Why are some alpine lakes so blue?

The concentration of the blue colour of a glacial lake depends on the amount of rock flour suspended in the water column and the angle of solar irradiation. The concentration of the blue colour of a glacial lake depends on the amount of rock flour suspended in the water column and the angle of insolation of the sun. Notice how little vegetation lines the valleys around the Tasman and Godley rivers compared to the valleys north of Lake Wanaka and Lake Hāwea. The mountain lakes of Banff National Park are a beautiful turquoise blue.

The characteristic milky turquoise of mountain lakes disappears with the glaciers that feed them, according to new research. The lakes in the mountains, which are bright blue and green, are fed by glaciers.

Why is the water in Glacier National Park so blue?

In general, the water quality in Glacier National Park is very high because it is located at the headwaters of the North American continent. The turquoise blue of the lakes in Glacier National Park is caused by crushed rock fragments and sediments called “glacial flour”. This gives park officials the opportunity to combine water quality monitoring with monitoring other vital indicators, such as air quality, in the park. This explains why many glaciers are covering less and less ground over the years and some are even disappearing altogether.

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Why is a lake so blue?

Because you can only see the true colour of water by looking through it, the blue is easiest to see when you look up from the lake. Scientists at the University of California at Davis, in their State of the Lake report this year, for the first time quantified the blue colour of Lake Tahoe based on measuring the wavelength of light coming from the lake. Over the past two decades, the colour of Lake Michigan has changed from green to blue as invasive mussel species have caused a massive decline in algae in the water. To see the most intense blue, you have to look at a glacial lake from an aeroplane when the sun is at its highest and the sky is cloudless.

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