DOI: 10.1016/j.quascirev.2013.06.015
Scopus记录号: 2-s2.0-84900407512
论文题名: Neoglacial change in deep water exchange and increase of sea-ice transport through eastern Fram Strait: Evidence from radiogenic isotopes
作者: Werner K. ; Frank M. ; Teschner C. ; Müller J. ; Spielhagen R.F.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 92 起始页码: 190
结束页码: 207
语种: 英语
英文关键词: Arctic
; Fram Strait
; Holocene
; Multiproxy study
; Neodymium
; Radiogenic isotopes
Scopus关键词: Isotopes
; Lead
; Neodymium
; Seawater
; Sediments
; Weathering
; Arctic
; Fram strait
; Holocenes
; Multi proxies
; Radiogenic isotopes
; Ice
; chemical weathering
; continental margin
; deep water
; freshwater input
; granite
; ice flow
; ice-rafted debris
; isotopic composition
; lead isotope
; neodymium isotope
; Neoglacial
; paleoceanography
; radionuclide
; sea ice
; seawater
; sediment core
; Arctic
; Arctic Ocean
; Fram Strait
; Kara Sea
; Norwegian Sea
; Spitsbergen
; Svalbard
; Svalbard and Jan Mayen
英文摘要: Sediment core MSM5/5-712 from the West Spitsbergen continental margin has been investigated at high resolution for its seawater-derived neodymium (Nd) and lead (Pb) isotope compositions stored in ferromanganeseoxyhydroxide coatings of the sediment particles to reconstruct Holocene changes in the sources and mixing of bottom waters passing the site. The radiogenic isotope data are used in combination with a multitude of proxy indicators for the climatic and oceanographic development of the eastern Fram Strait during the past 8500 years. To calibrate the downcore data, seawater and core top samples from the area were analysed for their radiogenic isotope compositions. Core top leachates reveal relatively high (more radiogenic) Nd isotope compositions between εNd -9.7 and -9.1, which are higher than present-day seawater εNd in eastern Fram Strait (-12.6 to -10.5) and indicate that the seawater values have only been established very recently. The core top data agree well with the downcore signatures within the uppermost 40cm of the sediment core (εNd -9.1 to -8.8) indicating a reduced inflow of waters from the Nordic Seas, concurrent with cool conditions and a south-eastward shift of the marginal ice zone after ca 2.8calkaBP (Late Holocene). High sea-ice abundances in eastern Fram Strait are coeval with the well-known Neoglacial trend in the northern North Atlantic region. In contrast, warmer conditions of the late Early to Mid-Holocene were accompanied by lower (less radiogenic) εNd signatures of the bottom waters indicating an increased admixture from the Nordic Seas (-10.6 to -10.1).A shift to significantly more radiogenic εNd signatures of the detrital material also occurred at 3calkaBP and was accompanied by a marked increase in supply of fine-grained ice-rafted material (IRF) from the Arctic Ocean to the core site. The most likely source areas for this radiogenic material are the shallow Arctic shelves, in particular the Kara Sea shelf.The evolution of the Pb isotope compositions of past seawater was dominated by local signatures characterized by high 208, 207, 206Pb/204Pb values during the warm Early and Mid-Holocene periods related to enhanced chemical weathering on Svalbard and high glacial and riverine input derived from young granitic (more radiogenic) material to the West Spitsbergen margin. At 3calkaBP both detrital and seawater Pb isotope data changed towards more Kara Sea-like signatures. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60287
Appears in Collections: 过去全球变化的重建
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作者单位: GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstraße 1-3, 24148 Kiel, Germany; Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A5, 14473 Potsdam, Germany; Academy of Sciences, Humanities and Literature Mainz, Geschwister-Scholl-Straße 2, 55131 Mainz, Germany
Recommended Citation:
Werner K.,Frank M.,Teschner C.,et al. Neoglacial change in deep water exchange and increase of sea-ice transport through eastern Fram Strait: Evidence from radiogenic isotopes[J]. Quaternary Science Reviews,2014-01-01,92