1. Welcome Back Scientists!
Ch. 14: The Movement of Ocean Water

2. Learning Target:
I will be able to explain how currents affect our lives.

3. - “Rivers” of circulating water
Currents
What are currents?
- “Rivers” of circulating water
Causes?
- Wind
- Coriolis effect
- Continental deflection

4. 2 types of OCEAN currents
1. SURFACE currents
2. DEEP currents

5. Surface Ocean Currents
Wind generated
creates circular gyres

6. Surface Currents (Notice deflection/changes direction when hits land)

7. Surface Currents are caused by Global winds (and deflected by Earth’s rotation)
Affect climates and transports sea plants and animals

8. What are Deep Currents?
Caused by density differences
Currents below the surface
Water density depends on:
1. temperature (cold sinks)
2. salinity (saltier water sinks)

9. Example of cold water sinking

10. Deep Ocean Currents Moves from North to South
Flows beneath the surface
Crosses the equator
Moves from North to South

11. The Cause of Deep Currents
Deep currents are separated from surface currents by boundary called a “Thermohaline”
(difference in densities).
A difference in density is the main cause of deep currents.

12. Importance Of Deep Currents
Upwelling/ Importance of deep currents
Brings deep water to surface
Circulates nutrients up
Moves plankton & larvae

13. Coriolis Effect
The apparent curving of the path of a moving object from an otherwise straight path
Caused by Earth’s rotation

14. Click the links below for the Coriolis effect demonstration:

15. Direction currents flow due to the Coriolis Effect
Northern Hemisphere – clockwise (Right)
Southern Hemisphere – counterclockwise (Left)

16. Gulf Stream - In the North Atlantic
- Brings warm water from equator north along east coast of N. A.
Sometimes form eddies – circulating water that pinches off from the current

17. IMPORTANCE OF SURFACE CURRENTS
2. NAVIGATION
1. MIGRATION
3. WEATHER

18. Questions 1. What are surface currents caused by?
2. Deep currents are caused by differences in _____________.
3. What is the importance of deep currents (what does it help do)?
4. Explain the Coriolis effect
5. What is the importance of surface currents?