Alaska North Slope
Herschel Island
Daring Lake
Zackenberg
Svalbard
Abisko
Vorkuta
Nadym
Samoylov / Tiksi
Spasskaya Pad
Kytalik
Cherskii
Secondary sites
Primary sites
Continuous permafrost
Discontinuous permafrost
Sporadic permafrost
Isolated permafrost
Subsea permafrost
Source: Brown et al. (1997)
International Permafrost Association