1. Ocean Water Chemistry

3. Figure 4.17a

6. Distribution of Earth’s Water
Oceans %
Ice Caps and Glaciers %
Atmosphere %
Rivers and Lakes %
Inland Seas %
Groundwater %

7. Ocean Water is SALTY Salinity: Total amount of dissolved solids
Units: o/oo = 1/1000
Range: 33 – 37 o/oo
Increase in salinity:
Increase in Density
Decrease in Freezing Point
Decrease in Vapor Pressure
Increase in Osmotic Pressure

8. Origin of Salts in Oceans
Rivers (largest transport of chemicals to ocean)
Rain + CO2  H2CO3
Si, Al, Na, K, Mg
Volcanoes
Cl, S, CO2
Dust / Rain
Fe, Si
Anthropogenic
CO2, P

9. Example Geochemical Cycle
Concept of Steady State

10. Example 2 Geochemical Cycle

11. Residence Time (T = Ocean amount/Output rate)
Concentration of elements in seawater is determined by their removal rate
Conservative elements:
Major Elements: Cl, Na, SO4, Mg, Ca, K
Minor Elements: Br, Sr, B, C, F
Non Conservative Elements
Nutrients: N, P, Si
Dissolved gases: O2, CO2, N2
Trace Elements: Fe, Al, Mn
Organic Compounds

12. Residence Time - Concentration
Element Res. Time (yrs) Na Cl Mg K SO Ca Mn
Fe 100
Concentration
Crust (%) Ocean (mg/l)

14. Dissolved Gases Gas Solubility: Decreases with Temp. and Salinity
Increases with Pressure

15. Gases in Atmosphere & Oceans
Percent Gas Phase by Volume
Gas
Atmosphere
Surface Ocean
Total Ocean N2
79%
48%
11% O2
21%
36% 6%
CO2
0.04%
15%
83%

17. Seawater pH Pure water pH = 7 Seawater pH = 7.5 – 8.1
Seawater is very well buffered!
CO2(gas)+H2OH2CO3H++HCO32H++CO32

21. H2O: Universal Polar Solvent

22. H20: Temperature and Density

23. H2O: Frozen & Liquid density

24. H2O: Heat Capacity
Heat Capacity: heat needed to change the temperature of a substance
Water has higher heat capacity than:
All solids
All liquids, except liquid ammonia
Latent heat of Vaporization: heat needed to evaporate a liquid
Water has the highest of all substances

25. Seawater: Temperature and Density

26. Seawater: Temperature and salinity

27. Seawater: Ice Formation

29. Electromagnetic wave penetration

30. Open water (low productivity)

31. Coastal and Estuarine waters (high productivity)

33. Nuclear Missile Submarine

37. How do we measure light penetration?
Secchi Disc
How do we measure light penetration?

38. Water Refraction
Eschrichtius robustus

39. Sound Velocity Influenced by Salinity, Temperature and Pressure
Increases with Salinity
Increases with Temperature
Increases with Pressure
Concept of Midwater Sound Channel
Study in Detail Fig 5-19!

40. Sound Channel

42. Humpback Whales Megaptera novaeangliae

43. Gray Whale & Sonar Proposal
Eschrichtius robustus

44. Gray Whale Migration
                                                                            

45. Acoustic Pollution