TY  - JOUR
A1  - Wetterich, Sebastian
A1  - Schirrmeiste, Lutz
A1  - Nazarova, Larisa B.
A1  - Palagushkina, Olga
A1  - Bobrov, Anatoly
A1  - Pogosyan, Lilit
A1  - Savelieva, Larisa
A1  - Syrykh, Liudmila
A1  - Matthes, Heidrun
A1  - Fritz, Michael
A1  - Günther, Frank
A1  - Opel, Thomas
A1  - Meyer, Hanno
T1  - Holocene thermokarst and pingo development in the Kolyma Lowland (NE Siberia)
JF  - Permafrost and Periglacial Processes
N2  - Ground ice and sedimentary records of a pingo exposure reveal insights into Holocene permafrost, landscape and climate dynamics. Early to mid-Holocene thermokarst lake deposits contain rich floral and faunal paleoassemblages, which indicate lake shrinkage and decreasing summer temperatures (chironomid-based T-July) from 10.5 to 3.5 cal kyr BP with the warmest period between 10.5 and 8 cal kyr BP. Talik refreezing and pingo growth started about 3.5 cal kyr BP after disappearance of the lake. The isotopic composition of the pingo ice (delta O-18 - 17.1 +/- 0.6 parts per thousand, delta D -144.5 +/- 3.4 parts per thousand, slope 5.85, deuterium excess -7.7 +/- 1.5 parts per thousand) point to the initial stage of closed-system freezing captured in the record. A differing isotopic composition within the massive ice body was found (delta O-18 - 21.3 +/- 1.4 parts per thousand, delta D -165 +/- 11.5 parts per thousand, slope 8.13, deuterium excess 4.9 +/- 3.2 parts per thousand), probably related to the infill of dilation cracks by surface water with quasi-meteoric signature. Currently inactive syngenetic ice wedges formed in the thermokarst basin after lake drainage. The pingo preserves traces of permafrost response to climate variations in terms of ground-ice degradation (thermokarst) during the early and mid-Holocene, and aggradation (wedge-ice and pingo-ice growth) during the late Holocene.
KW  - bioindicators
KW  - cryolithology
KW  - hydrochemistry
KW  - Khalerchinskaya tundra
KW  - stable water isotopes
Y1  - 2018
U6  - https://doi.org/10.1002/ppp.1979
SN  - 1045-6740
SN  - 1099-1530
VL  - 29
IS  - 3
SP  - 182
EP  - 198
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Fritz, Michael
A1  - Opel, Thomas
A1  - Tanski, George
A1  - Herzschuh, Ulrike
A1  - Meyer, Hanno
A1  - Eulenburg, A.
A1  - Lantuit, Hugues
T1  - Dissolved organic carbon (DOC) in Arctic ground ice
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Thermal permafrost degradation and coastal erosion in the Arctic remobilize substantial amounts of organic carbon (OC) and nutrients which have accumulated in late Pleistocene and Holocene unconsolidated deposits. Permafrost vulnerability to thaw subsidence, collapsing coastlines and irreversible landscape change are largely due to the presence of large amounts of massive ground ice such as ice wedges. However, ground ice has not, until now, been considered to be a source of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and other elements which are important for ecosystems and carbon cycling. Here we show, using biogeochemical data from a large number of different ice bodies throughout the Arctic, that ice wedges have the greatest potential for DOC storage, with a maximum of 28.6 mg L-1 (mean: 9.6 mg L-1). Variation in DOC concentration is positively correlated with and explained by the concentrations and relative amounts of typically terrestrial cations such as Mg2+ and K+. DOC sequestration into ground ice was more effective during the late Pleistocene than during the Holocene, which can be explained by rapid sediment and OC accumulation, the prevalence of more easily degradable vegetation and immediate incorporation into permafrost. We assume that pristine snowmelt is able to leach considerable amounts of well-preserved and highly bioavailable DOC as well as other elements from surface sediments, which are rapidly frozen and stored in ground ice, especially in ice wedges, even before further degradation. We found that ice wedges in the Yedoma region represent a significant DOC (45.2 Tg) and DIC (33.6 Tg) pool in permafrost areas and a freshwater reservoir of 4200 km(2). This study underlines the need to discriminate between particulate OC and DOC to assess the availability and vulnerability of the permafrost car-bon pool for ecosystems and climate feedback upon mobilization.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 493 
KW  - last glacial maximum
KW  - Beaufort Sea coast
KW  - Cape Mamontov Klyk
KW  - permafrost carbon
KW  - Laptev Sea
KW  - Lyakhovsky Island
KW  - climate-change
KW  - old carbon
KW  - hologene
KW  - Siberia
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-408155
SN  - 1866-8372
IS  - 493
ER  -