Ocean+Salinity-Matt+and+Manny

=__//**Ocean Salinity by Matt and Manny Blue Class**//__=

__The Basic Information on Salinity__
Ocean Salinity - the amount of dissolved solids in sea water Salt = NaCl

__Salinity Facts__
If all salt in the oceans was removed, it would be 500 feet thick across the Earth's land surface; which is the same as the height a 40 story building across. Also, if all the salt in the oceans was removed, it would be 200 ft. thick across the Earth's water surface.

In deeper oceans, the parts per 1000 is closer to the average than it is in more shallow waters where it can vary from 33 parts per 1000 to 37 parts per 1000. However in shallow waters, the PPT (parts per thousand) is usually on the lower end of the scale. This you can see in the chart below, the deeper the waters the higher the salinity and the shallower the water, the lesser salinity.

In climates that get a lot of rain the salinity is lower because the fresh water that enters the water lowers the ratio of salt to water.

Salinity is often higher in warm climates because the oceans lose water to evaporation leaving less water, and with less water yet the same amount of salt, the ratio of water to salt raises.

Salinity is also higher in polar waters because when water freezes only the fresh water turns into ice. This leaves salt in the already salty water. However due to the melting of the ice masses over the past few years this affect has started to even out since the former ice (fresh water) is melting back into the ocean.

Salinity can be lowered when bodies of water have sources from fresh water areas such as lakes, glaciers or rivers.

Salinity changes the density of water - the higher the salinity the more dense the water is.

The more salinity in the water, the more buoyant the water is.

Water that contains salt has a lower freezing point than water that does not have salt in it.

The Dead sea's salinity is 40 PPTs, the highest salinity ever measured. The lowest salinity in the world is not measured because there is fresh water that has VERY little to NO salt.

El Nino weather is influenced by surface salinity - [|Learn Why]

__**Composition of Ocean Water?**__
What's in ocean water? Find out here.............[|Pie Chart of OceanComposition] http://www.lumison.co.uk/~dryden/chemicals/salt/seawater.gif

__How Did the Salt Get There?__
The salt in our oceans comes from our atmosphere; but also from rocks and minerals that are broken down in running water and the salt that helps to make them up is then dissolved and swept into our oceans.

__How Do We Measure the Amount of Salt in the Water__?
The way that the salt in the water is measured is through parts. Say we have a sample of water that has average salinity; it has 35 parts per 1000. What this means is that it has 35 parts of salt and 965 parts of water. In other words on average, salt makes up 3.5% of sea water. The symbol for parts per 1000 is very similar to the symbol for percent, %. The only difference is that instead of have one very little "O" on the bottom there are two very little "Os".

One of the ways to test if water has any salt in it is to check its conductivity. The saltier the water the easier time it has conducting electricity. There are light bulbs, like the one Ms. Fretz has, that are not completed circuits so when you put them in the salt water, the circuit is completed and light is produced. An example of one is shown below.

__Why do we Measure the Salinity of Water?__
Oceanographers like to find the salinity of water because it helps them track and find water masses. By knowing the salinity the oceanographers have a much easier job of tracking the water as it moves throughout the ocean. Also, if they, the oceanographers know the temperature of the water as well as the salinity, they can determine the density of the water. Below is a diagram that maps out the movement of high salinity waters along with lower salinity waters through the "Global Conveyor Belt".

__Mining Sea Water__
Salt along with magnesium can be profitably mined from the sea water in the Earth's oceans. One of the reasons that mining it is profitable is because the only energy that it calls for in order to be evaporated is sun light. If you were to take on cubic kilometer of sea water, you could evaporate nearly 27 million metric tons of salt!!!!!!!!

__References__
If you are looking for more information and you are in Ms. Fretz's blue class you can look at your science notes from 4/11/07. We are not sure if that is the same date for Ms. Fretz's other classes, but its pretty close.

For more information you can look at the Salinity Lab, it has to do with Salinity if you did not catch on.

There is also a good amount of information from the Earth Science textbook. You can find this information in Chapter 17 Section II of our textbooks. For quicker access the section starts on page 312.