that the ocean is blue due to the reflections from the sky on its
surface. This is not true, but was believed to be so decades ago. The
reason the ocean is blue is because water, pure water, is
Yes, according to its frequency
spectra, water is a very light shade of
But you need a huge amount of it to really see its color. It’s like a teaspoon of oil, it looks transparent on a white spoon, but in the bottle looks yellowish.
If the ocean owed its color to the
would be a different shade of blue and it would be white on cloudy
You can see clouds reflected in the surface on the sea, but they don’t
completely change its color.
|I asked Prof. Bob Stewart from Texas
to explain this in simple words so
even kids could understand it, and
is his response.
Why is the ocean blue?
The ocean is blue because it absorbs all the other colors.
The only color left to reflect out of the ocean is blue.
Here is what happens:
Sunlight shines on the ocean, and
colors of the rainbow go into the water.
Observe how difference is the tone of blue of the water and how it varies according to reef and algae content. See more photos below.
|Robert Stewart, Professor
Department of OceanographyPhone:(979) 845 2995
Note in this picture above and the one on the very top,
show the color of the ocean changes as the depth changes.
The deeper it gets, the larger the concentration of water molecules and therefore it's easier to see it real color.
The color of the sky, on the other hand, its due to Rayleigh scattering of light of
higher frequencies on the visible spectrum, i.e.,
blue-violet or indigo color, which is very different to the turquoise
color of pure water.
|Ice is also blue.
This is easily observable below where the ice is not dirty and it's more dense it looks turquoise.
Why is water blue?
Water is faint blue. Although water appears clear in small quantities (like a glass of water), the blue color becomes visible the more water we look through. Thus, deep lakes and seas are bluer than a shallow river.
Other factors can
the color we see:
1. Particles and solutes can absorb light, as in tea or coffee.
Green algae in rivers and streams often lend a blue-green
color. The red sea has occasional blooms of red Trichodesmiumerythraeum algae.
2. Particles in water can scatter
The Colorado riveris often muddy red because of suspended
reddish silt in the water. Some mountain lakes and streams with finely gound rock, such as glacial
flour, are tourquise. Light scattering by suspended matter is required in order that the blue light
produced by water's absorption can return to the surface and be observed. Such scattering can
also shift the spectrum of the emerging photons toward the green, a color often seen when water
laden with suspended particles is observed.
3. The surface of seas and lakes often
blue skylight, making them appear bluer. [[[ Montana
reflection.]]] The relative contribution of reflected skylight and the light scattered back from the
depths is strongly dependent on observation angle.