globalchange  > 过去全球变化的重建
DOI: 10.1016/j.palaeo.2017.08.006
论文题名:
Middle to late Wisconsinan climate and ecological changes in northern Alaska: Evidences from the Itkillik River Yedoma
作者: Lapointe E. L.; Talbot J.; Fortier D.; Fréchette B.; Strauss J.; Kanevskiy M.; Shur Y.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: Arctic ; Beringia ; Paleoclimate ; Paleoecology ; Syngenetic permafrost ; Wisconsinan glaciation
英文摘要: Continuous paleoenvironmental records covering the period prior to the Last Glacial Maximum in northeastern Beringia are sparse. This study presents a multi-proxy analysis of a 35-m-high yedoma exposure located on the right bank of the Itkillik River in Alaska. The exposure accumulated over 39thousand years (kyr) during the Middle Wisconsinan Interstadial and the Late Wisconsinan glacial advance. We identified five stratigraphic units based on pollen, carbon and ice content, and isotopic composition (δ18O) of the sediments. Middle Wisconsinan climate in northern Alaska promoted peat accumulation prior to 33.6calkyrBP (calibrated kyr before present). Reconstructed July air temperatures were 1-2°C lower than current at 34.8calkyrBP, consistent with the timing of the interstadial climatic optimum in interior Alaska and Yukon. Colder (by up to 4°C) and drier conditions characterize the transition from interstadial to glacial conditions between 33.6 and 29.8calkyrBP. Late Wisconsinan (29.8-17.9calkyrBP) July air temperatures were 2-3°C lower than today, with grassland vegetation dominated by Poaceae, Artemisia and forbs, in contrast to the modern Cyperaceae dominance. Moister and warmer environmental conditions after 17.9cal kyr BP correspond to the Late Glacial to Early Holocene interval. © 2017 Elsevier B.V.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68061
Appears in Collections:过去全球变化的重建

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作者单位: Department of Geography, Université de Montréal, Montréal, 520 Chemin de la Côte-Sainte-Catherine, Outremont, QC H2V 2B8, Canada; Center for Northern Studies, Université Laval, 2405, rue de la Terrasse, Québec, QC G1V 0A6, Canada; Geotop Research Centre on the Dynamics of the Earth System, Université du Québec à Montréal, 201 Avenue du Président-Kennedy, Montréal, QC H2X 3Y7, Canada; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A45, 14471 Potsdam, Germany; Institute of Northern Engineering, University of Alaska Fairbanks, 306 Tanana Loop, Fairbanks, AK 99775-5910, USA

Recommended Citation:
Lapointe E. L.,Talbot J.,Fortier D.,et al. Middle to late Wisconsinan climate and ecological changes in northern Alaska: Evidences from the Itkillik River Yedoma[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01
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