scholarly journals Middle and Late Pleistocene climate and continentality inferred from ice wedges at Batagay megaslump in the Northern Hemisphere’s most continental region, Yana Highlands, interior Yakutia

2018 ◽  
Author(s):  
Thomas Opel ◽  
Julian B. Murton ◽  
Sebastian Wetterich ◽  
Hanno Meyer ◽  
Kseniia Ashastina ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Late Holocene ◽  
Winter Climate ◽  
Isotopic Signatures ◽  
Pleistocene Climate ◽  
Winter Temperatures ◽  
Ice Wedge ◽  
Middle And Late Pleistocene ◽  
Sand Sheets ◽  
Ice Complex

Abstract. Ice wedges in the Yana Highlands of interior Yakutia – the most continental region of the Northern Hemisphere – were investigated to elucidate the winter climate and continentality during the Middle to Late Pleistocene. The Batagay megaslump exposes ice wedges and composite wedges that were sampled from three cryostratigraphic units: the lower sand unit of Marine Isotope Stage (MIS) 6 age, the upper Ice Complex (Yedoma) and the upper sand unit (both MIS3 to MIS2). A terrace of the nearby Adycha River provides a Late Holocene (MIS1) ice wedge that serves as a modern endmember for analysis. Stable-isotope values of ice wedges in the MIS3 upper Yedoma Ice Complex at Batagay are more depleted (mean δ18O about −35 ‰) than those from 17 other ice-wedge sites across coastal and central Yakutia. This observation points to lower winter temperatures and, therefore, higher continentality in the Yana Highlands during MIS3. Likewise, more depleted isotope values compared to other sites in Yakutia are found in Holocene wedge ice (mean δ18O about −29 ‰). Ice-wedge isotopic signatures of the MIS6 lower sand unit (mean δ18O about −33 ‰) and of the MIS3-2 upper sand unit (mean δ18O from about −33 to −30 ‰) are less distinctive regionally and preserve traces of fast formation in rapidly accumulating sand sheets and of post-depositional fractionation.

scholarly journals Past climate and continentality inferred from ice wedges at Batagay megaslump in the Northern Hemisphere's most continental region, Yana Highlands, interior Yakutia

2019 ◽  
Vol 15 (4) ◽  
pp. 1443-1461 ◽  
Author(s):  
Thomas Opel ◽  
Julian B. Murton ◽  
Sebastian Wetterich ◽  
Hanno Meyer ◽  
Kseniia Ashastina ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Isotopic Fractionation ◽  
Middle Pleistocene ◽  
Winter Climate ◽  
Isotopic Signatures ◽  
Mis 3 ◽  
Winter Temperatures ◽  
Ice Wedge ◽  
Study Sites ◽  
Ice Complex

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 δ18O about −35 ‰) 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 δ18O about −29 ‰) compared to other sites in Yakutia. Ice-wedge isotopic signatures of the lower ice complex (mean δ18O about −33 ‰) and of the MIS 3–2 upper sand unit (mean δ18O from about −33 ‰ to −30 ‰) are less distinctive regionally. The latter unit preserves traces of fast formation in rapidly accumulating sand sheets and of post-depositional isotopic fractionation.

scholarly journals Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)

2017 ◽  
Author(s):  
Thomas Opel ◽  
Sebastian Wetterich ◽  
Hanno Meyer ◽  
Alexander Yu. Dereviagin ◽  
Margret C. Fuchs ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Late Quaternary ◽  
Cold Winter ◽  
Winter Climate ◽  
Climate Conditions ◽  
Winter Conditions ◽  
Winter Temperatures ◽  
Siberian Arctic ◽  
Ice Wedge

Abstract. To reconstruct palaeoclimate and palaeonvironmental conditions in the Northeast Siberian Arctic, we studied late Quaternary permafrost deposits at the Oyogos Yar coast (Dmitry Laptev Strait). New infrared stimulated luminescence ages for distinctive floodplain deposits of the Kuchchugui Suite (112.5 ± 9.6 kyr) and thermokarst lake deposits of the Krest Yuryakh Suite (102.4 ± 9.7 kyr), respectively, provide new substantial geochronological data and shed light on the landscape history of the Dmitry Laptev Strait region during the Marine Isotope Stage (MIS) 5. Ground ice stable-isotope data are presented together with cryolithological information for eight cryostratigraphic units and are complemented by data from nearby Bol'shoy Lyakhovsky Island. Our combined record of ice-wedge stable isotopes as proxy for past winter climate conditions covers the last about 200 thousand years and is supplemented by texture-ice stable isotopes which contain annual climate conditions overprinted by freezing processes. Our ice wedge stable-water isotope data indicate substantial variations in Northeast Siberian Arctic winter climate conditions during the late Quaternary, in particular between Glacial and Interglacial but also over the last millennia to decades. Stable isotope values of Ice Complex ice wedges indicate cold to very cold winter temperatures about 200 kyr ago (MIS7), very cold winter conditions about 100 kyr ago (MIS5), very cold to moderate winter conditions between about 60 and 30 kyr ago, and extremely cold winter temperatures during the Last Glacial Maximum (MIS2). Much warmer winter conditions are reflected by extensive thermokarst development during the MIS5c and by Holocene ice-wedge stable-isotopes. Modern ice-wedge stable isotopes are most enriched and testify the recent winter warming in the Arctic. Hence, ice-wedge based reconstructions of changes in winter climate conditions add substantial information to those derived from paleoecological proxies stored in permafrost and allow for distinguishing between seasonal trends of past climate dynamics. Future progress in ice-wedge dating and an improved temporal resolution of ice-wedge derived climate information may help to fully explore the palaeoclimatic potential of ice wedges.

scholarly journals Extent and age of Middle and Late Pleistocene glaciations andperiglacial episodes in southern Jylland, Denmark

2007 ◽  
Vol 55 ◽  
pp. 9-35
Author(s):  
Michael Houmark Nielsen
Keyword(s):  
Late Pleistocene ◽  
Luminescence Dating ◽  
Scandinavian Ice Sheet ◽  
Ice Wedge ◽  
Low Arctic ◽  
Middle And Late Pleistocene ◽  
Late Weichselian ◽  
The Baltic ◽  
Growth Formation ◽  
Pleistocene Sediment

New evidence on distribution and chronology of glaciations in southern Jylland is presented. Ten stratigraphic units including four till-formations have been identified in Middle- and Late Pleistocene sediment successions. The timing of successive glaciations and periglacial interludes based on luminescence dating is established for the past c. 200 kyr. The OSL-chronology predicts that deposition of Lillebælt Till (Late Saalian, Warthe Glaciation) occurred at 180-160 kyr. Deglaciation followed and barren periglacial environments existed until beginning of the Eemian. Periglacial conditions were restored c. 115 kyr ago and lasted well into the Middle Weichselian. Expansion of the Scandinavian Ice Sheet through the Baltic depression into southern Jylland caused deposition of Ristinge Klint Till (Ristinge Glaciation) c. 55–50 kyr ago. Glaciers flowed westwards beyond the Main Stationary Line (MSL) and may have terminated along ice showed ridges in the periglacially smoothed landscape east of the present North Sea coast. This traditionally named “Old Baltic”glaciation is now recognized elsewhere in the circum Baltic region besides Denmark. Deglaciation was succeeded by periglacial environments with cryoturbation, ice wedge growth, formation of wind abrasion pavements and low arctic habitats. Approaching the global glacio-eustatic low stand of the Last Glacial Maximum increased cooling and enhanced down slope creep caused widespread solifluction. In a sequence of Late Weichselian glacier advances, Mid Danish Till, East Jylland Till and Bælthav Till was deposited under progressing deglaciation between 25 and 18 kyr ago. Retarded melting of dead ice from the Ristinge Glaciation formed thermo karst depressions on the surfaceof outwash plains in front of MSL.

scholarly journals Microbial and Geochemical Evidence of Permafrost Formation at Mamontova Gora and Syrdakh, Central Yakutia

2021 ◽  
Vol 9 ◽  
Author(s):  
M. Yu. Cherbunina ◽  
E. S. Karaevskaya ◽  
Yu. K. Vasil’chuk ◽  
N. I. Tananaev ◽  
D. G. Shmelev ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Community Composition ◽  
Similarity Metrics ◽  
Community Similarity ◽  
Geologic History ◽  
Isotopic Signatures ◽  
Central Yakutia ◽  
Water Origin ◽  
Ice Wedge ◽  
Ice Complex

Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community.

scholarly journals Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)

2017 ◽  
Vol 13 (6) ◽  
pp. 587-611 ◽  
Author(s):  
Thomas Opel ◽  
Sebastian Wetterich ◽  
Hanno Meyer ◽  
Alexander Y. Dereviagin ◽  
Margret C. Fuchs ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Late Quaternary ◽  
Cold Winter ◽  
Winter Climate ◽  
Climate Conditions ◽  
Winter Conditions ◽  
Winter Temperatures ◽  
Siberian Arctic ◽  
Ice Wedge

Abstract. To reconstruct palaeoclimate and palaeoenvironmental conditions in the northeast Siberian Arctic, we studied late Quaternary permafrost at the Oyogos Yar coast (Dmitry Laptev Strait). New infrared-stimulated luminescence ages for distinctive floodplain deposits of the Kuchchugui Suite (112.5 ± 9.6 kyr) and thermokarst-lake deposits of the Krest Yuryakh Suite (102.4 ± 9.7 kyr), respectively, provide new substantial geochronological data and shed light on the landscape history of the Dmitry Laptev Strait region during Marine Isotope Stage (MIS) 5. Ground-ice stable-isotope data are presented together with cryolithological information for eight cryostratigraphic units and are complemented by data from nearby Bol'shoy Lyakhovsky Island. Our combined record of ice-wedge stable isotopes as a proxy for past winter climate conditions covers about 200 000 years and is supplemented by stable isotopes of pore and segregated ice which reflect annual climate conditions overprinted by freezing processes. Our ice-wedge stable-isotope data indicate substantial variations in northeast Siberian Arctic winter climate conditions during the late Quaternary, in particular between glacial and interglacial times but also over the last millennia to centuries. Stable isotope values of ice complex ice wedges indicate cold to very cold winter temperatures about 200 kyr ago (MIS7), very cold winter conditions about 100 kyr ago (MIS5), very cold to moderate winter conditions between about 60 and 30 kyr ago, and extremely cold winter temperatures during the Last Glacial Maximum (MIS2). Much warmer winter conditions are reflected by extensive thermokarst development during MIS5c and by Holocene ice-wedge stable isotopes. Modern ice-wedge stable isotopes are most enriched and testify to the recent winter warming in the Arctic. Hence, ice-wedge-based reconstructions of changes in winter climate conditions add substantial information to those derived from paleoecological proxies stored in permafrost and allow a distinction between seasonal trends of past climate dynamics. Future progress in ice-wedge dating and an improved temporal resolution of ice-wedge-derived climate information may help to fully explore the palaeoclimatic potential of ice wedges.

scholarly journals Late Pleistocene climate induced changes in paleo-vegetation in Borneo: Possible implications to human divergence

2021 ◽  
Vol 267 ◽  
pp. 107109
Author(s):  
Zaibao Yang ◽  
Yanli Lei ◽  
Yair Rosenthal ◽  
Tiegang Li ◽  
Zhimin Jian
Keyword(s):  
Late Pleistocene ◽  
Pleistocene Climate ◽  
Induced Changes
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