Sastrugi dunes, and the resulting drifting snow shapes are also popularly referred to as "barchans". Inuit of Canada call them "kalutoqaniq". When winds slacken, the drifted formations consolidate via sublimation and recrystallization. Subsequent winds erode kalutoqaniq into the sculptured forms of sastrugi. Inuit call large sculpturings "kaioqlaq" and small ripples "tumarinyiq". Further erosion may turn "kaioqlaq" back into drifting "kalutoqaniq". An intermediate stage of erosion is "mapsuk", an overhanging shape. On the windward side of a ridge, the base erodes faster than the top, producing a shape like an anvil tip pointing upwind. Sastrugi are more likely to form on first-year
Surface wave inversion modify seismic equipment and experimental procedures to remove surface wave information from the data. Earthquake seismologists however require the information seismic surface waves provide and thus design their equipment to amplify and gather as much information on these waves as possible. The work by early earthquake seismologists to extract substantial information from surface wave data was the basis for surface wave inversion theory. The usefulness of surface waves in determining subsurface elastic properties arises from the way in which they disperse. Dispersion (geology) is the way in which surface waves spread out as they travel across the surface of the