1. (means total salts content)
Chemical Oceanography:
Salinity
(means total salts content)

2. That’s a lot of salt!
It has been calculated that if all the salts in the oceans of the world were dried up they would yield approximately 4.4 million cubic miles of rock salt. (~50 million billion tons) That's enough salt to cover all the landmasses of the world to a depth of ______ m.

3. Salt is essential…
Virtually every culture has customs and traditions relating to salt:
About 4,700 years ago the earliest known treatise on pharmacology was published. A major portion of this writing was devoted to a discussion of more than 40 kinds of salt and healing properties.
A far-flung trade in ancient Greece involving exchange of salt for slaves gave rise to the expression, "not worth his salt."
Special salt rations given early Roman soldiers were known as "salarium argentum," the forerunner of the English word “____________________."

4. Salt played a key role in the history of West Africa, particularly during the trading empire of Mali in the 13th through 16th centuries. Salt was traded ounce-for-ounce for gold.
Venice rose to economic greatness through its salt monopoly.
A salt tax (gabelle) was a significant cause of the French Revolution.
Thousands of Napoleon's troops died during his retreat from Moscow because their wounds would not heal as a result of a lack of salt.
During the War of 1812, salt brine was used to pay soldiers in the field, as the government was too poor to pay them with money.[
The British planted the Great Hedge across India to prevent tax-evading salt smuggling and implemented a salt starvation policy, but were trumped by Mahatma Ghandi’s non-violent resistance, epitomized by his famous march to the sea to make (untaxed) salt.

5. Where does the salt come from?
Weathering of _____________ on land
Volcanic ________________
Circulation at Deep Sea Hydrothermal _________________
NOTE: Sea water is ___________ saltier than fresh water in lakes.

6. Where does the salt come from?
Weathering of Rocks
Rain is slightly ______________ and dissolves rocks and sediments in a slow process called weathering.
__________________________________is particularly vulnerable to weathering.
Runoff and rivers carry approximately __________ billion metric tons of salts into the ocean every year.
Sphinx

7. Volcanic Gases
Volcanoes spew gas rich in _________________, ____________________, sulfates, bromine, and boron from the Earth’s interior.

8. Deep Sea Hydrothermal Vents
Occur along mid-ocean ridges where clouds of mineral-rich superheated water erupt from fissures in the seafloor.
Chemical interactions that occur in the underlying molten material cause seawater to lose ___________________ and gain ________________.

9. Why doesn’t salinity increase with time?
There is a constant inflow and outflow of water and salts.
Inflow:
Dissolved _______________ from the land and fresh rain/runoff
Outflow:
Water evaporation and sea spray depositing salt on coastlines; precipitation of minerals; organisms building shells or skeletons (CaCO3, SiO2, etc)

10. Sea Shells by the Sea Shore…
Foraminifers (very small one-celled sea animals) take out large amounts of ____________________ to build their bodies.
What creatures use silica? _______________, members of the plankton community, require silica to form their shells and they draw heavily on the ocean's silica for this purpose.

11. Ocean Salt Content

12. Resources in the Oceans
Chemical Resources: ~ ____% of world’s table salt is extracted from sea water. ~ ____% of the world’s magnesium comes from the sea and ____% of the world’s bromine ___ million tons of gold and ___ billion tons of uranium are dissolved in the world’s seawater, but the concentration is so low (1 ppb or less) that there is no economic way to recover these minerals. (ppb = part per billion)

13. Salt Recovery – Warm Climate
In warm dry climates seawater may flow into shallow ponds and evaporate down to a concentrated brine solution.
Full evaporation forms a thick white salt deposit on the bottom of the pond. This salt is then collected and refined to produce table salt.
See Pamekkule video

14. Measuring salt…
Salinity is measured in parts per thousand 0/00 Average sea water is ______ 0/00
Freshwater salinity is usually less than ___ ppt. Water between 0.5 ppt and ____ ppt is called _________________________.
Why can you not really swim in the Dead Sea?
Why does drinking only sea water kill you?