Passage I
Earthquakes produce seismic waves that can travel long distances through Earth. Two types of seismic waves are p-waves and s-waves. P-waves typically travel 6-13 km/sec and s-waves typically travel 3.5-7.5 km/sec. Figure 1 shows how p-waves and s-waves move and are refracted (bent) as they travel through different layers of Earth’s interior. Figure 2 shows a seismograph (an instrument that detects seismic waves) recording of p-waves and s-waves from an earthquake. Figure 3 shows, in general, how long it takes p-waves and s-waves to travel given distances along the surface from an earthquake focus (point of origin of seismic waves).
4. Based on the information provided, the “time earth- quake starts at the focus” in Figure 2 corresponds to which of the following points on Figure 3 ?
Your Answer is
Correct Answer is F
Explanation
At the beginning of the earthquake, the distance from the epicenter should be 0 km, and the time should also be 0 min