Major ion composition of seawater (mg/L)

Typical Seawater Eastern Mediterranean Arabian Gulf at Kuwait Red Sea at Jeddah Chloride (Cl-) 18.980 21.200 23.000 22.219 Sodium (Na+) 10.556 11.800 15.850 14.255 Sulfate (SO4

2-) 2.649 2.950 3.200 3.078 Magnesium (Mg2+) 1.262 1.403 1.765 742 Calcium (Ca2+) 400 423 500 225 Potassium (K+) 380 463 460 210 Bicarbonate(HCO3

-) 140 - 142 146 Strontium (Sr2+) 13 - - - Bromide (Br-) 65 155 80 72 Borate (BO3

3-) 26 72 - - Fluoride (F-) 1 - - - Silicate (SiO3

2-) 1 - 1,5 - Iodide (I-) <1 2 - - Others - - - - Total dissolved solids (TDS) 34.483 38.600 45.000 41.000

1. Graph the top concentration of the top six ions in seawater. Use different colors to show the source of the sample.

2. Which ocean has the highest concentration of sodium and chlorine ions? 3. Explain what conditions in the area contribute to the higher levels of sodium and chlorine in question 3? 4. Iodide is an important trace element in the human diet. Why is their concentration so low in the Arabian

Gulf and the Red Sea? 5. Which sea would you expect to have the densest water? Explain your answer. 6. How would you expect the ionic composition of water at the mouth of the Mississippi river to be different

from these four samples?

OCEAN SALINITY

The table below lists the approximate surface water salinities at various latitudes in the Atlantic and Pacific Oceans.

1. Using the data construct a salinity curve for each ocean. Use different colored pencils to graph each ocean. Answer the following questions.

2. At which latitudes are the highest surface salinities found. Suggest a reason why this is so? 3. Which of the ocean has the higher average salinity? 4. Suggest a reason for the difference in salinities between the oceans at the same latitude. A globe might

help you find the answers.

All measurements is in parts per million.

LATITUDE ATLANTIC OCEAN PACIFIC OCEAN 600N 33.0 31.0 500N 33.7 32.5 400N 34.8 33.2 300N 36.7 34.2 200N 36.8 34.2 100N 36.0 34.4 00 Equator 35.0 34.3 100S 35.9 35.2 200S 36.7 35.6 300S 36.2 35.7 400S 35.3 35.0 500S 34.3 34.4 600S 33.9 34.0