Color of Lakes and Oceans
Lakes and oceans appear blue for several reasons. One is that the surface of the water reflects the color of the sky. While this reflection contributes to the observed color, it is not the sole reason.
Some constituents of sea water can influence the shade of blue of the ocean. This is why it can look greener or bluer in different areas. Water in swimming pools (which may also contain various chemicals) with white-painted sides and bottom will appear as a turquoise blue.
Clean water appears blue in white-tiled swimming pools as well as in indoor pools where there is no blue sky to be reflected. The deeper the pool, the bluer the water.
Scattering from suspended particles also plays an important role in the color of lakes and oceans. A few tens of meters of water will absorb all light, so without scattering, all bodies of water would appear black. Because most lakes and oceans contain suspended living matter and mineral particles, known as colored dissolved organic matter (CDOM) light from above is reflected upwards. Scattering from suspended particles would normally give a white color, as with snow, but because the light first passes through many meters of blue-colored liquid, the scattered light appears blue. In extremely pure water—as is found in mountain lakes, where scattering from white-colored particles is missing—the scattering from water molecules themselves also contributes a blue color.
Another phenomenon that occurs is Rayleigh scattering in the atmosphere along one's line of sight: the horizon is typically 4–5 km distant and the air (being just above sea level in the case of the ocean) is at its densest. This mechanism would add a blue tinge to any distant object (not just the sea) because blue light would be scattered into one's line of sight.
The surfaces of seas and lakes often reflect blue skylight, making them appear bluer. The relative contribution of reflected skylight and the light scattered back from the depths is strongly dependent on observation angle.
Read more about this topic: Color Of Water
Famous quotes containing the words color of, color, lakes and/or oceans:
“Pockets: What color is a giraffe?
Dallas: Well, mostly yellow.
Pockets: And what’s the color of a New York taxi cab?
Dallas: Mostly yellow.
Pockets: I drove a cab in Brooklyn. I just pretend it’s rush hour in Flatbush and in I go.”
—Leigh Brackett (1915–1978)
“When a bachelor of philosophy from the Antilles refuses to apply for certification as a teacher on the grounds of his color I say that philosophy has never saved anyone. When someone else strives and strains to prove to me that black men are as intelligent as white men I say that intelligence has never saved anyone: and that is true, for, if philosophy and intelligence are invoked to proclaim the equality of men, they have also been employed to justify the extermination of men.”
—Frantz Fanon (1925–1961)
“I walk toward one of our ponds; but what signifies the beauty of nature when men are base? We walk to lakes to see our serenity reflected in them; when we are not serene, we go not to them. Who can be serene in a country where both the rulers and the ruled are without principle? The remembrance of my country spoils my walk. My thoughts are murder to the State, and involuntarily go plotting against her.”
—Henry David Thoreau (1817–1862)
“It isn’t the oceans which cut us off from the world—it’s the American way of looking at things.”
—Henry Miller (1891–1980)