Frozen Lake on Mars

Blue ice comes from high frequency (blue) light having more energy than low and medium frequency light. Blue light has enough energy to avoid being absorbed by ice crystals . If ice is dense enough, lower frequency light is absorbed by ice crystals while high frequency light is allowed to pass through. If only blue light can pass through the ice and the rest is absorbed, all we see is blue. The reason we don`t see blue ice/snow all the time is because the ice/snow may not be dense enough. If there are air bubbles in the medium low, medium and high frequency light are all reflected giving off white rather than blue. Last I checked the ocean wasn`t dense ice. It`s blue because of the sky.