In everyone's definition, the sea is naturally blue, just like the sky is blue and the clouds are white, they are all the products of nature. But if you look closely, you can find that the seawater is colorless and transparent. Why is the sea consisting of transparent seawater blue?
One of many people hear is that because the sky is blue, and the sea reflects the color of the sky, the sea looks blue. This is actually a misunderstanding. Indeed, the blue sky will change the color of the sea, but this is not the main reason why seawater looks blue.
There is a reflection and absorption between light and seawater. Light consists of seven colors, which is also called a spectrum. In the spectrum, the light near the green wavelength range is easily absorbed by water molecules, and the light of the blue part will be reflected, making the sea appear blue.
It turns out that one of the reasons for blue or green being presented by seawater is the reflection and absorption of light and seawater. When the sun was shot to the sea, some light was reflected back, and the other part of the light refracted into the water.
The light entering the water will be absorbed by the water during the spread. The absorption of water on light is related to the wavelength of light, that is, water will choose to absorb light.
Water molecules absorb infrared, red, and ultraviolet light first, then yellow, green, and violet light. Blue light is the last to be absorbed, meaning it has the greatest penetration through the water.
Another reason is the depth of the water. The sea is blue because of the depth of the seabed and the volume of the water. The depth of the ocean is very great, and there are no terrestrial lighting tools at the bottom of the sea, so sometimes the bottom of the sea can be very dark.
Of course, as the depth of the seawater increases, the light that can penetrate the seawater will become less and less and darker. These make the colors in the deep sea look dark blue.
As you get closer and closer to the surface, the sea gets brighter and brighter. Then it creates a bright scene, like the dark blue sky. So in people's eyes, can see the color of the sea is blue.
And that is why the same seawater that you hold in your hand and that you put in a bottle is transparent, but the seawater in the ocean is blue.
The color of the seawater is also related to the surrounding environment. Maybe everyone has heard of the Red Sea or the Black Sea. In fact, seawater is not just blue, because the substances contained in the seawater in each region will also affect its color changes.
We usually see green water, mainly because the water body contains a large number of green algae.
The red sea between the Asian and African continents is red because the water temperature there is extremely high, and much reddish-brown seaweed has grown.
The reason why the Black Sea is black is that the strait is narrow and the bottom salt content is high, resulting in poor water flow in the Black Sea. Therefore, the bottom of the Black Sea is hypoxic, which causes a large number of biochemical excrement and rotten corpses to be discharged, so the Black Sea becomes black.