> I agree, Emerald is wrong; there's no green in it. It IS a unique color,
> found in some mountain lakes. AG say glacier
> fed, I can't disagree, although I'm not sure it's that simple.
I agree that the color description is somewhat incorrect. "Teal" or
"turquoise" is probably more accurate. But I'm saying "somewhat"
because it is very dependent upon the angle and type of light, as well
as the waves. Eklutna Lake is probably one of the most variable in
this aspect of any body of water in the region. However, down on the
Kenai Peninsula, the Kenai River is also extremely variable with
colors ranging from bright, intense green to a blue so pure that it
makes you want to cry. The Kenai River is quite legendary when it
comes to the colors.
The variability of color changes with temperatures, month, high
clouds, low clouds, intense blue skies with white puffy clouds, time
of day, viewing angle, type of wind and direction. It never really
looks the same way twice.
The normal snowmelt carries with it surface silt and organics which
usually settle out fairly quickly, but the "rock flour" in glacial
melt water stays suspended, and it absorbs and reflects light. The
reflected water color to the human eye is dependent on so many factors
and can end up ranging across the entire blue-green spectrum.
Most of the glacier fed rivers tend towards the milky white color if
there is a large enough ratio of normal rain or snow melt included.
Rivers, like the Susitna, will sometimes look like tea with a lot of
milk mixed in. But they lack the colors. The glaciers around Prince
William Sound tend to be directly feeding into a fiord with almost a
complete lack of anything other than barren rock surrounding. Those
fiords get some insanely intense colors. The Eagle River, which runs
behind our house, will sometimes get colorful, but is usually a
silvery-blue color with almost no greens. But the South Fork Eagle
River, will be a little more blue-green in color depending on time of
year, but with very little rock flour. Most of the Eagle River
watershed has low-silt blue-green water.
The non-glacial side waters that feed into the rivers are extremely
important for the salmon. The problem salmon have is that a heavily
silted river clogs up their ability to breath. So, there are little
side pools or feeder rivers they'll pop into to get the gills cleaned
Regardless, I've enjoyed color photography here more than I ever
expected. Winter is rather monochromatic, but everything else is
Themed Olympus Photo Exhibition: http://www.tope.nl/