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 subsurface profiles. Foti, S., Comina, C., Boiero, D., Socco, L. V., 2009, Non-uniqueness in surface-wave inversion and consequences on seismic site response analyses: Soil Dynamics and Earthquake Engineering, v. 29, p. 982-993. Kennett, B.L.N., 1976, The inversion of surface wave data: Pure and Applied Geophysics, v. 114, p 747-751. Luke, B., Calderon-Macias, C., 2007, Inversion of seismic surface wave data to resolve complex profiles: Journal of Geotechnical and Geoenvironmental Engineering, v. 133, p. 155-165. Lai, C. G., Foti, S., and Rix, G. J., 2005, Propagation of data uncertainty in surface wave inversion: Journal of Environmental & Engineering Geophysics, v. 10,