The picture below shows the triangle trade route in the 1500s The picture below shows the triangle trade route in the 1500s. Why did ships sail in this clockwise direction?

The North Atlantic gyre (a current) moved ships in that direction The North Atlantic gyre (a current) moved ships in that direction. It was easier to move with the current than against it.

Name the Earth’s Oceans!!!

Why 9 oceans and not 7? The Atlantic and Pacific oceans are split into North and South because water in these regions follow a particular pattern and behavior.

What is a current? A word that describes the movement of water

Two Types Surface Currents Deep Ocean Currents

Surface Currents These are currents that are on the top layer of the ocean (up to several hundred meters deep). They are caused mainly by the wind that occurs at the ocean’s surface. They are also controlled by the Coriolis effect and continental deflections.

Global Winds Winds that blow across the Earth’s surface The force of these winds move the water Different winds cause currents to flow in different directions Winds near the equator move east to west Winds near the poles move west to east

Coriolis Effect The apparent curving of the path of a moving object from an otherwise straight path due to the Earth's rotation.

Continental Deflection If the earth’s Surface were covers completely in water, the currents would travel freely across the globe in a very uniform pattern. Well we have huge land masses on our Earth called continents. When surface currents meet continents, the currents deflect, or change direction.

Currents are Affected by Temperature Warm-water currents begin near the equator and carry warm water to other parts of the ocean. Cold-water currents begin closer to the poles and carry cold water to other parts of the ocean.

Gyres – A ring like system of ocean currents

Deep Ocean Currents A stream like movement of water FAR below the surface.

Deep Ocean Currents Cause = Formed in parts of the ocean where water density changes. The density of the ocean water is affected by temperature and salinity The colder the water is…the more dense The more salt in the water… the more dense the water is

Deep Ocean Currents Denser (Colder and higher salinity levels) water sinks!

How this works… Surface currents carry the warmer, less-dense water from other ocean regions to the poles. Once the temperature gets colder and the salinity levels increase, the water becomes more dense and sinks Deep ocean currents carry the cold, dense water across the ocean floor from polar regions to other regions in the ocean Once the water warms and its salinity levels decrease, it becomes less dense and rises.