Trigger a fault rupture and watch P, S and surface waves race outward — then read the synthetic seismogram: S−P time lag gives the distance, amplitude gives the magnitude, and seismic attenuation by rock type shapes what the station actually feels. Change magnitude, depth, distance and crustal quality, then re-trigger.
Wave speeds Vp ≈ 6.2 km/s, Vs ≈ 3.5 km/s (Vp/Vs ≈ √3), so S−P = r·(1/3.5 − 1/6.2) directly gives hypocentral distance. Radiated energy E ≈ 10^(1.5·M + 4.8) J (Gutenberg–Richter). Ground motion decays with geometric spreading 1/r and anelastic attenuation exp(−πf·r/(Q·c)). PGA scaled from magnitude and distance; Modified Mercalli intensity from PGA via MMI ≈ 1.5·log₁₀(a) + 3.9.