Ch. 9 Ocean Currents

What are ocean currents?

Continuous, directed movement of seawater caused by various forces.

What are the two main types of ocean currents?

Surface currents and deep ocean currents.

What are the main factors influencing ocean currents?

Wind, Coriolis Effect, temperature & salinity, coastlines, and gravity.

How does the Coriolis Effect influence ocean currents?

Deflects currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

What are gyres?

Large circular current systems in ocean basins.

Name the five major ocean gyres.

North Atlantic, North Pacific, South Atlantic, South Pacific, Indian Ocean gyres.

What is the difference between western and eastern boundary currents?

Western boundary currents (e.g., Gulf Stream) are warm and fast-moving, while eastern boundary currents (e.g., California Current) are cold and slow-moving.

What drives deep ocean currents?

Temperature and salinity differences (thermohaline circulation).

What is the global conveyor belt?

A system of deep ocean currents that circulates water around the globe.

What is upwelling?

The rise of cold, nutrient-rich water to the surface, supporting marine life

What is downwelling?

The sinking of surface water, transporting oxygen to deeper layers.

How do ocean currents affect climate?

They regulate temperatures, such as the Gulf Stream warming Europe and the California Current cooling the U.S. west coast.

What are El Niño and La Niña?

El Niño weakens trade winds, causing warm water buildup, while La Niña strengthens trade winds, increasing upwelling and cooling.

How do humans impact ocean currents?

Climate change alters circulation, pollution accumulates in gyres, and overfishing disrupts ecosystems.

What is the Great Pacific Garbage Patch?

A massive collection of plastic waste trapped in the North Pacific Gyre.