Ocean Currents

EQ: How does water move around the ocean?

Ocean CurrentsMass movement or flow of ocean water

“River within the ocean”

2 Types:

Surface currents or circulation

Deep ocean currents or circulation

a) Gyres: Huge whirls of ocean water

1. 5 main ones in the world: North Pacific, South Pacific, North Atlantic, South Atlantic, and Indian Ocean

I. Surface Circulation

What causes surface currents?

Global Winds

Global Winds

B. Coriolis effect: the effect of earth’s rotation on the currents moving them away from their original path

I. Surface Circulation

II. Effects of CirculationA. The currents have a large effect on climate

Warm water currents

- On the east coasts of continents

- Brings warm water to colder regions

II. Effects of CirculationA. The currents have a large effect on climate

Cold water currents

- On the west coasts of continents

- Brings cold water to warmer regions

B. Upwelling: the movement of deep, colder, nutrient rich water upward to replace the hot water at the surface.

C. Nutrients promote growth of fish and plants

II. Effects of Circulation

A. In the deep-ocean the currents do not move horizontally but vertically called density currents

i. Density currents: vertical currents that result from the density difference among the water masses

ii. Caused by changes in temperature or salinity

III. Deep-Ocean Circulation

Thermohaline Circulation

III. Deep-Ocean CirculationB. This happens most at high latitudes

i. The water is cold, consistently at all depths

ii. Ice forms at the top which increase density of the water, sinking it to the bottom.

C. These combine to create a conveyor belt