Why is Glacier Ice Blue?
Updated: Mar 7, 2022
Have you wondered? That’s one of the most frequent questions we get during the glacier tours. The blue colors of glaciers are tied with our company identity as well, as it’s one of the main features of the glaciers.
Then why is glacier ice blue?
You can see the dramatic blue color melt pools in summer glacier tours. Is the water blue too?
The answer is in physics. In a short answer, glacier ice looks blue because the long-wavelength (red) of the sunlight is absorbed by ice and the short-wavelength (blue) is transmitted and scattered.
Then why do ice cubes from the freezer don’t look blue? That’s because if you look at it closely, ice cubes are created with many air bubbles. Glacial ice is a lot different from the frozen water you get out of the freezer. The ice on a glacier has been there for a really long time and has been compacted down so that its structure is pretty different from the ice you normally see. After a season of snowfall, older glacier ice gets buried under heavy younger ice, causing the ice to become denser with very few air bubbles. Air bubbles are squeezed out of the ice. Air bubbles scatter light and reflect the full spectrum of white light. However, since glacier ice has very few air bubbles, dense ice reflects only a short-wavelength (blue) and absorbs all others. The longer the path light travels in ice, the bluer it appears.
Glacier ice is so dense, it doesn’t melt like regular ice cubes. You might have a chance to pick up a chunk of glacier ice during the glacier tours (usually in summer) and you might be able to notice how long those chunks of ice last.
Knik Glacier, one of the largest glaciers in the area, is just around the corner from us which provides us with plenty of opportunities to observe these amazing colors. There are also fascinating glacier features you can see as well.
We hope this solves your burning question! Grab your chance to see the unbelievable shades of glacier blue with us.