Ocean Chemistry  Chemical Properties  Physical Properties

Foundations  Aristotle  Robert Boyle  Edmund Halley  Count Luigi Ferdinando Marsigli  Antoine Laurent Lavosier  Joseph Louis Gay-Lussac  Alexander Marcet  Johann Georg Forchhammer  William Dittmar  Justus von Liebig  James Johnstone  Vladimir Ivanovich Vernadsky  Alfred Redfield

Forms of Matter

The Water Molecule

Dissolving Ability  Universal solvent  Polar nature & hydrogen bonding

 Conservative ions  Major constituents have very constant ratios to one another  Not generally removed or added by living organisms  Nonconservative ions  Change concentrations depending on season, locale and biological processes

Dissolved Gases  The most abundant gases in the atmosphere and in the oceans:  Nitrogen (N 2 )  Oxygen (O 2 )  Carbon dioxide (CO 2 )

Dissolved Gases  Saturation concentration  The maximum amount of any gas that can be held in solution  Temp, salinity & pressure  Solubility has an inverse relationship with temp and salinity  Solubility has a direct relationship with pressure

Distribution with Depth  Photosynthesis  Sunlight + H 2 O + CO 2  C 6 H 12 O 6 + O 2  Respiration  Organics + O 2  CO 2 + H 2 O + Energy  Decomposition  Uses up oxygen

O2O2  Hypoxic  Anoxic  Anaerobic

O 2 and CO 2  CO 2  45 – 54 mL/L  Oxygen minimum zone

Sources of Salt  Continental weathering  Riverine input  Volcanic gases

Source (& Sink) of Salt  Hydrothermal vents  Discovered in 1977  Geyser on the seafloor  Spews super-hot, mineral-rich water  Very biodiverse

Source (& Sink) of Salts  Hydrothermal vents  Black Smokers Hottest of the vents Spew iron and sulfide, which combine to form iron monosulfide (FeS)  White Smokers Cooler temp Barium, Calcium and Silicon

Regulating the Salt Balance - Sources & Sinks

Residence Time  RT = Amount of ion Rate of input or removal

CO 2 and The World Ocean

The pH of Seawater  H+  Hydrogen cation  OH-  Hydroxide anion H + = OH - H + < OH - H + > OH - NeutralAlkalineAcidic

Buffering Capacity of CO 2  Buffer  Substance that prevents sudden, or large, changes in acidity or alkalinity of a solution CO 2 + H 2 O  H 2 CO 3  H + + HCO 3 -  2H + + CO 3 2-

Fig. 6.18

Fig. 6.19

Fig. 6.20

Fig. 6.21

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