why is the sea blue?

Question

la lang!

Answer 1

The color of water is the subject of some deal of misconception. It is commonly believed by some that in large bodies, such as the oceans, the water's color 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 real reason the ocean is blue is because pure water is blue. According to its frequency spectra, water is a very light shade of turquoise blue. It is only when collected in a large body that the blue color becomes apparent.

((If the oceans owed their color to the sky, they would be a lighter shade of blue and would be white on cloudy days.)) Some contents of sea water can influence the shade of blue you see in the ocean. This is why it can look greener or bluer or even yellow (exempli gratia the Yellow Sea) in different areas. ((Swimming pools with white bottom, would have water that looked transparent not turquoise blue, as it is observed even in indoor pools, where there’s no sky to be reflected)). The scientific explanation involves the theory of radiative transfer (absorption and scattering), and material electromagnetic spectra.

The color of a water sample is caused by both dissolved and particulate material in water, and is measured in Hazen Units (HU). Either of these components can be deeply colored, for instance dissolved organic molecules called tannins can result in dark brown colors, or algae floating in the water ("particles") can impart a green color. But in a lot of cases water is a clear to neutral color due to a lack of pigments in the water. (exempli gratia the sea)

The color of a water sample can be reported as:

1. Apparent color
2. True color

Apparent color is the color of the whole water sample, and consists of color due to both dissolved and suspended components.

True color is measured by filtering the water sample to remove all suspended material, and measuring the color of the filtered water, which represents color due to dissolved components.

Testing for color can be a quick and easy test which often reflects the amount of organic material in the water (although certain inorganic components like iron or manganese can also impart color).


For the second time: If the color of the sky contributed to the color of the water then why are white-painted, indoor swimming pools with white paint on the ceiling and walls a very light shade of blue? Food coloring?

Answer 2

Both answers are correct: The sea does tend to reflect the colour of the sky, and can be a grey colour on an overcast day. But the blue colour is also due to the scattering of light; for the same reason that the sky is blue (without going into the detail of this, look up the question 'why is the sky blue?', which has been asked over 400 times, or look up 'blue sky' in wikipedia for a comprehensive answer)

The scattering effect of water molecules on light can be seen very well with ice. If you are a skier, you have probably noticed a blue colour, if you poke a hole in the snow with a stock, and you may have seen the intense beautiful blue colour if you look down a crevasse in a glacier.

If the water contains suspended solids (such as clay particles in a flooded quarry), then the scattering effect is enhanced, and the water can be intensely blue.

Answer 3

If you go to the Yellow Sea you will find it is actually yellow. That is because of the sand from the Yangzhea River is dumped into the bay.
As a former sailor I have seen different shades of blue. Near Japan, for example it is dark blue and choppy because of the wind. The Indian ocean is such a rich blue it can hypnotize you. The Persian Gulf the sea is sometimes glassy with a fog.
Blue light has a higher frequency than red light. That means it is more likely to hit water and air molecules. That is why the sky and ocean are blue. Incidentally, the lunar eclipse tonight is red because the red light waves have reached the moon.

Answer 4

This due to collision of air molecules up the sky thus scattering blue like color.This is what reflected on earth and sea acting as a mirror absorbs this bluish color.

Answer 5

The sea water is blue from the relection of the Sky.

Answer 6

it's not. It is clear. The colours come from what is in the water and reflection from the sky. The sky is not actually blue. This colour come from the reflection of dust particles in the atmosphere.

Answer 7

water is colourless AND SO IT REFLECTS THE COLOUR OF THE SKY which is blue THE SKY IS BLUE BECAUSE BLUE IS THE COLOUR WHICH EASILY SPREADS
............ AND also blue has a small wave length which is also the cause . HOPE IT HELPS

Answer 8

its not. it's a reflection of the sky in the water that causes it to appear blue. water is clear.

Answer 9

reflects the blue sky..it's all to do with light