Dome dunes: Distribution and morphology

Abstract

Dome dunes are mounds of sand that generally lack external slipfaces. There are two main types. Mini-domes are typically just a few metres in height and some tens of metres across. Some of these may either be proto- or degraded barchans and the two forms occur in close proximity. Large areas of mini-domes occur in Mauritania, the Libyan Desert of southern Egypt, the Danakil Depression of east Africa, and the Qaidam Basin of China. Mega-domes are tens of metres high and hundreds of metres in width. In Africa, they are found in the Grand Erg Occidental, the Grand Erg Oriental, the Murzuk and Ubari sandseas of Libya, the Qattara Depression of Egypt, and the Red Sea Province of Sudan. In Asia they occur in the Nefud of Saudi Arabia, the Rub’ al Khali, and the Taklimakan and Wulanbuhe Deserts of China. They have a range of morphologies, from almost perfectly circular through to elongated, triangular and barchanoid types. Morphometric analysis using Google Earth Pro demonstrates that the mean densities of mega-domes (per 100 km2) are 32.8, their heights average 66.1 m, and their widths average 1459 m.