A Bit of Switzerland between Nan and Lis

[Puff Addy]

Thank you, Flutterby.

Most of the Bearded Vulture sightings in Switzerland are in the neighbouring canton of Valais, but they are being seen with more frequency in the Bern Alps (still under 10% of all sightings, though). We were very lucky.

[Richprins]

Well done, Puffie! At last a bird pic!

Is that the same vulture species you find here in SA?

Why is the water so blue?

[Lisbeth]

In the case of our mountain lakes, every day during the summer melt, they receive hundreds of tonnes of fine glacial material known as rock flour. It is very light, and stays suspended for quite some time. When the light hits the surface of these mountain lakes, the suspended material distorts the wavelengths of light, reflecting back more of the green and blue end of the spectrum – hence we see emeralds and blues. Also, since each lake gets a varying amount of this material, each lake will have its own shade of blue. This shade will also vary over the course of the year. In the spring, there is little suspended rock flour, so the lakes are the same colour as lakes elsewhere – deep blue. As more material flows into the lake with the spring runoff, the lakes progressively change to their famous colours.

[Puff Addy]

Is that the same vulture species you find here in SA?

Yes.

Why is the water so blue?

It is a glacial lake and as such contains so-called "rock flour", material that has been deposited from the action of the glaciers. This plus the absorption (or lack thereof) of certain light spectra, results in the colour. That's what I've read, anyway.

Edit: Great minds, Lisbeth!

[Richprins]

Ooh!

[Lisbeth]

It is a glacial lake and as such contains so-called "rock flour", material that has been deposited from the action of the glaciers. This plus the absorption (or lack thereof) of certain light spectra, results in the colour. That's what I've read, anyway.

Edit: Great minds, Lisbeth!

Sorry to have taken the words out of your mouth, Puffie, but I was not sure if you knew

[Puff Addy]

I only knew after having read about it!

[Flutterby]

Very interesting!

[Puff Addy]

After another rainy day, we went to the valley called Gasteretal in the bright sunshine.

In fact, it was too bright, and too warm! After two hours we went back to our lodgings.

Not many photos were made on the day, but here are a few:

The Balmhorn rises over 2000 metres above the Gasteretal



A Swallowtail



Geranium pyrenaicum

[Flutterby]

Lovely purple flower!