Earthquakes produce two kinds of seismic waves: he longitudinal primary waves (c

Question

Earthquakes produce two kinds of seismic
waves: he longitudinal primary waves (called
P waves) and the transverse secondary waves
(called S waves). Both S waves and P waves
travel through Earth’s crust and mantle, but
at different speeds; the P waves are always
faster than the S waves, but their exact speeds
depend on depth and location. For the pur-
pose of this exercise, we assume the P wave’s
speed to be 9090 m/s while the S waves travel
at a slower speed of 4070 m/s.
If a seismic station detects a P wave and
then 54.5 s later detects an S wave, how far
away is the earthquake center?
Answer in units of km.

Explanation / Answer

Modified: ----------- Speed of P wave’s speed v = 9090 m/s
Speed of S waves v ' = 4070 m/s.
Time interval between P and S waves is t = 54.5 s Let the required distance be S time taken for the p -wave travel this distance is T = S / v                                                                              = S / 9090 Time taken for S-wave to tarvel this distance T ' = S /v '                                                                           = S / 4070 from problem T ' - T = t             [(S/4070)-(S/9090)]= 54.5 0.0002457002 S -0.000110011 S = 54.5 1.35689*10^-4 S = 54.5                             S = 4.016 * 10^5 m 1.35689*10^-4 S = 54.5                             S = 4.016 * 10^5 m

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.