The Major Ocean Currents of the World
If you look at a world map, you can see that Earth’s 5 oceans are vast. In fact, they cover more than 70% of Earth.
Water is always on the move. Ocean currents are like giant conveyor belts flowing through the oceans moving huge amounts of water all the time.
From cold to hot (and vice versa), oceans transport water like a giant conveyor belt. The major ocean currents roughly follow a common set of circular paths.
While wind drives surface ocean currents from the Coriolis effect, temperature and salt gradients mostly influences deep ocean currents.
What are the types of ocean currents in the world? Why are ocean currents important? And what are the names of some of their names? So ahoy, matey! Let’s set sail on a journey to our major ocean currents.
List of major ocean currents in the world
Here is a list of the major ocean currents that circulate water in our 5 oceans:
|Gulf Stream||Warm ocean current originating in Gulf of Mexico along the east coast of the United States|
|Labrador Current||Cold ocean current flowing from the Arctic Ocean south along the east coast of Canada|
|North Equatorial Current||East-to-west flowing current from 10°-20°N in the Pacific and Atlantic Ocean|
|North Equatorial Counter Current (NECC)||West-to-east flowing current from 3°-10°N in the Atlantic, Indian Ocean and Pacific Ocean|
|South Equatorial Current||East-to-west current flowing between the equator and about 20°S in the Pacific, Atlantic, and Indian Ocean|
|South Equatorial Counter Current (SECC)||Weak east-flowing current near 8°S in the Atlantic and Pacific Ocean|
|Kuroshio Current||North-flowing warm current off the coast of Japan in the Pacific Ocean|
|Alaska Current||Southwestern warm water current off the coast of Alaska and west coast of Canada.|
|California Current||Southward flowing current off the west coast of the United States in the Pacific Ocean|
Differences between warm currents vs cold currents
The wind and sun makes ocean currents move. At the equator, the sun is strongest heating water the most there. When water heats, water molecules vibrate faster and eventually move farther apart.
From the equator, hot water pushes outward to north and south pole south pole. At the same time, cold water from the north and south poles collide with this warm water.
Because Earth spins on its axis, water flows in a circular pattern. For example, oceans in the northern hemisphere move mostly clockwise. But in the southern hemisphere, ocean currents move mostly counter-clockwise.
For example, the Gulf stream current pushes warm air to Europe. It flows around the Atlantic ocean like a clock. Because of the Gulf stream, this is why parts of Europe has such a temperate climate.
Ocean water can hold more heat than air. For example, thermohaline currents (thermo = temperature, haline = salt) with warm, salt water sinking and rising. Salty water pushes not so salty water away. We get a current. Winds can also make ocean currents.
Satellites track ocean movement
Self-locating datum marker buoys monitor currents by sending out a radio signal. By monitoring these signals, we can follow and see where ocean currents are flowing. But we need a lot of them to get the whole picture.
Alternatively, fleet of underwater robots or “Argo” research deep ocean currents. For example, Argo research vessels conduct research on ocean heat and our changing oceans.
But lately, NASA satellites like Poseidon and Jason have been observing ocean currents from space. These satellites monitor ocean motion by measuring sea surface height.
Overall, satellites have gained a better picture of Earth’s ocean movement as a whole. For example, NASA/JPL’s visualization shows ocean surface currents from around the world during the period from June 2005 through December 2007.
Why rivers don’t have salt and oceans do
What makes oceans different from freshwater is that they contain salt and minerals. This is because heat from the sun evaporates water. When water evaporates, salt remains in the ocean.
The water vapor rises into the sky, cools and forms clouds. Then, it falls down as rain again. When rain water falls on the land, it washes minerals and salt from the soil into lakes and rivers. But they don’t stay there.
They float downhill to an outlet at the nearest ocean. So lakes and rivers constantly have the minerals washed away. Oceans are salty because runoff transports minerals and salts from the surface.
With the exception of the Great Salt Lake which doesn’t have an outlet. Salt built up in the Great Salt Lake until its 4 times greater than oceans.
When ocean evaporates from heat, salt remains in the ocean and water rises. So unlike salty oceans, lakes and rivers constantly have the minerals washed away.
Living things rely on ocean currents
Fish rely on moving water for food and oxygen. That’s why aquariums have artificial currents moving water.
And living things need ocean currents for food, climate and transportation
Wind and salt keep ocean water moving.
For example, our ocean’s motion significantly affect Earth’s weather and climate.
READ MORE: 10 Unbelievable Weather and Climate Facts