Question

A seismograph station is located 2000 km from the earth's epicenter. Explain the order that the S and P waves will arrive at the station, Using what you know about the characteristics of the different waves, explain your answer.

Answer 1

The P-waves will arrive first at the seismograph station, followed by the S-waves. The time difference between their arrivals can be used to estimate the distance to the source of the earthquake.

Step-by-step explanation:

The order in which the S and P waves will arrive at the seismograph station can be determined by considering their respective speeds. P-waves, also known as primary waves, are the fastest seismic waves and they travel at a speed of 7.20 km/s. On the other hand, S-waves, also known as secondary waves, travel at a speed of 4.00 km/s. Since the station is located 2000 km from the epicenter, the P-waves will arrive first, followed by the S-waves. The time difference between their arrivals can be calculated by dividing the distance by their respective speeds:

Time difference = Distance / Speed

For P-waves: Time difference = 2000 km / 7.20 km/s

For S-waves: Time difference = 2000 km / 4.00 km/s

By calculating these values, you can determine the order in which the waves will arrive and the time difference between their arrivals, which can be used to estimate the distance to the source of the earthquake.

Answer 2

The Primary waves will reach first, then The Secondary waves, then the Surface Waves. (you can figure this out by its names too) Since primary waves pull and compress and expand like an accordion, they will reach the seismograph station first (due to them heading straight). The Secondary waves reach second because they move back and forth in a zig-zag pattern, rather than a straight line- like the primary waves. Since surface waves move the slowest, they make the most severe ground movement- also hence it coming last.