1. A seismograph station is located 2000 km from an earthquake'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.

The P waves vibrate very quickly out from the epicenter first in all directions, in a circular way passing the station. The S waves then vibrate out from the epicenter a few seconds later and cause the sideways shaking of the land as they pass the station. The P wave then reflects off the core of the Earth and bounces back past the station, followed by the S wave a few seconds later because both waves reflect off the earths core back to the epicenter.