Seismic Wave Propagation

P-waves & S-waves through Earth's layered interior

P-wave
S-wave
Reflected
Layer boundary
Wave Frequency1.5
Source Depth0 km
Animation Speed1.0x
P-waves (compressional) travel through both solid and liquid; S-waves (shear) cannot pass through the liquid outer core — creating the S-wave shadow zone (103°–180°). The P-wave shadow zone (103°–142°) forms because refraction in the core bends P-waves away from that range. Travel-time curves (below) show Jeffreys–Bullen travel times for direct arrivals.