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 states be satisfied for each formula_24 separately and for each formula_24 a single, but generally different energy level for the surface state is obtained. A surface state is described by the energy formula_26 and its wave vector formula_24 parallel to the surface, while a bulk state is characterized by both formula_28 and formula_29 wave numbers. In the two-dimensional Brillouin zone of the surface, for each value of formula_28 therefore a rod of formula_29 is extending into the three-dimensional Brillouin zone of the Bulk. Bulk energy bands that are being cut by these rods allow states that penetrate deep into the crystal.