The Movement Of Ocean Water Flashcards
What was Heyerdahl’s theory
Theory: That the inhabitants of Polynesia originally sailed from Peru on rafts powered by only the wind and ovean currents
How did Heyerdahl prove his theory (though it was false)
1947
•Heyerdahl + 5 man crew set sail from Peru on a raft- Kon-Tiki.
•landed in Polynesia on the 97th day of the expedition
Surface current
A horizontal movement of ocean water that is caused by wind and that occurs at or near the ocean’s surface
Coriolis Effect
The apparent curving of the path of a moving object from an otherwise straight path due to the Earth’s rotation
What causes currents to move in curved paths instead of straight lines
Coriolis effect
What 3 factors control surface currents
Global winds. Coriolis effect. Continental deflections
Deep current
A streamlike movement of a ocean water far below the surface
All three factors-Global winds. Coriolis effect. Continental deflections- work together to do what
To form a pattern of surface currents on Earth which are also affected by the temps. in which they form
When warm water currents begin near the equator what happens?
They carry warm water to orher parts of the ocean
When cold water currents begin closer to the poles and do what?
Carry cool water to other parts of the ocean
Unlike surface currents, deep currents are not directly controlled by wind. What are they formed/ controlled by?
They form in parts of the ocean where water density increases
Density
The amount of matter that is in a given space or volume
How is the ocean’s density controlled?
By temperature and salinity
- both decreasing the temperature of ocean water and increasing the water’s salinity increase the water’s density
Salinity
A measure of the amount of dissolved salts or solids in a liquid
Deep current
A stream like movement of ocean water far below the surface
What do warm and cold water currents have to do with the weather?
Well the Gulf Stream is coming north from the equator. This warm water current travels up the side of America,!then to Canada and soon to the British Isles that are at a much higher latitude
warm weather where the warn water stream takes it•••••cold weather where the cold water stream takes it•••••
How do deep currents form
Polar regions cold air chills and slows down the ocean water molecules. The volume decreases>so it becomes denser. The water then sinks, traveling towards the equator as a deep current along the ocean floor.
If while chilling the water freezes at the surface, ice will float on top of the water because it is less dense than the water. Dissolved solids are squeezed out of the ice to go into the water. This increases the salinity and the density if the water.
Evaporation of surface water. This removes the fresh water snd leaves the salt and other solids behind. The density then increases. Increasing salinity through freezing or evaporation to become denser, to sink to the ocean floor, and to form a deep current. Usually in commonly warm climates.
Ocean currents
A movement of ocean water that follows a regular pattern
