# What can the time lag between the first arrival of the P-wave and first arrival of the S-wave be used to determine?

##### 1 Answer

Feb 2, 2016

Difference in arrival times between P and S waves can be used to determine the distance between the station and an earthquake.

#### Explanation:

- Different waves each travel at different speeds and therefore arrive at a seismic station at different times.
- By knowing how far away the quake was from three stations we can draw a circle around each station with a radius equal to its distance from the earthquake. The earthquake occurred at the point where all three circles intersect.