Häilu (Häil)

Type of kettle or kettle-hole, a geographical feature represented by a steeper-sided (>10°), flat-bottomed kettle (sulglohk, lit. feather depression), i.e. basin formed by the weight of ‘dead ice’ (i.e. containing debris slowing its melting) on the moraines of retreating glaciers. The term is more commonly used for a treefall gap, a clear ‘hole’ in woodland canopy due usually to a falling tree or large branch. Part of a hydrologically-oriented group, see Külmallika.