake Review
8. Use the graph above to find the distance for each city.
City
Lag Time
Distance
Detroit, MI
3 min
Charleston, SC
7 min 20 sec
Minneapolis, MN
5 min 20 sec
2000
km
6000
km
4,200
km
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