Why are glaciers blue

A glacier is simply a huge body of ice formed through accumulation of snow and sleet over a period of many years. Anyone who has seen a glacier on television or in real life knows that a glacier appears blue in color. Rayleigh effect plays an important part in the blue appearance of a glacier much like it does in the appearance of the sky as blue. The key of this theory lies in the fact that sunlight is “white light”, which contains all wavelengths of color in it. The principle colors in the spectrum are blue and red, so when sunlight passes through the transparent ice, red is absorbed by the ice because it is the nature of ice crystals to absorb colors of long wavelength. As ice is also reflective in nature, the blue color of short wave length, unabsorbed by ice travels all through the depths of the huge mass of ice and is reflected so as to make the glacier appear blue in color. As the Tyndall effect is based on reflection and scattering, the extremely reflective nature of ice makes the blue light appear darker and darker as the sunlight passes right in and out of the depths of the glacier.

After the above explanation it should also now be easy to understand why a huge glacier would appear to be more deeply blue colored than a comparatively smaller glacier. There is also one other reason as to why glaciers appear different to each other in terms of their shades of blue. Glaciers of similar proportions can also be of significantly different shades. The reason is that the shade of blue also depends on the purity and age of the ice that constitutes the glacier. Age determines the purity in this case, because air bubbles that reflect back the ‘white light’ in its original form are eliminated each time a part of a glacier melts and freezes again later.

Glaciers are actually not blue, in fact they are of the same color as that of ice, which is colorless, but the effect of sunlight makes them a beautiful natural spectacle to behold, much like but not identical to other natural phenomenon like the “blue sky” or the “blue sea”.