Origins of Ocean Salts

10% 90% of rainfall is on the oceans

Watershed River basin Drainage basin Catchment Total land area that drains surface water to a common point. Rain that falls anywhere within a given body of water's watershed or basin will eventually drain into that body of water.

Amazon Watershed Atlantic

salts Watersheds, Erosion and Dissolution salts Dissolution of salts; erosion of rocks and minerals rain

Dissolved in water water Minerals and Erosion KAlSi 3 O 8 CaAl 2 Si 2 O 8 NaAlSi 3 O 8 K +, Ca 2+, Na +, Si 4+ Feldspars KAlSi 3 O 8 CaAl 2 Si 2 O 8 NaAlSi 3 O 8 granite

Dissolved Salts and Minerals KCl NaCl MgCl 2 CaCO 3 CaSO 4 KCl NaCl MgCl 2 CaCO 3 CaSO 4 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 Rivers contain small amounts of dissolved salts that are delivered to the oceans

Amazon Watershed Atlantic K Na Mg Cl Ca CO 3 Ca SO 4 Si K Na Mg Cl Ca CO 3 Ca SO 4 Si

Rivers < 500 mg/L Oceans35,000 mg/L If rivers have low salt contents and they are delivering salts to the oceans, why do oceans have such high salt contents? Total Salts

Salts left behind evaporation The primary factor leading to ocean salinity.

Salts are delivered to the oceans in small amounts Evaporation removes water from the oceans, but leaves the salts behind. Rainfall on land dissolves more salts, which are subsequently delivered to the oceans

What kind of Salts?

KCl NaCl MgCl 2 CaCO 3 CaSO 4 KCl NaCl MgCl 2 CaCO 3 CaSO 4 River Water 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

Ocean Salt Composition Ion Chloride Sodium Sulfate Magnesium Calcium Potassium Carbonate Silicate Sea Water (%) Dominated by Chloride and Sodium Na + and Cl - (85% of total) Cl - Na +

River Water Sea Water Ion Carbonate Calcium Silicate Sulfate Chloride Sodium Magnesium Potassium Percentage of Total Dissolved Minerals } 79% } 85%

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

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

Ion Chloride Sodium Sulfate Magnesium Calcium Potassium Carbonate Silicate Sea Water (%) Both chloride salts and sodium salts are extremely soluble in water and do not combine with other elements to form solids

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

Sodium Chloride Sulfate Ca +2 Cl - Na + CO 3 -2 SO 4 -2 solid Carbonate Calcium Precipitation and Carbonate Removal Calcium and carbonate are at near saturation levels in oceans (amounts are close to a threshold for precipitation) Ca 2+ + CO 3 2- = CaCO 3

Corals Mollusks CaCO 3 MgCO 3 Marine Calcium and Magnesium Carbonate Carbonate Deposition/Sedimentation Foraminifera Algae

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

River Water Sea Water Ion Carbonate Calcium Silicate Chloride Sodium Magnesium Potassium Sulfate Percentage of Total Dissolved Minerals

Next: Saltwater to Freshwater