Unit 4 3.4

Question 1

Coriolis effect

Answer 1

The deflection of objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to the rotation of the earth.

Stronger winds are deflected more, weaker winds are deflected less.

Winds @ poles (high latitudes) deflected more than at the equator.

Question 2

What is an ocean current?

Answer 2

Large volume of water flowing in a certain direction

Question 3

What is a surface current?

Answer 3

Carry warm or cold water horizontally across the ocean’s surface

Question 4

Factors that form surface currents

Answer 4

Solar radiation
Gravity
Winds

Question 5

Solar Radiation: Suns heating causes evaporation of water changing salinity therefore density. Also causes formation of wind

Answer 5

Suns heating causes evaporation of water changing salinity therefore density. Also causes formation of wind

Question 6

Gravity:

Answer 6

Expansion of water @ equator causes equatorial bulge. Slope of Earth causes water to run “downhill” under gravity. Therefore the water flows from equator to poles

Question 7

Winds:

Answer 7

Friction between wind and water surface transfers energy to surface.

Question 8

Eckman Spiral

Answer 8

Wind effects the first layer of water at the same angle as the wind. The first layer moves due to the wind at pulls the layer below it at an angle. The coriolis force exaggerates the change in angle between each layer. Therefore as the depth increases, there is a larger change in angle per layer. Overall, there is a 90 degree net movement of water to the original surface wind. The resulting phenomenon is a column of spiraling water called the Ekman Spiral.

Question 9

West coast southern hemisphere upwelling

Answer 9

Wind moves parallel to coast (southerly winds)
Due to the coriolis effect, there is a 90 degree net movement to the wind away from the shore
Since there is a deficit of water at the shore, deep waters from below the pycnocline are pulled to the surface in a process called upwelling.
More nutrient rich waters increases the phytoplankton population, therefore more fish gravitate to those areas, making the area good for fishing.

Question 10

West coast southern hemisphere downwelling

Answer 10

Northerly winds cause net movement of water toward the coast.
Water moves deeper into the ocean in a process called downwelling.
Waters around the coast therefore have less nutrients, decreasing the phytoplankton population then the fish population.