What are ocean currents?

Up from the Depths…Mixture of Water Observations

Warm Water Placed Above Cold Water

The warm red H2O remained on top of the cold H2O ; very little mixing. No turning over

Cold Water Placed Above Warm Water

The cold, blue H2O did not remain on top of the warm, red H2O. Little mixing, the H2O turned over

Salty Water Placed Above Fresh Water

The red salty H2O did not remain on top of the fresh, blue H2O. The H2O turned over

Fresh Water placed Above Salty Water

The blue tap H2O remained on top of the red, salt H2O. The H2O did not turn over.

Analyze your Observations… 1. Compare the results of your four

trials. Explain why you think the water turned over in some of the trials, but not in all of them.

In each case, the denser water sank to the bottom. When put in the beaker with warm water, the cold water always went to the bottom.

Salt water is denser than fresh water. The salt water went to the bottom.

What is the effect of salinity and temperature on the density of water?

The density of water increases as its temperature decreases. COLD WATER IS DENSER THAN WARM WATER.

The density of water increases as the SALINITY increases. SALT WATER IS DENSER THAN FRESH WATER!

Currents are what??????????

How does a letter in a bottle thrown in the ocean travel from around the world?

Currents are streams of water flowing in the ocean.

What makes these currents flow?

What is Density?

Density is the amount of mass (g) in a given volume (mL)

Types of Currents…

1.Surface Currents

2.Deep (Density) Currents

Deep (Density) Currents…

Differences in density can cause currents to move up and down in the ocean depths.

Differences in temperature and salinity cause density currents.

Ocean currents can be warm (near the Equator) or cold (near the Poles)

Salt Water & Cold Water….

Salt water is more dense than fresh water. Contains more mass!

Cold water is more dense than warm water. Water molecules are closer together in cold water Warm water allows molecules to spread further

apart.

Surface Currents: Wind causes most surface currents. Winds near the Equator blow mainly

from the East to the West. Earth’s rotation causes the winds in

our hemisphere, the NORTHERN, to curve towards the west.

This is called the CORIOLIS EFFECT!

What is the effect of salinity…

The density of water increases as its temperature decreases.

The density of water increases as the SALINITY increases. More salt = more mass.

Remember Convection! All fluids transfer heat through convection!

Warm air/water/magma rises and cool air/water/magma sinks…because of density!

What is the Coriolis Effect?

The Coriolis Effect is the bending of Earth’s winds and ocean currents due to Earth’s rotation.

The currents move clockwise in the northern

hemisphere; counterclockwise in the southern hemisphere.

Ticket Out the Door…

1. Ocean currents are streams of flowing ___________ in the oceans.

2. Most surface currents are caused by __________.

3. Differences in ________ can cause currents to move up and down in the ocean depths.

4. The ________ ________ is caused by Earth’s rotation.