Late Quaternary ice sheet history of northern Eurasia

Continental ice sheets are a key component of the Earth's climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former icesheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate-lake-FIS system, linked to changes in the availability of subglacial water, led to abrupt drainage cycles of the FIS into the BS watershed. This phenomenon raised the BS water level by ∼100 m until the sill of the Bosphorus Strait was reached, flooding the vast northwestern BS shelf and deeply affecting the hydrology and circulation of the BS and, probably, of the Marmara and Aegean Seas.ice dynamics | meltwater routing | European hydrographic network

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“…The Eurasian Fennoscandian Ice Sheet (FIS) formed the second-largest ice mass of the Northern Hemisphere (8) (Fig. 1A).…”

mentioning

confidence: 99%

Abrupt drainage cycles of the Fennoscandian Ice Sheet

Soulet

Ménot

Bayon

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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“…The longer ACEX record shows that this pattern is not observed previously in the Quaternary sediment record (O'Regan et al, 2009). This change in depositional mode has been linked by Spielhagen et al (2004) to terrestrial reconstructions of the BarentseKara ice sheet (Svendsen et al, 2004). The input of large amounts of coarse-grained material is tentatively tied to the marine based part of this ice sheet in the Kara Sea Haley et al, 2008).…”

Section: Links Between Composite Stratigraphiesmentioning

confidence: 92%

Spatial and temporal Arctic Ocean depositional regimes: a key to the evolution of ice drift and current patterns

Sellén

O’Regan

Jakobsson

2010

Quaternary Science Reviews

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a b s t r a c tSediment physical properties measured in cores from all the major ridges and plateaus in the central Arctic Ocean were studied in order to analyze the spatial and temporal consistency of sediment depositional regimes during the Quaternary. In total, six physiographically distinct areas are outlined. In five of these, cores can be correlated over large distances through characteristic patterns in sediment physical properties. These areas are (1) the southern Mendeleev Ridge, (2) the northern Mendeleev Ridge and Alpha Ridge, (3) the Lomonosov Ridge, (4) the Morris Jesup Rise and (5) the Yermak Plateau. Averaged downhole patterns in magnetic susceptibility, bulk density and lithostratigraphy were compiled to establish a composite stratigraphy for each area. In the sixth physiographic area, the Chukchi Borderland, repeated ice-grounding during recent glacial periods complicates the stratigraphy and prevents the compilation of a composite stratigraphy using the studied material. By utilizing published age models for the studied cores we are able to show that the northern Mendeleev Ridge and Alpha Ridge have the lowest average late Quaternary sedimentation rates, while intermediate sedimentation rates prevail on the southern Mendeleev Ridge and the Morris Jesup Rise. The second highest sedimentation rate is observed on the Lomonosov Ridge, whereas the average sedimentation rate on the Yermak Plateau is more than twice as high. The close correlation of physical properties within each area suggests uniform variations in sediment transport through time, at least throughout the later part of the Quaternary. The unique stratigraphic characteristics within each area is the product of similar past depositional regimes and are key for furthering our understanding of the evolution of ice drift and current patterns in the central Arctic Ocean.

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“…These include: (a) western Jutland, a zone that represents the part of the land base that was not affected by the last Weichsel glacial maxima in Eurasia (Svendsen et al., 2004), (b) eastern Jutland, and (c) the islands. Both eastern Jutland and the islands are dominated by young soils formed on moranic tills, while major parts of western Jutland are an outwash plain dominated by sandy soils and weathered deposits from previous glaciations (European Soil Bureau, 2005; Jakobsen, Hermansen, & Tougaard, 2015; Krüger, 1987).…”

Section: Methodsmentioning

confidence: 99%

Untargeted metabolic profiling reveals geography as the strongest predictor of metabolic phenotypes of a cosmopolitan weed

Ahlstrand

Reghev

Markussen

et al. 2018

Ecology and Evolution

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Plants produce a multitude of metabolites that contribute to their fitness and survival and play a role in local adaptation to environmental conditions. The effects of environmental variation are particularly well studied within the genus Plantago; however, previous studies have largely focused on targeting specific metabolites. Studies exploring metabolome‐wide changes are lacking, and the effects of natural environmental variation and herbivory on the metabolomes of plants growing in situ remain unknown. An untargeted metabolomic approach using ultra‐high‐performance liquid chromatography–mass spectrometry, coupled with variation partitioning, general linear mixed modeling, and network analysis was used to detect differences in metabolic phenotypes of Plantago major in fifteen natural populations across Denmark. Geographic region, distance, habitat type, phenological stage, soil parameters, light levels, and leaf area were investigated for their relative contributions to explaining differences in foliar metabolomes. Herbivory effects were further investigated by comparing metabolomes from damaged and undamaged leaves from each plant. Geographic region explained the greatest number of significant metabolic differences. Soil pH had the second largest effect, followed by habitat and leaf area, while phenological stage had no effect. No evidence of the induction of metabolic features was found between leaves damaged by herbivores compared to undamaged leaves on the same plant. Differences in metabolic phenotypes explained by geographic factors are attributed to genotypic variation and/or unmeasured environmental factors that differ at the regional level in Denmark. A small number of specialized features in the metabolome may be involved in facilitating the success of a widespread species such as Plantago major into such wide range of environmental conditions, although overall resilience in the metabolome was found in response to environmental parameters tested. Untargeted metabolomic approaches have great potential to improve our understanding of how specialized plant metabolites respond to environmental change and assist in adaptation to local conditions.

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Late Quaternary ice sheet history of northern Eurasia

Cited by 1,352 publications

References 95 publications

Abrupt drainage cycles of the Fennoscandian Ice Sheet

Abrupt drainage cycles of the Fennoscandian Ice Sheet

Spatial and temporal Arctic Ocean depositional regimes: a key to the evolution of ice drift and current patterns

Untargeted metabolic profiling reveals geography as the strongest predictor of metabolic phenotypes of a cosmopolitan weed

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