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52-728: The desert geology consists of sand seas near the coast, while gravel plains and scattered mountain outcrops occur further inland. The sand dunes, some of which are 300 metres (980 ft) high and span 32 kilometres (20 mi) long, are the second-largest in the world after the Badain Jaran Desert dunes in China. Temperatures along the coast are stable and generally range between 9–20 °C (48–68 °F) annually, while temperatures further inland are variable—summer daytime temperatures can exceed 45 °C (113 °F) while nights can be freezing. Fogs that originate offshore from

104-685: A common sight include the eponymous Welwitschia Plains, which are adjacent to the Husab uranium mine , one of the largest of its kind in the world. " Fairy circles ", which are circular patches of land barren of plants, varying between 22 and 12 metres (7 and 39 ft) in diameter and often encircled by a ring of stimulated growth of grass, are found in the Namib, such as those near the Wolwedans desert camp. The Namib fauna mostly comprises arthropods and other small animals that can live on little water, but

156-524: A few species of bigger animals are also found, including antelopes (such as gemsboks and springboks ), common ostriches , and in some areas even desert elephants or lions . All these species have developed techniques to survive in the Namib environment. Several endemic darkling beetles species have different methods of collecting water droplets from morning fog; they are collectively known as "fog beetles". For example, one beetle, Onymacris unguicularis , has smooth elytrons that cause humidity from

208-540: A geological feature that can be found on planets where an atmosphere capable of significant wind erosion acts on the surface for a significant period of time, creating sand and allowing it to accumulate. Today at least three bodies in the Solar System , apart from Earth, are known to feature ergs on their surface: Venus, Mars and Titan. At least two ergs have been recognized by the Magellan probe on Venus :

260-648: A large part of the Namib Desert, is the largest game reserve in Africa and one of the largest in the world. While most of the park is hardly accessible, several well-known visitor attractions are found in the desert. The prominent attraction is the Sossusvlei area, where high orange sand dunes surround vivid white salt pans, creating a fascinating landscape. Access to the park is either by gravel roads or dust roads (except for 60 km of concrete road from

312-436: A shrub-like plant, it grows two long strap-shaped leaves continuously throughout its lifetime. These leaves may be several meters long, gnarled, and twisted from the desert winds. The taproot of the plant develops into a flat, concave disc in age. Welwitschia is notable for its survival in the extremely arid Namib conditions, made possible by its ability to capture moisture from coastal sea fogs. Areas where Welwitschias are

364-597: A stronger and more rapid runoff and increased erosion of the Swakop Marshlands . Because of its size and scope, the Swakop has a very diverse catchment area. 29% of the area is in highveld savanna , 28% in thornveld savanna, 34% in semidesert and savanna transition zone, and 9% in the central Namib Desert . In the Highlands a more or less dense bush vegetation prevails. In the arid lower reaches there

416-524: Is 460 km (290 mi) long and has a 30,100 km (11,600 sq mi) large catchment area (including its tributaries). The name comes from the Khoekhoe phrase Tsoa-xaub , from tsoa 'anus‘ and xaub 'excrement'. The name derives from the observation of the flow of large amounts of brownish sludge that discharge into the Atlantic Ocean with the rains. The area around

468-486: Is a more limited flora in the Swakop River valley itself, with the typical gallery vegetation from ana trees ( Faidherbia albida ), tamarisk ( Tamarix ), camel thorn ( Acacia erioloba ), Salvadora , various fig species, Euclea and also tobacco ( Nicotiana spp.), Jimsonweed ( Datura ) and mesquite ( Prosopis spp.) as invasive species . Wildlife in the Swakop River valley is found practically only in

520-604: Is also unpredictable. Western Namib gets less rain (5 mm) than eastern Namib (85 mm). This is due to several factors. Winds coming from the Indian Ocean lose part of their humidity when passing the Drakensberg mountains, and are essentially dry when they reach the Namib Escarpment at the eastern end of the desert. On the other hand, winds coming from the Atlantic Ocean are pressed down by hot air from

572-579: Is derived from the Arabic word ʿirq ( عرق ), meaning "dune field". Strictly speaking, an erg is defined as a desert area that contains more than 125 km (48 sq mi) of aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara , covers 9 million square kilometres (3.5 × 10 ^  sq mi) and contains several ergs, such as

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624-627: Is halted or slowed by topographic barriers to windflow or by convergence of windflow. Entire ergs and dune fields tend to migrate downwind as far as hundreds of kilometers from their sources of sand. Such accumulation requires long periods of time. At least one million years is required to build ergs with very large dunes, such as those on the Arabian Peninsula , in North Africa, and in central Asia. Sand seas that have accumulated in subsiding structural and topographic basins, such as

676-482: Is undertaken in the Swakop River valley. Thus, the region is well known for its fresh produce, especially tomatoes , asparagus and olives . There are some fears of salt and uranium (possibly natural, possibly from the Rössing uranium mine ) endangering this farming industry. The Swakop drains a catchment area of 30,100 km extending from the mouth into the Atlantic Ocean at Swakopmund over Otjimbingwe and in

728-1050: The Chech Erg and the Issaouane Erg in Algeria . Approximately 85% of all the Earth's mobile sand is found in ergs that are greater than 32,000 km (12,355 sq mi), the largest being the Rub' al Khali , the Empty Quarter of the Arabian Peninsula . Ergs are also found on other celestial bodies , such as Venus , Mars , and Saturn 's moon Titan . Sand seas and dune fields generally occur in regions downwind of copious sources of dry, loose sand, such as dry riverbeds and deltas , floodplains , glacial outwash plains , dry lakes , and beaches . Ergs are concentrated in two broad belts between 20° to 40°N and 20° to 40°S latitudes, which include regions crossed by

780-654: The Langer Heinrich mine , in the lower reaches of the Swakop, and the Rössing Mine at Khan use enormous quantities of water that further lower the water table. In addition, it is also often claimed that radioactive dust across the Khan gets into the Swakop, and therefore the vegetables cultivated there are contaminated by radioactive materials. The Swakop Bridge in Swakopmund is a notable man-made sight near

832-734: The Murzuk Sand Sea of Libya , may attain great thicknesses (more than 1000 m ) but others, such as the ergs of linear dunes in the Simpson Desert and Great Sandy Desert of Australia, may be no thicker than the individual dunes superposed on the alluvial plain . Within sand seas in a given area, the dunes tend to be of a single type. For example, there are ergs or fields of linear dunes, of crescentic dunes, of star dunes, and of parabolic dunes, and these dune arrays tend to have consistent orientations and sizes. By nature, ergs are very active. Smaller dunes form and migrate along

884-532: 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. The Namib's aridity is caused by the descent of dry air of the Hadley cell , cooled by the cold Benguela Current along the coast. It has less than 10 mm (0.39 in) of rain annually and is almost completely barren. Besides rain being scarce, it

936-621: The Ovahimba and Obatjimba Herero in the north, and the Topnaar Nama in the central region. Owing to its antiquity, the Namib may be home to more endemic species than any other desert in the world. Most of the desert wildlife is arthropods and other small animals that live on little water, although larger animals inhabit the northern regions. Near the coast, the cold ocean water is rich in fishery resources and supports populations of brown fur seals and shorebirds, which serve as prey for

988-499: The Sesriem gate to Sossusvlei) or by light aircraft from Windhoek (the capital of Namibia, about 480 km or 300 mi northeast of the centre of the desert), or Swakopmund and Walvis Bay at the north end of the desert. Sand sea An erg (also sand sea or dune sea , or sand sheet if it lacks dunes ) is a broad, flat area of desert covered with wind -swept sand with little or no vegetative cover. The word

1040-578: The Uniab River (north) to the town of Lüderitz (south) and from the Atlantic Ocean (west) to the Namib Escarpment (east). It is about 1,600 km (1,000 mi) long from north to south and its east–west width varies from 50 to 160 kilometres (30 to 100 miles). To the north, the desert leads into the Kaokoveld ; the dividing line between these two regions is roughly at the latitude of

1092-555: The escarpment . Several types of trees are also able to survive the extremely arid climate. The name Namib is of Khoekhoegowab (or Nama language) origin, and has been variously reported to mean "vast place" and "an area where there is nothing". 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 square kilometres (31,250 sq mi), stretching from

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1144-493: The river mouth and the surrounding dunes are also known for rich bird life and some unusual plant species (like the Welwitschia ) that use the regular fog drifting in from the sea to sustain themselves in the absence of other moisture. Groundwater levels in the area have dropped about 0.3 m further due to the presence of two big dams built on the Swakop River. Notwithstanding the river’s irregular flow, some agriculture

1196-495: The 20th century, some San roamed the Namib, gathering edible plants on the shore, hunting in the interior, and drinking the juice of the tsamma melon for water. Today, some Herero still herd their livestock in the Kaokoveld in the Namib and take them from waterhole to waterhole. A few Nama Khoikhoi still graze their livestock on the banks of the Kuiseb River in the desert. Most of the native people have left, leaving

1248-577: The Aglaonice dune field, which covers approximately 1,290 km (500 sq mi), and the Meshkenet dune field (~17,120 km or 6,600 sq mi). These seem to be mostly transverse dune fields (with dune crests perpendicular to prevailing winds). Mars shows very large ergs, especially next to the polar caps, where dunes can reach a considerable size. Ergs on Mars can exhibit strange shapes and patterns, due to complex interaction with

1300-538: 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

1352-419: The Namib, Desert Research Station, and Gobabeb for instance. This event recurs approximately mid-decade (recent examples are 1974, 1986, 1994, 1995, and 2006). Several unusual species of plants and animals are found in this desert, many of which are endemic and highly adapted to the specific climate of the area. One of the most well-known endemic plants of the Namib is the bizarre Welwitschia mirabilis ;

1404-618: The Pacific event in its environmental change in the seas) spreads from the Kunene estuary southward to, on occasion, south of Luderitz. Warm waters with depth and associated water flow from the northwest were first fully catalogued by Sea Fisheries researchers, in Cape Town (L V Shannon et al. ). The research noted the positive effect of Benguela's El Niño on the rainfall of the interior. Rainfall records also show positive values variously across

1456-551: The Skeleton Coast's lions . Further inland, the Namib-Naukluft National Park supports population of mountain zebras , and other large mammals. Further north near the Skeleton Coast, lions , elephants and rhinos can be found. Although the outer Namib is largely barren of vegetation, lichens and succulents are found in coastal areas, while grasses, shrubs, and ephemeral plants thrive near

1508-665: The Sossusvlei area, several dunes exceed 300 meters (1,000 feet) 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. The source of the unconsolidated sand (the most recent sand sea) is dominantly from the Orange River, which drains into the Atlantic south of the Namib Sand Sea, with minor contributions in

1560-519: The area at the mouth of the Orange River . Although the desert is largely unpopulated and inaccessible, there are year-round settlements at Sesriem , close to the Sossusvlei area, and other small outposts in other locations. Moçâmedes in Angola, and Lüderitz , Walvis Bay , and Swakopmund in Namibia, bordering on the desert, are the main settlements in the area. The 2015 film Mad Max: Fury Road

1612-602: 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 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 in the world, ranging in color from pink to vivid orange. In

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1664-564: The collision of the cold Benguela Current and warm air from the Hadley cell create a fog belt that frequently envelops parts of the desert. Coastal regions can experience more than 180 days of thick fog a year. While this has proved a major hazard to ships—more than a thousand wrecks litter the Skeleton Coast —it is a vital source of moisture for desert life. The Namib is almost completely uninhabited by humans except for several small settlements and indigenous pastoral groups, including

1716-409: The desert causes immense fogs and strong currents. It causes sailors to lose their way; this is testified by the remnants of several shipwrecks that can be found along the Skeleton Coast , in northern Namib. Some of these wrecked ships can be found as much as 50 metres (55 yards) inland, as the desert slowly moves westwards into the sea, reclaiming land over many years. Benguela's El Niño (similar to

1768-528: The dry, subsiding air of the trade winds . Active ergs are limited to regions that receive, on average, no more than 150 mm of annual precipitation. The largest are in northern and southern Africa , central and western Asia , and Central Australia . In South America , ergs are limited by the Andes Mountains , but they do contain extremely large dunes in coastal Peru and northwestern Argentina . They are also found in several parts of

1820-569: The east from the (now ephemeral) rivers that drain into the sand sea. For this reason, the Namib Sand Sea has been referred to as the "wind displaced delta of the Orange River." Moving north from Sossusvlei, the sand gradually gives way to a rocky desert that extends from Sossusvlei to the Swakop river. This area is traversed by the Tropic of Capricorn and is mostly flat, although some scenic canyons and elevations are found in some areas, for example in

1872-505: The east to about 50 km from Okahandja , and in the south to Khomas Highlands outside Windhoek . The highest point of the watershed is located at 2,480 m. Annual rainfall varies from 0 mm in the lower reaches up to 475 mm in the eastern Khomas Highlands. Rainfall exceeds 300 mm per year in 39% of the catchment area, and up to 80% of the catchment experiences annual rainfall above 100 mm. The Von Bach Dam near Okahandja and Swakoppoort Dam west of Gross Barmen in

1924-428: The east; their humidity thus forms clouds and fog. Morning fogs coming from the ocean and pushing inwards into the desert are a regular phenomenon along the coast, and much of the life cycle of animals and plants in the Namib relies on these fogs as the main source of water. The dry climate of Namib reflects the almost complete lack of bodies of water on the surface. Most rivers flow underground and/or are dry for most of

1976-462: The flanks of the larger dunes and sand ridges. Occasional precipitation fills basins formed by the dunes; as the water evaporates, salt deposits are left behind. Individual dunes in ergs typically have widths, lengths, or both dimensions greater than 500 m (1,600 ft). Both the regional extent of their sand cover and the complexity and great size of their dunes distinguish ergs from dune fields. The depth of sand in ergs varies widely around

2028-430: The groundwater in agriculture and the high water consumption in cities result in the lowering of the water table . This leads, particularly in the lower reaches, to the drying up of many springs as well as to the death of the gallery vegetation. Due to agricultural practices, erosion has greatly increased, so that more and more valuable soil is lost and the intensity of the Swakop floods increases. Uranium mines such as

2080-562: The ice bedrock, possibly in the form of flash floods. Alternatively, the sand could also have come from organic solids produced by photochemical reactions in Titan's atmosphere. Swakop The Swakop River ( Khoekhoe : Tsoaxaub ) is a major river in western central Namibia . Its source is in the Khomas Highland . From there it flows westwards through the town of Okahandja , the historic mission station at Gross Barmen , and

2132-730: The largest dune field coverage in the Solar System identified to date. The sand dunes are believed to be formed by wind generated as a result of tidal forces from Saturn on Titan's atmosphere. The images are evidence that these dunes were built from winds that blow in one direction before switching to another and then back to the first direction and so on, causing the sand dunes to build up in long parallel lines. These tidal winds combined with Titan's west-to-east zonal winds create dunes aligned west-to-east nearly everywhere except close to mountains, which alter wind direction. The sand on Titan might have formed when liquid methane rained and eroded

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2184-557: The morning fogs to condense into droplets, which roll down the beetle's back to its mouth. Another beetle, the Lepidochora discoidalis , builds "water-capturing" webs. Black-backed jackals lick humidity from stones. Gemsboks (also known as the South African oryx) can raise the temperature of their bodies to 40 °C in the hottest hours of the day. The desert is also home to meerkats and several species of lizards. Before

2236-1017: The northeast coast of Brazil . The only active erg in North America is in the Gran Desierto de Altar that extends from the Sonoran Desert in the northwestern Mexican state of Sonora to the Yuma Desert of Arizona and the Algodones Dunes of southeastern California . An erg that has been fixed by vegetation forms the Nebraska Sandhills . Almost all major ergs are located downwind from river beds in areas that are too dry to support extensive vegetative cover and are thus subject to long-continued wind erosion. Sand from these abundant sources migrates downwind and builds up into very large dunes where its movement

2288-477: The population in the catchment area is more than 200,000 persons. While in the upper reaches of the river the farms are often far from the river and extensive grazing is operated, the dams and the high groundwater level along the entire Swakop River valley make intensive farming and even gardening, such as the cultivation of asparagus in Swakopmund Goanikontes, possible. The extensive use of

2340-451: The settlement of Otjimbingwe . It then crosses the Namib desert and reaches the Atlantic Ocean at Swakopmund ( German : Mouth of the Swakop ). The Swakop is an ephemeral river; its run-off is roughly 40 million cubic metres per annum. The Swakop River, along with its main tributary Khan , is one of the largest temporary water-bearing rivers in the dry western part of Namibia. It

2392-428: The sparsely populated lower reaches and is limited to antelope , smaller predators and birds. Animals such as elephants , rhinos , lions and other big cats are no longer to be found. Unlike the rest of the dry rivers in western Namibia, there are large human settlements in the basin of the Swakop River, such as the towns of Usakos , Karibib , Otjimbingwe , Okahandja and Namibia's capital, Windhoek , so that

2444-539: The underlying surface and wind direction. Radar images captured by the Cassini spacecraft as it flew by Titan in October 2005 show sand dunes at Titan's equator much like those in deserts of Earth. One erg was observed to be more than 930 miles (1,500 km) long. Dunes are a dominant landform on Titan. Approximately 15-20% of the surface is covered by ergs with an estimated total area of 12–18 million km making it

2496-428: The upper reaches of the Swakop are of great importance for the water supply of Central Namibia. Like all rivers, the Swakop also has a number of major sources and major wetlands in the lower reaches. Existing groundwater, however, is often salty due to soil salinity . On the lower reaches of the river, flooding has become ever more increasing, due to increased land use of the Swakop gallery forests . This contributes to

2548-498: The vast majority of the desert uninhabited. The steppes in the southern half of the desert are mostly made up of ranches run by Europeans, who raise Karakul sheep with local help and send the pelts of the lambs to Europe for use in fur coats. Most of the rest of the desert is set aside for conservation. A vast portion of the desert, called the Sperrgebiet , was access-restricted due to the presence of diamonds, which are mined in

2600-597: The world, ranging from only a few centimeters deep in the Selima Sand Sheet of Southern Egypt, to approximately 1 m (3.3 ft) in the Simpson Desert, and 21–43 m (69–141 ft) in the Sahara. This is far shallower than ergs in prehistoric times were. Evidence in the geological record indicates that some Mesozoic and Paleozoic ergs reached a mean depth of several hundred meters. Ergs are

2652-463: The year. Even when they are not, they usually drain into endorheic basins, without reaching the sea. The Swakop and the Omaruru are the only rivers that occasionally drain into the ocean. All along the coast, but mostly in the northernmost part of it, the interaction between the water-laden air coming from the sea via southerly winds , some of the strongest of any coastal desert, and the dry air of

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2704-547: Was filmed here. In 2019 the Namibian-German artist Max Siedentopf created an installation in the Namib consisting of a ring of large white blocks atop of which sit six speakers attached to a solar-powered MP3 player configured to continuously play the 1982 song " Africa " by the American band Toto . The exact location of the installation has not been disclosed. The Namib-Naukluft National Park, which extends over

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