# Potential permafrost areas A thematic map of the Atlas of Switzerland, the national atlas published by ETH Zurich. The map is drawn in the browser; this file describes it and lists its variants and links, but not the data values shown on the map. - Map: https://atlasderschweiz.ch/en/theme/potential-permafrost-areas/ - Short title: Permafrost extent - Map id: 225 - Categories: Nature and Environment › Ice and Snow › Permafrost - Keywords: Climate change, Soils - Published: 2010-11-26 - Last revised: 2023-02-23 - Content language: English - Other languages: [Deutsch](https://atlasderschweiz.ch/de/thema/potenzielle-permafrostgebiete.md), [Français](https://atlasderschweiz.ch/fr/theme/zones-potentielles-de-pergelisol.md), [Italiano](https://atlasderschweiz.ch/it/tema/zone-potenziali-di-permafrost.md) ## Description Permafrost is a feature of the high-mountain landscape in Switzerland, where it forms a part of many attractive geological structures. Permafrost itself can not be seen, which is perhaps why mythical-like characteristics are sometimes attributed to it. Permafrost refers to a situation in which substrate material (e.g. rock, rubble) remains below 0°C all year round for at least two consecutive years. Permafrost usually has an active layer of ground above it that displays sharp temperature fluctuations throughout the year and can thaw during the warmer months. Permafrost can be found in many different types of areas, whereby its presence depends heavily on topography, climate conditions and subsoil properties. Permafrost is almost always to be found above the tree line outside of shady forest areas. Permafrost accounts for approximately 4%-6% of the total land area of Switzerland. The calculated distribution of permafrost shown on the map here takes into account the factors of elevation, slope exposure and terrain. These factors determine whether permafrost will form in loose material, with ice content ranging from low to very high, or in bedrock with ice-filled joints. Ground ice can form when ground water freezes or when water from melted snow refreezes. In some cases, it can result from the remains of an avalanche or small glaciers. Because of its heavy dependence on temperature conditions, permafrost reacts very sensitively to climate changes. Construction projects in high-mountain regions therefore need to take permafrost factors into account as early as the design stage. Permafrost itself is not considered a natural hazard, but temperature changes in permafrost areas can influence the frequency and intensity of mudslides and landslides, rock slides, avalanches, etc. *Data basis* The modelling of the potential distribution of permafrost in 2005 was conducted by the Federal Office for the Environment with a 25x25m grid. The grid data were vectorised and straightened (edges rounded) for this map in order to achieve a more natural effect. The underlying data show a probability of occurrence of permafrost of between 1% and 99% for each 25x25m square. For this map, the subdivision was merged into four stages in order to enable a clear categorisation. The map therefore can not be used as a basis for planning construction projects in high-mountain regions but is instead meant to serve as a rough depiction of the situation in the Swiss Alps. ## Sources - SCNAT - akademie der naturwissenschaften: [Permafrost](https://naturwissenschaften.ch/snow-glaciers-permafrost-explained/permafrost). SCNAT - Keller et al. (2008): Permafrost und Klimawandel. Zürich: Compendio Bildungsmedien ## Data sources - Sektion ‘Rutschung, Lawinen, Schutzwald’, Abteilung Gefahrenprävention, BAFU (2005): Hinweiskarte der Permafrostverbreitung in der Schweiz. BAFU ## Data owners - [FOEN](https://www.bafu.admin.ch/bafu/de/home/amt/kontakt-und-standort-des-bafu.html) - [Hazard Prevention Division, FOEN](https://www.bafu.admin.ch/bafu/de/home/amt/geschaeftsleitung-des-bafu/direktionsbereich-naturgefahren-und-wald/abteilung-gefahrenpraevention.html) ## Citation The terms of use ask to name the Atlas of Switzerland and the data owners, and to keep the source references in exports, screenshots and embeds. Cite the map as: > Atlas of Switzerland (2023): Potential permafrost areas. ETH Zürich. Map data © FOEN, Hazard Prevention Division, FOEN. https://atlasderschweiz.ch/en/theme/potential-permafrost-areas/ ## Links The map opens at its full extent; a link cannot set the map position. - Map: https://atlasderschweiz.ch/en/theme/potential-permafrost-areas/ - Short link, stays valid when the title changes: https://atlasderschweiz.ch/en/t/225/ - Side by side with another map: https://atlasderschweiz.ch/en/comparison/?lt=225&rt={id of the other map}&ru={u of the other map, or leave out} Embed in another website (allowed by the terms of use, as long as the source references stay visible): ```html ``` In the embed URL, `dm` sets what is shown: `e` the map with its title bar (default), `p` also the values of an object clicked on the map, `m` only the map with a button that opens it in the atlas. `ig=1` (default) lets the map react to scrolling and dragging only after a click into it, `ig=0` right away. The size can be changed in `style`. For the use and citation of maps and data, see the [terms of use](https://atlasderschweiz.ch/en/terms-of-use/).