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, lakes and/or oceans:
“Rain falls into the open eyes of the dead
Again again with its pointless sound
When the moon finds them they are the color of everything”
—William Stanley Merwin (b. 1927)
“While the very inhabitants of New England were thus fabling about the country a hundred miles inland, which was a terra incognita to them,... Champlain, the first Governor of Canada,... had already gone to war against the Iroquois in their forest forts, and penetrated to the Great Lakes and wintered there, before a Pilgrim had heard of New England.”
—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)