Danakil Depression

The Danakil Depression lies at the triple junction of three tectonic plates and has a complex geological history. It has developed as 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.{{cite book|author=Thomas Schlüter|title=Geological Atlas of Africa: With Notes on Stratigraphy, Tectonics, Economic Geology, Geohazards, Geosites and Geoscientific Education of Each Country|url=https://books.google.com/books?id=IfvKWpsISTQC&pg=PA88 |year=2008 |publisher=Springer Science & Business Media|isbn=978-3-540-76373-4 |pages=88–89}}

In respect of it demonstrating 'the ongoing birth of an ocean witnessed through tectonics and volcanism in an extreme evaporite arid environment', 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 a substantial contribution to the development of geological sciences through history.'{{cite web |title=The First 100 IUGS Geological Heritage Sites |url=https://iugs-geoheritage.org/videos-pdfs/iugs_first_100_book_v2.pdf |website=IUGS International Commission on Geoheritage |publisher=IUGS |access-date=13 November 2022}}

The Danakil Depression is a plain approximately {{convert|200|by|50|km|mi|0|abbr=on}}, lying in the north of the Afar Region of Ethiopia, near the border with Eritrea. It is about {{convert|125|m|ft|0|abbr=on}} below sea level and is bordered to the west by the Ethiopian Plateau and to the east by the Danakil Alps, beyond which is the Red Sea.{{cite book|author=J.L. Melvin|title=Evaporites, Petroleum and Mineral Resources |url=https://books.google.com/books?id=ZTo-AANipecC&pg=PA44 |year=1991 |publisher=Elsevier |isbn=978-0-08-086964-3 |pages=44–45}}

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{{cite book|last1=Johanson |first1=Donald C. |last2=Blake |first2=Edgar|title=From Lucy to Language|url=https://archive.org/details/fromlucytolangua0000joha |url-access=registration |year=1996|publisher=Simon and Schuster|isbn=9780684810232|page=[https://archive.org/details/fromlucytolangua0000joha/page/119 119]}} 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.

File:ET Afar asv2018-01 img46 Dallol.jpgs in Danakil Depression offer a research opportunity for studying extremophile microbes.]]

The Danakil Depression 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 {{convert|100|m|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.{{cite web|url=http://ngm.nationalgeographic.com/2005/10/danakil-desert/morell-text |archive-url=https://web.archive.org/web/20100416095732/http://ngm.nationalgeographic.com/2005/10/danakil-desert/morell-text |url-status=dead |archive-date=16 April 2010 |title=Africa's Danakil Desert – National Geographic Magazine |publisher=Ngm.nationalgeographic.com |access-date=10 December 2013}}

Mount Ayelu is the westernmost and older of the two volcanoes at the southern end of 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.{{cite news |url=http://astrobiology.com/2016/04/hydrothermal-systems-show-spectrum-of-extreme-life-on-earth.html |title=Hydrothermal Systems Show Spectrum of Extreme Life on Earth |work=Europlanet |publisher=Astrobiology Web |date=26 April 2016 |access-date=1 May 2016 }} Many microorganisms living here are extremophilic microbes of 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.{{cite journal |author=Belita, Jodie |display-authors=et al. |title=Hyperdiverse archaea near life limits at the polyextreme geothermal Dallol area |date=28 October 2019 |journal=Nature Ecology and Evolution |volume=3 |issue=11 |pages=1552–1561 |doi=10.1038/s41559-019-1005-0 |pmid=31666740 |pmc=6837875 }}{{cite news |last=Andrews |first=Robin George |title=They Didn't Find Life in a Hopeless Place – In some of the world's wettest, most acidic bodies of superheated water, even the most extreme forms of archaea couldn't survive. |url=https://www.nytimes.com/2019/11/01/science/extreme-life-aliens.html |date=1 November 2019 |work=The New York Times |access-date=4 November 2019 }}

Among the geological points of interest to tourists are the hydrothermal system of Dallol{{Cite journal |last1=Kotopoulou |first1=Electra |last2=Huertas |first2=Antonio Delgado |last3=García-Ruiz |first3=Juan Manuel |last4=Dominguez-Vera |first4=Jose M. |last5=Lopez-Garcia |first5=Jose Maria |last6=Guerra-Tschuschke |first6=Isabel |last7=Rull |first7=Fernando |date=6 December 2018 |title=A poly-extreme hydrothermal system controlled by iron: the case of Dallol at the Afar Triangle |journal=ACS Earth and Space Chemistry |volume=3 |issue=1 |pages=90–99|doi=10.1021/acsearthspacechem.8b00141 |pmid=30801049 |pmc=6380227}} and the Yellow Lake.{{cite web|title=Yellow lake is located in the Danakil Depression|url=https://independent-travellers.com/ethiopia/danakil_depression/yellow_lake/|website=Independent Travellers|publisher=independent-travellers.com|access-date=13 June 2017}}

Gaet'ale Pond 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.{{Cite journal |last1=Perez |first1=Eduardo |last2=Chebude |first2=Yonas |date=April 2017 |title=Chemical Analysis of Gaet'ale, a Hypersaline Pond in Danakil Depression (Ethiopia): New Record for the Most Saline Water Body on Earth |journal=Aquatic Geochemistry |volume=23 |issue=2 |pages=109–117 |doi=10.1007/s10498-017-9312-z|s2cid=132715553 }} The pond was created in January 2005 following an earthquake, according to residents of the Ahmed'ela village, which reactivated the hot spring.{{Cite journal |last=Master |first=Sharad |date=2016 |title=Gaet'ale – a reactivated thermal spring and potential tourist hazard in the Asale salt flats, Danakil Depression, Ethiopia |journal=Journal of Applied Volcanology |volume=5 |pages=1–9 |doi=10.1186/s13617-015-0042-x |doi-access=free}}

• Afar Triangle
• Danakil Desert

{{Reflist}}

• [http://www.bbc.co.uk/programmes/p00377pl Danakil Depression] – video clip from BBC Planet Earth

{{Wikivoyage}}

{{Deserts}}

{{coord|14.2417|N|40.3|E|source:kolossus-eowiki|display=title}}

Category:Afar Region

Category:Deserts of Ethiopia

Category:Deserts of Eritrea

Category:First 100 IUGS Geological Heritage Sites

Category:Lowest points of countries