Changes in permafrost dynamics across north-western Russia between 1970 and 2005
Temperature records from boreholes going back four decades show that permafrost under Arctic lands has warmed by up to 2 centigrades, particularly in colder sites (typical permafrost temperatures range from -16 centigrades to just below 0 centigrades, depending on the location). The upper few metres of permafrost have disappeared altogether since 1970 at several low Arctic sites. In some areas with a shallow layer of permafrost, it has thawed completely. The southern limit of permafrost moved northward by 30 to 80 km in western Russia between 1970 and 2005, for instance, as presented in this figure.