1. Movements of the Ocean
Ocean Currents

2. Types of Currents
Surface Currents – currents that move on or near the surface of the ocean
Global Wind Belts
Location of Continents
Rotation of the Earth
Deep Currents – cold, dense currents far below the ocean’s surface
Differences in density

3. Surface Currents - Factors
Global Wind Belts
Trade Winds (east  west)
Westerlies (west  east)
Polar Easterlies (east  west)
Continental Barriers
Continents cause the current to turn or divide

4. Global Winds Westerlies Trade Winds Trade Winds Westerlies
Polar Easterlies
Westerlies
Trade Winds
Trade Winds
Westerlies
Polar Easterlies

5. Surface Currents - Factors
The Coriolis Effect
Northern Currents – CLOCKWISE
Southern Currents – COUNTER-CLOCKWISE

6. Coriolis Effect
The curving of ocean surface currents is due to the Earth’s rotation.

7. Gyres: Huge circles of moving ocean surface currents.
North Atlantic Gyre
North Pacific Gyre
South Pacific Gyre
South Atlantic Gyre
Indian Ocean Gyre

8. Water Density - Temperature
As the water cools, the molecules get closer together.
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9. Water Density - Temperature
As the water cools, the molecules get closer together.
This causes the water to become more dense and then will sink .
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10. Water Density - Temperature
As water warms, the molecules move away from each other.
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11. Water Density - Temperature
As water warms, the molecules move away from each other.
This causes the water to be less dense and thus rises.
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12. Water Density – Salinity
Salt
Water that contains salt is much denser than fresh water.
When mixed with fresh water, the salt-water will sink.
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13. Water Density – Turbidity
sediment
Water that contains sediment is much more dense than fresh water.
When mixed with “clean” water, the sediment-filled water will sink .
This is called a turbidity current.
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14. Deep Ocean Currents Arctic (N Pole) Antarctica (S Pole)
Warm, surface water
cold, salty
Antartic intermediate water
North Atlantic deep water
colder, saltier
Antartic bottom water
coldest, saltiest

15. Final Points: Surface currents are mostly affected by the wind.
Other two factors that affect surface currents are location of continents and the Coriolis Effect.
Deep currents are mostly affected by differences in density.
Density of water is affected by temperature, salinity, and turbidity. (temperature matters the most)