A stable isotope record of an ice core from Akademii Nauk ice cap, Severnaya Zemlya, Russian Arctic

• Main Authors: Fritzsche, Diedrich, Schütt, R., Meyer, Hanno, Miller, Heinrich, Wilhelms, Frank, Savatyugin, L. M.
• Format: Conference Object
• Language: unknown
• Published: 2005
• Subjects: Antarctic; Arctic; Severnaya Zemlya; Antarc*; Arctic and Antarctic Research Institute; glacier; Ice cap; ice core
• Online Access: https://epic.awi.de/id/eprint/12788/; https://hdl.handle.net/10013/epic.23199

In the Eurasian Arctic, the archipelago of Severnaya Zemlya is the easternmost one which is covered by considerable ice caps. This gives the opportunity to get regional paleo-climate information from ice core records. In 1986/87 the first ice core was drilled on Akademii Nauk ice cap, the northernmost one on Severnaya Zemlya (Savatyugin and Zagorodnov (1988), Klement'yev et al. (1991)). This core was analyzed with relatively low data resolution. A chronology was published by Klement'yev et al. (1988 and 1991) and Kotlyakov et al. (1990). These authors claimed a Late Pleistocene bottom age for this core. From 1999 to 2001 a new 724 m long ice core was drilled on Akademii Nauk to proof the maximum resolution possible to be obtained and to check the time-scale published so far for this glacier (Savatyugin et al. (2001), Fritzsche et al. (2002)). This project was carried out in co-operation between the Alfred Wegener Institute (AWI), Germany, the Arctic and Antarctic Research Institute (AARI) St. Petersburg and the Mining Institute St. Petersburg, Russia. The knowledge of annual layer thickness is the basis for the chronology of the core. One of the main problems is that infiltration processes caused by melting and even rain during summer time will smooth or destroy seasonal signals. The variation of stable isotopes of water (dD and d18O) is the most common tool to reconstruct the annual layer thickness also in areas with percolation as Pohjola et al. (2002) have demonstrated but sometimes oscillations in D-excess values better resolve the annual variation (Stichler et al. (1979)). We used D-excess and d18O for determination of layer thickness.A recent mean accumulation rate of about 460 kgm-2a-1 was found at the drilling site close to the summit of Akademii Nauk using horizons with increased 137Cs radioactivity as time markers. Pinglot et al. (2003) have found two such peaks coursed by nuclear weapon tests in the beginning of 1960s and by the accident of Chernobyl nuclear power station in 1986. Zagorodnov et al. ...