Editing Earthquake (section)

==== Speed of seismic waves ====
[[Propagation velocity]] of the seismic waves through solid rock ranges from approx. {{Convert|3|km/s|mi/s|abbr=on}} up to {{Convert|13|km/s|mi/s|abbr=on}}, depending on the [[density]] and [[Elasticity (physics)|elasticity]] of the medium. In the Earth's interior, the shock- or P waves travel much faster than the S waves (approx. relation 1.7:1). The differences in travel time from the [[epicentre|epicenter]] to the observatory are a measure of the distance and can be used to image both sources of earthquakes and structures within the Earth. Also, the depth of the [[hypocenter]] can be computed roughly.

'''P wave speed'''
* Upper crust soils and unconsolidated sediments: {{Convert|2-3|km|mi|abbr=on}} per second
* Upper crust solid rock: {{Convert|3-6|km|mi|abbr=on}} per second
* Lower crust: {{Convert|6-7|km|mi|abbr=on}} per second
* Deep mantle: {{Convert|13|km|mi|abbr=on}} per second.

'''S waves speed'''
* Light sediments: {{Convert|2-3|km|mi|abbr=on}} per second
* Earths crust: {{Convert|4-5|km|mi|abbr=on}} per second
* Deep mantle: {{Convert|7|km|mi|abbr=on}} per second