Transcript Movements of the Ocean

Movements of the Ocean
Ocean Currents
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
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
Global Winds
Polar Easterlies
Westerlies
Trade Winds
Trade Winds
Westerlies
Polar Easterlies
Surface Currents - Factors
• The Coriolis Effect
– Northern Currents –
CLOCKWISE
– Southern Currents –
COUNTER-CLOCKWISE
Coriolis Effect
The curving of ocean surface currents is due to the Earth’s rotation.
Gyres: Huge circles of moving
ocean surface currents.
North
Atlantic
Gyre
North
Pacific
Gyre
South
Pacific
Gyre
South
Atlantic
Gyre
Indian
Ocean
Gyre
Water Density Temperature
H2O
H2O
H2O
H2O
H2O
• As the water cools, the
H2O
H2O
H2 O
molecules get closer
together.
Water Density Temperature
• As the water cools,
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
•
the molecules get
closer together.
This causes the water
to become more
dense and then will
sink .
Water Density Temperature
• As water warms, the
molecules move away
from each other.
H2O
H2O
H2O
H2O
H2O
H2O
Water Density Temperature
• As water warms, the
•
H2O
H2O
H2O
H2O
H2O
H2O
molecules move away
from each other.
This causes the water
to be less dense and
thus rises.
Water Density – Salinity
H2O
H2O
Salt
• Water that contains salt
H2O
Salt
H2O
H2O
Salt
H2O
Salt
H2 O
H2O
•
is much denser than
fresh water.
When mixed with fresh
water, the salt-water
will sink.
Water Density – Turbidity
H2O sediment
H2O
H2O
• Water that contains
sediment
H2O
H2O
sediment
H2O
H2 O
sediment
H2O
•
•
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.
Deep Ocean Currents
Arctic
(N Pole)
Antarctica
(S Pole)
Warm, surface water
cold, salty
Antartic intermediate water
colder, saltier
North Atlantic deep water
Antartic bottom water
coldest,
saltiest
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)