Name_________________
“Where Do Earthquakes Happen” and “Finding an Epicenter”
Lab Quiz
Where Do Earthquakes Happen
1. Where do most earthquakes occur? Why?
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2. If you wanted to live in a part of the world with the least probability of earthquake
activity, where would you live?
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3. Does the data on your map support your answer to #2? Why or Why not?
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4. Name a specific area in which the probability of an earthquake is the highest.
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5. Name the major plate that encompasses the area that describes your answer to #3.
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Finding an Epicenter
6. If the average speed of a P wave is 7 km/s and the average speed of an S wave is 5
km/s calculate the lag time between the arrive of P waves and S waves over a distance of
100 km. SHOW YOUR WORK!!! NO WORK, NO CREDIT!!!
7.
City
Lag Time
Austin
Bismark
Portland
130 seconds
150 seconds
100 seconds
Distance from city to
Epicenter
Use the lag times provided and lag time found in #6 to calculate the distance from each
city to the epicenter of the earth quake using the equation provided in your lab (#4).
SHOW WORK!!!
8. Why must measurements from three locations be used to find the epicenter of an
earthquake?
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