Project 1 from Group Four

Why is the Ocean Salty?

Humans breathe out Carbon Dioxide.  The rain that falls on the land contains some of this carbon dioxide.  This makes the rain like an acid.  When this rain falls on rocks it breaks them down into smaller and smaller pieces.  The rock pieces are carried in the rain as ions.  Ions are atoms that have an electric charge.  The ions in the rain are carried to the streams and rivers and then to the ocean.  The two ions that are most often found in the water that goes to the ocean are sodium and chloride.
 

Why doesn't the ocean become less salty when "fresh" water runs into the oceans.  Through the water that runs into the oceans may be considered fresh, it still contains the minerals and elements or ions, sodium and chlorine that come together to produce salt.  Scientists believe that the oceans get saltier as times goes on.  The water cycle has a lot to do with this.  As the sun heats the oceans surface, the water turns to water vapor, then lifts into the atmosphere or sky.  There the water vapor turns into clouds.  The clouds eventually cool and the water vapor condenses, or turns into water droplets, and it rains.  The rain then erodes more soil and allows sodium, chlorine, and ions to run into the water and back into the ocean.  This is called the water cycle, because the process repeats all the time and makes the oceans salty.

The Salty Ocean

The oceans are salty because salt is a rather common mineral on the Earth and dissolves easily in water. Small amounts of salt from the land areas dissolve in the waters of streams and the rivers, and are carried to the sea. This salt has steadily accumulated in the oceans for billions of years.

When water evaporates from the oceans into the atmosphere, the salt is left behind. The amount of salt dissolved in the oceans is, on average 34.5 percent by weight. Scientists believe that there may be fifty quadrillion tons of salt in the ocean. That's fifty million billion pounds! If we could take all the salt out of the ocean and spread it over the earth, it would be over 500 feet thick. That would almost cover the Washington Monument in Washington, D.C., which is 555 feet tall.

Experiment

About the same percentage can be obtained if three quarters of a teaspoon of salt is dissolved in eight ounces of water. To see how much salt is in the ocean, we can use one cup of water. One cup sea water equals one cup of water and 3/4 of a teaspoon salt.

Salinity Definition

Salinity is the total salt content in the sea water. The salinity of the ocean water can be affected and this will change the amount of salt in the water. Some factors that affect this are how much ice has melted, how much water ran from the rivers into the ocean, how much rain has fallen, and how much snow has fallen. The amount of wind, the motion of the waves, and the way the ocean currents run will change the salinity of the ocean by changing the mixture of the salt content.
 

Oceans and Seas with High Salinity

Salinity in water is measured by the symbol  0/00.  This means pounds of salt per 1000 pounds of sea water.

1).  The Salton Sea in California lying in the Sonaran desert was created by the Colorado River flooding over saltiest natural ocean.  This sea in California has 43-45 0/00.

2).  The Red sea and the Persian Gulf are at levels of 40 0/00.  This is because of the high temperature creating very high evaporation rates.

3).  In the North Atlantic Ocean, or more specifically the Sargasso Sea, the level is 37.9 0/00.  This is due to high water temperature reaching 83 degrees Fahrenheit causing evaporation.  Also since the location is very far from land, there is no fresh water flowing in.

4).  The Coast of Miami Beach Florida is at 34.8-35 0/00.
 

Areas with Low Salinity

Lower saltiness occur in colder seas and in places with lots of rain fall.
1). Great Salt Lake in Utah has a level of 27 0/00.

2).  Puget Sound Tacoma Washington with a level of 21-27 0/00.

3).  Black sea 20 0/00

4).  Baltic sea  5-15 0/00.

5).  Coast of Astoria, Oregon  .3 0/00-2.6 0/00.
 

Balancing Salt in the Oceans

Chemicals that are added to oceans and volcanoes on the ocean floors, help to remove salt to keep oceans salinity in balance.

Our Web Links

ht.://www.thenaturalworld.com/tidepool/salty/index.html
http://www.pulseplanet.com then go to Archives and then 1998 September
http://www.pausd.palo-alto.ca.us/k6science/then go to water, questions
http://www.ga.usgs.gov/edu/whyoceansalty.html