Why it is blue - I don't know. We have ice usually or transparent, or white, or greenish. There is ice not only blue on the glacier, but the water in the river, which has its source - glacier  is blue. Went a half a kilometer from the point of meeting tours, and crossed the bridge, we took the panorama on the other side of the stream, where is allowed to those who do not go on the tour. Along the icefall is a rope fence to tourists around and not want to climb on the glacier from here - the ice is covered with cracks, so that even comes close is dangerous.