The Bahamas
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The Bahamas

November 22, 2010
From space, bright peacock blue waters surrounding the Bahama Islands stand out in striking contrast to the deep blue waters of the Atlantic Ocean. The Moderate Resolution Spectroradiometer (MODIS) aboard NASA's Terra satellite passed over the islands on November 10, 2010 and captured this true-color image on a relatively cloudless day.

The glowing blue of the waters is a result of abundant reflection of light from shallow platforms which comprise the sea floor surrounding the islands. The platforms are made of submerged carbonate which has been laid down by the skeleton of organisms, such as coral polyps, and by small organisms (usually microbes) which precipitate calcareous deposits through their metabolic cycle. In some areas the skeletons have been eroded away to form sand, which is shaped into dunes by the ocean current. The carbonate in the platforms around the Bahama Islands have been accumulating since at least the Cretaceous Period.

The largest of the platforms, seen in the center of the image is known as the Grand Bahama Banks and encircles Andros Island. To the north, the Little Bahama Bank is associated with Grand Bahama Island. Some of the platforms are home to large living coral reefs, but where the water turbidity is high, such as in the Grand Bahama Banks, little living coral can be found.

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