Transcript Ocean Currents

Ocean Currents
Ocean Currents
• Mass movement or flow of
ocean water
• River within the ocean
• Two types
–Surface and Deep
Ocean Currents move as gyres.
A gyre is any large system of rotating ocean
currents.
Gyres are caused by the Coriolis effect and wind
currents that result from the friction caused by
the Earth’s rotation.
There are five major ocean-wide gyres — the North Atlantic, South Atlantic, North
Pacific, South Pacific, and Indian Ocean gyres
Video Clip (2min)
Currents controlled by three
factors
–Global winds
–Coriolis Effect
–Continental Deflections
• Coriolis Effect Link
–The apparent curving of moving
objects due to the Earth’s
rotation
–Northern Hemisphere =
clockwise
–Southern Hemisphere = counter
clockwise
Surface Current Link
• Horizontal, stream-like
movements of water that occur at
or near the surface of the ocean
• Can reach depths of several
hundred meters
• Largely responsible for the
climate in many parts of the world
• Warm water surface currents
–On the east coasts of continents
–Bring warm water to colder regions
• Cold water surface currents
–On the west coasts of continents
–Bring cold water to warmer regions
Water Temperatures Affect on
Surface Currents:
• Warm-water surface currents create a
mild to warm climate (ex. British Isles
and the Gulf Stream)
• Cold-water surface currents create a
cooler climate (ex. California current
cools of the Pacific coast all the way
down to Mexico)
Warm water surface currents along the east coast
Cold water surface currents along the west coast.
Deep Currents
• Stream like movement of ocean water
far below the surface
• Caused by changes in density
–Change in temperature
•Decreasing the temperature of water
increases density
–Change in salinity
•Increasing the salinity of water
increases density
Upwelling Link
• The movement of deep, cold,
nutrient rich water to the surface
• Nutrients promote growth of fish
and plants
• Areas are important fishing
grounds
9min
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Janeiro
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