photos: Hoh rainforest, 10-11 Sep 2005

[eub]

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That blue Hoh River water -- I don't remember scattering mechanisms. Wikipedia says that glacial rock flour is "grains of a size between 0.002 to 0.00625 mm", 2000 - 6250 nm. I thought you needed to be smaller than the wavelengths of the light if you wanted preferential scattering of high frequencies. Help me out here?

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[randomdreams.livejournal.com]

And this says:

"As the glacial mass of ice and embedded rock moves along the ground, it grinds the surface below and the rocks within it, creating a fine dust called "glacial flour." This flour makes glacial rivers look opaque and milky. The opaque water varies in color from chocolate brown to turquoise green, depending on the type and amount of sediment it contains. Streams that do not drain from glaciers are called clearwater streams to differentiate from those of glacial origin. Glacial streams can also run clear if the glacier is not melting, such as those seen during winter."

[eub.livejournal.com]

The chocolate brown sounds like a hint that absorptive coloring happens, but it leaves open the possibility that the turquoise is scattering coloring, from a different size of flour, doesn't it.

[randomdreams.livejournal.com]

I would totally believe that limestone or marble glaciers are absorptively blue rather than raman-scattering blue.

[eub.livejournal.com]

I could be convinced. I don't think of limestone as blue-green, but I don't know it very well. No idea what the Olympics are made of, either.