Wave Notes (NBp 46) Types of Seismic Waves type of wave starting pt & arrival motion speed travels through what we feel body P (primary) S (secondary) focus arrive first arrive second compressing in the direction the wave travels shearing (side to side or up & down) moving perpendicular to the direction the wave travels fast slower than P moves from focus outward in concentric rings solids & liquids solids only jolt sway surface love Rayleigh epicenter (occur when P & S waves reach surface) last to arrive circular move slower than body waves surface only produce severe ground movements like rolling or jerking http://www.phschool.com/atschool/phsciexp/active_art/seismic_waves/index.html