What makes the water of Havasu Falls so vibrantly blue?

October 29, 2014, 1 p.m.
waterfall at Epupa Falls, Namibia
Photo: Ennio Vanzan/Flickr/MNN Photo Pool

A spectacle for the eyes

Havasu Falls is a popular destination, if not the destination, for visitors to Havasupai in Arizona. One reason is because 90-foot waterfalls are a spectacle, especially in the arid Southwest. But another reason is because the water is outstandingly beautiful, made even more so as it contrasts with the red color of the rock walls surrounding it. It's just so blue. The color has been astounding humans for centuries — in fact, the name Havasu means blue-green water, and the native tribe's name, Havasupai, means people of the blue-green water.

But how does it get like that?

The secret is calcium carbonate and magnesium, which occur naturally in the creek's waters. The calcium carbonate is deposited onto rocks and other surfaces, building up pools and natural dams. Meanwhile, magnesium is left in the water. This chemistry is what gives the water its striking color. Because the calcium carbonate is constantly being deposited and broken away with varying water levels including floods, the flow of the falls and the arrangement of the pools below it are in constant flux. But the color — that vivid blue — is always there.

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