<p>An earthquake generates waves that move through the earth in different ways. Two of the principle waves are the compressional P wave and the shear S wave.  P waves move faster than S waves, so by timing the difference in arrival time of the two waveforms we can estimate the distance to the epicentre.</p>
<p><a href="https://i.sstatic.net/C3DCe.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/C3DCe.png" alt="A seismograph showing the interval between P and S waves" /></a></p>
<p><a href="https://www.bgs.ac.uk/discovering-geology/earth-hazards/earthquakes/how-are-earthquakes-detected/" rel="nofollow noreferrer">https://www.bgs.ac.uk/discovering-geology/earth-hazards/earthquakes/how-are-earthquakes-detected/</a></p>

CC BY-SA 4.0
2021-03-26T16:11:26.220Z
2021-03-26T16:11:26.220Z
Andy M
<p>How can we tell the difference between a seismograph of a local earthquake and that of a distant earthquake?</p>

<earthquakes><seismology>
Difference between Earthquake Seismographs
Rim Sleimi
# Difference between Earthquake Seismographs

(Asked by: username_0 on 2021-03-26)

How can we tell the difference between a seismograph of a local earthquake and that of a distant earthquake?

**Tags:** earthquakes, seismology


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## 1 answers

### Answer by username_1 on 2021-03-26. Score: 3

An earthquake generates waves that move through the earth in different ways. Two of the principle waves are the compressional P wave and the shear S wave. P waves move faster than S waves, so by timing the difference in arrival time of the two waveforms we can estimate the distance to the epicentre.

[![A seismograph showing the interval between P and S waves](https://i.sstatic.net/C3DCe.png)](https://i.sstatic.net/C3DCe.png)

<https://www.bgs.ac.uk/discovering-geology/earth-hazards/earthquakes/how-are-earthquakes-detected/>


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