Sastrugi breaking equipment—ripples and waves are often undercut and the surface is hard and unforgiving, with constant minor topographic changes between ridge and trough. The words "sastrugi" and "zastrugi" are Russian-language plurals; the singular is "sastruga" or "zastruga". The form "sastruga" started as the German-language transliteration of the Russian word заструга (plural: заструги). A Latin-type analogica singular "sastrugus" is used in various writings on exploration of the South Pole, including Robert Falcon Scott's expedition's diaries and Ernest Shackleton's "The Heart of the Antarctic". Under the action of steady wind, free snow particles accumulate and drift like the sand grains in barchan
Surface wave inversion inversion theory. Since Rayleigh waves are composed of P and S-waves and Love waves are composed of only S waves, Haskell derived the elastic wave equations for both P and S-waves. These equations were modified to show Rayleigh wave motion. After assuming a free surface boundary where no stresses or strains cross, the Rayleigh wave equation is simplified. Inputting different values for layer thicknesses, densities, and elastic parameters in the form of P and S wave velocities into the equation will yield a dispersion curve. Parameters can be modified to fit the derived dispersion curve to actual data (Figure 4).