Namib Desert - Geography and Geology

Geography and Geology

The Namib Desert is one of the 500 distinct physiographic provinces of the South African Platform physiographic division. It occupies an area of around 80,950 km² (31,200 square miles), stretching from the Usiab River (north) to the town of Lüderitz (south) and from the Atlantic Ocean (west) to the Namib Escarpment (east). It is about 1,000 miles (1,600 km) long from north to south and its east-west width varies from 30 to 100 miles (50–160 km). To the north, the desert leads into the Kaokoveld; the dividing line between these two regions is roughly at the latitude of the city of Walvis Bay, and it consists in a narrow strip of land (about 50 km wide) that is the driest place in Southern Africa. To the south, the Namib borders on the South African Karoo semi-desert.

Southern Namib (between Lüderitz and the Kuiseb River) comprises a vast dune sea with some of the tallest and most spectacular dunes of the world, ranging in color from pink to vivid orange. In the Sossusvlei area, several dunes exceed 300 meters (984 ft) in height. The complexity and regularity of dune patterns in its dune sea have attracted the attention of geologists for decades, but it remains poorly understood.

Moving north from Sossusvlei, the sand gradually gives way to a rocky desert that extends all the way from Sossusvlei to the Swakop river. This area is traversed by the Tropic of Capricorn and it's mostly flat, although some scenic canyons and elevations are found in some areas, for example in the Moon Valley system. While most of the soil is rocky, sand dunes are still occasionally found in this region; for example, sand dunes occupy much of the coastline between Walvis Bay and Swakopmund.

The Namib desert is an important location for the mining of tungsten, salt and diamonds.

Several rivers and streams run through the Namib, although all of the rivers south of the Cunene River and north of the Orange River are ephemeral and rarely or never reach the ocean. These rivers arise in the interior mountains of Namibia and flow after summer rain storms.