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PALEOSALINITY RECONSTRUCTIONS BASED ON STABLE HYDROGEN ISOTOPIC COMPOSITION OF ALGAL BIOMARKERS. RECENT DEVELOPMENTS! Marcel T.J. van der Meer (NIOZ) Marianne Baas (NIOZ) Ellen Hopmans (NIOZ) Albert Benthien (AWI) Ingrid Zondervan (AWI) Jelle Bijma (AWI) Jaap S. Sinninghe Damsté (NIOZ/UU)
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PALEOSALINITY RECONSTRUCTIONS BASED ON STABLE HYDROGEN ISOTOPIC COMPOSITION OF ALGAL BIOMARKERS. RECENT DEVELOPMENTS! Marcel T.J. van der Meer (NIOZ) Marianne Baas (NIOZ) Ellen Hopmans (NIOZ) Albert Benthien (AWI) Ingrid Zondervan (AWI) Jelle Bijma (AWI) Jaap S. Sinninghe Damsté (NIOZ/UU) Stefan Schouten (NIOZ)
● Testing climate models for future climate change critically depend on our ability to quantitatively reconstruct past climate. ● Paleosalinity is the single most important oceanographic parameter which currently can still not be accurately quantified from sedimentary records. ● dDwater correlates strongly with salinity.
Estimating dD water from dD alkenones. ● Paul (2002): relatively constant fractionation of ~232 ‰ between δDwater and the δD of C37 alkenones produced by E. huxleyi. ● Englebrecht and Sachs (2005) reported a similar fractionation of ~225 ‰. ● Schouten et al. (2006) have shown that hydrogen isotope fractionation by E. huxleyi and Gephyrocapsa oceanica depends on: - δDwater - salinity - growth rate
Black Sea BC53 Cruise 134/8 R/V Knorr 1988
Shift from Unit II to Unit I: The invasion of E. huxleyi has been attributed to a increase in salinity from below 11 in Unit II to above 11 in Unit I(Bukry, 1974) varved coccolith ooze: Unit I 1635±60 1st occurrence of E. Huxleyi Salinity > 11 transition sapropel Salinity < 11 organic-rich sapropel: Unit II 2720±160 yrs BP Jones and Gagnon, 1994
Paleo-salinity estimates based on alkenones and on dinosterol
Black Sea salinity gradient Leonov 2003
-170.0 C37:3 C37:2 Weigthed average -190.0 dD (‰ vs. VSMOW) -210.0 -230.0 8 10 12 14 16 18 20 22 Temp (°C) dD of individual alkenones versus temperature
dD of individual alkenones versus Uk’37. dD (‰ vs. VSMOW) Uk’37
dD of individual alkenones versus salinity. dD (‰ vs. VSMOW) Salinity
C37:2 The idea! Warm C37:2 C37:3 C37:2 C37:3 C37:3 C37:2 Cold low dD High dD
Red Sea TEX86 and qualitative salinity indicator. Bab el Mandeb
Relationship between TEX86 index and sea surface temperature and salinity in the Red Sea Southern Red Sea Northern Red Sea TEX86 TEX86 Global calibration Gulf of Aden Salinity SST (°C) Trommer et al., in preparation
Interpretation of the TEX86 index in the Red Sea Trommer et al., in preparation
Calculated contribution of the endemic Red Sea Crenarchaeota population. Trommer et al., in preparation
Qualitative salinity indicator: diether membrane lipid produced by halophilic Archaea.
Qualitative salinity indicator S < 38.6
Light experimentdD versus light intensity http://en.wikipedia.org/wiki/Image:Thylakoid_membrane.png