One measurement that is widely used to determine how far the focus of an earthquake is from the seismograph where it is recorded is ________.
A)the amplitude of the P-wave
B)the amplitude of the S-wave
C)the difference in travel time between the P and the S wave
D)the difference in amplitude between the P and the S wave

Question

Quizplus · Accepted Answer

The difference in travel time between the P and S waves is used to determine the distance to the earthquake's focus. This difference in time is due to the fact that P-waves are faster than S-waves and therefore arrive at the seismograph first. The distance can be calculated by determining the time difference between the arrival of the P-wave and the S-wave and using this to plot a distance on a travel-time curve.

One Measurement That Is Widely Used to Determine How Far