The eerie glow of the close up of the Mendenhall Glacier. The glacier is constantly moving on it's shelf and has rocks and soil in it and picks up many things along the way. Glacial ice is so blue because the dense ice of the glacier absorbs every other color of the spectrum except blue - so blue is what we see. Sometimes the glacial ice appears almost turquoise and casts an other worldly color. Its crystalline structure strongly scatters blue light. 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.