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Dunes in the Tenere Desert
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| [Note Guidelines] Photographer's Note [French] |
The topic
Here is a photograph of the dunes of the Tenere desert. Among all classes of dunes, they are part of the class of linear dunes. These dunes are more elongated than wide and more or less parallel to each other. These dunes can reach gigantic proportions: several hundreds of kilometers long and several hundred meters in width, the height is limited to a few tens of meters.
These dunes often come from the accumulation of debris brought by the wadis and supplemented by aeolian sand. They are relatively stable and in general, the peaks are mobile, while the bodies of the dunes are stable. In the Sahara, the dunes are often of ancient origin (it can be traced back to the Pleistocene).
This type of dune is always grouped into sets of massive parallel, the ergs. Although these are drylands with high amplitudes of temperature (-5 degrees at night to +55 ° C during the day), the dunes can accumulate in their bodies to scarce rainfall and allow the creation of zones pastures.
Photography
The photograph was taken from an airliner flying at 10,000 feet. The atmosphere was clear despite a haze due to wind-driven sand (which gives the harmattan blowing from north to south, not to be confused with the sirocco blowing from south to north).
With a sensitivity of iso-200 and a focal length of 18 mm, the speed was calculated at 1 / 480 th of a second for an aperture of f / 7 (to achieve a compromise sharpness / diffraction / depth of field).
Photography high resolution
You can see a high definition picture here and hear the song of the dunes here. The song of the dunes is an amazing physical phenomenon. It can be scary and soothing depending on the complexion of each. It has already been mentioned by Maupassant in his tale "La peur"and recognized by the Bedouins as a proof of the existence of spirits, the "jinn".
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- anel
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(40574) - [2011-06-11 10:43]
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Bonjour Philippe,
Une image au coloris de grande finesse et aux formes artistiques crées par la nature. J'ai eu beaucoup de plaisir à écouter le chant des dunes! Excellente idée de nous avoir mis le lien.
Bon weekend de Pentecôte
Amitiés
Anne
Excellent photo, sharp, colourful and nice composition!
Fabrizio
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