Turquoise Water, the science behind the travel pics

A few months back I was in Canada, specifically in Banff. For half of my trip I was staying in the amazing Banff Fairmont and after that I moved to another B&B. On my first days in the big fancy hotel I found one very big photography of Lake Louise in during the summer. Even though tha landscape was pretty awesome itself, the most eye-capturing thing in the picture was the colour of the lake… It had turquoise water!

Where does the turquoise water colour come from?

Well, Lake Louise is a glaciar lake, and from that is where it all comes from. During most of the year the mountains are covered in ice. Ice that goes into each one of the breaches within the rocks and expands. And contracts. And expands again. It acts like sandpaper and a sponge. It removes am exremely thin layer of rock particles that are then absorbed by the ice. Those particles are what is known as rock flour. When the summer comes and the ice thaws, that rock fluor goes down the streams to the turquoise water lake.

But the rocks are not turquoise so why is the water like that?

Well, it has to do with light and refraction. The lake does not actually have turquoise water, the water is mostly colourless though a little cloudy. And the cloudiness comes from the rock flour. These particles are the ones that are small enough to float and reflect light of a specific colour: turquoise.

The more complex explanation goes for how these particles reflect light from different wavelengths more or less efficiently. Since green and blue tones are less absorved for the water, the lake gets these turquoise water tone so appealing.

Other non glacial-lakes that are also turquoise

Some other lakes and rivers have similar colours, even if their water doesn’t come from glacial mountains. A good example is Urederra in the north of Spain. Even though the river starts in Los Picos de Europa (translated as The Peaks of Europe), a set of mountains not that high, the water has a very similar tone. Right now the elevation of these mounains is not much, their origin is Glacial. This means that the water that passes through the rocks will still drag the same type of sediment. So the lakes will contain the same type of rock flour and the lake will still look as if it had turquoise water.

Other lakes with funny colours

Because I am a curious person, I also know of a couple of other lakes that are pretty cool.

A very original case is Kelimutu. This place is in Indonesia and comprises three different lakes. Each one of them with its own colour. Though the most interesting thing is that these coulours actually change. These lakes are found in the top of a volcano and because their water comes from very deep down the earth, the colour of the water can change every day and it depends on the gases and reactions underneath the earth surface.

Credit to Global Volcanism Program from the Smithsonian Institution

Usually, there is a lake with turquoise water, another one with green water, and then a third with red/black water. In some cases some of these lakes have even had white or dark red water. Pretty cool, right? Of course, the locals have plenty of stories around it, some of them saying that each lake is the place of rest of the souls of the old and the young (blue/green lakes) and the evil (black/reddish) souls. Since all the very few people that has fallen to any of the lakes has died (and their body was never recovered)… There might be some part of truth there.

And VERY weird colours

Another interesting case of weirdly coloured lakes is Spencer Lake… or Pink Lake. Yes, there is a lake with a gum-like colour. Check out the photo if you don’t believe me. This is a salt-water lake and in this case the colour has nothing to do with the water composition. It turns out that this lake is very rich in a specific salt-tolerant alga that has this colour. When I say alga we all tend to imagine that disgusting things that cling on you after bathing in the sea. Well, most algaes are actually microschopic, and so is this one. The red comes from the alga producing their own sun-protecting balm that has a reddish-pink tone. I would say that it is a unique lake…. if there were not another one: Lake Retba. Pretty near the capital of Senegal, there is this “small” lake with the exact same tone that Spencer lake, and caused by the exact same type of algae.

Credit to garypeppergirl.com

So, about the colour of the water

I hope you found this post as interesting as I do, if you like it, pin it for later or share it. We live in an amazing world filled with colours and weird things to discover!