Nature

Why is glacier ice blue?

Inside an ice cave, colour tells the story of light travelling through ice.

As light travels a long way through ice, more red light is absorbed than blue. The light reaching your eyes can therefore look blue, without any blue pigment.

Snow often looks white because its small ice grains scatter light back near the surface. Lighting, viewing angle and the distance light travels through ice all influence the colour you see.

Blue is a result of light travelling through ice.