G131 HOME	INFORMATION	SCHEDULE	RESOURCES	EXERCISES
NOTES Links to summaries of key issues for each topic PREAMBLE Introduction History PART I Water Planet Plate Tectonics Sea Floor Review 1 Physical Prop. Chemistry Ocean Stuct. PART II Atmosphere Currents Review 2 Waves Tides PART III Coasts/Beaches Environ. for Life Production Plankton Nekton Benthos Review 3 VISUALS Links to images employed in lectures TEXT Link to chapter outlines at online learning center	SECOND REVIEW SESSION (contd.)  Chapter 7. The Chemistry of Seawater Learning Objectives: Understanding of Fundamental Concepts The controls on ocean salinity exerted by evaporation and precipitation. Local influences on salinity from freshwater, meltwater and basin isolation.  The concentrations of dissolved salts as major, minor, and trace constituents.  The conservative or non-conservative behavior of salts, dependent on biology. The constant proportions of salts and the relation of salinity to chlorinity.  Dissolution and exsolving of gases at the air-water interface. The influence of photosynthesis and respiration on CO 2 and O2 concentrations. pH buffering of seawater by CO2 and the biological pump of CO2 to deep ocean. The biological demand for nutrient (nitrate, NO3 - and phosphate, PO43-). Seawater desalination by freezing or evaporation, ion exchange, electrodialysis or reverse osmosis. Terminology and Details: Specific Components of the Topic Typical marine salinity: ~35%o; highest at mid latitudes (~25°)  Salts: major ions (>99% total) Cl¯, Na +, SO42¯, Mg 2+, Ca2+, K + Residence times: amount present/removal rate, Na 260Ma, Al 100a  Variations in gas solubility: N2 < O 2 < CO2 The affects of photosynthesis and respiration on gas depth profiles Compensation depth: rate of production = rate of respiration CO2 controls pH (acidity); seawater pH range: 7.5 - 8.5, ave. 7.8  Seawater as resource: salt, Mg, Br and water   << Back       Department of Geological Sciences,  1001 E. Tenth Street, Bloomington, IN 47405-1403 Phone: (812) 855-5582  Last updated: 17 September 2000 Comments: simon@indiana.edu Copyright 2000, The Trustees of Indiana University