DOI: 10.1016/j.quascirev.2017.12.005
Scopus记录号: 2-s2.0-85038104870
论文题名: Increased Amazon freshwater discharge during late Heinrich Stadial 1
作者: Crivellari S. ; Chiessi C.M. ; Kuhnert H. ; Häggi C. ; da Costa Portilho-Ramos R. ; Zeng J.-Y. ; Zhang Y. ; Schefuß E. ; Mollenhauer G. ; Hefter J. ; Alexandre F. ; Sampaio G. ; Mulitza S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 181 起始页码: 144
结束页码: 155
语种: 英语
英文关键词: Amazon Basin
; Continental precipitation
; Heinrich Stadial 1
; Lipid biomarkers
; Planktonic foraminifera
Scopus关键词: Carbon
; Geochemistry
; Isotopes
; Palmitic acid
; Paraffins
; Saturated fatty acids
; Sediments
; Submarine geology
; Surface waters
; Vegetation
; Amazon basin
; Atlantic meridional overturning circulations
; Heinrich Stadial 1
; Lipid biomarkers
; Planktonic foraminifera
; Precipitation anomalies
; Sea surface temperature (SST)
; Stable hydrogen isotope
; Oceanography
; biomarker
; climate variation
; discharge
; freshwater
; freshwater input
; geochemical survey
; Heinrich event
; hydrogen isotope
; hydrography
; marine sediment
; meridional circulation
; oxygen isotope
; paleoceanography
; paleosalinity
; paleotemperature
; planktonic foraminifera
; precipitation (climatology)
; sea surface salinity
; sea surface temperature
; stable isotope
; temporal variation
; Amazon Basin
; Amazon River
; Atlantic Ocean
; Foraminifera
; Globigerinoides ruber
英文摘要: The temporal succession of changes in Amazonian hydroclimate during Heinrich Stadial 1 (HS1) (ca. 18–14.7 cal ka BP) is currently poorly resolved. Here we present HS1 records based on isotope, inorganic and organic geochemistry from a marine sediment core influenced by the Amazon River discharge. Our records offer a detailed reconstruction of the changes in Amazonian hydroclimate during HS1, integrated over the basin. We reconstructed surface water hydrography using stable oxygen isotopes (δ18O) and Mg/Ca-derived paleotemperatures from the planktonic foraminifera Globigerinoides ruber, as well as salinity changes based on stable hydrogen isotope (δD) of palmitic acid. We also analyzed branched and isoprenoid tetraether concentrations, and compared them to existing bulk sediment ln(Fe/Ca) data and vegetation reconstruction based on stable carbon isotopes from n-alkanes, in order to understand the relationship between continental precipitation, vegetation and sediment production. Our results indicate a two-phased HS1 (HS1a and HS1b). During HS1a (18–16.9 cal ka BP), a first sudden increase of sea surface temperatures (SST) in the western equatorial Atlantic correlated with the slowdown of the Atlantic Meridional Overturning Circulation (AMOC) and the associated southern hemisphere warming phase of the bipolar seesaw. This phase was also characterized by an increased delivery of terrestrial material. During HS1b (16.9–14.8 cal ka BP), a decrease in terrestrial input was, however, associated with a marked decline of seawater δ18O and palmitic acid δD. Both isotopic proxies independently indicate a drop in sea surface salinity (SSS). A number of records under the influence of the North Brazil Current, in contrast, indicate increases in SST and SSS resulting from a weakened AMOC during HS1. Our records thus suggest that the expected increase in SSS due to the AMOC slowdown was overridden by a two-phased positive precipitation anomaly in Amazonian hydroclimate. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112317
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Geosciences, University of São Paulo, São Paulo, Brazil; School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil; MARUM -, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany; INPE -, National Institute for Space Research, Cachoeira Paulista, Brazil
Recommended Citation:
Crivellari S.,Chiessi C.M.,Kuhnert H.,et al. Increased Amazon freshwater discharge during late Heinrich Stadial 1[J]. Quaternary Science Reviews,2018-01-01,181