Why are the travel- time curves for the P- wave and S- wave arrivals curved and not straight lines?
A) The greater the distance, the deeper the P and S waves travel, refracting through progressively denser layers.
B) They should be straight lines. Earth is flat and the time- travel graph proves it!
C) During an earthquake, Earth shakes so much that it is like a quivering rubber ball and all of the distances are wrong.
D) They have to bend with the curvature of the Earth.

Question

Quizplus · Accepted Answer

The curvature of the travel-time curves for P-waves and S-waves is due to the fact that these waves travel deeper into the Earth as the distance increases, encountering layers of varying densities which affect their speed and direction through refraction. This results in a non-linear relationship between travel time and distance.

Why Are the Travel- Time Curves for the P- Wave