
The Etosha Pan is a large
endorheic
An endorheic basin ( ; also endoreic basin and endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water (e.g. rivers and oceans); instead, the water drainage flows into permanent ...
salt pan, forming part of the
Cuvelai-Etosha Basin in the north of
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
. It is a vast hollow in the ground in which water may collect or in which a deposit of salt remains after water has evaporated. The 120-kilometre-long (75-mile-long) dry lakebed and its surroundings are protected as
Etosha National Park
Etosha National Park is a national park in northwestern Namibia and one of the largest national parks in Africa. It was proclaimed a game reserve in March 1907 in Ordinance 88 by the Governor of German South West Africa, Friedrich von Lindequist. ...
, Namibia's second-largest wildlife park, covering . The pan is mostly dry, but after heavy rains, it is flooded with a thin layer of water, which is heavily salted by the mineral deposits on the surface.
Location and description
Etosha, meaning 'Great White Place' in
Oshindonga, is made of a large mineral pan.
The area exhibits a characteristic white and greenish surface, which spreads over .
''Encyclopædia Britannica – Etosha Pan.''
/ref> The pan is believed to have developed through tectonic
Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons.
These processes ...
activity over about ten million years. Around 16,000 years ago, when ice sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice s ...
s were melting across the land masses of the Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...
, a wet-climate phase in Southern Africa caused the Etosha Lake to be filled up. Today, however, the Etosha Pan is mostly made up of dry clay split into hexagonal shapes as it dries and cracks, and is seldom seen with even a thin sheet of water covering it.
It is assumed that the Kunene River
The Cunene (Portuguese spelling) or Kunene (common Namibian spelling) is a river in Southern Africa. It flows from the Angola highlands southwards to the border with Namibia. It then flows in a westerly direction along the border until it reaches ...
fed the lake in the distant past, but tectonic plate movements over time caused a change in river direction, resulting in the lake running dry and leaving a salt pan. Nowadays the Ekuma River, the Nipelo River, the Cuvelai River, and the Omurambo Ovambo River are the sole seasonal sources of water for the lake. Typically, not much river water or sediment reaches the dry lake, because water seeps away into the riverbed along its course, reducing discharge along the way.
History
In the colonial era, the first non-Africans to explore this area were the Europeans Charles John Andersson and Francis Galton
Sir Francis Galton (; 16 February 1822 – 17 January 1911) was an English polymath and the originator of eugenics during the Victorian era; his ideas later became the basis of behavioural genetics.
Galton produced over 340 papers and b ...
in 1851.
Plants and animals
The surrounding area is dense mopane
''Colophospermum mopane'', commonly called mopane, mopani, butterfly tree, turpentine tree, or balsam tree, is a tree in the legume family (Fabaceae), that grows in hot, dry, low-lying areas, in elevation, in parts of Southern Africa. The tree ...
woodland, which is occupied by herds of elephant
Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...
s on the south side of the lake. Mopane trees are common throughout south-central Africa, and host the mopane worm, which is the larval form of the moth '' Gonimbrasia belina'', and an important source of protein for rural communities.
The salt desert supports very little plant life except for the blue-green algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
that gives the Etosha Pan its characteristic colouring, and grasses like '' Sporobolus spicatus'' which quickly grow in the wet mud following good rains. Surrounding the pan, grasslands provide food for grazing animals.
This harsh, dry land with its sparse vegetation and insufficient amount of salty water, supports little wildlife all year round, but is sometimes inhabited by a large number of migratory birds. The hypersaline pan supports brine shrimp and a number of extremophile
An extremophile () is an organism that is able to live (or in some cases thrive) in extreme environments, i.e., environments with conditions approaching or stretching the limits of what known life can adapt to, such as extreme temperature, press ...
micro-organisms tolerant of the highly saline conditions.(C.Michael Hogan. 2010.) In particularly good rainy seasons, the Etosha pan is turned into a shallow lake approximately 10 cm in depth and becomes the breeding ground for flamingo
Flamingos or flamingoes () are a type of wading bird in the family Phoenicopteridae, which is the only extant family in the order Phoenicopteriformes. There are four flamingo species distributed throughout the Americas (including the Caribbe ...
s, which arrive in their thousands, and great white pelicans (''Pelecanus onocrotalus'').
The surrounding savanna is home to thousands of mammals that will visit the pan and surrounding waterholes when there is water. These include quite large numbers of zebra
Zebras (, ) (subgenus ''Hippotigris'') are African equines with distinctive black-and-white striped coats. There are three living species: Grévy's zebra (''Equus grevyi''), the plains zebra (''E. quagga''), and the mountain zebra (''E. ...
, wildebeest
Wildebeest ( , ,), also called gnu ( or ), are antelopes of the genus ''Connochaetes'' and native to Eastern and Southern Africa. They belong to the family Bovidae, which includes true antelopes, cattle, goats, sheep, and other even-toed ...
, gemsbok
The gemsbok (''Oryx gazella''), or South African oryx, is a large antelope in the genus '' Oryx''. It is endemic to the dry and barren regions of Botswana, Namibia, South Africa and (parts of) Zimbabwe, mainly inhabiting the Kalahari and Nami ...
, springbok
The springbok or springbuck (''Antidorcas marsupialis'') is an antelope found mainly in south and southwest Africa. The sole member of the genus (biology), genus ''Antidorcas'', this bovid was first Species description, described by the Germa ...
, and eland, as well as black rhinoceros
The black rhinoceros (''Diceros bicornis''), also called the black rhino or the hooked-lip rhinoceros, is a species of rhinoceros native to East Africa, East and Southern Africa, including Angola, Botswana, Eswatini, Kenya, Lesotho, Malawi, Moza ...
, bush elephants, lions
The lion (''Panthera leo'') is a large cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body; a short, rounded head; round ears; and a dark, hairy tuft at the tip of its tail. It is se ...
, leopards
The leopard (''Panthera pardus'') is one of the five extant cat species in the genus ''Panthera''. It has a pale yellowish to dark golden fur with dark spots grouped in rosettes. Its body is slender and muscular reaching a length of with a ...
, and giraffes
The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa.'' It is the tallest living terrestrial animal and the largest ruminant on Earth. It is classified under the family Giraffidae, along with its closest extant re ...
.
Threats and protection
The Etosha Pan is situated completely within the boundaries of the Etosha National Park
Etosha National Park is a national park in northwestern Namibia and one of the largest national parks in Africa. It was proclaimed a game reserve in March 1907 in Ordinance 88 by the Governor of German South West Africa, Friedrich von Lindequist. ...
and is designated as a Ramsar wetland of international importance and a World Wildlife Fund
The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the ...
ecoregion
An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...
(Etosha Pan halophytic
A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. ...
s).
References
*
*C.Michael Hogan. 2010
''Extremophile''
eds. E.Monosson and C.Cleveland. Encyclopedia of Earth. National Council for Science and the Environment, Washington DC
*
Etosha National Park
{{Authority control
Salt pans of Namibia
Etosha National Park
Ecoregions of Namibia
Zambezian region