Editing P wave (section)

==Nomenclature==
The name ''P wave'' can stand for either '''pressure wave''' (as it is formed from alternating [[compression (physical)|compression]]s and [[rarefaction]]s) or '''primary wave''' (as it has high velocity and is therefore the first wave to be recorded by a seismograph).<ref name="John">{{cite book|last=Milsom|first=J.|title=Field Geophysics|publisher=John Wiley and Sons|year=2003|series=The geological field guide series|volume=25|page=232|isbn=978-0-470-84347-5|url=https://books.google.com/books?id=T7CKj8bqVlwC&pg=PA179|access-date=2010-02-25}}</ref> The name ''[[S wave]]'' represents another seismic wave propagation mode, standing for secondary or shear wave, a usually more destructive wave than the primary wave.