Translations:Wave velocity/6/en

is a relationship between the shear velocity, $V_{\rm {S}}$, and the compressional velocity, $V_{\rm {P}}$, in terms of Poisson’s ratio. In an ideal elastic solid, Poisson’s ratio equals 0.25, and $V_{\rm {S}}{\rm {=}}V_{\rm {P}}{\rm {/}}{\sqrt {\rm {3}}}$. Steel is a good example of an ideal solid. Poisson ratios for rocks vary in the range of ~0.2 to ~0.4. The upper bound on Poisson’s ratio is 0.5. For that value, $V_{\rm {S}}$ is zero, and there are no shear waves. That is the condition that holds for fluids and gases.