Ocean Water Chemistry

1
Ocean Water Chemistry
2
(No Transcript)
3
Figure 4.17a
4
(No Transcript)
5
http//www.nhptv.org/
6
Distribution of Earths Water

• Oceans 97.2
• Ice Caps and Glaciers 2.15
• Atmosphere 0.001
• Rivers and Lakes 0.009
• Inland Seas 0.008
• Groundwater 0.625

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 60 000 000
• Cl 80 000 000
• Mg 10 000 000
• K 6 000 000
• SO4 9 000 000
• Ca 1 000 000
• Mn 7 000
• Fe 100

• Concentration
• Crust () Ocean (mg/l)
• 2.4 10 770
• 0.013 19 500
• 2.3 1 290
• 2.1 380
• 0.026 905
• 4.1 412
• 0.5 0.0002
• 2.4 0.002

13
(No Transcript)
14
Dissolved Gases
Gas Solubility Decreases with Temp. and
Salinity Increases with Pressure
15
Gases in Atmosphere Oceans
Percent Gas Phase by Volume Percent Gas Phase by Volume Percent Gas Phase by Volume
Gas Atmosphere Surface Ocean Total Ocean
N2 79 48 11
O2 21 36 6
CO2 0.04 15 83
16
(No Transcript)
17
Seawater pH

• Pure water pH 7
• Seawater pH 7.5 8.1
• Seawater is very well buffered!
• CO2(gas)H2O??H2CO3??HHCO3??2HCO32

18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
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
28
(No Transcript)
29
Electromagnetic wave penetration
30
Open water(low productivity)
31
Coastal and Estuarine waters (high productivity)
32
(No Transcript)
33
Nuclear Missile Submarine
34
(No Transcript)
35
(No Transcript)
36
http//www.nhptv.org/
37
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
41
(No Transcript)
42
Humpback WhalesMegaptera novaeangliae
43
Gray Whale Sonar Proposal

• Eschrichtius robustus

44
Gray Whale Migration
45
Acoustic Pollution
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)