Ethiopian Highlands

Coordinates: 12°32′00″N 41°23′8″E / 12.53333°N 41.38556°E / 12.53333; 41.38556
Source: Wikipedia, the free encyclopedia.
Ethiopian Highlands
Semien Mountains National Park
Highest point
Elevation4,550 m (14,930 ft)
Geography
LocationEthiopia
Geology
Age of rock75 million years
Mountain typeMountain range

The Ethiopian Highlands (also called the Abyssinian Highlands)[1][2] is a rugged mass of mountains in Ethiopia in Northeast Africa. It forms the largest continuous area of its elevation in the continent, with little of its surface falling below 1,500 m (4,900 ft), while the summits reach heights of up to 4,550 m (14,930 ft). It is sometimes called the "Roof of Northeastern Africa" due to its height and large area.[3] It is the only country in the region with such a high elevated surface. This elevated surface is bisected diagonally by the Great East African Rift System which extends from Syria to Mozambique across the East African Lakes. Most of the Ethiopian Highlands are part of central and northern Ethiopia, and its northernmost portion reaches into Eritrea.

History

A coffee cup from the era of the Kaffa Kingdom

In the southern parts of the Ethiopian Highlands once was located the

Arabic: قهوة (qahwah)[4] and is traced to Kaffa.[4][5]

Physical geography

The Highlands are divided into northwestern and southeastern portions by the

Semien Mountains, part of which has been designated the Simien Mountains National Park. Its summit, Ras Dashen (4,550 m), is the highest peak in Ethiopia. Lake Tana, the source of the Blue Nile
, also lies in the northwestern portion of the Ethiopian Highlands.

The southeastern portion is known as the Harar Massif.

Mount Tullu Demtu (4,337 m), which is the second-highest major independent mountain in Ethiopia, and Mount Batu
(4,307 m).

Most of the country's major cities are located at elevations of around 2,000–2,500 m (6,600–8,200 ft) above sea level, including Addis Ababa, Ethiopia's capital and largest city, and historic capitals such as Gondar and Axum.

Geology

Dendi Caldera, a collapsed volcano in the mountain region

The Ethiopian Highlands began to rise 75 million years ago,[7] as magma from the Earth's mantle uplifted a broad dome of the ancient rocks of the Arabian-Nubian Shield. The opening of the Great Rift Valley split the dome of the Ethiopian Highlands into three parts; the mountains of the southern Arabian Peninsula are geologically part of the ancient Ethiopian Highlands, separated by the rifting which created the Red Sea and Gulf of Aden and separated Africa from Arabia.

Around 30 million years ago, a flood basalt plateau began to form, piling layers upon layers of voluminous fissure-fed basaltic lava flows. Most of the flows were tholeiitic, save for a thin layer of alkali basalts and minor amounts of felsic (high-silica) volcanic rocks, such as rhyolite. In the waning stages of the flood basalt episode, large explosive caldera-forming eruptions also occurred.

The Ethiopian Highlands were eventually bisected by the Great Rift Valley as the African continental crust pulled apart. This rifting gave rise to large alkaline basalt shield volcanoes beginning about 30–31 million years ago.[8]

The northern Ethiopian Highlands contain four discernible planation surfaces, the oldest one being formed not later than in the Ordovician Period.[9] The youngest surface formed in the Cenozoic, being partly covered by the Ethiopia-Yemen Continental Flood Basalts.[9] Contrary to what has been suggested for much of Africa, planation surfaces in northern Ethiopia do not appear to be pediplains nor etchplains.[9]

Climate

Main article: Climate of Ethiopia

Spatial distribution of temperature in Ethiopia is determined primarily by altitude and latitude. Altitude is the main factor that determines the spatial distribution of temperature in Ethiopia. Ethiopia lies within the tropics, a zone of maximum insolation, where every place has overhead sun twice a year. However, considerable portions of Ethiopia are highland areas, and their altitudes give them non-tropical temperatures. Ethiopia's tropical climate occur in lowlands at the country's peripheries. The predominant climate of the Ethiopian Highlands is the Alpine climate.

Because the highlands elevate Ethiopia, located close to the equator, this has resulted in giving this country an unexpectedly temperate climate. Further, these mountains catch the precipitation of the monsoon winds of the Indian Ocean, resulting in a rainy season that lasts from June until mid-September.[10] These heavy rains cause the Nile to flood in the summer, a phenomenon that puzzled the ancient Greeks, as the summer is the driest season in the Mediterranean climate that they knew.

Ecology

Ras Dashan
in the background

The Ethiopian Highlands share a similar flora and fauna to other mountainous regions of Africa; this distinctive flora and fauna is known as Afromontane, but from the time of the last ice age the region has been populated with some Eurasian (palearctic) flora. The habitats are somewhat different on either side of the Great Rift Valley which splits the highlands.

At lower elevations, the highlands are surrounded by tropical savannas and grasslands, including the Sahelian Acacia savanna to the northwest and the East Sudanian savanna to the west.

Gestet
forest

The highlands themselves are divided into three distinct

conifers Afrocarpus gracilior and Juniperus procera. The lower portion of the Harenna Forest is a distinct woodland community, with an open canopy of Warburgia ugandensis, Croton macrostachyus, Syzygium guineense, and Afrocarpus gracilior, with wild coffee
(Coffea arabica) as the dominant understory shrub. The southwesterly winds bring rainfall from May to October with moisture from the Red Sea coming in from the east year round. Fauna at these elevations includes the endemic Harwood's spurfowl (Pternistis harwoodi), Prince Ruspoli's turaco (Tauraco ruspolii) and yellow-throated seedeater (Serinus flavigula)[11]

The

Dodola, the lakeside Bishoftu, the largest city in the southwest Jimma, the market town of Nekemte, and the capital of the Tigray Region, Mek'ele. Awash National Park
is a site for birdwatching.

Remaining woodland in the drier areas contains much endemic flora and primarily consists of the conifers

Olea africana
.

As the lower slopes of the mountains are so heavily populated, even the high altitude moorlands are affected by human interference, such as the grazing of livestock and even farming. There are two protected areas of high moorland:

Harar Wildlife Sanctuary, Awash National Park, Omo National Park, and Nechisar National Park
) are even less secure.

Above 3,000 meters elevation lie the high

Afroalpine region in Africa. The montane moorlands lie above the tree line, and consist of grassland and moorland
with abundant herbs and some shrubs that have adapted to the high mountain conditions. In Ethiopia, Afro-Alpine and Sub-Afro-Alpine vegetations are found in the Highlands of Semein and Highlands of Bale.

Fauna

These slopes are home to a number of endemic wildlife species, including the endangered

Rueppell's chat, the finch Ankober serin (Serinus ankoberensis), white-winged flufftail (Sarothrura ayresi), and blue-winged goose. The farmland is home to many butterflies, especially Papilio, Charaxinae, Pieridae and Lycaenidae
.

There are several endemic animal species, one of which, the

greenshank
(Tringa nebularia).

Other fauna in the area also includes aardvark, eagle, Egyptian wolf, gelada, secretarybird, Nubian ibex, and marabou stork and Ethiopian endemic species such as the shrew (Crocidura harenna), the narrow-footed woodland mouse (Grammomys minnae), and Menelik's bushbuck (Tragelaphus scriptus meneliki), which is a subspecies with long, dark fur.

See also

References

  1. ^ "Overview About Ethiopia". Embassy of Ethiopia in the UK. 2019-01-25. Retrieved 2023-03-11.
  2. ISSN 0036-9225
    .
  3. ^ Paul B. Henze, Layers of Time (New York: Palgrave, 2000), p. 2.
  4. ^ a b Oxford English Dictionary, 1st ed. "coffee, n." Oxford University Press (Oxford), 1891.
  5. ISBN 978-0-415-92722-2
    . Retrieved 18 November 2015.
  6. ^ a b Mairal, M., Sanmartín, I., Herrero, A. et al. Geographic barriers and Pleistocene climate change shaped patterns of genetic variation in the Eastern Afromontane biodiversity hotspot. Sci Rep 7, 45749 (2017). https://doi.org/10.1038/srep45749
  7. ^ "Africa: Physical Geography | National Geographic Society". www.nationalgeographic.org. Archived from the original on 2022-03-24. Retrieved 2021-06-16.
  8. ^ January 2005: The Ethiopian Large Igneous Province
  9. ^
    doi:10.1016/j.geomorph.2006.12.007
    .
  10. ^ An explanation of this unusual rain pattern can be found at Ethiopia: Drought intensifies during corn and sorghum harvest (ReliefWeb)
  11. ^ "Eastern Africa: Ethiopia, extending into Eritrea, | Ecoregions | WWF".

External links

12°32′00″N 41°23′8″E / 12.53333°N 41.38556°E / 12.53333; 41.38556

  1. ^ "Ethiopian Plateau | Map, Mountains, & Facts | Britannica". www.britannica.com. Retrieved 2023-10-07.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ethiopian_Highlands&oldid=1219141780"