oscarps
Sometimes the ice looks blue. The white light of the Sun is actually made up of a mixture of colors, from red to violet, as seen when a ray of light is passed through a glass prism or in the rainbow. The bluer waves of light have more energy than the yellow ones or the red ones. The snow is white because all the light that comes to it is reflected in a very thin layer that is on its surface.
#1
In other words, the more compact ice, like glacial ice, behaves in a special way when receiving light. By striking a beam of light, only the blue component of solar radiation has enough energy to penetrate the interior of the mass of ice. Therefore, when absorbing the other colors, glacial ice appears blue.
#2
Red photons, which have less energy than blues, penetrate less distance and are absorbed earlier. On average, the absorption of red light in the ice is six times more efficient than the absorption of blue light; Therefore, the more distance traveled a white beam of light loses in its path more and more photons red, yellow, green ... and it is the blue ones that "survive". This is the reason for the blue color of pure ice, and of a glacier or an iceberg.
#3
The small air bubbles that are trapped in the ice reflect the light, multiple times and all the colors, from red to violet, escape, so that the light we receive is white light. The ice appears blue when it has a very high consistency and the air bubbles do not impede the passage of light through it. Without the "dispersive" effect of the bubbles, light can penetrate into the ice by being absorbed gradually on its way to the deeper parts.
#4
The expansion of water upon solidification has important geological effects. The water that enters the tiny cracks of the rocks of the earth surface creates an enormous amount of pressure when solidifying, and leaves or breaks the rocks. This ice action plays an important role in erosion. In addition, glaciers, by friction, polish the terrain where they circulate.
