TY  - JOUR
A1  - Opel, Thomas
A1  - Murton, Julian B.
A1  - Wetterich, Sebastian
A1  - Meyer, Hanno
A1  - Ashastina, Kseniia
A1  - Günther, Frank
A1  - Grotheer, Hendrik
A1  - Mollenhauer, Gesine
A1  - Danilov, Petr P.
A1  - Boeskorov, Vasily
A1  - Savvinov, Grigoriy N.
A1  - Schirrmeister, Lutz
T1  - Past climate and continentality inferred from ice wedges at Batagay Highlands, interior Yakutia
JF  - Climate of the past : an interactive open access journal of the European Geosciences Union
N2  - Ice wedges in the Yana Highlands of interior Yakutia - the most continental region of the Northern Hemisphere - were investigated to elucidate changes in winter climate and continentality that have taken place since the Middle Pleistocene. The Batagay megaslump exposes ice wedges and composite wedges that were sampled from three cryostratigraphic units: the lower ice complex of likely pre-Marine Isotope Stage (MIS) 6 age, the upper ice complex (Yedoma) and the upper sand unit (both MIS 3 to 2). A terrace of the nearby Adycha River provides a Late Holocene (MIS 1) ice wedge that serves as a modern reference for interpretation. The stable-isotope composition of ice wedges in the MIS 3 upper ice complex at Batagay is more depleted (mean delta O-18 about -35 parts per thousand) than those from 17 other ice-wedge study sites across coastal and central Yakutia. This observation points to lower winter temperatures and therefore higher continentality in the Yana Highlands during MIS 3. Likewise, more depleted isotope values are found in Holocene wedge ice (mean delta O-18 about -29 parts per thousand) compared to other sites in Yakutia. Ice-wedge isotopic signatures of the lower ice complex mean delta O-18 about -33 parts per thousand) and of the MIS 3-2 upper sand unit (mean delta O-18 from about -33 parts per thousand to -30 parts per thousand) are less distinctive regionally. The latter unit preserves traces of fast formation in rapidly accumulating sand sheets and of post-depositional isotopic fractionation.
Y1  - 2019
U6  - https://doi.org/10.5194/cp-15-1443-2019
SN  - 1814-9324
SN  - 1814-9332
VL  - 15
IS  - 4
SP  - 1443
EP  - 1461
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Wetterich, Sebastian
A1  - Rudaya, Natalia
A1  - Kuznetsov, Vladislav
A1  - Maksimov, Fedor
A1  - Opel, Thomas
A1  - Meyer, Hanno
A1  - Günther, Frank
A1  - Bobrov, Anatoly
A1  - Raschke, Elena
A1  - Zimmermann, Heike Hildegard
A1  - Strauss, Jens
A1  - Starikova, Anna
A1  - Fuchs, Margret
A1  - Schirrmeister, Lutz
T1  - Ice Complex formation on Bol'shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka
JF  - Quaternary research : an interdisciplinary journal
N2  - Late Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol'shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the Marine Oxygen Isotope Stage (MIS) 7a–c interglacial period. The preservation of the ice-rich Yukagir IC proves its resilience to last interglacial and late glacial–Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3, and MIS 2 ages exposed on Bol'shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveal grass-shrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. IC data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.
KW  - Cryostratigraphy
KW  - Ice wedges
KW  - Stable isotopes
KW  - Pollen
KW  - Radioisotope disequilibria dating
KW  - Beringia
Y1  - 2019
U6  - https://doi.org/10.1017/qua.2019.6
SN  - 0033-5894
SN  - 1096-0287
VL  - 92
IS  - 2
SP  - 530
EP  - 548
PB  - Cambridge Univ. Press
CY  - New York
ER  -