A reconstruction of the thawing of the permafrost during the last 170 years on the Taimyr Peninsula (East Siberia, Russia)

Reconstructing the temporal and spatial changes in climate on a seasonal basis during the past few centuries may help us better understand the modern-day interplay between natural and anthropogenic climate variability. The objective of this paper is to reconstruct the thawing of the permafrost at 71°N in Arctic Siberia during the termination of the Little Ice Age and the subsequent Recent Warming period. Sediment samples from two lakes on the Taimyr Peninsula were analysed by high-resolution X-ray fluorescence spectroscopy at a scan resolution of 1 mm, and pollen analyses were conducted. The depth-age models of the cores were constructed using 210Pb and 137Cs activity according to the constant rate of supply (CRS) model. The lake sediment cover of these lakes began to form ca. 1840. We defined three periods of increased permafrost thawing during the last 170 years. The first maximum of permafrost melting occurred from 1870 to 1880, the second episode was from 1900 to 1930 and the third began between 1960 and 1965. During these periods, the maxima of permafrost melting occurred with a specific time lag following.

► The objective of this paper is to reconstruct permafrost thawing of arctic Siberia.
► We used high-resolution geochemical proxies and pollen dates.
► Intense permafrost thawing was calculated from the level matter supplied by meltwater into the lakes.
► We defined three periods of increased permafrost thawing during the last 170 years.