Namib

Satellite image of the Namib between Walvis Bay and Lüderitz

Dune near the Sossusvlei

The Namib ( Khoekhoegowab for more space ) is a desert on the southwest coast of Africa . It lies for the most part in the territory of Namibia and Angola and is home to the national parks Namib-Skeleton Coast , Tsau--Khaeb- (restricted area) and Dorob in Namibia and Iona in Angola. Since the Namib begins directly on the coast of the Atlantic , it is one of the few coastal and foggy deserts on earth.

Since June 20, 2013, large parts of the Namib are UNESCO World Heritage as the Namib Sand Sea (" Namib Sand Sea ") .

The name of the state of Namibia is derived from the Namib . It was chosen as a neutral designation during independence so as not to disadvantage any of the many Namibian peoples. Namibia's namesake is Mburumba Kerina .

geography

Big Daddy Düne (left) and Dead Vlei (light area)

The extension of the Namib from the north ( Benguela , Angola ) to the south (to the Orange ; according to some sources, even beyond South Africa) is around 2000 kilometers, it extends up to 160 kilometers into the country. The Namib is about 95,000 km² and is on average just under 500 meters above sea level. The “Namib Sand Sea”, classified as a UNESCO World Heritage Site, has an area of around 31,000 km², and a further 9,000 km² are defined as a buffer zone .

In its northern part towards the border river Kunene it forms the skeleton coast known as the ship cemetery , where numerous ship skeletons protrude from the sand. Its middle section is home to Swakopmund and Walvis Bay, two of the country's most important cities and the only deep-sea port in Namibia. In the south, on the other hand, the restricted diamond area around Lüderitz extends over a length of about 500 kilometers , where gemstones are still extracted today. However, the focus of diamond mining has shifted to the Orange River and its mouth in the Atlantic ( offshore mining ). Diamond mining accounts for a third of Namibian export earnings.

The Namib is known for its sand dunes , which change their colors intensely depending on the position of the sun and moisture content. The dunes between Swakopmund and Walvis Bay, the dune 45 ( 24 ° 43 ′ 53.8 ″ S , 15 ° 28 ′ 19.5 ″ E )-24.731610781111 15.472090664167 650 and the dunes at the - often referred to as the highest dunes on earth - should be mentioned here Sossusvlei , about the Big Daddy dune ( 24 ° 45 ′ 47.5 ″ S , 15 ° 18 ′ 11.7 ″ E )-24.763183785556 15.303246921667 690 , which is around 380 meters high. The red dunes of the southern Namib are only accessible in the Tiras Mountains , on the Gunsbewys farm , except in Sossusvlei .

climate

Water in a vlei in the southern Namib near the Tsausberge after rare rain in October 2018

With an age of around 80 million years, the Namib is the oldest desert in the world and at the same time one of the most inhospitable places on the planet. With daytime temperatures well above 50 ° C, night temperatures below 0 ° C, dry periods lasting for decades and frequent sandstorms , plants and animals are exposed to extreme living conditions. However, since these have remained stable over very long periods of time, a number of living beings have managed to adapt and (only) to become at home here, such as the Welwitschia ( Welwitschia mirabilis ).

The drought of the Namib is due to the coastal, cold ocean currents, similar to the Atacama Desert in Chile : the Benguela Current from the Antarctic flows on the coast of the Atlantic and supplies the region with comparatively cold Antarctic water (see also coastal desert ). This leads to condensation of the moisture contained in the air . Due to the cold water, the air stratification is always very stable, so there is almost no high convection and therefore no rain. Instead, there is fog in the coastal region on around 200 days a year . This fog precipitates in the cold early morning hours and is the only source of moisture for many of the animals and plants living there (see fog condensation and fog desert).

Paleoclimate

The age of the Namib is still (as of 2010) discussed controversially. The problem here is a distinction between a Mesozoic Gondwana inland desert and today's pronounced coastal desert. The beginning of the coastal desert seems to go hand in hand with the glaciation of the Antarctic and the start of the thermohaline circulation as well as the Benguela Current and falls into the Neogene , more precise details here refer to the Middle and Upper Miocene . Much older formations could, however, also prove the existence of the desert after the Gondwana inland desert and would thus fall into the Mesozoic.

During the maximum of the last ice age around 20,000 years ago, highly arid conditions prevailed in all of South West Africa right up to the Kalahari Basin. About 8000–4000 years ago the Namib reached a very small extent; since then it has grown again.

Flora and fauna

Welwitschie in the Welwitschia Plain, Central Namib

Dried out camel thorns ( Acacia erioloba ) in Dead Vlei

Even in this hostile environment, plants and animals have settled and adapted to the special conditions. One of the most famous plants in the southwest African desert is the Welwitschia , named after its discoverer, the Austrian biologist Friedrich Welwitsch . It can live to be over 2000 years old and only produces two leaves in its long life. The leaves grow continuously, can be up to eight meters long, but break off again and again at the ends, partly due to wild animals , and form real bushes.

In the more humid parts of the Namib, the Naras shrub can be found, whose nutritious fruit, the Naras melons, are used as a food source for a variety of animals including elephants , porcupines and gerbils .

The animals living here have developed special skills that help them survive in the heat and drought. The Namib sand gecko runs on legs spread like a net across the desert floor, which is up to 70 ° C, and constantly changes its legs when it rests for a short time. If it gets too hot for him, he digs himself in - a strategy that also helps the dwarf puff adder (sidewinder snake) through the hot hours, with its tail peeking out of the sand. This attracts reptiles on the hunt for small animals and serves as bait for the snake. Other animals have all moved their habitat under the earth, like the Wüstenmull (see also fukomys ) or soft heat of the day out by being nocturnal.

Larger animals have also adapted to the desert climate: black rhinos by enlarging their territory. They roam areas of up to 2,000 square kilometers, a multiple of what their relatives claim in other parts of Africa. Thanks to their slightly larger feet, the heavy loners do not sink into the sand. The desert elephants living here have acquired special skills in tracing and uncovering underground water veins - so successfully that their population has outgrown the "threat of extinction" over the past ten years. A prime example of adaptability are the Gemsbok (also called Gemsbok or Oryx): they can do without free water at all and cover their fluid needs from food alone; they can also live with a body temperature of well over 40 ° C. Therefore, the billy goat was chosen as the heraldic animal of Namibia. Furthermore, feral horses have managed to adapt.

The beneficiaries of the cold and very fish-rich Benguela Current are also the South African fur seals , which live in the hundreds of thousands on the Namib coast and give birth to their young here. Some of these seal colonies are located in the diamond restricted area or in the specially protected Skeleton Coast Park and are therefore not freely accessible. Such a colony can only be visited at Cape Cross north of Swakopmund . The large seal populations in turn form the food basis for black-backed jackals , black-backed hyenas ( also known as beach wolves because of their habitat ) and the so-called beach lions .

The cold Benguela Current also causes the occurrence of penguins - above all on the coast of the Cape Peninsula and only in smaller numbers on the penguin island off Lüderitz.

The Namib is increasingly being developed for tourism. More and more people are looking for the solitude of the desert. The emergence of private wilderness areas and new lodges has resulted in desert animals returning in greater numbers.

literature

Jürgen Wettke: The Namib Desert. Art. Structures. Colors. de / en. teNeues, Kempen 2016, ISBN 978-3-8327-6914-7 .
Mary Seely, John Pallett: Namib - Secrets of a desert uncovered. Venture Publications, Windhoek 2008, ISBN 978-3-941602-06-9 .
Mary Seely: The Namib: Natural History of an Ancient Desert. Desert Research Foundation of Namibia, Windhoek 2004, ISBN 99916-68-16-0 .
Rüdiger Glaser , Klaus Kremb, Axel Dreschner: Africa . WBG, Darmstadt, 2010, ISBN 978-3-534-19699-9 .