There was a good chance that a landing on Barchan might be final.

In this way the crescentic barchan form is developed.

In mid-2010, several smaller barchan dunes are approaching the Carretera from the south.

The orientation of the barchan dunes suggest that they were generated by northeasterly winds.

So tell us all about Barchan."

Thus, the slip face of the barchan advances by a process of oversteepening and shearing.

Smaller barchan dunes often bump into larger ones from behind because they move faster and are carried by winds blowing in one direction.

Any kind of dune, from very fine ripples underfoot to truly gargantuan barchan dunes.

"Let's take a look at a few pictures of Barchan, close-in to Cassay.

Simple barchan dunes may stretch from meters to a hundred meters or so between the tips of the horns.

Gilby had warned them that Barchan would be a terrible choice for a trial (but he had said that about most places!)

A barchan or barkhan dune is an arc-shaped sand ridge, comprising well-sorted sand.

According to Bagnold, the barchan is formed when the wind is nearly unidirectional: it is orientated with the horns downwind.

Small simple barchan dunes and large mega-barchans are common at the margins of Olympia Undae and in areas where the sand cover is thin.

Simple barchan dunes may appear as larger, compound barchan or megabarchan dunes, which may migrate with the wind.

The Great Sand Dunes National Park in the American state of Colorado has spectacular examples of barchan dunes.

The slightly smaller one, approaching from behind, swallows so much sand as it begins to fuse with the larger, more sluggish barchan that at some point it becomes bigger.

In a second case, Mr. Schwämmle found, one barchan can melt into another and then emerge - this time as two smaller ones - at the horns of the larger dune.

On a seif dune the slip face develops on the side facing away from the strong wind, while the slip face of a barchan faces the direction of movement.

Olympia Undae contains a variety of dune forms and wind-related (aeolian) depositional features, including sand sheets, transverse dunes, simple barchan dunes, mega-barchans, and complex barchanoid ridges.

The founders of AlmostFamous are Tedd Bernard and Jon Barchan, two alumni from the University of Miami School of Business Administration.

He recognized two basic dune types, the crescentic dune, which he called "barchan," and the linear dune, which he called longitudinal or "seif" (Arabic for "sword").

As barchan dunes migrate, smaller dunes outpace larger dunes, bumping into the rear of the larger dune and eventually appear to punch through the large dune to appear on the other side.

The seif dune differs from the barchan, therefore, in that the slip faces are on the side away from the strong wind and not facing the direction of advance as in the barchan.

His students have included Jonathan Lloyd, Daniel Giorgetti, Kenneth Hesketh, Dai Fujikura, Luke Bedford, Stephen Mark Barchan, David Warburton and Helen Grime.