Limit of cultivation of sand dunes

2009/02/26 Kortabitarte Egiguren, Irati - Elhuyar Zientzia

• Geologia

Researchers from the Paris Laboratory of Physics and Mechanics of Heterogeneous Media have analysed to what extent the giant dunes of deserts can grow. It is said that this limit is established by a thin atmospheric layer located several kilometers from the Earth.

The giant sand dunes can be several meters wide and kilometers wide. The smaller dunes are also found in the deserts, and their union gives rise to giant dunes. However, until now they did not know how much they can grow.

Satellite and aerial photographs have been analyzed, especially to measure the average width of the large African, South American and Chinese dunes. In addition, the temperature measurements of each zone have been used to measure the height of this boundary layer. This layer separates the turbulent air from the soil from the atmospheric air, more stable. The researchers have found that the width of the dune depends on the height of the air layer that limits the growth of the giant dunes.

Image: Image: Philippe Claudin (École Supérieure de Physique et de Chimie Industrielles, Paris, France)