What Is Salt Water?
Seventy percent of the earth is made up of water. Of this, 97 percent is seawater, which contains a significant amount of dissolved salts. Salt content is measured by the weight of salt in water. Water with less than 1,000 parts per million of dissolved salt is classified as freshwater. Any more and it is salt water.
Other People Are Reading
-
Categories
-
Saline water is categorized by the following concentrations of salt in the water:
Slightly saline water: 1,000 to 3,000 parts per million
Moderately saline water: 3,000 to 10,000 parts per million
Highly saline water: 10,000 to 35,000 parts per million
Another way of measuring is in parts per thousand. A salinity of 30 parts per thousand, for example, means there are 30 parts of salt for every 1,000 parts of water. Seawater has a concentration of 3.5 percent, which means that for every 1,000 grams of water there are 35 grams of dissolved salts.
Causes of Salinity
-
The following natural processes contribute to the ocean's salinity:
1. Erosion and Weathering: Rainwater slowly erodes the land on which it falls and carries that eroded soil and its salts to the rivers and then to the seas.
2. Evaporation: Water evaporates from the ocean's surface. This causes the salts to become more concentrated.
3. Outgassing: Underwater volcanoes and hydrothermal vents spew chemicals into the water. This process is known as "outgassing." -
Composition:
-
What are the salts that make seawater salty? At the least all the naturally occurring elements on earth are also in the sea. In order of abundance the salts are:
1. Chloride
2. Sodium
3. Magnesium
4. Sulfate
5. Calcium
6. Potassium
7. Trace Elements
Interestingly, although rivers carry down more calcium than any other salt, the greatest constituent of the sea salts is chloride, followed by sodium. This is because the biochemical processes taking place in the ocean use up a lot of the calcium coming in with the river water. Mollusks, crustaceans and small one-celled animals use the calcium to build their skeletons and shells. Coral reefs are composed of calcium carbonate.
Other salts are also used by the marine life. Diatoms use silica. Some creatures, such as sea cucumbers, excrete mineral salts.
Uses:
-
As the world population grows, the requirement for water goes up also. Freshwater is becoming such a scarce resource there is a push to find ways of desalinating large amounts water in an economical manner and also to seek more uses for salt water.
The biggest user of saline water is the power industry, which uses the water to cool the heavy generating machinery. Slightly salinated water is used for agriculture. Brine is used to preserve meats and fresh fruits and vegetables. Probably the best-known product of salt water is table salt.
Density of Salt Water
-
Salt water is denser than freshwater. The following are the two factors that influence the density:
1. Temperature: The colder the saline water, the denser it is.
2. Salinity: The saltier the water, the denser it is.
Waters of the landlocked seas are denser because they have a greater concentration of salts.
-
