1. Ocean Currents 1

2. Message In A Bottle
Have you ever heard of someone putting a message in a bottle and throwing it out into the sea? 2

3. If you throw a message in a bottle out to sea, do you think it would be possible to predict where the bottle will land? 3

4. Ocean currents are stream-like movements of water in the ocean.
There is a way to predict where the bottle will end up! We could use ocean currents to predict where it might land.
Ocean currents are stream-like movements of water in the ocean. 4

5. SURFACE
CURRENTS

6. occur at or near the surface of the ocean
Can reach depths of several hundred meters and lengths of several thousand kilometers and can travel across oceans
EX: The Gulf Stream is one of the longest surface currents. It transports 25 times more water than all the rivers in the world.

8. Surface currents are controlled by 3 factors:
Global Winds
2. The Coriolis Effect
3. Continental deflections
These 3 factors keep surface currents flowing in distinct patterns around the earth. 8

9. 1. Global Winds Winds that blow across the Earth’s surface
It is kind of like blowing hot chocolate. The ripples would be caused by the wind from your breath. 9

11. 2. Coriolis Effect
Earth’s rotation causes wind and surface currents to appear to move in curved paths, not straight lines.
The Coriolis Effect is the apparent curving of the path of a moving object from an otherwise straight path due to the Earth’s rotation. 11

13. 3. Continental Deflections
If Earth’s surface were covered only with water, surface currents would travel across the oceans in a uniform pattern.
However, continents cover 1/3 of the earth’s surface.
When surface currents meet continents, the currents change direction. 13

15. DEEP WATER CURRENTS

16. Not all ocean currents are found at the surface of the ocean.
Currents that flow far below the surface are called deep water currents.
Deep water currents are controlled by water density, NOT wind! 16

17. Density Density is the amount of matter in a given space or volume.
Deep currents form when the density of ocean water increases and it sinks toward the bottom of the ocean creating a convection current.

18. Surface Currents and Deep Currents Work Together

19. Density of Water Increases by:
Decreasing Temperature
(Cold is denser than warm)
Increasing salinity through freezing and evaporation

21. Ocean Convection Current
Draw and Label this diagram. If you have colored pencils, outline the red and blue lines to show warm and cold water.
Warm water moves along the top from equator
It warms
and
rises
Ocean Convection
Current
It cools and sinks
Cool water moves back to equator along the bottom