Ocean Currents Chapter 16.1

Ocean Currents – masses of ocean water that flow from one place to another.

There are 2 kinds of currents…

Surface currents: flow horizontally in upper part of ocean First kind of current: Surface currents: flow horizontally in upper part of ocean Most are caused by wind Friction between wind blown air and the water surface causes the water to move Controlled by wind belts, earth’s rotational effect and location of continents

Surface Currents

What direction do most currents NORTH of the equator move?

CLOCKWISE!

What direction do most currents SOUTH of the equator move?

COUNTERCLOCKWISE!

Gyre – huge circular-moving current systems that dominate the surface of the oceans Five Major Ocean Gyres 1. North Pacific Gyre South Pacific Gyre North Atlantic Gyre South Atlantic Gyre Indian Ocean Gyre

Western side of ocean has warm currents traveling from equator Eastern side of ocean has cool currents moving toward equator

Examples of warm water currents: Gulf Stream Brazil Kuroshio

Examples of cold water currents: California current Canary current Labrador current

Upwelling – the rising of cold water from deeper layers to replace warmer surface water. Brings greater concentrations of dissolved nutrients, such as nitrates and phosphates of the ocean surface

Second kind of current: 2. Deep density currents: vertical currents of ocean water that result from density differences Occurs when denser seawater moves towards an area of less dense seawater

In the deep ocean, denser water around the Poles sinks and travels along the ocean floor toward the equator. At the same time, less dense water at the equator rises and moves towards the poles along the surface. These two events form a continuous cycle that circulate ocean water.