1. Composition of Ocean Waters

2. Salts and Salinity

3. Ions Ions are stable forms of elements that acquire an electrical charge by gaining or losing electrons Elements that lose electrons and become positively charged are called cations. Elements that gain electrons and become negatively charged are called anions. Cations: K +, Na +, Mg 2+, Ca 2+ Anions: Cl -, CO 3 -2, SO 4 -2

4. Salts KCl, NaCl, MgCl 2, CaCO 3, CaSO 4 Cations: K +, Na +, Mg 2+, Ca 2+ Anions: Cl -, CO 3 -2, SO 4 -2 Salts are formed by combining cations and anions to form solids that have no charge. K + + Cl - = KCl Ca +2 + 2Cl - = CaCl 2

5. Conversely, if solid salts are mixed with water they dissolve and the ions go into solution KClK + + Cl - NaClNa + + Cl - Water solid solution CaCO 3 CaSO 4 Ca +2 and CO 3 -2 Ca +2 and SO 4 -2

6. Ocean Salinity originates from dissolution of salts and erosion of rocks and minerals as water moves at or below the earth surface River water contains dilute amounts of dissolved salts that are ultimately delivered to the oceans As water evaporates, the oceans concentrate the salts to levels far exceeding those found in rivers. Average Ocean Salinity = 3.5%

7. What kind of Salts?

8. KCl NaCl MgCl 2 CaCO 3 CaSO 4 KCl NaCl MgCl 2 CaCO 3 CaSO 4 River Water 35.15 20.39 12.14 11.67 5.68 5.79 3.41 2.12 Ion Carbonate Calcium Sulfate Silicate Chloride Sodium Magnesium Potassium River Salt Composition Dominated by Carbonate, Calcium, Sulfate, and Silicate KAlSi 3 O 8 CaAl 2 Si 2 O 8 NaAlSi 3 O 8 KAlSi 3 O 8 CaAl 2 Si 2 O 8 NaAlSi 3 O 8

9. Ocean Salt Composition Ion Chloride Sodium Sulfate Magnesium Calcium Potassium Carbonate Silicate Sea Water (%) 55.04 30.62 7.68 3.69 1.15 1.10 0.40.0004 Dominated by Chloride and Sodium Na + and Cl - (85% of total) Cl - Na +

10. River Water 35.15 20.39 11.67 12.14 5.68 5.79 3.41 2.12 Sea Water.40 1.15.0004 7.68 55.04 30.62 3.69 1.10 Ion Carbonate Calcium Silicate Sulfate Chloride Sodium Magnesium Potassium Percentage of Total Dissolved Minerals } 79% } 85%

11. Enrich Chloride and Sodium in ocean water Remove Silica, Calcium, Carbonate from river water Alterations

12. sodium, potassium, and ammonium salts are soluble chloride, bromide and iodide salts are soluble. NaCl Solubility 350 g/L Solubility: ease of salt dissolution in water Enriching Sodium and Chloride Once these types of ions reach the oceans they stay dissolved

13. Ion Chloride Sodium Sulfate Magnesium Calcium Potassium Carbonate Silicate Sea Water (%) 55.04 30.62 7.68 3.69 1.15 1.10 0.40.0004 Both chloride salts and sodium salts are extremely soluble in water and do not combine with other elements to form solids

14. Enrich Chloride and Sodium in ocean water Remove Silica, Calcium, Carbonate from river water Alterations

15. Calcium and Carbonate Removal Incorporation into shells of marine invertebrates Ca 2+ + CO 3 2- = CaCO 3

16. Diatoms Life and Silica Remove Silica, Calcium, Carbonate Use silica as structural material

17. River Water 35.15 20.39 11.67 5.68 5.79 3.41 2.12 12.14 Sea Water.40 1.15.0004 55.04 30.62 3.69 1.10 7.68 Ion Carbonate Calcium Silicate Chloride Sodium Magnesium Potassium Sulfate Percentage of Total Dissolved Minerals

18. Extra Credit Questions 1. Cations become positively/negatively charged by gaining/losing electrons. 2. The dominant ion in river water is ___ 3. The dominant ion in sea water is ___ 4. Marine invertebrate shells are made from ____

19. Other Constituents in Ocean Water

20. The Oceans, Heat, and Carbon Dioxide

21. Middle Ages Industrial Revolution 380 ppm CO 2 Global Temperature

22. Ocean Temperature Oceans can buffer changes in atmospheric temperature

23. Gas Gases/Heat Present and Future Problems Warmer oceans ?

24. October, 2005

25. Rising CO 2 and Ocean Chemistry

26. Gases Dissolve in Water Gas Gases dissolution

27. Composition of the Atmosphere Gases Nitrogen78.1% Oxygen20.9% Argon0.93% CO 2 0.038%

28. Oxygen Solubility: 0.043 g/L (20 o C)

29. Carbon Dioxide C O O - - + Solubility = 1.69 g/L

30. Middle Ages Industrial Revolution removed about 118 billion metric tons of CO 2. Between 1800 and 1994, the oceans have Equivalent to 48 percent of all fossil fuel emissions 380 ppm Solubility = 1.69 g/L CO 2 Buffering

31. Carbon Dioxide also is an Acid

32. CO 2 Water Acid CO 2 + H 2 O H 2 CO 3 H 2 CO 3 H + + HCO 3 - H + is acid Acids (H + ) are reactive and dissolve a number of substances Dissolution of Carbon Dioxide

33. Common Acid Dissolution CuO + 2HCl → CuCl 2 + H 2 O Ag 2 O + 2 HCl → 2 AgCl + H 2 O View edEx's map Taken in a place with no name (See more photos or videos here)more photos or videos here CaCO 3 + H + Ca 2+ + HCO 3 - Fe 2 O 3 + 6H + 2Fe 3+ + 3H 2 O Fe 2 O 3 CaCO 3

34. Invertebrate shells and skeletons largely CaCO 3 Corals, “lithic” plankton, clams, oysters

35. CaCO 3 + H + Ca 2+ + HCO 3 - CO 2 Water H+H+ Acidification of the oceans Inhibits the calcification and growth of invertebrates Analysis of coral cores shows a steady drop in calcification over the last 20 years pH change: 8.179 to 8.104

36. Coral Reef Bleaching http://www.npr.org/templates/story/story.php?storyId=17243164 Temperature and Acidity

37. Anthropogenic Inputs of Solutes to the Oceans Homework II Oceanic Dead Zones Due Friday, October 2 nd in class Assignment is posted on the website