Density of the Earth & by Williamson & Adams (1923). Here, elastic constants of various rock types ... & gravitational data. Their work was marked by taking into account ... & the longitudinal & shear seismic wave velocities Vp & Vs) & mineral properties (Ks, the adiabatic bulk modulus & density, x1a), via d x1aðr Þ = – gðr Þdr _jðr Þ, ½1Š ... & is given by j(r) = V2 p (r)–4_3V2 s (r) = Ks (r) x1a (r) ½2Š. ... (...)