Wave velocities

The earth's crust is approximately a Poisson solid, with elastic constant 0.3 Tdyn/square(cm). Thus, for a density of 3 g/cub(cm), the P-wave velocity is 5.5 km/s. Similarly, The S-wave velocity is 3.2 km/s. Hence a P wave propagating with a velocity of 5.5 km/s and a period of 2 shas a wavelength of 11 km and the wavenumber is 0.57 per km. On the other hand, a wave with a period of 10 s and the same velocity has a wvelength of 55 km and a frequency of 0.1 Hz. The longer-period wave has a longer wavelength and a lower frequency.