The two types of waves you need to know are P-waves and S-waves. Their behavior is necessary to calculate the epicenter (location) of an earthquake.
The P-wave compresses matter, moving the sensor side to side.
The S-wave moves perpindicularly, moving the sensor up and down.
Move the slider to the right to simulate the travel of the wave.
Below is an interactive example of how to calculate the epicenter distance based on P-wave and S-wave arrival times.
Drag the underlined minute values to change the time it takes for each wave to reach the point.
How long did it take the P-wave to reach the point? (drag left and right to change time)
P-wave Travel Time = minutes
How long did it take the S-wave to reach the point?(drag left and right to change time)
S-wave Travel Time = minutes
This means the difference in time was Difference = minutes
(note that as you adjust the values, the slider on the graph changes length)
Drag the slider at the top of the graph to determine the distance at which the time difference betweent the two waves equals minutes (the line between the wave graphs will turn green).