Ocean currents are something that people do not think about every day.  When flooding occurs in an area of Southeast Asia, a hurricane is forming in the Atlantic, or a beautifully sunny day warms Western Europe, ocean currents do not immediately come to mind.  Likewise, when a package arrives from China or a pod of whales is spotted off the coast, the aid of currents is not mentioned.  Even when gas prices soar and a quest for alternative energy sources begins ocean currents are far from sight.  However, they may just be the cause of these events.   Despite the lack of recognition ocean currents receive, they may just play a part in every one of the events listed above.  Ocean currents are the most powerful and underrated natural phenomenon on Earth.

It is evident by looking out into the ocean that the waters never stand still, however, how they move cannot always be seen from the surface.  Ocean currents occur in two major forms: surface currents and deep currents.  Surface currents are created by the wind.  When the wind blows consistently in one direction over the surface of the ocean waters it creates movement of the top level of water in a certain direction.  Consistent wind direction and water movement creates a continuous ocean current.  These currents are large circular formations called gyres.  Surface currents only occur in the top 400 meters of ocean water and usually flow in a consistent direction due to the Coriolis Effect.  However, the Somalian Current, off the coast of eastern Africa, is unique as it changes directions during the monsoon season when the winds shift.  The Coriolis Effect is created by the rotation of the Earth in the same direction which causes the objects on the Earth to deviate slightly from their original target paths they would follow had the Earth been standing still.  This deviation creates a clockwise motion in the northern hemisphere and a counterclockwise motion in the southern hemisphere.  The wind combined with the Coriolis Effect creates the seventeen major surface currents of the Earth.  The most well-known surface current in the United States is the Gulf Stream current which runs along the eastern border of the US from the Caribbean Sea to northern Europe.

The other major type of current which occurs is deep sea currents.  These currents are controlled by the temperature and the salinity of the water.  Usually referred to as the “underwater conveyor belt”, deep sea currents move at an extremely fast rate.  The current is created when water nears the poles of the Earth and cools down.  This cooler water will freeze and in the process of freezing will lose the salt usually in ocean water.  As the water loses its salt it becomes denser forcing the water to sink.  Warmer water takes this now dense water’s place and in the process creates a continuous cycle and eventually a current.  This cooler water travels toward the equator where it is warmed and regains its salinity and rises, completing the current.  Along with tides, created by the gravitational pull of the moon, surface and deep sea currents greatly affect life on Earth.

Perhaps the biggest way life is affected is by the creation of climates due to the traveling of the currents.  The biggest example is again the Gulf Stream Current off the eastern United States.  This current originates in the warm near-equator ocean waters and travels to northern Europe.  As it travels through the Atlantic Ocean it brings with it the warm waters of the Caribbean.  Although parts of Scotland and Scandinavia are extremely close to the North Pole, their weather is still somewhat temperate because of the heat brought by the current.  This is also why the region experiences foggy weather.  As warm ocean water is evaporated into the atmosphere and collides with cool polar air, it creates a foggy and rainy weather condition.  This is just one example of how ocean currents can affect weather patterns on Earth.

Animals are very deliberate in their use of the ocean current throughout their life cycles.  Much of the sea life such as plankton needs the sun and warm water to survive.  As this warm water moves from place to place so do the plankton.  Because plankton is such a rich source of food for many sea creatures they migrate to follow it.  As the plankton drifts along the current so do many species of sea life.  The European Eel takes this a step further.  After being born in the rivers of Europe these creatures travel along an ocean current to the warm waters of the Caribbean where they lay their eggs.  After the eggs hatch they travel in the Gulf Steam Current back to Europe where they spend their adult lives.  Their entire life cycle revolves around the ocean currents.  Even in pop culture animal migration shows itself.  In popular animated movie Finding Nemo,  Crush  a turtle, is migrating along the East Australian Current.  Many species use the current to help migrate periodically during their lives.

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