DOI: 10.1016/j.quascirev.2012.10.006
Scopus记录号: 2-s2.0-84881229005
论文题名: Insights into Circum-Arctic sea ice variability from molecular geochemistry
作者: Stoynova V. ; Shanahan T.M. ; Hughen K.A. ; de Vernal A.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 79 起始页码: 63
结束页码: 73
语种: 英语
英文关键词: Arctic
; Biomarkers
; IP25
; PIP25
; Sea ice
Scopus关键词: Arctic
; Highly branched isoprenoid
; IP<sub>25</sub>
; Logarithmic relationship
; Marine productivity
; Molecular geochemistries
; PIP<sub>25</sub>
; Sea ice reconstruction
; Biomarkers
; Productivity
; Submarine geology
; Sea ice
; alkene
; biological production
; biomarker
; diatom
; geochemistry
; ice cover
; isoprenoid
; long-term change
; marine sediment
; molecular analysis
; paleoceanography
; reconstruction
; sea ice
; Arctic
; Bacillariophyta
; Haslea
英文摘要: Geological records of past sea ice, such as those contained in Arctic marine sediments, offer an opportunity to strengthen our understanding of long-term sea ice variability, provided unambiguous paleo-sea ice proxies can be developed. One such recently proposed proxy is IP25, a highly branched isoprenoid alkene biosynthesized exclusively by sea-ice dwelling diatoms (Haslea spp.), which is well preserved in marine sediments and could be used to reconstruct past changes in spring sea-ice extent. However, little is known about regional-scale controls on IP25 production in sea ice, limiting its wider applicability as a paleo-sea-ice proxy. To address this issue we examined the distributions of IP25 and the marine productivity biomarkers dinosterol and brassicasterol in a suite of surface sediment samples distributed across the Arctic. We find a statistically significant, logarithmic relationship between IP25 and spring sea ice cover in sediment samples from arctic and subarctic sites in the Pacific (n=96, R2=0.67, P<0.0001) and the Atlantic n=25, R2=0.50, P<0.0001), though the absolute concentrations of IP25 are generally higher in the Atlantic (1.6-166.4μg/gOC) than in the Pacific (0-38.5μg/gOC) for equivalent sea-ice cover, and there are regional and basin-specific differences in the slope of the IP25 - sea ice relationship. Using the PDIP25 index, which also includes a biomarker for marine productivity (e.g., dinosterol) the relationship with sea ice cover is improved in all of the study areas (R2=0.86 and R2=0.75 for Atlantic and Pacific, respectively) and most basin specific differences in the proxy-sea ice relationships are significantly reduced. However, there remain differences in the absolute magnitudes of the PDIP25 index for equivalent amounts of sea ice cover between the Atlantic and the Pacific, and with previously published data from Fram Strait. Nevertheless, this work demonstrates that the PDIP25 index can provide a valuable tool for sea ice reconstructions at local and regional scales. © 2012 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60471
Appears in Collections: 过去全球变化的重建
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作者单位: Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78712, United States; Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States; GEOTOP-UQAM-McGill, Montreal, QC H3C 3P8, Canada
Recommended Citation:
Stoynova V.,Shanahan T.M.,Hughen K.A.,et al. Insights into Circum-Arctic sea ice variability from molecular geochemistry[J]. Quaternary Science Reviews,2013-01-01,79