Barchans are landforms indicative of neither net erosion nor net deposition, but of transport. Sand is blown onto and over the dunes, being deposited on a slip face in its lee between its curving horns. The dune is streamlined; it “points” upwind and migrates downwind. The barchans shown here are similar in shape and size to those found in many terrestrial deserts and are smaller than the dunes of similar shape shown in the next slide.
Location: Latitude 73.5°, Longitude 57.5°. Viking photograph 525B15, NGF orthographic version, minus-blue filter.