measured temperature data for a particular year. For a correlation like this it is important to understand different factors which might influence the isotope composition of the ice wedge. One such factor is isotope fractionation during refreezing, which was studied using a highresolution experiment and turned out to be negligible. Additionally environmental conditions like temperature and snow-depth influence frost cracking and therefore determine the time period of ice wedge growth. These conditions were investigated by frost-cracking experiments, which identified December as the main season for thermal-contraction cracking at Samoylov Island. Two main seasons for penetration of snow and melt water into frost cracks were found: the first one in December when frost cracking takes place and the second one at snow melt in spring. Therefore the isotope signal of an ice wedge represents spring and winter temperatures. A shift in seasonality between the first two years and the later years was observed in the isotope signal. For the years 2004 to 2010 a isotope-temperature equation was obtained. Recent ground ice from an ice-wedge was successfully attributed to the year of its formation and showed that the isotope signal from ice-wedge samples is influenced by both, spring and winter temperatures.