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  • 1
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    Unknown
    Stable isotope characteristics of precipitation in southeast Siberia (2019)
    PANGAEA
    In:  Supplement to: Kostrova, Svetlana S; Meyer, Hanno; Fernandoy, Francisco; Werner, Martin; Tarasov, Pavel E (2020): Moisture origin and stable isotope characteristics of precipitation in southeast Siberia. Hydrological Processes, 34(1), 51-67, https://doi.org/10.1002/hyp.13571
    Details
    Publication Date: 2023-03-16
    Description: The paper presents oxygen and hydrogen isotopes of 284 precipitation event samples systematically collected in Irkutsk, in the Baikal region (southeast Siberia), between June 2011 and April 2017. This is the first high-resolution dataset of stable isotopes of precipitation from this poorly studied region of continental Asia, which has a high potential for isotope-based palaeoclimate research. The dataset revealed distinct seasonal variations: relatively high δ¹⁸O (up to -4‰) and δD (up to -40‰) values characterize summer air masses, and lighter isotope composition (-41‰ for δ¹⁸O and -322‰ for δD) is characteristic of winter precipitation. Our results show that air temperature mainly affects the isotope composition of precipitation, and no significant correlations were obtained for precipitation amount and relative humidity. A new temperature dependence was established for weighted mean monthly precipitation: +0.50‰/°C (r² = 0.83; p 〈 0.01; n = 55) for δ¹⁸O and +3.8‰/°C (r² = 0.83, p 〈 0.01; n = 55) for δD. Secondary fractionation processes (e.g., contribution of recycled moisture) were identified mainly in summer from low d excess. Backward trajectories assessed with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicate that precipitation with the lowest mean δ¹⁸O and δD values reaches Irkutsk in winter related to moisture transport from the Arctic. Precipitation originating from the west/southwest with the heaviest mean isotope composition reaches Irkutsk in summer, thus representing moisture transport across Eurasia. Generally, moisture transport from the west, that is, the Atlantic Ocean predominates throughout the year. A comparison of our new isotope dataset with simulation results using the European Centre/Hamburg version 5 (ECHAM5)-wiso climate model reveals a good agreement of variations in δ¹⁸O (r² = 0.87; p 〈 0.01; n = 55) and air temperature (r² = 0.99; p 〈 0.01; n = 71). However, the ECHAM5-wiso model fails to capture observed variations in d excess (r² = 0.14; p 〈 0.01; n = 55). This disagreement can be partly explained by a model deficit of capturing regional hydrological processes associated with secondary moisture supply in summer.
    Keywords: AWI_Envi; DATE/TIME; Deuterium excess; Irkutsk_prec; Irkutsk, Russia; Polar Terrestrial Environmental Systems @ AWI; Sample code/label; Sample type; Water sample; WS; δ18O, water; δ Deuterium, water
    Type: Dataset
    Format: text/tab-separated-values, 1420 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 2
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    Oxygen isotope composition of diatoms from Lake Kotokel (southern Siberia, Russia) (2021)
    PANGAEA
    Details
    Publication Date: 2023-06-27
    Description: This is a diatom oxygen isotope record from Lake Kotokel (southern Siberia, Russia), with implications for responses of the lake system and its environment to global change over the past 46 cal. ka BP. The δ¹⁸O diatom values vary between +23.7 and +31.2‰ over the record. The results present mainly diatom assemblages of summer blooming periods, except for the time span between 36 and 32 cal. ka BP, when the isotopic signal records mainly a shift from summer to spring blooming conditions. Possible water temperature changes only partly explain the changes in the isotopic record. The observed isotopic patterns are mainly produced by isotope changes in lake water in response to variations in air temperature, hydrology, and atmospheric circulation in the region. During Marine Isotope Stage (MIS) 2 (Last Glacial maximum), high δ¹⁸O diatom resulted from rapid evaporation and low fluvial inputs. The relatively high δ¹⁸O diatom values during the first half of MIS 1 (Holocene interglacial) suggest an increased portion of summer precipitation associated with southern/southeastern moisture transport. The decrease in δ¹⁸O diatom values during the second half of MIS 1 is due to the overall hemispheric cooling and increased moisture supply to the area by the Atlantic air masses. The Lake Kotokel record provides an example of complex interplay among several climatic/environmental controls of δ¹⁸O diatom during the Late Pleistocene and the Holocene.
    Keywords: AGE; Aluminium oxide in diatoms; AWI_Envi; biogenic silica; Climate changes; Contamination; Core; DEPTH, sediment/rock; Diatoms, δ18O; Diatoms, δ18O, corrected; Elemental analyzer (PDZ Europa); hydrological changes; isotope analysis; KTK2; Lake Kotokel; Livingstone piston corer; LPC; Polar Terrestrial Environmental Systems @ AWI; Silicon dioxide in diatoms; southern Siberia
    Type: Dataset
    Format: text/tab-separated-values, 826 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 3
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    Holocene hydrological variability of Lake Ladoga, northwest Russia, as inferred from diatom oxygen isotopes (2019)
    PANGAEA
    In:  Supplement to: Kostrova, Svetlana S; Meyer, Hanno; Bailey, Hannah; Ludikova, Anna V; Gromig, Raphael; Kuhn, Gerhard; Shibaev, Yu A; Kozachek, A V; Ekaykin, Alexey A; Chapligin, Bernhard (2019): Holocene hydrological variability of Lake Ladoga, northwest Russia, as inferred from diatom oxygen isotopes. Boreas, 48(2), 361-376, https://doi.org/10.1111/bor.12385
    Details
    Publication Date: 2023-10-21
    Description: This article presents a new comprehensive assessment of the Holocene hydrological variability of Lake Ladoga, northwest Russia. The reconstruction is based on oxygen isotopes of lacustrine diatom silica (δ18O diatom) preserved in sediment core Co 1309, and is complemented by a diatom assemblage analysis and a survey of modern isotope hydrology. The data indicate that Lake Ladoga has existed as a freshwater reservoir since at least 10.8 cal. ka BP. The δ18O diatom values range from +29.8 to +35.0‰, and relatively higher δ18O diatom values around +34.7‰ between c. 7.1 and 5.7 cal. ka BP are considered to reflect the Holocene Thermal Maximum. A continuous depletion in δ18O diatom since c. 6.1 cal. ka BP accelerates after c. 4 cal. ka BP, indicating Middle to Late Holocene cooling that culminates during the interval 0.8-0.2 cal. ka BP, corresponding to the Little Ice Age. Lake-level rises result in lower δ18O diatom values, whereas lower lake levels cause higher δ18O diatom values. The diatom isotope record gives an indication for a rather early opening of the Neva River outflow at c. 4.4-4.0 cal. ka BP. Generally, overall high δ18O diatom values around +33.5‰ characterize a persistent evaporative lake system throughout the Holocene. As the Lake Ladoga δ18O diatom record is roughly in line with the 60°N summer insolation, a linkage to broader-scale climate change is likely.
    Keywords: Aluminium oxide; AWI_Envi; biogenic silica; Calcium oxide; Calendar age; Climate changes; Co1309; Contamination; Contamination corrected; Core; CORE; DEPTH, sediment/rock; Diatoms, δ18O; Iron oxide, FeO; Ladoga Lake, Russia; lake sediments; Magnesium oxide; Manganese oxide; Measured; palaeohydrology; Paleolimnological Transect; PLOT; Polar Terrestrial Environmental Systems @ AWI; Potassium oxide; Silicon dioxide; Sodium oxide; Stable isotopes; Sum
    Type: Dataset
    Format: text/tab-separated-values, 336 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 4
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    Oxygen isotope composition of diatoms from Lake Emanda (northeastern Siberia, Russia) (2021)
    PANGAEA
    Details
    Publication Date: 2023-11-02
    Description: The sedimentary sequence of core Co1412 from Lake Emanda (65°17′N; 135°45′E; 671 m a.s.l) has been retrieved in August 2017 using gravity and percussion piston corers (UWITEC Ltd., Austria) and investigated within the German-Russian 'Paleolimnological Transect' (PLOT) project. Well preserved diatoms occur only in the upper 125-cm interval of a 6.1-m sediment core covering the last 13.2 cal. ka BP. Diatoms were purified to 〉98% SiO₂ and 〈0.8% Al₂O₃ suitable for oxygen isotope analysis. The δ¹⁸O diatom values were corrected for contamination and range between +22.5‰ and +27.8‰. A new dataset on diatom oxygen isotope composition provides insights into the climate and environmental dynamics in an extreme continental setting in northeastern Siberia. The δ¹⁸O diatom record reveals an obvious shift of 2‰ in the δ¹⁸O diatom record at 11.7−11.5 cal. ka BP reflecting the onset of the Holocene. Relatively high δ¹⁸O diatom during the Early Holocene suggests relatively warm and/or dry climate with associated evaporation effects. The absolute maximum in δ¹⁸O diatom of +27.7‰ consistent with high values of diatom indices at 7.9−7.0 cal. ka BP suggests a Mid Holocene Thermal Maximum. A continuous depletion in δ¹⁸O diatom since ~5.0 cal. ka BP is interpreted as Middle to Late Holocene cooling reaching the absolute minimum at 0.4 cal. ka BP (i.e. the Little Ice Age).
    Keywords: AGE; Aluminium oxide in diatoms; AWI_Envi; Climate change; Co1412; Contamination; Core; DEPTH, sediment/rock; diatoms; Diatoms, δ18O; Diatoms, δ18O, corrected; eastern Siberia; Elemental analyzer (PDZ Europa); Lake Emanda; lake sediments; northeastern Siberia; Paleolimnological Transect; PLOT; Polar Terrestrial Environmental Systems @ AWI; SEDCO; Sediment corer; Silicon dioxide in diatoms; stabe isotopes
    Type: Dataset
    Format: text/tab-separated-values, 276 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 5
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    A global compilation of diatom silica oxygen isotope records from lake sediment (2024)
    PANGAEA
    Details
    Publication Date: 2024-04-25
    Description: Oxygen isotopes in biogenic silica (δ18O BSi) from lake sediments allow for quantitative reconstruction of past hydroclimate and proxy–model comparison in terrestrial environments. The signals of individual records have been attributed to different factors, such as air temperature (T air ), atmospheric circulation patterns, hydrological changes and lake evaporation. Here, we provide 55 composite down–core records published to date and complemented with additional lake basin parameters (e.g. lake water residence time and catchment size) to best characterize the signal properties. Records feature widely different temporal coverage and resolution ranging from decadal–scale records covering the last 150 years to records with multi–millennial scale resolution spanning glacial–interglacial cycles. Best coverage in number of records (N=37) and datapoints (N=2112) is available for northern hemispheric (NH) extra–tropic regions throughout the Holocene (corresponding to Marine Isotope Stage 1; MIS 1).
    Keywords: Compilation; delta O-18; Diatom; Lake sediment core; paleoclimate proxy
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 6
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    Lacustrine diatom oxygen isotopes as palaeo precipitation proxy of sediment core Co1321, Lake Bolshoye Shchuchye, Polar Urals, Russia (2023)
    PANGAEA
    Details
    Publication Date: 2024-04-24
    Description: The dataset comprises the main geochemical characteristics of purified lake sediment samples from Lake Bolshoye Shchuchye, in the Polar Ural based on EDS and stable isotope data. Moreover, core segment (column A), composite depth (in cm; column B); calibrated age (in cal ka BP; column C) are given. Details on coring and age model are given in Lenz et al. (2021) Energy-Dispersive X-ray Spectroscopy (EDS) was carried out with a scanning electron microscope (SEM) at the German Research Centre for Geosciences (GFZ Potsdam, Germany) to assess contamination of all diatom samples (following Chapligin et al., 2012). Three replicate analyses were carried out with an excited-area size with a radius of ~200 μm at an acceleration voltage of 20.0 kV. All detectable elements were normalized to 100% weight. The results were expressed as weight percentages (in %) and displayed as oxides: SiO2 content (%); Al2O3 content (%); Na2O content (%); MgO content (%); K2O content (%); CaO content (%); MnO content (%); FeO content (%): Total sum (%) of the purified sediment sample (columns D to L). Details are given in Meyer et al. (2022) The diatom oxygen isotope composition (δ18Odiatom) from lacustrine sediments helps tracing the hydrological and climate dynamics in individual lake catchments. The oxygen isotope data has been generated in the ISOLAB Facility Potsdam including all d18Odiatom values (all in ‰ vs. VSMOW). The measured δ18O values (δ18Omeas), the standard deviation (SD) and number of replicates (N) are given (columns M to O), as well as the calculated contamination (ccont; in %) and δ18O values corrected for contamination (δ18Ocorr) (columns P to Q). The details of the contamination correction and isotope analytics are given in Meyer et al. (2022)
    Keywords: AGE; Aluminium oxide; biogenic silica; Calcium oxide; chironomid-inferred temperature reconstructions; Climate change; Co1321; Contamination; Core; Corrected; DEPTH, sediment/rock; Diatom; Diatoms, δ18O; Diatoms, δ18O, standard deviation; hydrological fluctuations; Iron oxide, FeO; Isotope ratio mass spectrometry; Lake Bolshoye Shchuchye, Polar Urals, Russia; Lake sediment; Magnesium oxide; Manganese oxide; oxygen isotopes; Paleolimnological Transect; PCUWI; Piston corer, UWITEC; PLOT; Potassium oxide; Replicates; Scanning electron microscope (SEM) equipped with electron-dispersive x-ray spectroscopy (EDX); Silicon dioxide; Sodium oxide; Total; δ18O, adjusted/corrected
    Type: Dataset
    Format: text/tab-separated-values, 720 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 7
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    A global compilation of diatom silica oxygen isotope records from lake sediment: additional information on the lakes and sites corresponding to the records (2024)
    PANGAEA
    Details
    Publication Date: 2024-04-26
    Description: Oxygen isotopes in biogenic silica (δ18O BSi) from lake sediments allow for quantitative reconstruction of past hydroclimate and proxy–model comparison in terrestrial environments. The signals of individual records have been attributed to different factors, such as air temperature (T air ), atmospheric circulation patterns, hydrological changes and lake evaporation. Here, we provide 55 composite down–core records published to date and complemented with additional lake basin parameters (e.g. lake water residence time and catchment size) to best characterize the signal properties. Records feature widely different temporal coverage and resolution ranging from decadal–scale records covering the last 150 years to records with multi–millennial scale resolution spanning glacial–interglacial cycles. Best coverage in number of records (N=37) and datapoints (N=2112) is available for northern hemispheric (NH) extra–tropic regions throughout the Holocene (corresponding to Marine Isotope Stage 1; MIS 1).
    Keywords: 03-2K, 05-4P; Age, interval; Alps; Americium-241 (yes/no); Argon-40/Argon-39 chronology (yes/no); AWI Arctic Land Expedition; BAIK13; Baikal; BALGGU171; Baringo-Bogoria Basin; Baunt Lake; BD_4; BDP1996; BDP96-2; BNT14_1-8; BUCKET; Bucket water sampling; Caesium-137 (yes/no); Calendar age, maximum/old; Calendar age, minimum/young; Carbon-14, number of samples used for chronology; Carbon-14 chronology (yes/no); Catchment area; Chronology; Co1309; Co1321; Co1412; Comment; COMPCORE; Compilation; Composite Core; CON01-6; CON01-603-2; CON01-605-3; Continent; Core; CORE; Core III; Core length; Country; D110; D160; Dating; delta O-18; Depth, description; Depth, sampling; Dethlingen; Diatom; Diatoms, δ18O (yes/no); Discharge, average per year; DRILL; Drilling/drill rig; EC1; ELEVATION; Elgygytgyn2003; Elgygytgyn crater lake, Sibiria, Russia; Event label; EWK; From the HydroLakes database; From the original publication; G7/02; Garba Guracha; GC; Gear; GL1; Grandfather Lake; Gravity corer; Hausberg Tarn; Heart Lake; HL-1; HT1; Identification; Isotope notation; Isotopes, precipitation (yes/no); Isotopes, water (yes/no); Kamchatka2007; KL_Mg; KOL; KTK2; KULC; KULLENBERG corer; L850; Ladoga Lake, Russia; Lago Chungara; Laguna Verda Baja; Laguna Verde Alta; Laguna Zacapu; Lake; Lake, depth, maximum; Lake, depth, mean; Lake 850; Lake Baikal, Russia; Lake Baikal/Academician Ridge; Lake Bolshoye Shchuchye, Polar Urals, Russia; Lake Brazi; Lake Challa; Lake Chuna; Lake Emanda; Lake Gosciaz; Lake Kotokel; Lake Malawi; Lake Petit; Lake Pinarbasi; Lake Pupuke; Lake Rutundu; Lake sediment core; Lake Spaime; Lake Stuor Goussasjavri; Lake surface area; Lake Tilo; Lake type; Lake water volume; LATITUDE; LB03-01; LB04-02; LC-1; LCHA-1; Lead-210 (yes/no); Lead-214 (yes/no); Les Echets; LG-1; Linsley Pond; Livingstone piston corer; Location type; LONGITUDE; LP1; LPC; LR-1; LS-1; LSG-1; LT1; LVA-1; LVB-1; Lz1024; Lz1029; M98-2P; MACC; Mackereth corer; Magnetic susceptibility (yes/no); Makgadikgadi; MBG-1; MC-2; Mica Lake; NAR0110; Nar Golu; Nettilling Lake; Ni-2B; northeastern Siberia; Number of points; NW-Spain; Optically stimulated luminescence chronology (yes/no); OUTCROP; Outcrop sample; P2; P210; P260; paleoclimate proxy; Paleomagnetics (yes/no); PCOR; PCUWI; Percussion corer; Persistent Identifier; PET09P2; PG1857-2; Piston corer, UWITEC; Piston corer (Kiel type); Piston corer Meischner large; PN94C; Profile; PTAU1; Radium-226 (yes/no); Reference/source; Residence time; RM1; RU-Land_2003_Elgygytgyn; RU-Land_2007_Kamchatka; RUSC; Russian corer; Sampling/drilling in lake; Schrader Pond; SCP16-2A; SEDCO; Sediment corer; SHT1; SIL-MC; Simba Tarn; Small Hall Tarn; SQRL; Square-rod Livingston piston sampler; ST1; Sunken Island Lake; Tauca; TDB-1; Tephra/volcanic ash; Time resolution; TL1; Tonsberg Lake; Two-Yurts Lake; Type; Uranium-thorium chronology (yes/no); Used in paper for synthesis and analysis; Varve chronology (yes/no); VAY1; Vereshchagin; Vuolep Allakasjaure; Year of publication; Year of sampling; Yellowstone Lake; YL16-2C; ZAC/3; ZK2
    Type: Dataset
    Format: text/tab-separated-values, 2978 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 8
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    A global compilation of diatom silica oxygen isotope records from lake sediment: individual datasets in a single table (2024)
    PANGAEA
    Details
    Publication Date: 2024-04-25
    Description: Oxygen isotopes in biogenic silica (δ18O BSi) from lake sediments allow for quantitative reconstruction of past hydroclimate and proxy–model comparison in terrestrial environments. The signals of individual records have been attributed to different factors, such as air temperature (T air ), atmospheric circulation patterns, hydrological changes and lake evaporation. Here, we provide 55 composite down–core records published to date and complemented with additional lake basin parameters (e.g. lake water residence time and catchment size) to best characterize the signal properties. Records feature widely different temporal coverage and resolution ranging from decadal–scale records covering the last 150 years to records with multi–millennial scale resolution spanning glacial–interglacial cycles. Best coverage in number of records (N=37) and datapoints (N=2112) is available for northern hemispheric (NH) extra–tropic regions throughout the Holocene (corresponding to Marine Isotope Stage 1; MIS 1).
    Keywords: 03-2K, 05-4P; AGE; Alps; Aluminium oxide; AWI Arctic Land Expedition; BAIK13; Baikal; BALGGU171; Baringo-Bogoria Basin; Baunt Lake; BD_4; BDP1996; BDP96-2; BNT14_1-8; BUCKET; Bucket water sampling; Co1309; Co1321; Co1412; COMPCORE; Compilation; Composite Core; CON01-6; CON01-603-2; CON01-605-3; Core; CORE; Core III; Corrected for contamination; D110; D160; delta O-18; Depth, composite bottom; Depth, composite mean; Depth, composite top; Depth, relative; Dethlingen; Diatom; Diatoms, δ18O; Diatoms, δ18O, standard deviation; DRILL; Drilling/drill rig; EC1; Elgygytgyn2003; Elgygytgyn crater lake, Sibiria, Russia; Event label; EWK; G7/02; Garba Guracha; GC; GL1; Grandfather Lake; Gravity corer; Hausberg Tarn; Heart Lake; HL-1; HT1; Identification; Kamchatka2007; KL_Mg; KOL; KTK2; KULC; KULLENBERG corer; L850; Laboratory code/label; Ladoga Lake, Russia; Lago Chungara; Laguna Verda Baja; Laguna Verde Alta; Laguna Zacapu; Lake 850; Lake Baikal, Russia; Lake Baikal/Academician Ridge; Lake Bolshoye Shchuchye, Polar Urals, Russia; Lake Brazi; Lake Challa; Lake Chuna; Lake Emanda; Lake Gosciaz; Lake Kotokel; Lake Malawi; Lake Petit; Lake Pinarbasi; Lake Pupuke; Lake Rutundu; Lake sediment core; Lake Spaime; Lake Stuor Goussasjavri; LB03-01; LB04-02; LC-1; LCHA-1; Les Echets; LG-1; Linsley Pond; Livingstone piston corer; LP1; LPC; LR-1; LS-1; LSG-1; LVA-1; LVB-1; Lz1024; Lz1029; M98-2P; MACC; Mackereth corer; Makgadikgadi; MBG-1; MC-2; Mica Lake; NAR0110; Nar Golu; Nettilling Lake; Ni-2B; northeastern Siberia; NW-Spain; OUTCROP; Outcrop sample; P2; P210; P260; paleoclimate proxy; PCOR; PCUWI; Percussion corer; PET09P2; PG1857-2; Piston corer, UWITEC; Piston corer (Kiel type); Piston corer Meischner large; PN94C; PTAU1; Raw data; RM1; RU-Land_2003_Elgygytgyn; RU-Land_2007_Kamchatka; RUSC; Russian corer; Sample code/label; Sampling/drilling in lake; Schrader Pond; SCP16-2A; Section; SEDCO; Sediment corer; SHT1; Silicon dioxide; SIL-MC; Simba Tarn; Small Hall Tarn; SQRL; Square-rod Livingston piston sampler; ST1; Sunken Island Lake; Tauca; TDB-1; TL1; Tonsberg Lake; Two-Yurts Lake; VAY1; Vereshchagin; Vuolep Allakasjaure; Yellowstone Lake; YL16-2C; ZAC/3; ZK2; δ13C, diatom-bound organic matter
    Type: Dataset
    Format: text/tab-separated-values, 19805 data points
    Location Call Number Limitation Availability
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  • 9
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    Holocene hydrological variability of Lake Ladoga, northwest Russia, as inferred from diatom oxygen isotopes (2019)
    WILEY-BLACKWELL PUBLISHING
    In:  EPIC3Boreas, WILEY-BLACKWELL PUBLISHING, pp. 1-16, ISSN: 0300-9483
    Details
    Publication Date: 2019-05-19
    Description: This article presents a new comprehensive assessment of the Holocene hydrological variability of Lake Ladoga, northwest Russia. The reconstruction is based on oxygen isotopes of lacustrine diatom silica (δ18Odiatom) preserved in sediment core Co 1309, and is complemented by a diatom assemblage analysis and a survey of modern isotope hydrology. The data indicate that Lake Ladoga has existed as a freshwater reservoir since at least 10.8 cal. ka BP. The δ18Odiatom values range from +29.8 to +35.0‰, and relatively higher δ18Odiatom values around +34.7‰ between c. 7.1 and 5.7 cal. ka BP are considered to reflect the Holocene Thermal Maximum. A continuous depletion in δ18Odiatom since c. 6.1 cal. ka BP accelerates after c. 4 cal. ka BP, indicating Middle to Late Holocene cooling that culminates during the interval 0.8–0.2 cal. ka BP, corresponding to the Little Ice Age. Lake‐level rises result in lower δ18Odiatom values, whereas lower lake levels cause higher δ18Odiatom values. The diatom isotope record gives an indication for a rather early opening of the Neva River outflow at c. 4.4–4.0 cal. ka BP. Generally, overall high δ18Odiatom values around +33.5‰ characterize a persistent evaporative lake system throughout the Holocene. As the Lake Ladoga δ18Odiatom record is roughly in line with the 60°N summer insolation, a linkage to broader‐scale climate change is likely.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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    PAPER (OA)
  • 10
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    Oxygen isotope composition of diatoms from sediments of Lake Kotokel (Buryatia). (2016)
    ELSEVIER SCIENCE BV
    In:  EPIC3Russian Geology and Geophysics, ELSEVIER SCIENCE BV, 57, pp. 1213-1221, ISSN: 1068-7971
    Details
    Publication Date: 2016-08-14
    Description: This is a summary of new oxygen isotope data for diatoms from Lake Kotokel sediments, with implications for responses of the lake system and its environment to global change over the past 46 kyr. Fossil diatoms in all samples are free from visible contamination signatures and contain no more than 2.5% Al2O3, which ensures reliable reconstructions. The δ18O values in diatoms vary between +23.7 and +31.2‰ over the record. The results mainly represent diatom assemblages of summer blooming periods, except for the time span between 36 and 32 kyr, when the isotopic signal rather records a shift from summer to spring blooming conditions. Possible water temperature changes only partly explain the changes in the isotopic record. The observed isotopic patterns are produced mainly by isotope changes in lake water in response to variations in air temperature, hydrology, and atmospheric circulation in the region. During Marine Isotope Stage (MIS) 2 (Last Glacial maximum), high δ18Odiatom resulted from rapid evaporation and low fluvial inputs. The high δ18O values of about +29 to +30‰ during the first half of MIS 1 (Holocene interglacial) suggest an increased share of summer rainfalls associated with southern/southeastern air transport. The δ18O decrease to +24‰ during the second half of MIS 1 is due to the overall hemispheric cooling and increased moisture supply to the area by the Atlantic transport. The record of Lake Kotokel sediments provides an example of complex interplay among several climatic controls of δ18Odiatom in the Late Pleistocene and the Holocene.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
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