Sandy deserts of Iceland: an overview

Iceland has over 20,000 km2of sandy deserts with active aeolian processes. The sandy areas have black surfaces due to their basaltic origin, and the sand is often dominated by volcanic glass. The sand originates largely from glacial margins, glacio-fluvial deposits and volcanic eruptions, but also sedimentary rocks. The sand has a wide range of textural properties according to the nature and distance from the sand source. The sandy areas are spreading. Rich and vegetated ecosystems are replaced by sandy deserts with low fertility and water-holding capacity. Threshold values for Icelandic sand were determined with automatic sensors and dust traps. The threshold values are influenced by the surface roughness and the texture of the sand. Wet sand is observed to move during storm events, and coarse, light density tephra >1 mm is easily moved by the wind.