Is the Red Sea really red?

The Red Sea acquired its name from blooms produced by abundant algae.

This is an underwater photo of white, green, and reddish-pink coral reef surrounded by a school of little yellow Anthias fish. It was taken in the Red Sea.
The color of the Red Sea is normally an intense turquoise.
(Image credit: Csaba Tökölyi via Getty Images)

Satellite images taken from space show the Red Sea as a blue line running roughly from north to south along the northeastern edge of the African continent. The intense blueness of the water, which stands in stark contrast to the drab brown of the surrounding landscape, belies the sea's famous name. There's seemingly nothing "red" about the Red Sea. 

So, how did the Red Sea acquire its famous moniker? 

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Tom Garlinghouse

Tom Garlinghouse is a journalist specializing in general science stories. He has a Ph.D. in archaeology from the University of California, Davis, and was a practicing archaeologist prior to receiving his MA in science journalism from the University of California, Santa Cruz. His work has appeared in an eclectic array of print and online publications, including the Monterey Herald, the San Jose Mercury News, History Today, Sapiens.org, Science.com, Current World Archaeology and many others. He is also a novelist whose first novel Mind Fields, was recently published by Open-Books.com.