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Using the following seismograph and the time distance curve for P-, S-, and L-wa

ID: 803716 • Letter: U

Question

Using the following seismograph and the time distance curve for P-, S-, and L-waves, answer the following: Estimate, to the nearest tenth of a minute, the times of arrival of the P-waves and S-waves. First P-wave arrival time First S-wave arrival time S-P time (minutes) What is the distance of this seismic station to the epicenter? Will this station experience a surface wave (L-wave) If the station will experience a surface wave, what time will it arrive? If there were not a time scale on the graph but instead the chart rotated on the seismograph such that: 1 inch = 1 minute 1 cm = 1 minute distance to the epicenter = distance to the epicenter = Can you locate the epicenter of the earthquake with any of this data? Why, or why not?

Explanation / Answer

1) P-wave arrival time = 8:09

S-wave arrival time = 8:13

S-P time = 0.04 minutes

2) dp= rp*tp

= 5 * 8.09 * 60 (multiplied by 60 to convert in seconds)

distance to epicenter = 2427 Km

3) Yes, this station will experience a L-wave. because L-waves decay very slowly it can reach great distances. it decays at a rate of 1/r(1/2).