Speed Problems with Earthquake Waves
Name ________________________
1. Below is a graph of the 2 types of earthquake waves. Use it to fill out this table
Time to get
to 2,000 Km
Relative Speed
(faster/slower)
Type of Wave
(P/S)
Amount of Shaking/Impact
(More / Less)
Curve A
Curve B
A
B
Time
Minutes
Distance 103 Kilometers
2. a.Based on the graph, how long did it take the S waves to get to 1,000 km? ______
b. Convert that time to seconds:
c. Calculate the speed in km/sec for S waves:
3. a. Based on the graph, how long did it take the P waves to get 1,000 km?
______
b. Convert that time to seconds:
c. Calculate the speed in km/sec for P waves:
4. A. Using those speeds how long would it take for an P wave to go 800. Km?
B. Using those speeds how long would it take for an S wave to go 800. Km?
C. At 800. Km how much time is there between the smaller P’s and the bigger S’s? How much
warning would you have that a worse wave is coming?
5. A. Using those speeds how long would it take for an P wave to go 200. Km?
B. Using those speeds how long would it take for an S wave to go 200. Km?
C. How much warning would you have at 200. km that a worse wave is coming?
6. How much warning time do you think is needed to get people into safer situations? Suppose a p
wave reached a seismographic station, triggered a signal to send an emergency alert to every
local cell phone and then people got under their desks at school or pulled over if driving before
the S waves hit. How much time do you think that process would take?
7. Based on your answers to 4 - 6 do you think a p wave based early detection system is feasible?