1. What determines whether infiltration or run off will

occur?

2. Where is the 3% of Earth’s freshwater found?

3. Where is 97% of Earth’s water located?

4. What is density?

5. What are convection currents?

6. What effect does density have on convection currents?

Do Now

Objective 2.3.1:

We will be able to explain how the density of ocean

water is affected by temperature and

salinity

#5.11 Aim:What are

some aspects of the ocean?

AgendaQOD (10)

Lesson: oceanogra

phy(15)

Activity: Ocean

currents! (15)

Share (5)

Summaryshare (5)

HW #12

Ocean waterDoes not just contain water!

Ocean water has ~3.5% dissolved minerals which we call “Salt”

Three Important Factors in Oceans:• Salinity: is the total amount of

solid material dissolved in water (how salty the water is)

• Density: how heavy something is for its size (mass per unit volume)

• Temperature: influenced

by the sun’s radiation and the

depth of the ocean water

Ocean Density Variations:

• Salinity: increases with ocean depth

• Temperature: decreases with ocean depth

• Density: increases with ocean depth– As the depth of the ocean

water increases, the temperature DECREASES

and the density INCREASES

Drastic Changes in Temperature and Density:

• Thermocline: layer of ocean between 300-1000 meters where there is a rapid decrease in TEMPERATURE with depth

• Pycnocline: layer of ocean between 300-1000 meters where there is a rapid increase in DENSITY with depth

Three Ocean Layers:• Surface Zone:

– 2% of ocean water is found in the surface zone

– Lowest density, lowest salinity and highest water temperatures

• Transition Zone:

– 18% of ocean water is found in the transition zone

– The layer is in between the warmer surface zone and the colder deep zone

– The thermocline and pycnocline are located in the transition zone

• Deep Zone:

– 80% of ocean water found in the deep zone

– Sunlight never reaches the deep zone

– Water temperature is only a few degrees

above freezing

– Highest density, highest salinity, lowest temperatures

#5.11 Aim:What are

some aspects of the ocean?

AgendaQOD (10)

Lesson: oceanogra

phy(15)

Activity: Ocean

currents! (15)

Share (5)

Summaryshare (5)

HW #12

Ocean structure

- Colder, saltier water is more dense and sinks

- Surface water temperature changes much more than deep water

#5.11 Aim:What are

some aspects of the ocean?

AgendaQOD (10)

Lesson: oceanogra

phy(15)

Activity: Ocean

currents! (15)

Share (5)

Summaryshare (5)

HW #12

Horizontal movementDensity differences, sunlight, and wind cause currents

Ocean currents play a major role in maintaining Earth’s heat balance:

• Heat is transferred from the tropics (near the equator) where there is excess heat, to the polar region where there is less heat

#5.11 Aim:What are

some aspects of the ocean?

AgendaQOD (10)

Lesson: oceanogra

phy(15)

Activity: Ocean

currents! (15)

Share (5)

Summaryshare (5)

HW #12

Vertical movement

Upwelling – water rich in nutrients from the bottom rises (excellent for fisheries!)

Downwelling – water rich in dissolved gases sinks (brings O2 to deep-water life!)

Oceans Density Lab

Ocean Density LabDensity =

Salinity =

Pre-Lab Questions1. How does salinity affect density?

2. How does temperature affect density?

3. Where do you think the coldest water is located in the ocean?

4. Which is the most dense layer of the ocean?

5. Which is the least dense layer of the ocean?

6. Which layer of the ocean contains the most salt?

SALINITY AND DENSITY DEMO

1. In which beaker does the golf ball sink?

1. In which did it float?

1. What was different about the two beakers?

1. What conclusion can you make about the effect of salinity on the density of water?

Lab Demos & Videos 

• Temperature & Density Lab:• http://www.youtube.com/watch?v=Ak9CB

B1bTcc&feature=related– What do you predict will occur when

cold tap water and hot tap water mix?

PREDICT!

1. How does temperature affect density? 2. Why don’t the ocean layers mix together

(include salinity and density in this answer)3. List the ocean layers in order of least dense

to most dense: ______________________, ________________________, ________________________________.

4. Now read pages 426-427 of your Earth Science book and explain HOW and WHY ocean layers formed: (3-4 complete sentences)

• In oceans near the Equator, the Sun heats the water at the surface. As you travel deeper into the water, the temperature quickly begins to drop because of lack of sunlight. This rapid drop in temperature as you go deeper is called the thermocline. Once you get past the thermocline, about 1000 meters into the water, the temperature is only a few degrees above freezing!

• As the temperature gets colder, the water gets more and more dense. Remember, hot stuff rises because it’s less dense and cold stuff sinks because it’s more dense. Just like there’s a rapid drop in temperature as you go deeper into the ocean, there’s also a rapid rise in density. This rapid rise is called the pycnocline. Therefore, the less dense, warmer water will be at the surface of the ocean and the more dense, colder water will be at the bottom of the ocean.

1. Describe the thermocline.

1. Describe the pycnocline. 

1. What are the characteristics of the water you would find at the surface of the ocean? At the bottom?

• Ocean currents are the large-scale water movements that happen at the surface and depths of the oceans. Surface currents are driven by global wind patterns, while currents below the surface are driven by differences in water density. The major surface currents are called gyres—huge circles of water current that are pushed along by the wind. When wind moves the warm, less dense water along the surface, the colder, more dense water rises to take its place. This process is called upwelling.

 1. What are ocean currents? 2. What factor drives surface ocean currents? What

is a gyre?

Biodiversity in the Ocean

• http://www.youtube.com/watch?v=ohj1wiy6PFo

#5.11 Aim:What are

some aspects of the ocean?

AgendaQOD (10)

Lesson: oceanogra

phy(15)

Activity: Ocean

currents! (15)

Share (5)

Summaryshare (5)

HW #12

Exit Ticket1) Which of the following affects the density of ocean water?a) salinity and salt contentb) temperature and ocean animalsc) salinity and ocean floor depthd) salinity and temperature 2) Which is the shallowest zone that only makes up 2% of all ocean water?a) the surface zoneb) the transition zonec) the deep zoned) the mixed transition zone

3) Where would you find the lowest density seawater?a) surface mixed zoneb) deep zonec) transition zoned) abyssal zone

4) Why does ocean water form in layers?a) because low-density water exists near the surface, and higher density water occurs

belowb) because temperatures vary at each depth of the oceanc) because salinity is increased in the surface zone and decreased in the deep zoned) because salinity varies in different regions of the world