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:
“... it is not the color of the skin that makes the man or the woman, but the principle formed in the soul. Brilliant wit will shine, come from whence it will; and genius and talent will not hide the brightness of its lustre.”
—Maria Stewart (1803–1879)
“‘Twas mercy brought me from my Pagan land,
Taught my benighted soul to understand
That there’s a God, that there’s a Saviour too:
Once I redemption neither sought nor knew.
Some view our sable race with scornful eye,
“Their color is a diabolic die.”
Remember, Christians, Negroes, black as Cain,
May be refin’d, and join th’ angelic train.”
—Phillis Wheatley (c. 1753–1784)
“The Indian navigator naturally distinguishes by a name those parts of a stream where he has encountered quick water and forks, and again, the lakes and smooth water where he can rest his weary arms, since those are the most interesting and more arable parts to him.”
—Henry David Thoreau (1817–1862)
“You there, I here,
With just the door ajar
That oceans are,
And prayer,
And that pale sustenance,
Despair!”
—Emily Dickinson (1830–1886)