Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Temperature and Salinity along the BosporusSlide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Lecture 19 Redox Environments in the OceansMulti-colored sediments!What’s going on here???Aerobic Respiration in Red Clay SedimentsMurray and Grundmanis, 1980Denitrification and MnO2 reduction – Hemipelagic SedimentsEmerson et alGuatemala Basin, North PacificIron reduction – Hemipelagic SedimentsEmerson et alEast Pacific Rise – North PacificSulfate ReductionMethane ProductionAnaerobic Methane ConsumptionSaanich Inlet, BCSedimentsKuivila and Murray (1990)The Black SeaWhy is the Black Sea Interesting to Oceanographers?1. The classic anoxic basin.Oxic layer over sulfidic layer.2.Model for modern and ancient anoxic environments.3. Well developed transitionor suboxic zone. Model forworld’s organic rich sediments.4. Suboxic reactions easy to study here because of predictable depth locations.5. An ideal location to study effect of climate forcing on ocean distributions.The Bosporus Strait connects the Black Sea with the Marmara Seaand is the only source of (relatively warm) salty water.Marmara SeaBlack SeaTemperature and Salinity along the Bosporus•Some CIW advected into strait in upper half of interface•T minimum in deep water erased over South SillGregg et al (1999)Bosporus Inflow and Entrainment of CIL CIL(from NW Shelfin winter)from Ozsoy et al.,(1993)Bosporus InflowCIL/BI ≈ 4 for deep Black Seafrom 50m to 2000mThe Suboxic Zone: Oxygen – Sulfide Depth versus DensityTotal depth = 2200m0 1 0 0 2 0 0 3 0 0 4 0 0O x y g e n (M )1 71 6 . 51 61 5 . 51 51 4 . 51 41 3 . 5S i g m a T h e t a0 1 0 2 0 3 0 4 0 5 0H y d r o g e n S u l f i d e (M )S t . 7 L e g 8 K n o r r 2 0 0 3O x y g e nH y d r o g e n S u l f i d e0 1 2 3 4 5N O3- M1 71 6 . 51 61 5 . 51 51 4 . 51 41 3 . 5S i g m a T h e t a0 5 1 0 1 5 2 0 2 5N H4+ M0 0 . 0 2 0 . 0 4 0 . 0 6 0 . 0 8 0 . 1N O2- MS t 7 L e g 8 K n o r r 2 0 0 3N i t r a t eA m m o n i aN i t r i t e Example of NO3-, NO2- and NH4+ for R/V Knorr 2003 suboxic zoneCILData suggests anammoxFirst seen during 1988 ExpeditionResults from Knorr 1988 Cruise(w/ Pump Profiling System)Oxygenated surface layer over a sulfide rich deep layerwith a suboxic zone at the interfaceO2H2SNO3Suboxic ZoneNO2Murray et al
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