1. Ch. 22 Ocean Currents

2. Ocean Currents Movements of the ocean’s waters in giant “streams”
2 Major Currents:
Surface Currents
Deep Currents

3. Surface Currents Move on or near the surface Driven by winds
Factors affecting Surface Currents:
Wind Belts
Rotational Effects
Location of Continents

4. How do wind belts affect surface ocean currents?
Energy from the movement of both the trade winds and westerlies is transferred to the surface of the ocean.

6. What are rotational effects and how do they affect ocean surface currents?
Coriolis effect: the twisting or deflection of the ocean’s currents due to Earth’s rotation.
creates Gyres: large circles of moving water

7. Deep Currents
Cold, dense currents that flow very slowly, deep beneath the surface.

8. How do deep Currents form?
As cold dense water of the polar regions sinks, it flows beneath warmer ocean waters towards the equators.
Movement is caused
by density differences

10. Turbidity Currents
A strong current caused by an underwater land slide.

11. 22.2 Ocean Waves
Waves: periodic up and down movement of water

12. Wave period: time it takes for one complete wavelength to pass a given point
Wave Speed = wavelength
Period

13. Wave energy Waves are caused by a transfer of wind energy to the water
If there were no wind, what would happen to the waves????
So no wind = no wave energy
Add wind = more wave energy

14. Water Movement in a Wave
The individual water molecules themselves are moving very little!!!

15. Wave Size Three Factors that affect wave size: Speed of wind
Amount of time the wind blows
Fetch: distance that the wind blows

16. Waves and the Shore
Breakers
Refraction

17. Waves and the Shore
Undertows
Rip Currents

18. Longshore Currents
Tsunamis

19. 22.3 Tides The daily changes in the levels of the ocean
What causes tides???
The gravitional interactions between the Earth and the Moon!!!

20. Tidal Range

21. Behavior of Tides When the earth, moon, and sun are aligned
The combined gravitational pull causes the range in tides.

22. When the sun and moon are at right angles relative to the earth
The gravitational pulls do not act together and the daily tidal range is small

23. Tidal Variations Influenced by the Ocean Basin’s: Size Shape Depth
Location

24. Tidal Currents
Flow of oceans towards and away from coasts as the tides rise and fall.
Most influential closer to coastlines
Tidal Bore: a surge of water due to tidal currents in a long bay.

25. The End
Ocean Currents Activity