Question: why is the blue lake blue in mt gambier

title: Blue Lake (South Australia)
text: During December to March , the lake turns to a vibrant cobalt blue colour , returning to a colder steel grey colour for April to November . The exact cause of this phenomenon is still a matter of conjecture , but it is generally considered likely that it revolves around the warming of the surface layers of the lake during the summer months to around 20 ° C ( 68 ° F ) , causing calcium carbonate to precipitate out of the solution and enabling micro-crystallites of calcium carbonate to form . This results in scatter of the blue wavelengths of sunlight . During winter the lake becomes well mixed , and recent research indicates that during this phase of the colour cycle the lake is somewhat murkier due to the redistribution of tannins and calcium carbonate particles throughout the lake . Solar elevation has also been found to influence the perceived colour of the lake . The movement of planktonic life - forms within the lake during the seasons and during the day may additionally play a part in the colour change . 

Answer: answer: The exact cause of this phenomenon is still a matter of conjecture, but it is generally considered likely that it revolves around the warming of the surface layers of the lake during the summer months to around 20 ° C, causing calcium carbonate to precipitate out of the solution and enabling micro-crystallites of calcium carbonate to form. This results in scatter of the blue wavelengths of sunlight. The movement of planktonic life-forms within the lake during the seasons and during the day may additionally play a part in the colour change.
answer: The exact cause of the lake turning to a vibrant cobalt blue colour and retuning to a colder steel grey colour is still a matter of conjecture, but it is generally considered likely that it revolves around the warming of the surface layers of the lake during the summer months to around 20 ° C, causing calcium carbonate to precipitate out of the solution and enabling micro-crystallites of calcium carbonate to form. This results in scatter of the blue wavelengths of sunlight. The movement of planktonic life-forms within the lake during the seasons and during the day may additionally play a part in the colour change.