Sometimes Turquoise



I remember reading somewhere recently about why the sea is sometimes turquoise as at Cala Mitjana in Menorca. One theory is that it is seaweed but I decided I should look into this phenomina. Search as I may I could not find any information on Cala Mijana's turquoise colour. I decided to extend my search and this was my first mistake. Do you know how much there is on sea colour from NASA downwards? If you really want to see just type "why is the sea blue" into any browswer. if you prefer to to stay with my precis then read on!

I mentioned particles in seawater. Any particles suspended in the water will increase the scattering of light. Some types of particles particularly the cells of phytoplankton, or algae contain light absorbing substances.

The most important light absorbing substance in the oceans is chlorophyll. Chlorophyll has a green pigment which absorbs the red and blue portions of the light spectrum to carry out photosynthes the essential plant process for growth. The overall effect is that green light is reflected. Thus the the ocean and seas with high concentrations of phytoplankton will appear in varying shades of blue-green or sometimes turquoise.

The reason for my finding such a significant amount of information on the colour of seawater is that its study helps scientists gain a better understanding of phytoplankton and its impact on the Earth system. According to NASA "these small organisms can affect a system on a very large scale such as climate change. Phytoplankton use carbon dioxide for photosynthesis and in turn provide almost half the oxygen we breathe. The larger the world's phytoplankton population, the more carbon dioxide gets pulled from the atmosphere, hence the lower the average temperature due to lower volumes of this greenhouse gas. Scientists have discovered that phytoplankton can double its numbers about once per day. Therefore phytoplankton can respond very rapidly to changes in their environment. Over a long period of time significantly lower atmospheric carbon dioxide levels and thus lower average temperatures. They have also found that Carbon can be stored in oceanic sediments when organic matter sinks and becomes buried in the ocean floor. For more information visit the NASA Science site.

Leave Sometimes Turquoise