🌍 Seismic Waves

Epicentre angle: 30° No. of ray paths: 12

Epicentre angle30°

P-wave arrivals—

S-wave arrivals—

Shadow zone103°–142°

P-wave (primary)

S-wave (secondary)

Shadow zone

Earth layers

Snell's Law: sin(θ₁)/v₁ = sin(θ₂)/v₂
P-waves travel through all layers. S-waves are blocked by the liquid outer core. The P-wave shadow zone (103°–142°) exists because the core refracts rays inward.

Seismograph trace at selected station