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  • 1
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    Effects of climate change and industrialization on Lake Bolshoe Toko, eastern Siberia (2021)
    Biskaborn, Boris K. ; Narancic, Biljana ; Stoof-Leichsenring, Kathleen R. ; [et al.]
    Springer Netherlands
    Details
    Publication Date: 2023-12-19
    Description: Industrialization in the Northern Hemisphere has led to warming and pollution of natural ecosystems. We used paleolimnological methods to explore whether recent climate change and/or pollution had affected a very remote lake ecosystem, i.e. one without nearby direct human influence. We compared sediment samples that date from before and after the onset of industrialization in the mid-nineteenth century, from four short cores taken at water depths between 12.1 and 68.3 m in Lake Bolshoe Toko, eastern Siberia. We analyzed diatom assemblage changes, including diversity estimates, in all four cores and geochemical changes (mercury, nitrogen, organic carbon) from one core taken at an intermediate water depth. Chronologies for two cores were established using 210Pb and 137Cs. Sedimentation rates were 0.018 and 0.033 cm year〈sup〉−1〈/sup〉 at the shallow- and deep-water sites, respectively. We discovered an increase in light planktonic diatoms (Cyclotella) and a decrease in heavily silicified euplanktonic Aulacoseira through time at deep-water sites, related to more recent warmer air temperatures and shorter periods of lake-ice cover, which led to pronounced thermal stratification. Diatom beta diversity in shallow-water communities changed significantly because of the development of new habitats associated with macrophyte growth. Mercury concentrations increased by a factor of 1.6 since the mid-nineteenth century as a result of atmospheric fallout. Recent increases in the chrysophyte Mallomonas in all cores suggested an acidification trend. We conclude that even remote boreal lakes are susceptible to the effects of climate change and human-induced pollution.
    Description: Projekt DEAL
    Keywords: ddc:577.5 ; Diatoms ; Recent climate change ; Mercury ; Lake sediment cores ; Human impact
    Language: English
    Type: doc-type:article
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    CITATION GEO-LEO
  • 2
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    Deglacial Land-Ocean Linkages at the Alaskan Continental Margin in the Bering Sea (2021)
    Frontiers
    Details
    Publication Date: 2024-02-07
    Description: A marine sediment record from the central Bering Sea, spanning the last 20 thousand years (ka), was studied to unravel the depositional history with regard to terrigenous sediment supply and biogenic sedimentation. Methodic approaches comprised the inference of accumulation rates of siliciclastic and biogenic components, grain-size analysis, and (clay) mineralogy, as well as paleoclimatic modelling. Changes in the depositional history provides insight into land-ocean linkages of paleoenvironmental changes. During the finale of the Last Glacial Maximum, the depositional environment was characterized by hemipelagic background sedimentation. A marked change in the terrigenous sediment provenance during the late Heinrich 1 Stadial (15.7–14.5 ka), indicated by increases in kaolinite and a high glaciofluvial influx of clay, gives evidence of the deglaciation of the Brooks Range in the hinterland of Alaska. This meltwater pulse also stimulated the postglacial onset of biological productivity. Glacial melt implies regional climate warming during a time of widespread cooling on the northern hemisphere. Our simulation experiment with a coupled climate model suggests atmospheric teleconnections to the North Atlantic, with impacts on the dynamics of the Aleutian Low system that gave rise to warmer winters and an early onset of spring during that time. The late deglacial period between 14.5 and 11.0 ka was characterized by enhanced fluvial runoff and biological productivity in the course of climate amelioration, sea-level rise, seasonal sea-ice retreat, and permafrost thaw in the hinterland. The latter processes temporarily stalled during the Younger Dryas stadial (12.9-11.7 ka) and commenced again during the Preboreal (earliest Holocene), after 11.7 ka. High river runoff might have fertilized the Bering Sea and contributed to enhanced upper ocean stratification. Since 11.0 ka, advanced transgression has shifted the coast line and fluvial influence of the Yukon River away from the study site. The opening of the Bering Strait strengthened contour currents along the continental slope, leaving behind winnowed sand-rich sediments through the early to mid-Holocene, with non-deposition occurring since about 6.0 ka.
    Type: Article , PeerReviewed
    Format: text
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 3
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    Electrical resistivity tomography profiles collected in floating electrode mode from the lagoon's water surface, Profile A'-A (2019)
    PANGAEA
    Details
    Publication Date: 2023-03-16
    Keywords: AWI_Envi; AWI_PerDyn; AWI_Perma; AWI Arctic Land Expedition; DEPTH, water; Electrical resistivity tomography; ERT; LATITUDE; Lena2017; LONGITUDE; Permafrost Research; Permafrost Research (Periglacial Dynamics) @ AWI; Polar Fox Lagoon; Polar Terrestrial Environmental Systems @ AWI; Position; Profile; ProfileA-A; Resistivity, apparent; RU-Land_2017_Lena
    Type: Dataset
    Format: text/tab-separated-values, 9375 data points
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    DATA PANGAEA
  • 4
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    Electrical resistivity tomography profiles collected in floating electrode mode from the lagoon's water surface, Profile B-B' (2019)
    PANGAEA
    Details
    Publication Date: 2023-03-16
    Keywords: AWI_Envi; AWI_PerDyn; AWI_Perma; AWI Arctic Land Expedition; DEPTH, water; Electrical resistivity tomography; ERT; LATITUDE; Lena2017; LONGITUDE; Permafrost Research; Permafrost Research (Periglacial Dynamics) @ AWI; Polar Fox Lagoon; Polar Terrestrial Environmental Systems @ AWI; Position; Profile; ProfileB-B; Resistivity, apparent; RU-Land_2017_Lena
    Type: Dataset
    Format: text/tab-separated-values, 2150 data points
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    DATA PANGAEA
  • 5
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    Multi-proxy records of Two-Yurts Lake (2015)
    PANGAEA
    In:  Supplement to: Hoff, Ulrike; Biskaborn, Boris K; Dirksen, Veronika G; Dirksen, Oleg V; Kuhn, Gerhard; Meyer, Hanno; Nazarova, Larisa B; Roth, Alexandra; Diekmann, Bernhard (2015): Holocene environment of Central Kamchatka, Russia: Implications from a multi-proxy record of Two-Yurts Lake. Global and Planetary Change, 134, 101-117, https://doi.org/10.1016/j.gloplacha.2015.07.011
    Details
    Publication Date: 2023-03-07
    Description: Within the scope of Russian-German palaeoenvironmental research, Two-Yurts Lake (TYL, Dvuh-Yurtochnoe in Russian) was chosen as the main scientific target area to decipher Holocene climate variability on Kamchatka. The 5x2 km large and 26 m deep lake is of proglacial origin and situated on the eastern flank of Sredinny Ridge at the northwestern end of the Central Kamchatka Valley, outside the direct influence of active volcanism. Here, we present results of a multi-proxy study on sediment cores, spanning about the last 7000 years. The general tenor of the TYL record is an increase in continentality and winter snow cover in conjunction with a decrease in temperature, humidity, and biological productivity after 5000-4500 cal yrs BP, inferred from pollen and diatom data and the isotopic composition of organic carbon. The TYL proxy data also show that the late Holocene was punctuated by two colder spells, roughly between 4500 and 3500 cal yrs BP and between 1000 and 200 cal yrs BP, as local expressions of the Neoglacial and Little Ice Age, respectively. These environmental changes can be regarded as direct and indirect responses to climate change, as also demonstrated by other records in the regional terrestrial and marine realm. Long-term climate deterioration was driven by decreasing insolation, while the short-term climate excursions are best explained by local climatic processes. The latter affect the configuration of atmospheric pressure systems that control the sources as well as the temperature and moisture of air masses reaching Kamchatka.
    Keywords: AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI
    Type: Dataset
    Format: application/zip, 12 datasets
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    DATA PANGAEA
  • 6
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    Diatom species assemblages and sediment-geochemical measurements from Lake Bolshoe Toko short cores (2021)
    PANGAEA
    Details
    Publication Date: 2023-03-16
    Description: This data set describes times series of diatom species counts, organic matter measurements including total carbon TC, total organic carbon TOC, nitrogen N, stable carbon isotopes d13C, and mercury Hg concentrations in four short cores (PG2133, PG2139, PG2203, PG2208 from Lake Bolshoe Toko, eastern Siberia. These short core have been dated using 210Pb and 137Cs methods covering the transition zone of the industrialization until 2013 CE. Methods are provided in the associated paper (Biskaborn et al. 2021).
    Keywords: AWI_Envi; d13C; diatoms; Geochemistry; Lake sediment core; mercury; Polar Terrestrial Environmental Systems @ AWI
    Type: Dataset
    Format: application/zip, 7 datasets
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    DATA PANGAEA
  • 7
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    Age determination, sedimentological, biogeochemical, and plant macrofossils analyses of outcrop PG2038-1
    PANGAEA
    In:  Supplement to: Schleusner, Philipp; Biskaborn, Boris K; Kienast, Frank; Wolter, Juliane; Subetto, Dmitry A; Diekmann, Bernhard (2015): Basin evolution and palaeoenvironmental variability of the thermokarst lake El'gene-Kyuele, Arctic Siberia. Boreas, 44(1), 216-229, https://doi.org/10.1111/bor.12084
    Details
    Publication Date: 2023-05-12
    Description: Thermokarst lakes are a widespread feature of the Arctic tundra, in which highly dynamic processes are closely connected with current and past climate changes. We investigated late Quaternary sediment dynamics, basin and shoreline evolution, and environmental interrelations of Lake El'gene-Kyuele in the NE Siberian Arctic (latitude 71°17'N, longitude 125°34'E). The water-body displays thaw-lake characteristics cutting into both Pleistocene Ice Complex and Holocene alas sediments. Our methods are based on grain size distribution, mineralogical composition, TOC/N ratio, stable carbon isotopes and the analysis of plant macrofossils from a 3.5-m sediment profile at the modern eastern lake shore. Our results show two main sources for sediments in the lake basin: terrigenous diamicton supplied from thermokarst slopes and the lake shore, and lacustrine detritus that has mainly settled in the deep lake basin. The lake and its adjacent thermokarst basin rapidly expanded during the early Holocene. This climatically warmer than today period was characterized by forest or forest tundra vegetation composed of larches, birch trees and shrubs. Woodlands of both the HTM and the Late Pleistocene were affected by fire, which potentially triggered the initiation of thermokarst processes resulting later in lake formation and expansion. The maximum lake depth at the study site and the lowest limnic bioproductivity occurred during the longest time interval of ~7 ka starting in the Holocene Thermal Maximum and lasting throughout the progressively cooler Neoglacial, whereas partial drainage and an extensive shift of the lake shoreline occurred ~0.9 cal. ka BP. Correspondingly, this study discusses different climatic and environmental drivers for the dynamics of a thermokarst basin.
    Keywords: AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI; SibLake
    Type: Dataset
    Format: application/zip, 3 datasets
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    DATA PANGAEA
  • 8
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    Profiles of diatoms, pollen, XRD, XRF and organic composition of two sediment cores (PG2022 and PG2023) from Lake Kyutyunda in Yakutia, NE Siberia, Russia
    PANGAEA
    In:  Supplement to: Biskaborn, Boris K; Subetto, Dmitry A; Savelieva, Larissa A; Vakhrameeva, Polina; Hansche, Andreas; Herzschuh, Ulrike; Klemm, Juliane; Heinecke, Liv; Pestryakova, Luidmila A; Meyer, Hanno; Kuhn, Gerhard; Diekmann, Bernhard (2016): Late Quaternary vegetation and lake system dynamics in north-eastern Siberia: Implications for seasonal climate variability. Quaternary Science Reviews, 147, 406-421, https://doi.org/10.1016/j.quascirev.2015.08.014
    Details
    Publication Date: 2023-05-12
    Description: Although the climate development over the Holocene in the Northern Hemisphere is well known, palaeolimnological climate reconstructions reveal spatiotemporal variability in northern Eurasia. Here we present a multi-proxy study from north-eastern Siberia combining sediment geochemistry, and diatom and pollen data from lake-sediment cores covering the last 38,000 cal. years. Our results show major changes in pyrite content and fragilarioid diatom species distributions, indicating prolonged seasonal lake-ice cover between ~13,500 and ~8,900 cal. years BP and possibly during the 8,200 cal. years BP cold event. A pollen-based climate reconstruction generated a mean July temperature of 17.8°C during the Holocene Thermal Maximum (HTM) between ~8,900 and ~4,500 cal. years BP. Naviculoid diatoms appear in the late Holocene indicating a shortening of the seasonal ice cover that continues today. Our results reveal a strong correlation between the applied terrestrial and aquatic indicators and natural seasonal climate dynamics in the Holocene. Planktonic diatoms show a strong response to changes in the lake ecosystem due to recent climate warming in the Anthropocene. We assess other palaeolimnological studies to infer the spatiotemporal pattern of the HTM and affirm that the timing of its onset, a difference of up to 3,000 years from north to south, can be well explained by climatic teleconnections. The westerlies brought cold air to this part of Siberia until the Laurentide ice-sheet vanished 7,000 years ago. The apparent delayed ending of the HTM in the central Siberian record can be ascribed to the exceedance of ecological thresholds trailing behind increases in winter temperatures and decreases in contrast in insolation between seasons during the mid to late Holocene as well as lacking differentiation between summer and winter trends in paleolimnological reconstructions.
    Keywords: AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI; SibLake
    Type: Dataset
    Format: application/zip, 12 datasets
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    DATA PANGAEA
  • 9
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    Mineralogy of sea-floor surface sediments, Sonne cruise SO202/1 to the North Pacific and Bering Sea (2016)
    PANGAEA
    In:  Supplement to: Wang, Rong; Biskaborn, Boris K; Ramisch, Arne; Ren, Jian; Zhang, Yongzhan; Gersonde, Rainer; Diekmann, Bernhard (2016): Modern modes of provenance and dispersal of terrigenous sediments in the North Pacific and the Bering Sea: Implications and perspectives for palaeoenvironmental reconstructions. Geo-Marine Letters, 36(4), 259-270, https://doi.org/10.1007/s00367-016-0445-7
    Details
    Publication Date: 2023-01-27
    Description: During expedition 202 of research vessel SONNE in 2009, 39 sea-floor surface sediments were sampled over a wide area across the North Pacific and the Bering Sea, which are well suited as reference archives of modern environmental processes. In this study, we used the samples to infer the documentation of land-ocean linkages of terrigenous sediment supply. We followed an integrated approach of grain-size analysis, bulk mineralogy, and clay mineralogy in combination with statistical data evaluation (end-member modelling of grain-size data, fuzzy-cluster analysis of mineralogical data), in order to identify the significant sources and modes of sediment transport in an overregional context. We also compiled literature data on clay mineralogy and updated those with the new data. Today, two processes of terrigenous sediment supply prevail in the study area: far-distant aeolian sediment supply to the pelagic North Pacific as well as hemipelagic sediment dispersal from nearby land sources by ocean currents along the continental margins and island arcs of the study area. The aeolian particles show the finest grain sizes (clay and fine silt), while the hemipelagic sediments have high abundances of sortable silt, particles 〉10 microns.
    Type: Dataset
    Format: application/zip, 3 datasets
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    DATA PANGAEA
  • 10
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    Age determination and bulk geochemistry of sediment core KK12-1, Lake Karakul, Tajikistan in 2012 (2017)
    PANGAEA
    In:  Supplement to: Heinecke, Liv; Mischke, Steffen; Adler, Karsten; Barth, Anja; Biskaborn, Boris K; Plessen, Birgit; Nitze, Ingmar; Kuhn, Gerhard; Rajabov, Ilhomjon; Herzschuh, Ulrike (2017): Climatic and limnological changes at Lake Karakul (Tajikistan) during the last ~29 cal ka. Journal of Paleolimnology, 58(3), 317-334, https://doi.org/10.1007/s10933-017-9980-0
    Details
    Publication Date: 2023-03-16
    Description: We present results of analyses on a sediment core from Lake Karakul, located in the eastern Pamir Mountains, Tajikistan. The core spans the last ~29 cal ka. We investigated and assessed processes internal and external to the lake to infer changes in past moisture availability. Among the variables used to infer lake-external processes, high values of grain-size end-member (EM) 3 (wide grain-size distribution that reflects fluvial input) and high Sr/Rb and Zr/Rb ratios (coinciding with coarse grain sizes), are indicative of moister conditions. High values in EM1, EM2 (peaks of small grain sizes that reflect long-distance dust transport or fine, glacially derived clastic input) and TiO 2 (terrigenous input) are thought to reflect greater influence of dry air masses, most likely of Westerly origin. High input of dust from distant sources, beginning before the Last Glacial Maximum (LGM) and continuing to the late glacial, reflects the influence of dry Westerlies, whereas peaks in fluvial input suggest increased moisture availability. The early to early-middle Holocene is characterised by coarse mean grain sizes, indicating constant, high fluvial input and moister conditions in the region. A steady increase in terrigenous dust and a decrease in fluvial input from 6.6 cal ka BP onwards points to the Westerlies as the predominant atmospheric circulation through to present, and marks a return to drier and even arid conditions in the area. Proxies for productivity (TOC, TOC/TN, TOC Br ), redox potential (Fe/Mn) and changes in the endogenic carbonate precipitation (TIC, d18 O) indicate changes within the lake. Low productivity characterised the lake from the late Pleistocene until 6.6 cal ka BP, but productivity increased rapidly afterwards. Lake level remained low until the LGM, but water depth increased to a maximum during the late glacial and remained high into the early Holocene. Subsequently, the water level decreased to its present stage. Today the lake system is mainly climatically controlled, but the depositional regime is also driven by internal limnogeological processes.
    Keywords: AWI_Envi; AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI; Polar Terrestrial Environmental Systems @ AWI
    Type: Dataset
    Format: application/zip, 2 datasets
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    DATA PANGAEA
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