DOI: 10.1016/j.quascirev.2016.02.006
Scopus记录号: 2-s2.0-84958168223
论文题名: Multiple water isotope proxy reconstruction of extremely low last glacial temperatures in Eastern Beringia (Western Arctic)
作者: Porter T.J. ; Froese D.G. ; Feakins S.J. ; Bindeman I.N. ; Mahony M.E. ; Pautler B.G. ; Reichart G.-J. ; Sanborn P.T. ; Simpson M.J. ; Weijers J.W.H.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 137 起始页码: 113
结束页码: 125
语种: 英语
英文关键词: Eastern Beringia
; Fossil plant waxes
; Hydrated volcanic glass shards
; Precipitation isotopes
; Relict ice
; Temperature reconstruction
Scopus关键词: Climate models
; Fractionation
; Glacial geology
; Glass
; Hydration
; Isotopes
; Snow melting systems
; Soil moisture
; Soils
; Volcanoes
; Climate model simulations
; Eastern Beringia
; Fossil plant
; Mean annual precipitation
; Temperature depression
; Temperature reconstruction
; Volcanic glass
; Warm season precipitation
; Ice
; Beringia
; climate modeling
; fossil record
; Holocene
; isotopic composition
; Last Glacial
; Last Glacial Maximum
; marine isotope stage
; paleoclimate
; paleotemperature
; precipitation assessment
; proxy climate record
; reconstruction
; soil water
; volcanic glass
; wax
; Canada
; Klondike
; Yukon Territory
英文摘要: Precipitation isotopes are commonly used for paleothermometry in high latitude regions. Here we present multiple water isotope proxies from the same sedimentary context - perennially frozen loess deposits in the Klondike Goldfields in central Yukon, Canada, representing parts of Marine Isotope Stages (MIS) 4, 3 and 2 - allowing us to uniquely corroborate fractionations and temperature conversions during these Late Pleistocene cold stages. We include new and existing proxy data from: relict wedge ice, a direct archive for snowmelt; relict pore ice, an archive for bulk soil water integrating year-round precipitation; and hydrated volcanic glass shards and fossil plant waxes, which are also thought to integrate year-round precipitation but are subject to large fractionations. In some cases, our temperature estimates based on existing proxy data are much cooler than previously estimated due to our use of source water corrections for the glacial ocean, new transfer functions calibrated specifically for northern North America (δDprecip = 3.1‰·°C-1 × T - 155‰; and δ18Oprecip = 0.41‰·°C-1 × T - 20.2‰), and novel insights on the apparent net fractionation correction for Eastern Beringian steppe-tundra plant waxes (εwax/precip = -59 ± 10‰). The snowmelt origin of wedge ice ensures a relatively constrained winter-spring seasonality of contributing precipitation, as supported by the consistency between water isotope measurements from Late Holocene wedge ice and modern winter-spring precipitation. Wedge ice dating to the transitional MIS 3/2 is isotopically depleted relative to modern spring-winter precipitation by an amount that indicates a temperature depression of ~14 ± 5 °C below modern. The soil water origin of pore ice, and other proxies integrating year-round precipitation from soil water, allows for a more variable precipitation seasonality. The isotopic composition of modern pore ice is consistent with mean annual precipitation. However, the isotopic composition of pore ice during MIS 3/2 converges on wedge ice values, signalling an increase in the ratio of cold-to-warm-season precipitation integrated by pore ice during glacial times, possibly due to drier summers as supported by the fossil record and climate model simulations. In the study region, water isotope proxies integrating year-round precipitation may overestimate annual temperature differences between today and recent cold stages due to transient precipitation seasonality, as detected here, and thus are best interpreted as upper bound estimates. Based on these proxies, we estimate that annual temperatures during MIS 4, 3/2 and 2 were depressed below the modern climate to a maximum of ~18 °C, 16 °C and 21 °C ± 4-°C, respectively. Our study highlights the value of multiple water isotope proxies towards understanding changes in precipitation seasonality and developing robust reconstructions of past climate, and may be particularly important for studies of the major climate transformations over glacial-interglacial timescales. © 2016 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59650
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geography, University of Toronto Mississauga, Mississauga, ON, Canada; Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, Canada; Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States; Department of Geological Sciences, University of Oregon, Eugene, OR, United States; Advanced Chemistry Development, Inc., Toronto, ON, Canada; Department of Earth Sciences, Utrecht University, P.O. Box 80.021, Utrecht, Netherlands; Royal Netherlands Institute for Sea Research, Department of Ocean Systems, P.O. Box 59, Den Burg, Texel, Netherlands; Ecosystem Science and Management Program, University of Northern British Columbia, Prince George, BC, Canada; Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada; Environmental NMR Centre, University of Toronto Scarborough, Toronto, ON, Canada; Shell Global Solutions International, Rijswijk, Netherlands
Recommended Citation:
Porter T.J.,Froese D.G.,Feakins S.J.,et al. Multiple water isotope proxy reconstruction of extremely low last glacial temperatures in Eastern Beringia (Western Arctic)[J]. Quaternary Science Reviews,2016-01-01,137