What makes the ocean water different colors, such as aqua, dark blue, green?
Everything from the quality of the sunlight, to dissolved minerals, to the microscopic organisms living it the water contribute to the color. These sites have some good information… http://www.noc.soton.ac.uk/JRD/SCHOOL/mt/mt001a_5.html http://vathena.arc.nasa.gov/curric/oceans/ocolor/index.html Around the island of St. Maarten in the Caribbean the water varies from sky blue, to sapphire, to emerald green. It is really amazing to see how vividly colored and still clear the water can be.
The color of water has to do with both the things living in it and the dirt that’s stirred up in it. Lots of things affect how much life there is in the water, but the most obvious is the type of dirt that makes up the sea bed in the area. The sea bed near Florida is mostly sand, which doesn’t dissolve easily in the water. It sinks, and so you see mostly clear water. The warm water also helps keep down algae, which keeps the water from turning green. Further north, the clay soils turn the water turbid, and the cool water supports a lot of microscopic life forms. Together, they can turn the water green or brown.
First you need to understand that sunlight is composed of all colors. Some sunlight is reflected off the surface of the water, and reflects the blue color of the sky. Of the sunlight that penetrates, much of it is scattered. This may cause the ocean to appear a certain color, based upon how scattering is occurring. Generally, the deeper the water, the bluer it is, because blue has a much longer wavelength. The scattering effect disperses much of the lesser wavelengths. Other factors may be plants beneath the surface of the water or local pollutants. The Red Sea, for example, is filled with algae that are red in color. The Black Sea gets it’s unique coloration from the presence of high concentrations of hydrogen sulfide in the water.
