Call number:
AWI G5-10-0057
Description / Table of Contents:
The Arctic has been affected by the ongoing climate and environmental change more than other regions of the earth. For the next century, increasing rates of change have been predicted. Only a few Arctic meteorological records date back to the 19th century. Hence paleoclimate archives are of particular importance for the reconstruction and assessment of past climate variability and its causes. In this thesis, glacier and ground ice from the Russian Arctic, more precisely an ice core from Akademii Nauk ice cap (Severnaya Zemlya) and syngenetic ice wedges from Oyogos Yar (Dmitrii Laptev Strait), both covering the Late Holocene, were studied to contribute new paleoenvironmental information. Both archives were mainly analyzed by using stable water isotopes. This thesis demonstrates the great potential of Akademii Nauk ice core for the high resolution reconstruction of regional climate and environmental variability. In particular, its delta-O-18 data can be used as proxy for temperature in the Western Eurasian Arctic revealing significant changes on different timescales. The 20th century was the warmest period of the last two millennia, with an absolute double-peaked maximum around AD 1920 - 1940. Of particular interest are rapid decadal-scale climate changes, which occured in the 15th and 16th century as well as at about AD 1900, most probably caused by internal dynamics of the Arctic climate system. Deuterium excess d provides valuable information on the participation of regional moisture in the precipitation feeding Akademii Nauk ice cap, which is linked to the regional sea ice extent. Decreasing delta-O-18 and sea salt ion values due to the increasing ice cap altitude prove the growth of Akademii Nauk ice cap in the Late Holocene. A new approach, comprising high resolution sampling and radiocarbon dating, was used to gain paleoenvironmental information from the syngenetic Oyogos Yar ice wedges. Even through no continuous records could be obtained due to still inconsistent dating results, paleoclimatic information could be extracted. Ice wedge delta-O-18 data show evidence that winters in the last decades were the warmest in the Late Holocene. These were accompanied by changes in the moisture sources, related to changes in the atmospheric circulation patterns and / or sea ice dynamics. Envisaged follow-up research will continue the work on the studied objects and will facilitate new insights into the paleoenvironmental history of the Eurasian Arctic.
Type of Medium:
Monograph available for loan
Pages:
164 S. : Ill., graph. Darst.
Branch Library:
AWI Library
