Talik, also called tabetisol, is a Russian term applied to permanently unfrozen ground in regions of permafrost.
This usually applies to a layer that lies above the permafrost but below the active layer, that is, when the permafrost table is deeper than the depth reached by winter freezing from the surface. Talik is also found within and beneath permafrost; when it occurs beneath the permafrost it is equivalent to subgelisol.
A talik is a layer of year-round unfrozen ground that lies in permafrost areas. In regions of continuous permafrost, taliks often occur underneath shallow thermokarst lakes and rivers, where the deep water does not freeze in winter and thus the soil underneath does not freeze either. Sometimes closed, open, and through taliks are distinguished. These terms refer to whether the talik is surrounded by permafrost, open at the top (e.g. a thermokarst lake), or open both at the top and above an unfrozen layer beneath the permafrost.
