🌍 Earthquake Seismic Wave Propagation Through a Layered Crust: Travel-Time Curves and Epicentre Triangulation Lab

P, S and surface waves spread through a Blender-modelled 3D block of four crustal layers: wave speeds from bulk and shear moduli, ray-traced first-arrival travel-time curves with head waves and the Pn crossover, epicentre triangulation from three stations using S minus P times, the magnitude-energy relation and the whole-Earth shadow zone.