A new deep ice core from Academy of Science ice cap, Severnaya Zemlya - first results

• Main Authors: Fritzsche, Diedrich, Wilhelms, Frank, Savatyugin, L. M., Pinglot, J. F., Meyer, Hanno, Hubberten, Hans-Wolfgang, Miller, Heinrich
• Format: Conference Object
• Language: unknown
• Published: International Glaciological Society 2001
• Subjects: Greenland; Severnaya Zemlya; Antarc*; Antarctica; Arctic; Ice cap; ice core
• Online Access: https://epic.awi.de/id/eprint/48034/; https://hdl.handle.net/10013/epic.3a5d45d6-900d-4aeb-88c5-bd15210a376a

The paper presents first results from the upper 54 m of a 723.91 m ice core drilled on Academy of Sciences Ice Cap in 1999-2001, supplemented by data from shallow ice cores. The glacier's peculiarity is the infiltration and refreezing of melting water thereby changing original isotopic and chemical signals. Therefore, stratigraphical observations in these ice cores are more difficult than in those from central Greenland or Antarctica. However, the 1963 maximum of artificial radioactivity from atmospheric nuclear tests is clearly detectable in the deep ice core and the d180 profile of a 12.82 m shallow core shows annual variations. Consequently, an almost seasonal time resolution of paleoclirnate record could be expected at least for the upper part of the main core. The Chemobyl layer was detected by increased 137 Cs activity in depths between 11.81 m and 12.51 m related to the 2000 surface. The resulting mean annual net mass balance is 53 ± 2 g cm-2 a- 1. Data from dielectric profiling (DEP) of the main core show considerable peaks in conductivity; one of them was interpreted as volcano event. According to the resulting chronology this part of the core represents approximately the last 100 years.