Seismic waves
In an earthquake a sudden rupture of the earths’ structure releases a vast
quantity of energy which travels outwards across the earth’s surface in the
form of seismic waves. These waves exist in a variety of forms. The figures
above and below show two of them. Geologists refer to them as P-waves (above)
and S-waves (below). (P for primary, S for secondary: the P-waves travel faster
and get to you first!). We might also label them as ‘longitudinal’ and
‘transverse’. For more information, visit
the UPSeis site.