@article{MorgensternOverduinGuentheretal.2020,
  author    = {Morgenstern, Anne and Overduin, Pier Paul and G{\"u}nther, Frank and Stettner, Samuel and Ramage, Justine and Schirrmeister, Lutz and Grigoriev, Mikhail N. and Grosse, Guido},
  title     = {Thermo-erosional valleys in Siberian ice-rich permafrost},
  series = {Permafrost and Periglacial Processes},
  volume    = {32},
  journal   = {Permafrost and Periglacial Processes},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1045-6740},
  doi       = {10.1002/ppp.2087},
  pages     = {59 -- 75},
  year      = {2020},
  abstract  = {Thermal erosion is a major mechanism of permafrost degradation, resulting in characteristic landforms. We inventory thermo-erosional valleys in ice-rich coastal lowlands adjacent to the Siberian Laptev Sea based on remote sensing, Geographic Information System (GIS), and field investigations for a first regional assessment of their spatial distribution and characteristics. Three study areas with similar geological (Yedoma Ice Complex) but diverse geomorphological conditions vary in valley areal extent, incision depth, and branching geometry. The most extensive valley networks are incised deeply (up to 35 m) into the broad inclined lowland around Mamontov Klyk. The flat, low-lying plain forming the Buor Khaya Peninsula is more degraded by thermokarst and characterized by long valleys of lower depth with short tributaries. Small, isolated Yedoma Ice Complex remnants in the Lena River Delta predominantly exhibit shorter but deep valleys. Based on these hydrographical network and topography assessments, we discuss geomorphological and hydrological connections to erosion processes. Relative catchment size along with regional slope interact with other Holocene relief-forming processes such as thermokarst and neotectonics. Our findings suggest that thermo-erosional valleys are prominent, hitherto overlooked permafrost degradation landforms that add to impacts on biogeochemical cycling, sediment transport, and hydrology in the degrading Siberian Yedoma Ice Complex.},
  language  = {en}
}
@article{OpelMurtonWetterichetal.2019,
  author    = {Opel, Thomas and Murton, Julian B. and Wetterich, Sebastian and Meyer, Hanno and Ashastina, Kseniia and G{\"u}nther, Frank and Grotheer, Hendrik and Mollenhauer, Gesine and Danilov, Petr P. and Boeskorov, Vasily and Savvinov, Grigoriy N. and Schirrmeister, Lutz},
  title     = {Past climate and continentality inferred from ice wedges at Batagay Highlands, interior Yakutia},
  series = {Climate of the past : an interactive open access journal of the European Geosciences Union},
  volume    = {15},
  journal   = {Climate of the past : an interactive open access journal of the European Geosciences Union},
  number    = {4},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1814-9324},
  doi       = {10.5194/cp-15-1443-2019},
  pages     = {1443 -- 1461},
  year      = {2019},
  abstract  = {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.},
  language  = {en}
}
@article{WetterichRudayaKuznetsovetal.2019,
  author    = {Wetterich, Sebastian and Rudaya, Natalia and Kuznetsov, Vladislav and Maksimov, Fedor and Opel, Thomas and Meyer, Hanno and G{\"u}nther, Frank and Bobrov, Anatoly and Raschke, Elena and Zimmermann, Heike Hildegard and Strauss, Jens and Starikova, Anna and Fuchs, Margret and Schirrmeister, Lutz},
  title     = {Ice Complex formation on Bol'shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka},
  series = {Quaternary research : an interdisciplinary journal},
  volume    = {92},
  journal   = {Quaternary research : an interdisciplinary journal},
  number    = {2},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {0033-5894},
  doi       = {10.1017/qua.2019.6},
  pages     = {530 -- 548},
  year      = {2019},
  abstract  = {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.},
  language  = {en}
}