I took this image on a Zodiac-tour through the pack ice of Svalbard, almost 80 ° North. The blue color effect in this Image is called selective absorption. The short explanation: water absorbs other colors of the spectrum, so the one that's reflected back to your eyes is blue. Glacial ice starts out as white snow. As more snow falls, the layers below it become compressed, forming a glacier. Pressure squeezes out the air bubbles and imperfections, forming large ice crystals that permit light transmission. The top layer of a glacier may appear white either from snowfall or from fractures and weathering of the ice.