All About the Gyre

The lines and clumps of sargassum (reddish brown grass floating at sea that forms the foundation of a complex sea community) can stretch for miles along the ocean’s surface here in the North Atlantic. Get high above the surface and you’ll find the orange and brown seaweed as far as the eye can see. And you can’t see it all, because the area known as the Sargasso Sea stretches for almost 2 million square miles.

The Sargasso Sea is the only sea without a land boundary. And, if you look closely, you’ll find a lot of man-made debris mixed in with all the seaweed. While this area is better known as the Sargasso Sea, it is also becoming known as the North Atlantic Garbage Patch. But this collection of interesting facts still begs the question: why is it here at all?

The simple answer is that it’s all about the GYRE.

Specifically, it’s called the North Atlantic Gyre. It is a circular system of ocean currents that stretches across the North Atlantic from near the equator almost to Iceland, and from the east coast of North America to the west coasts of Europe and Africa.

The currents that make up this swirl include the Gulf Stream in the west, the North Atlantic Current in the north, the Canary Current in the east, and the Atlantic North Equatorial Current in the south.

The mixing and swirling of currents creates an area that is noted for its still waters and deep blue color. And much like a tornado, the mixing collects everything in the area and draws it into the vortex in the center, where it stays.

As for how the area got its name, thank the men sailing with Christopher Columbus. During his voyage of discovery across the Atlantic, Columbus’ crew was amazed to find giant masses of floating seaweed as far as the Azores. Because the air bladders on sargassum resembled yellow grapes, the sailors named it sargazo, after a variety of grape.

— Frank Graff

Frank Graff is a producer/reporter with UNC-TV, focusing on North Carolina Science Now, a weekly science series that airs Wednesdays, beginning in August 2013, as part of North Carolina Now on UNC-TV. In addition to producing these special segments, Frank will provide additional information related to his stories through this North Carolina Science Now Reporter's Blog!


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