Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Glacier Color



Vern Lindberg wrote:

In Banff and Jasper parks (Alberta) I've been told that the brilliant
color is due to the glacial silt that the lakes and streams have in
abundance. I've never done any calculations though.

But what is in the silt that produces the color?

Yes, if I recall correctly Lake Louise is green too, but the lakes I'm
thinking of (the ones I grew up around) are not glacial, they are found
in the foothill areas of the Cariboo in the BC interior - though green
lakes do abound in general in BC. I see a few things going in this
subthread:

1 - blue lakes result from a lambda^4 dependence of scattering

2 - green lakes can arise from organic material, and this may be related
to phosphate pollutants - eg. see the stuff on algae bloom at
http://www.gov.mb.ca/environ/pages/emd/quality/caddy.html

3 - there are many clear green lakes which I doubt have their basis of
color in either of the above. An introduction to lake coloring can be
found at
http://www.esr.pdx.edu/pub/biology/limnology/limn-7.htm
here we see that the standard basis for categorizing lake color is
comparison with dissolved metal salts. Hence, I still see copper as the
likely source and absorption not scattering being the coloring
mechanism.

\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\_/^\

Doug Craigen
http://www.dctech.com/physics/about_dc.html