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Lacustrine diatom oxygen isotopes as palaeo precipitation proxy - Holocene environmental and snowmelt variations recorded at Lake Bolshoye Shchuchye, Polar Urals, Russia
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  • Hanno Meyer,
  • Svetlana Kostrova,
  • Philip Meister,
  • Marlene M. Lenz,
  • Gerhard Kuhn,
  • Larisa Nazarova,
  • Liudmila Syrykh,
  • Yuri Dvornikov
Hanno Meyer
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research

Corresponding Author:[email protected]

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Svetlana Kostrova
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research
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Philip Meister
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research
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Marlene M. Lenz
University of Cologne
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Gerhard Kuhn
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
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Larisa Nazarova
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research
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Liudmila Syrykh
Herzen State Pedagogical University of Russia
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Yuri Dvornikov
Department of Landscape Design and Sustainable Ecosystem
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Abstract

The diatom oxygen isotope composition (δ18Odiatom) from lacustrine sediments helps tracing the hydrological and climate dynamics in individual lake catchments, and is generally linked to changes in temperature and δ18Olake. Lake Bolshoye Shchuchye (67°53’N; 66°19’ E; 186 m a.s.l) is the largest and deepest freshwater reservoir in the Polar Urals, Arctic Russia. Its δ18Odiatom record generally follows a decrease in summer insolation and the northern hemisphere (NH) temperature history. However, it displays exceptional, short-term variations exceeding 5‰, especially in Mid and Late Holocene. This centennial-scale variability occurs contemporaneously with and similarly to Holocene NH glacier advances. However, larger Holocene glacier advances in the Lake Bolshoye Shchuchye catchment are unknown and have not left any significant imprint on the lake sediment record. As Lake Bolshoye Shchuchye is deep and voluminous, about 30−50% of its volume needs to be exchanged with isotopically different water within decades to account for these shifts in the δ18Odiatom record. A plausible source of water with light isotope composition inflow is snow, known to be transported in surplus by snow redistribution from the windward to the leeward side of the Polar Urals. Here, we propose snow melt and influx changes being the dominant mechanism responsible for the observed short-term changes in the δ18Odiatom record. This is the first time such drastic, centennial-scale hydrological changes in a catchment have been identified in Holocene lacustrine diatom oxygen isotopes, which, for Lake Bolshoye Shchuchye, are interpreted as proxy for summer temperatures and palaeo precipitation.