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Why is the Red Sea called the Red Sea?
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Red Sea
Map showing the Red Sea and the countries surrounding it. The Red Sea is one of the most heavily traveled waterways in the world. It is about 1,200 miles (1,930 km) long, and its maximum width is about 190 miles (305 km).
The name of the Red Sea is derived from the occasional color changes observed in its waters. While the sea is typically an intense blue-green, it is sometimes populated by extensive blooms of the algae Trichodesmium erythraeum. When these organisms die off, they turn the water a reddish-brown color, which is believed to be the origin of the sea's name.12