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26-603: The Danakil Depression is the northern part of the Afar Triangle or Afar Depression in Ethiopia and Eritrea , a geological depression that has resulted from the divergence of three tectonic plates in the Horn of Africa . It is the third lowest lying location on the continent of Africa. The Danakil Depression lies at the triple junction of three tectonic plates and has a complex geological history. It has developed as

52-712: A volcanic eruption occurred within the Afar rift at the Dabbahu and Erta Ale volcanoes. Some 2.5 cubic kilometers of molten rock was injected from below into the plate along a dyke between depths of 2 and 9 km (1 and 6 mi), forcing open an 8 m (26 ft) wide gap on the surface, known as the Dabbahu fissure . Related eruptions have taken place in Teru and Aura woredas . The rift has recently been recorded by means of three-dimensional laser mapping. The region's salt deposits were created over time as water from

78-605: A major interest to astrobiologists . Nonetheless, in October 2019, scientists reported that terrestrial lifeforms , including extreme forms of archaea microorganisms, were not found to exist in the very hot, acidic and salty conditions present in some parts of the Danakil Depression. Among the geological points of interest to tourists are the hydrothermal system of Dallol and the Yellow Lake. Gaet'ale Pond

104-572: A new ocean basin as large as today's Red Sea, and separating the Somali plate and the Horn of Africa from the rest of the continent. The floor of the Afar Depression is composed of lava , mostly basalt . One of Earth's five lava lakes , Erta Ale is found here, as well as Dabbahu Volcano. It has been proposed that the Afar Depression is underlain by a mantle plume , a great upwelling of mantle that melts to yield basalt as it approaches

130-507: A result of Africa and Asia moving apart, causing rifting and volcanic activity. Erosion , inundation by the sea, the rising and falling of the ground have all played their part in the formation of this depression. Sedimentary rocks such as sandstone and limestone are unconformably overlain by basalt which resulted from extensive lava flows . In respect of it demonstrating 'the ongoing birth of an ocean witnessed through tectonics and volcanism in an extreme evaporite arid environment',

156-608: A substantial contribution to the development of geological sciences through history.' The Danakil Depression is a plain approximately 200 by 50 km (124 by 31 mi), lying in the north of the Afar Region of Ethiopia, near the border with Eritrea . It is about 125 m (410 ft) below sea level and is bordered to the west by the Ethiopian Plateau and to the east by the Danakil Alps , beyond which

182-587: Is a small hypersaline lake located over a tectonic hot spring in the Danakil Depression ( Afar , Ethiopia). With a salinity of 43%, Gaet'ale Pond is the saltiest water body on Earth . The pond was created in January 2005 following an earthquake, according to residents of the Ahmed'ela village, which reactivated the hot spring. 14°14′30″N 40°18′00″E  /  14.2417°N 40.3°E  / 14.2417; 40.3 Afar Triangle The Awash River

208-414: Is covered by salt deposits, and mining salt is a major source of income for many Afar groups. The Afar Depression biome is characterized as desert scrubland . Vegetation is mostly confined to drought-resistant plants such as small trees (e.g. species of the dragon tree ), shrubs, and grasses. Wildlife includes many herbivores such as Grévy's zebra , Soemmerring's gazelle , beisa and, notably,

234-480: Is the Red Sea. The area is often referred to as the cradle of humanity ; in 1974 Donald Johanson and his colleagues found the famous Australopithecus afarensis fossil Lucy , which has been dated 3.2 million years old and many other fossils of ancient hominins have been uncovered here, prompting many palaeontologists to propose that this area is where the human species first evolved. The Danakil Depression

260-535: Is the hottest place on Earth in terms of year-round average temperatures. It is also one of the lowest places on the planet at 100 metres (330 ft) below sea level, and without rain for most of the year. Here, the Awash River dries up in a chain of salt lakes such as Lake Afrera , never reaching the Indian Ocean. Mount Ayelu is the westernmost and older of the two volcanoes at the southern end of

286-485: Is the main waterflow into the region, but it runs dry during the annual dry season, and ends as a chain of saline lakes . The northern part of the Afar Depression is also known as the Danakil Depression . The lowlands are affected by heat, drought , and minimal air circulation, and contain the hottest places (year-round average temperatures) of anywhere on Earth. The Afar Triangle is bordered as follows (see

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312-480: The International Union of Geological Sciences (IUGS) included 'The Danakil Rift depression and its volcanism' in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. The organisation defines an IUGS Geological Heritage Site as 'a key place with geological elements and/or processes of international scientific relevance, used as a reference, and/or with

338-581: The McMurdo Dry Valleys such as Lake Vanda with salinity of over 35% (i.e. 10 times as salty as ocean water). The most saline water body in the world is the Gaet'ale Pond , located in the Danakil Depression in Afar , Ethiopia. The water of Gaet'ale Pond has a salinity of 43%, making it the saltiest water body on Earth (i.e. 12 times as salty as ocean water). Previously, it was considered that

364-517: The Middle Awash region and numerous prehistoric sites of fossil hominin discoveries, including: the hominids and possible hominins, Ardi , or Ardipithecus ramidus , and Ardipithecus kadabba , see below; the Gawis cranium hominin from Gona ; several sites of the world's oldest stone tools; Hadar , the site of Lucy , the fossilized specimen of Australopithecus afarensis ; and Dikika ,

390-525: The Danakil Depression. The other active volcano, Erta Ale , is one of several crater lakes of lava bubbling from the Earth's mantle. Additionally, the area contains the Dallol sulfur springs, or hot springs . These wet environments at the Danakil Depression are being investigated to help understand how life might arise on other planets and moons. Many microorganisms living here are extremophilic microbes of

416-491: The Red Sea periodically flooded the depression and evaporated; the most recent such flood was roughly 30,000 years ago. Over the next millions of years, geologists expect erosion and the Red Sea to breach the highlands surrounding the Afar Depression and flood the valley. Geologists predict that in about 10 million years the whole 6,000 km (3,700 mi) length of the East African Rift will be submerged, forming

442-640: The color of pink lakes . Some of these species enter a dormant state when desiccated , and some species are thought to survive for over 250 million years. The water in hypersaline lakes has great buoyancy due to its high salt content. Hypersaline lakes are found on every continent, especially in arid or semi-arid regions . In the Arctic , the Canadian Devon Ice Cap contains two subglacial lakes that are hypersaline. In Antarctica , there are larger hypersaline water bodies, lakes in

468-640: The earliest (fossil) hominins and of human tool culture, as well as many fossils of various flora and fauna. Dallol in the Danakil Depression is one of the hottest places year-round anywhere on Earth. There is no rain for most of the year; the yearly rainfall averages range from 100 to 200 mm (4 to 8 in), with even less rain falling closer to the coast. Daily mean temperatures at Dallol ranged from 30 °C (86 °F) in January to 39 °C (102 °F) in July in six years of observations from 1960 to 1966. The Awash River , flowing north-eastward through

494-584: The event. The Afar Depression is the product of a tectonic triple-rifts junction (the Afar triple junction), where the spreading ridges forming the Red Sea and the Gulf of Aden emerge on land and meet the East African Rift . The conjunction of these three plates of Earth's crust is near Lake Abbe . The Afar Depression is one of two places on Earth where a mid-ocean ridge can be studied on land,

520-522: The last viable population of African wild ass ( Equus africanus somalicus ). Birds include the ostrich , the endemic Archer's lark , the secretary bird , Arabian and Kori bustards , Abyssinian roller , and crested francolin . In the southern part of the plain lies the Mille-Serdo Wildlife Reserve . The Afar Triangle is a cradle source of the earliest hominins . It contains a paleo-archaeological district that includes

546-699: The most saline lake outside of Antarctica was Lake Assal , in Djibouti , which has a salinity of 34.8% (i.e. 10 times as salty as ocean water). The best-known hypersaline lakes are the Dead Sea (34.2% salinity in 2010) and the Great Salt Lake in the state of Utah , US (5–27% variable salinity). The Dead Sea , dividing Israel and the West Bank from Jordan , is the world's deepest hypersaline lake. The Great Salt Lake, while having nearly three times

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572-501: The other being Iceland . Within the triangle, the Earth's crust is slowly rifting apart at a rate of 1–2 cm (0.4–0.8 in) per year along each of the three rift zones forming the "legs" of the triple junction. The immediate consequences are recurring sequences of earthquakes with deep fissures in the terrain hundreds of metres long, and the valley floor sinking broadly across the depression. During September and October 2005 some 163 earthquakes of magnitudes greater than 3.9 and

598-524: The site of the fossilized child Selam , an australopithecine hominin. In 1994, near the Awash River in Ethiopia, Tim D. White found the then-oldest known human ancestor: 4.4 million-year-old Ar. ramidus . A fossilized almost complete skeleton of a female hominin which he named " Ardi ", it took nearly 15 years to safely excavate, preserve, and describe the specimen and to prepare publication of

624-639: The southern part of the Afar Region, provides a narrow green belt which enables life for the flora and fauna in the area and for the Afars , the nomadic people living in the Danakil Desert . About 128 kilometres (80 mi) from the Red Sea the Awash ends in a chain of salt lakes, where its waterflow evaporates as quickly as it is supplied. Some 1,200 km (460 sq mi) of the Afar Depression

650-558: The surface. 11°30′N 41°00′E  /  11.5°N 41.0°E  / 11.5; 41.0 Hypersaline lake A hypersaline lake is a landlocked body of water that contains significant concentrations of sodium chloride , brines , and other salts , with saline levels surpassing those of ocean water (3.5%, i.e. 35 grams per litre or 0.29 pounds per US gallon). Specific microbial species can thrive in high-salinity environments that are inhospitable to most lifeforms, including some that are thought to contribute to

676-766: The topographic map): on the west by the Ethiopian Plateau and escarpment ; to the north-east (between it and the Red Sea) by the Danakil block ; to the south by the Somali Plateau and escarpment; and to the south-east by the Ali-Sabieh block (adjoining the Somali Plateau). Many important fossil localities exist in the Afar region, including the Middle Awash region and the sites of Hadar , Dikika , and Woranso-Mille. These sites have produced specimens of

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