Starter Complete the #5-7 on page 2 of the sheet entitled, “Standardized Test Prep”. Answer all questions to the best of your ability. You may write on this sheet. When finished, turn your paper in the box on the cart!

1.Water rises to the surface under its own pressure in an __________ well. 2.Sinkholes form in areas that have __________ topography. 3.What is the relationship between a spring and the water table? 4.Why are leaking septic tanks of concern to people who use groundwater?

Objectives – Composition of Sea Water Page 28 Today, you will be able to: 1.List the sources of salt in ocean water. 2.Recognize the factors that affect the density of ocean water. 3.Compare and contrast the 3 main zones of the open ocean.

Vocabulary (Index Cards) 207. Salinity

Pure water vs. salt water The major difference between pure water and salt water is that: Seawater contains dissolved substances that give it a salty taste Salt content makes seawater unsuitable for drinking and for irrigating crops because of it is highly corrosive

Ocean Water Water is the major component of nearly every life form on Earth Our own body chemistry is similar to the chemistry of seawater

This circle graph shows that 1000 grams of seawater with a salinity of 3.5 % or 35 0 / 00 consists of 965 grams of water and 35 grams of various salts and other solids dissolved in the water.

Salinity (salinus=salt) Salinity is the total amount of solid material dissolved Because the proportion of the dissolved substances is such a small number, oceanographers express salinity in parts per thousand ( 0 /00 ) Average salinity is 3.5% or 35 0 / 00 Most of the salt in seawater is NaCl common table salt

Where does sea salt come from? Chemical weathering of rocks- these dissolved materials reach oceans through runoff from rivers and streams Earth’s interior (volcanic eruptions)

Processes that affect salinity To decrease salinity fresh water must be added to seawater Precipitation Runoff Icebergs melting Sea ice melting

Processes that affect salinity To increase salinity large amounts of freshwater must be removed from sea water Evaporation Formation of sea ice

Natural processes affect the salinity of seawater.. Apply concepts: Which processes decrease the salinity of seawater? Which processes increase it? Decrease Increase Melting  decrease Forming  increase Melting  decrease

Ocean Temperature The ocean’s surface water temperature changes with the amount of sunlight received (function of latitude) High latitude= low sea surface temperature Low latitude= high sea surface temperature

P. 424 At which latitudes is sea surface temperature highest? Why? O degrees latitude (Equator) because low latitudes receive the most sunlight.

Ocean temperature Ocean temperature decreases rapidly with depth because of the sun’s inability to penetrate very far into the ocean

Ocean Density Density is defined as mass per unit volume D=m/v Density is an important property of ocean water because it determines the water’s vertical position in the ocean Density differences cause ocean water to sink or rise.

Factors that affect density Seawater density is affected by 2 main factors: Salinity Temperature Increase in salinity  increase in seawater density Increase in temperature  decrease in seawater density

Layers of the Ocean Oceanographers recognize a 3-layered structure of the ocean Shallow surface mixed zone Transition zone Deep zone

Ocean Layers Water temperatures are the warmest because solar energy is received here Mixed zone created because of the waves, currents and tides Shallow (2% of ocean water) Surface (mixed) Zone

Ocean Layers Transition Zone Temperatures decrease rapidly in this zone 18% of ocean water Deep Zone Sunlight never reaches this zone (temperature just a few degrees above freezing) Water density is high 80% of ocean water

No sunlight Temperature just above freezing High density Temperature drops fast Warmest ocean layer Shallow

Ocean Layers In high latitudes (poles) the 3 layers do not exist because there is not a rapid change in density or temperature with depth. Good vertical mixing between surface and deep water occurs.

Reading Strategy: Complete chart in notebook pg 27 What processes affect seawater salinity? What are the sources of sea salt? What factors affect seawater temperature?

Post Test (page 28) 1.What is salinity? What units are used to express the salinity of ocean water? 2.Explain the relationship between latitude and sea surface temperature. 3.What are the 3 main zones of the open ocean?

Draw this illustration in your notebook- pg 27 Temperature drops fast Warmest ocean layer Shallow No sunlight Temperature just above freezing High density