Why glaciers look blue

We usually see the light coming back from the near surface layers less than 1 cm after it has been scattered or bounced off other snow grains only a few times, and it still appears white. In simplest of terms, think of the ice or snow layer as a filter. If it is only a centimeter thick, all the light makes it through; if it is a meter thick, mostly blue light makes it through.

This is similar to the way coffee often appears light when poured, but much darker when it is in a cup. Deeper in the snow , the preferential absorption of red begins to become noticeable. Just as with water, more red light is absorbed compared to blue. Not much more, but enough that over a considerable distance, say a meter or more, photons emerging from the snow layer tend to be made up of more blue light than red light. Rayleigh scattering occurs when light is scattered by particles smaller than the wavelength of the radiation.

Water and ice are blue because water molecules selectively absorb the red part of the visible spectrum, not because the molecules scatter the other wavelengths. In effect, ice appears blue because it is blue. While you may not get a chance to observe a glacier firsthand, one way to make blue ice is to repeatedly poke a stick down into the snow to compress the flakes.

If you have enough snow, you can build an igloo. When you sit inside, you'll see the blue color. You can also see blue ice if you cut a block of ice from a clean frozen lake or pond. Actively scan device characteristics for identification.

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To give a more familiar example of how adding bubbles can turn something transparent with a tint into something white, take the case of egg whites, which are transparent with a yellowish tint.

But as you whip it, adding in bubbles, it begins to turn into meringue which is perfectly white. However, there is a trick that can even make the blue color of seemingly-white snow noticeable. If you let a ray of light bounce on it many times, each time it will travel through a little bit of ice, getting a bit of blue tint each time, and after enough bounces it will look unquestionably blue.

That's what you see when looking at the entrance of a snow cave or a crevasse in a glacier. The light that comes from deeper in the cave has bounced many more times around the walls and becomes bluer: Picture taken from outdoorlifenorway. Sign up to join this community.

The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Why does glacier ice look blue? Ask Question. Asked 3 years, 9 months ago. Active 1 year, 10 months ago. Viewed 4k times. Improve this question. Community Bot 1. What is the stuff called that is either alive now or was alive in the past it may be trapped in glacier ice? True or False: Glacial ice is just like the water in your freezer.

What would be in your glass of water if the glacial ice melted? Glaciers are just frozen compacted snow. The ice on a glacier has been there for a long time and has been compacted down. Brain Challenge! If all the glaciers in the world melted, what would happen? Use your imagination! Exercise: Blue Ice 1. Glacier ice is blue because: A. Its structure strongly scatters or reflects blue light B. It is lonely C.

It absorbs every other color in the spectrum except blue D. Yellow and green make blue 2.