talik
Link: http://w3id.org/permafrost/v/ipaglossary/t0337
Within: IPA Permafrost Glossary
Definition: A layer or body of unfrozen ground occurring in a permafrost area due to a local anomaly in thermal, hydrological, hydrogeological, or hydrochemical conditions (see Figure 11).
| Term |
talik
fr
talik en |
|---|---|
| Comment |
Taliks may have temperatures above 0°C (noncryotic) or below 0°C (cryotic, forming part of the permafrost). Some taliks may be affected by seasonal freezing. Several types of taliks can be distinguished on the basis of their relationship to the permafrost (closed, open, lateral, isolated and transient taliks), and on the basis of the mechanism responsible for their unfrozen condition (hydrochemical, hydrothermal and thermal taliks): 1. closed talik - a noncryotic talik occupying a depression in the permafrost table below a lake or river (also called "lake talik" and "river talik"); its temperature remains above 0°C because of the heat storage effect of the surface water; 2. hydrochemical talik - a cryotic talik in which freezing is prevented by mineralized groundwater flowing through the talik. 3. hydrothermal talik - a noncryotic talik, the temperature of which is maintained above 0°C by the heat supplied by groundwater flowing through the talik; 4. isolated talik - a talik entirely surrounded by perennially frozen ground; usually cryotic (see isolated cryopeg), but may be noncryotic (see transient talik); 5. lateral talik - a talik overlain and underlain by perennially frozen ground; can be noncryotic or cryotic; 6. open talik - a talik that penetrates the permafrost completely, connecting suprapermafrost and subpermafrost water, (e.g., below large rivers and lakes). It may be noncryotic (see hydrothermal talik) or cryotic (see hydrochemical talik). SYNONYMS: (not recommended) through talik, penetrating talik, perforating talik, piercing talik; 7. thermal talik - a noncryotic talik, the temperature of which is above 0°C due to the local thermal regime of the ground; 8. transient talik - a talik that is gradually being eliminated by freezing, e.g., the initially noncryotic closed talik below a small lake which, upon draining of the lake, is turned into a transient isolated talik by permafrost aggradation (see also closed-system pingo).
en
|
| dcterms:source |
https://doi.org/10.4224/20386561
xsd:anyURI
|