Low-latitude sand seas (also called ergs) are extensive areas of sand dunes located in the tropical and subtropical deserts of the world, where they occupy as much as a third of the area classified as arid. Sand seas contain large volumes of sand and have accumulated episodically during the Quaternary. Their construction has therefore been determined by climatic, tectonic, and sea-level changes that have affected sand supply, availability, and mobility. The understanding of the history of sand seas and dunes has been revolutionized in recent years by the application of luminescence techniques to directly date periods of dune formation and/or reactivation. Compilations of information on directly dated periods of dune construction and/or reactivation indicate widespread dune activity in low-latitude deserts in the period 100-120, 35-10, and since 5 ka.

Keywords: Arabia, Australia, Climate change, Deserts, Eolian processes, Kalahari, Mojave, Namib, Sahara, Sand dunes, Sand seas, Thar Desert.