Holocene glacier activity reconstructed from proglacial lake Gjoavatnet on Amsterdamoya, NW Svalbard

QUATERNARY SCIENCE REVIEWS

卷:183

Article

de Wet, Gregory A.¹  Balascio, Nicholas L.²  D'Andrea, William J.³  Bakke, Jostein⁴  Bradley, Raymond S.¹  Perren, Bianca⁵ 

[1] Univ Massachusetts, Dept Geosci, Amherst, MA 01003 USA

[2] Coll William & Mary, Dept Geol, Williamsburg, VA 23187 USA

[3] Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA

[4] Univ Bergen, Dept Earth Sci, N-5007 Bergen, Norway

[5] British Antarctic Survey, Cambridge CB3 0ET, England

关键词: Holocene paleoclimate;    Svalbard;    Lake sediments;    Glaciers;    Fram strait;    Freshwater forcing;   

DOI  :  10.1016/j.quascirev.2017.03.018

来源: Elsevier

【 摘 要 】

Well-dated and highly resolved paleoclimate records from high latitudes allow for a better understanding of past climate change. Lake sediments are excellent archives of environmental change, and can record processes occurring within the catchment, such as the growth or demise of an upstream glacier. Here we present a Holocene-length, multi-proxy lake sediment record from proglacial lake Gjoavatnet on the island of Amsterdamoya, northwest Svalbard. Today, Gjoavatnet receives meltwater from the Annabreen glacier and contains a record of changes in glacier activity linked to regional climate conditions. We measured changes in organic matter content, dry bulk density, bulk carbon isotopes, elemental concentrations via Itrax core-scanning, and diatom community composition to reconstruct variability in glacier extent back through time. Our reconstruction indicates that glacially derived sedimentation in the lake decreased markedly at similar to 11.1 cal kyr BP, although a glacier likely persisted in the catchment until similar to 8.4 cal kyr BR During the mid-Holocene (similar to 8.4-1.0 cal kyr BP) there was significantly limited glacial influence in the catchment and enhanced deposition of organic-rich sediment in the lake. The deposition of organic rich sediments during this time was interrupted by at least three multi-centennial intervals of reduced organic matter accumulation (similar to 5.9-5.0, 2.7-2.0, and 1.7-1.5 cal kyr BP). Considering our chronological information and a sedimentological comparison with intervals of enhanced glacier input, we interpret these intervals not as glacial advances, but rather as cold/dry episodes that inhibited organic matter production in the lake and surrounding catchment. At similar to 1.0 cal kyr BP, input of glacially derived sediment to Gjoavatnet abruptly increased, representing the rapid expansion of the Annabreen glacier. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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