Danakil Depression

[[File:Map Danakil.jpg|thumb|Map of the Danakil Depression. Panel A shows the [[topography]] and the parts of the Depression situated below sea-level. Panel C show a [[Satellite imagery|satellite image]] showing the dark colours of the [[volcanic rock]]s in the south and the light colours of the [[Salt pan (geology)|salt plain]] and [[marine sediment]]s in the north.]] The '''Danakil Depression''' is a large valley of approximately {{convert|200|by|50|km|mi|0|abbr=on}}, across the north of the [[Afar Region]] of [[Ethiopia]] and [[Eritrea]]. It is about {{convert|125|m|ft|0|abbr=on}} below sea level and is bordered to the west by the [[Ethiopian Highlands|Ethiopian Plateau]] and to the east by the [[Danakil Alps]], beyond which is the Red Sea.<ref name="Melvin">{{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}}</ref> It is the third lowest-lying location on the continent of Africa.

The Danakil Depression is a geological [[Endorheic basin|depression]] formed by [[Rift|rifting]]. It constitutes the northern part of the [[Afar Triangle]] or Afar Depression.<ref name="Beyene_2005">{{Cite journal |last1=Beyene |first1=Alebachew |name-list-style=amp |last2=Abdelsalam |first2=Mohamed G. |year=2005 |title=Tectonics of the Afar Depression: A review and synthesis |journal=Journal of African Earth Sciences |volume=41 |issue=1–2 |pages=41–59 |doi=10.1016/j.jafrearsci.2005.03.003 |bibcode=2005JAfES..41...41B }}</ref><ref name="NYT-20170130">{{cite news |last=Yee |first=Amy |title=Gazing into Danakil Depression's Mirror, and Seeing Mars Stare Back |url=https://www.nytimes.com/2017/01/30/science/danakil-depression-ethiopia.html |date=30 January 2017 |work=The New York Times |access-date=31 January 2017 }}</ref>

==Geology== [[File:Danakil Landscape.jpg|thumb|Landscape of the Danakil Depression. The bright white coloured rocks are [[Pleistocene]] [[marine sediment]]s. The [[Erta Ale Range|Erta Ale range]] is visible in the background. ]] [[File:Afrera_NASA.jpg|thumb|Lake Afrera, Danakil Depression, Ethiopia]] The Danakil Depression is a large valley caused by the [[Extensional tectonics|extension]] between the [[Nubian plate]] and the [[Danakil microplate|Danakil (or Arrata) microplate]] (on which lie the [[Danakil Alps]]).<ref>{{Cite book |last=Varet |first=Jacques |date=2018 |title=Geology of Afar (East Africa) |url=https://link.springer.com/book/10.1007/978-3-319-60865-5 |series=Regional Geology Reviews |language=en |doi=10.1007/978-3-319-60865-5 |bibcode=2018geaf.book.....V |isbn=978-3-319-60863-1 |issn=2364-6438}}</ref><ref name=":0">{{Cite journal |last1=Viltres |first1=Renier |last2=Jónsson |first2=Sigurjón |last3=Ruch |first3=Joël |last4=Doubre |first4=Cécile |last5=Reilinger |first5=Robert |last6=Floyd |first6=Michael |last7=Ogubazghi |first7=Ghebrebrhan |date=2020-06-01 |title=Kinematics and deformation of the southern Red Sea region from GPS observations |url=https://academic.oup.com/gji/article/221/3/2143/5800989 |journal=Geophysical Journal International |volume=221 |issue=3 |pages=2143–2154 |doi=10.1093/gji/ggaa109 |doi-access=free |issn=0956-540X}}</ref> The velocity between these two plates is approximately 18 mm/yr in the south of the Depression and 8 mm/yr in the north of it.<ref name=":0" /> The Danakil Depression is thus a [[rift]], more precisely the northern tip of the [[Afar Triangle|Afar rift]].<ref name=":1">{{Cite journal |last1=Rime |first1=Valentin |last2=Foubert |first2=Anneleen |last3=Ruch |first3=Joël |last4=Kidane |first4=Tesfaye |date=2023-09-01 |title=Tectonostratigraphic evolution and significance of the Afar Depression |url=https://linkinghub.elsevier.com/retrieve/pii/S0012825223002088 |journal=Earth-Science Reviews |volume=244 |article-number=104519 |doi=10.1016/j.earscirev.2023.104519 |bibcode=2023ESRv..24404519R |issn=0012-8252|doi-access=free }}</ref>

The formation of the rift started approximately 11 million years ago (Ma) with the counterclockwise rotation of the Danakil microplate.<ref>{{Cite journal |last1=McClusky |first1=Simon |last2=Reilinger |first2=Robert |last3=Ogubazghi |first3=Ghebrebrhan |last4=Amleson |first4=Aman |last5=Healeb |first5=Biniam |last6=Vernant |first6=Philippe |last7=Sholan |first7=Jamal |last8=Fisseha |first8=Shimelles |last9=Asfaw |first9=Laike |last10=Bendick |first10=Rebecca |last11=Kogan |first11=Lewis |date=2010 |title=Kinematics of the southern Red Sea–Afar Triple Junction and implications for plate dynamics |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2009GL041127 |journal=Geophysical Research Letters |language=en |volume=37 |issue=5 |doi=10.1029/2009GL041127 |bibcode=2010GeoRL..37.5301M |issn=1944-8007}}</ref><ref name=":1" /><ref>{{Cite journal |last1=Eagles |first1=Graeme |last2=Gloaguen |first2=Richard |last3=Ebinger |first3=Cynthia |date=2002-10-30 |title=Kinematics of the Danakil microplate |url=https://linkinghub.elsevier.com/retrieve/pii/S0012821X02009160 |journal=Earth and Planetary Science Letters |volume=203 |issue=2 |pages=607–620 |doi=10.1016/S0012-821X(02)00916-0 |bibcode=2002E&PSL.203..607E |issn=0012-821X}}</ref> Since then, tectonic extension caused the thinning of the [[Crust (geology)|crust]] and the [[subsidence]] of the [[Structural basin|basin]] where both [[sediment]]s and [[volcanic rock]]s accumulated. In contrast to the neighbouring central Afar region which is closer to the Afar [[Hotspot (geology)|hotspot]], the Danakil Depression only experienced moderate volcanic activity during its first rifting phase.<ref name=":1" /> However, this volcanic activity increased significantly since at least 0.6 Ma, forming the [[Erta Ale Range|Erta Ale volcanic range]].<ref name=":1" /> This volcanic activity was probably triggered by the thinning of the crust and the [[adiabatic decompression]] of the underlying [[Mantle (geology)|mantle]], producing large quantities of [[magma]].<ref>{{Cite journal |last1=Bastow |first1=Ian D. |last2=Keir |first2=Derek |date=April 2011 |title=The protracted development of the continent–ocean transition in Afar |url=https://www.nature.com/articles/ngeo1095 |journal=Nature Geoscience |language=en |volume=4 |issue=4 |pages=248–250 |doi=10.1038/ngeo1095 |bibcode=2011NatGe...4..248B |issn=1752-0908|hdl=2158/1110138 |hdl-access=free }}</ref>

The southern part of the depression is dominated by the Erta Ale range featuring multiple [[Shield volcano|shield]] and [[stratovolcano]]es such as the [[Gada Ale]], [[Alu (Ethiopia)|Alu]], [[Dalaffilla|Dalafilla]], Bora Ale, [[Erta Ale]] and [[Ale Bagu]]. These [[volcano]]es mainly produced [[basalt]]ic rocks.<ref name=":2">{{Cite journal |last1=Barberi |first1=F. |last2=Varet |first2=J. |date=1970-12-01 |title=The Erta Ale volcanic range (Danakil depression, northern afar, ethiopia) |url=https://link.springer.com/article/10.1007/BF02596805 |journal=Bulletin Volcanologique |language=en |volume=34 |issue=4 |pages=848–917 |doi=10.1007/BF02596805 |bibcode=1970BVol...34..848B |issn=1432-0819|url-access=subscription }}</ref> The [[petrology]] and [[geochemistry]] of these rocks indicate an absence of [[continental crust]] under the volcanic range,<ref name=":2" /><ref>{{Cite journal |last1=Watts |first1=Emma J. |last2=Gernon |first2=Thomas M. |last3=Taylor |first3=Rex N. |last4=Keir |first4=Derek |last5=Siegburg |first5=Melanie |last6=Jarman |first6=Jasmin |last7=Pagli |first7=Carolina |last8=Gioncada |first8=Anna |date=2020-12-15 |title=Evolution of the Alu-Dalafilla and Borale volcanoes, Afar, Ethiopia |url=https://linkinghub.elsevier.com/retrieve/pii/S0377027320304327 |journal=Journal of Volcanology and Geothermal Research |volume=408 |article-number=107094 |doi=10.1016/j.jvolgeores.2020.107094 |bibcode=2020JVGR..40807094W |issn=0377-0273|hdl=2158/1233436 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Hutchison |first1=William |last2=Mather |first2=Tamsin A. |last3=Pyle |first3=David M. |last4=Boyce |first4=Adrian J. |last5=Gleeson |first5=Matthew L. M. |last6=Yirgu |first6=Gezahegn |last7=Blundy |first7=Jon D. |last8=Ferguson |first8=David J. |last9=Vye-Brown |first9=Charlotte |last10=Millar |first10=Ian L. |last11=Sims |first11=Kenneth W. W. |last12=Finch |first12=Adrian A. |date=2018-05-01 |title=The evolution of magma during continental rifting: New constraints from the isotopic and trace element signatures of silicic magmas from Ethiopian volcanoes |url=https://linkinghub.elsevier.com/retrieve/pii/S0012821X1830089X |journal=Earth and Planetary Science Letters |volume=489 |pages=203–218 |doi=10.1016/j.epsl.2018.02.027 |bibcode=2018E&PSL.489..203H |issn=0012-821X|url-access=subscription }}</ref><ref>{{Cite journal |last1=Barrat |first1=J. A. |last2=Fourcade |first2=S. |last3=Jahn |first3=B. M. |last4=Cheminée |first4=J. L. |last5=Capdevila |first5=R. |date=1998-01-01 |title=Isotope (Sr, Nd, Pb, O) and trace-element geochemistry of volcanics from the Erta'Ale range (Ethiopia) |url=https://linkinghub.elsevier.com/retrieve/pii/S0377027397000164 |journal=Journal of Volcanology and Geothermal Research |volume=80 |issue=1 |pages=85–100 |doi=10.1016/S0377-0273(97)00016-4 |bibcode=1998JVGR...80...85B |issn=0377-0273|url-access=subscription }}</ref><ref name=":3">{{Cite journal |last1=Pin |first1=Juliette |last2=Chazot |first2=Gilles |last3=France |first3=Lydéric |last4=Abily |first4=Bénédicte |last5=Gurenko |first5=Andrey |last6=Bertrand |first6=Hervé |last7=Loppin |first7=Alexandra |date=2024-12-01 |title=Protracted Magma Evolution and Transcrustal Magmatic Plumbing System Architecture at Erta Ale Volcano (Afar, Ethiopia) |url=https://academic.oup.com/petrology/article-abstract/65/12/egae118/7889295?redirectedFrom=fulltext |journal=Journal of Petrology |volume=65 |issue=12 |article-number=egae118 |doi=10.1093/petrology/egae118 |issn=0022-3530}}</ref> suggesting that the Nubian and Danakil plates are probably detached there. This indicates that the rift is at an advanced stage of evolution, close to continental breakup and [[oceanisation]]. However, the Erta Ale range does not represent a normal [[oceanic crust]] yet, but rather a transitional crust.<ref name=":3" /> In this part of the depression, most of the extension is accommodated by dike [[Igneous intrusion|intrusions]], and not by [[faulting]].<ref>{{Cite journal |last1=Illsley-Kemp |first1=Finnigan |last2=Keir |first2=Derek |last3=Bull |first3=Jonathan M. |last4=Gernon |first4=Thomas M. |last5=Ebinger |first5=Cynthia |last6=Ayele |first6=Atalay |last7=Hammond |first7=James O. S. |last8=Kendall |first8=J.-Michael |last9=Goitom |first9=Berhe |last10=Belachew |first10=Manahloh |date=2018 |title=Seismicity During Continental Breakup in the Red Sea Rift of Northern Afar |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017JB014902 |journal=Journal of Geophysical Research: Solid Earth |language=en |volume=123 |issue=3 |pages=2345–2362 |doi=10.1002/2017JB014902 |bibcode=2018JGRB..123.2345I |issn=2169-9356|hdl=2158/1136575 |hdl-access=free }}</ref>

The northern part of the Depression is dominated by [[sedimentary rock]]s. The extension is accommodated by tectonic faulting.<ref>{{Cite journal |last1=Bastow |first1=Ian D. |last2=Booth |first2=Adam D. |last3=Corti |first3=Giacomo |last4=Keir |first4=Derek |last5=Magee |first5=Craig |last6=Jackson |first6=Christopher A.-L. |last7=Warren |first7=John |last8=Wilkinson |first8=Jason |last9=Lascialfari |first9=Matteo |date=2018 |title=The Development of Late-Stage Continental Breakup: Seismic Reflection and Borehole Evidence from the Danakil Depression, Ethiopia |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2017TC004798 |journal=Tectonics |language=en |volume=37 |issue=9 |pages=2848–2862 |doi=10.1029/2017TC004798 |bibcode=2018Tecto..37.2848B |issn=1944-9194|hdl=2158/1136583 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Hurman |first1=Gareth L. |last2=Keir |first2=Derek |last3=Bull |first3=Jonathan M. |last4=McNeill |first4=Lisa C. |last5=Booth |first5=Adam D. |last6=Bastow |first6=Ian D. |date=2023 |title=Quantitative Analysis of Faulting in the Danakil Depression Rift of Afar: The Importance of Faulting in the Final Stages of Magma-Rich Rifting |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022TC007607 |journal=Tectonics |language=en |volume=42 |issue=6 |article-number=e2022TC007607 |doi=10.1029/2022TC007607 |bibcode=2023Tecto..4207607H |issn=1944-9194|hdl=10044/1/104631 |hdl-access=free }}</ref> Volcanic activity is less significant than in the southern part of the depression, but two volcanoes can be found: Maraho and [[Dallol (hydrothermal system)|Dallol]]. The intrusion of [[Dike (geology)|dikes]] has also been measured.<ref>{{Cite journal |last1=Nobile |first1=Adriano |last2=Pagli |first2=Carolina |last3=Keir |first3=Derek |last4=Wright |first4=Tim J. |last5=Ayele |first5=Atalay |last6=Ruch |first6=Joel |last7=Acocella |first7=Valerio |date=2012 |title=Dike-fault interaction during the 2004 Dallol intrusion at the northern edge of the Erta Ale Ridge (Afar, Ethiopia) |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2012GL053152 |journal=Geophysical Research Letters |language=en |volume=39 |issue=19 |doi=10.1029/2012GL053152 |bibcode=2012GeoRL..3919305N |issn=1944-8007|hdl=11568/500305 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Ruch |first1=Joël |last2=Keir |first2=Derek |last3=Passarelli |first3=Luigi |last4=Di Giacomo |first4=Domenico |last5=Ogubazghi |first5=Ghebrebrhan |last6=Jónsson |first6=Sigurjón |date=2021-08-16 |title=Revealing 60 years of Earthquake Swarms in the Southern Red Sea, Afar and the Gulf of Aden |journal=Frontiers in Earth Science |language=English |volume=9 |doi=10.3389/feart.2021.664673 |doi-access=free |bibcode=2021FrEaS...9..690R |issn=2296-6463|hdl=10754/672011 |hdl-access=free }}</ref> Close to the western margin of the depression, ephemeral rivers bring coarse sediments, forming [[alluvial fan]]s dominated by [[Conglomerate (geology)|conglomerates]]. During the [[Middle Pleistocene|Mid-]] and [[Late Pleistocene]], the basin was flooded at least four times by the [[Red Sea]] during [[Interglacial|periods of high sea-level]].<ref name=":4">{{Cite journal |last1=Jaramillo-Vogel |first1=David |last2=Foubert |first2=Anneleen |last3=Braga |first3=Juan Carlos |last4=Schaegis |first4=Jean-Charles |last5=Atnafu |first5=Balemwal |last6=Grobety |first6=Bernard |last7=Kidane |first7=Tesfaye |date=2019 |title=Pleistocene sea-floor fibrous crusts and spherulites in the Danakil Depression (Afar, Ethiopia) |url=https://onlinelibrary.wiley.com/doi/10.1111/sed.12484 |journal=Sedimentology |language=en |volume=66 |issue=2 |pages=480–512 |doi=10.1111/sed.12484 |bibcode=2019Sedim..66..480J |issn=1365-3091|url-access=subscription }}</ref><ref name=":5">{{Cite journal |last1=Foubert |first1=Anneleen |last2=Keir |first2=Derek |last3=Atnafu |first3=Balemwal |last4=Kidane |first4=Tesfaye |last5=the ADD-ON Workshop Consortium |date=2024-08-30 |title=Workshop report: Afar Dallol Drilling – ONset of sedimentary processes in an active rift basin (ADD-ON) |url=https://sd.copernicus.org/articles/33/207/2024/ |journal=Scientific Drilling |language=English |volume=33 |issue=2 |pages=207–218 |doi=10.5194/sd-33-207-2024 |doi-access=free |bibcode=2024SciDr..33..207F |issn=1816-8957|hdl=2158/1394234 |hdl-access=free }}</ref> The last flooding happened approximately 130,000 years ago.<ref name=":4" /><ref name=":5" /> These floods are testified by fossil [[coral reef]]s<ref name=":4" /><ref name=":5" /> and by thick (>500m) [[evaporite]] deposits (mainly [[halite]], i.e. salt) found in the central part of the basin.<ref>{{Cite journal |last1=Holwerda |first1=James G. |last2=Hutchinson |first2=Richard W. |date=1968-03-01 |title=Potash-bearing evaporites in the Danakil area, Ethiopia |url=http://pubs.geoscienceworld.org/economicgeology/article/63/2/124/17788/Potashbearing-evaporites-in-the-Danakil-area |journal=Economic Geology |language=en |volume=63 |issue=2 |pages=124–150 |doi=10.2113/gsecongeo.63.2.124 |bibcode=1968EcGeo..63..124H |issn=1554-0774|url-access=subscription }}</ref><ref name=":6">{{Cite journal |last1=Rime |first1=Valentin |last2=Negga |first2=Haileyesus |last3=Fentimen |first3=Robin |last4=Rüggeberg |first4=Andres |last5=El Korh |first5=Afifé |last6=Pirkenseer |first6=Claudius |last7=Schaegis |first7=Jean-Charles |last8=Hajdas |first8=Irka |last9=Adatte |first9=Thierry |last10=Atnafu |first10=Balemwal |last11=Kidane |first11=Tesfaye |last12=Foubert |first12=Anneleen |date=2025 |title=Nature and significance of Late Pleistocene to Holocene thick evaporite deposits of the Danakil Depression, Afar, Ethiopia |url=https://onlinelibrary.wiley.com/doi/10.1111/sed.13237 |journal=Sedimentology |language=en |volume=72 |issue=2 |pages=475–506 |doi=10.1111/sed.13237 |bibcode=2025Sedim..72..475R |issn=1365-3091}}</ref> The lower part of the evaporites, featuring halite and [[Potash|potash minerals]], deposited directly by evaporating [[seawater]] coming from the Red Sea during the last flooding.<ref name=":6" /> The upper part of the evaporites deposited in continental waters forming [[salt lake]]s and [[Salt pan (geology)|salt pans]]. These continental waters became [[Saline water|saline]] after dissolving older marine evaporites at the margins of the basin or at depth.<ref name=":6" /> This process is still ongoing, in particular around [[Lake Karum]].<ref name=":7">{{Cite journal |last1=López-García |first1=José M. |last2=Moreira |first2=David |last3=Benzerara |first3=Karim |last4=Grunewald |first4=Olivier |last5=López-García |first5=Purificación |date=2020-01-17 |title=Origin and Evolution of the Halo-Volcanic Complex of Dallol: Proto-Volcanism in Northern Afar (Ethiopia) |journal=Frontiers in Earth Science |language=English |volume=7 |doi=10.3389/feart.2019.00351 |doi-access=free |issn=2296-6463}}</ref><ref name=":6" />

=== Dallol === [[File:ET_Afar_asv2018-01_img37_Dallol.jpg|thumb|Landscape at Dallol, Afar Triangle, East Africa]] Dallol is a unique volcano situated in the central part of the salt plain. Magmatic fluids interact at depth with the evaporites, dissolving them and causing their ascent to the surface, and forming a salt volcano.<ref name=":7" /> The fluids escaping at the surface are extremely [[Acid|acidic]], [[Salinity|salty]] and hot. The [[oxidation]] of dissolved [[Salt (chemistry)|salts]], the [[complexation]] of [[Iron sulfate|iron]] and [[Sulfate chloride|chlorine sulfates]], and [[evaporation]] create complex coloured structures.<ref name=":8">{{Cite journal |last1=Kotopoulou |first1=Electra |last2=Delgado Huertas |first2=Antonio |last3=Garcia-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=2019-01-17 |title=A Polyextreme Hydrothermal System Controlled by Iron: The Case of Dallol at the Afar Triangle |journal=AijhkS Earth and Space Chemistry |volume=3 |issue=1 |pages=90–99 |doi=10.1021/acsearthspacechem.8b00141 |pmc=6380227 |pmid=30801049|bibcode=2019ESC.....3...90K }}</ref> These extreme conditions are also studied by [[biologist]]s looking for [[extremophile]]s, [[organism]]s living in conditions usually fatal to life.<ref>{{Cite journal |last1=Cavalazzi |first1=B. |last2=Barbieri |first2=R. |last3=Gómez |first3=F. |last4=Capaccioni |first4=B. |last5=Olsson-Francis |first5=K. |last6=Pondrelli |first6=M. |last7=Rossi |first7=A.P. |last8=Hickman-Lewis |first8=K. |last9=Agangi |first9=A. |last10=Gasparotto |first10=G. |last11=Glamoclija |first11=M. |last12=Ori |first12=G.G. |last13=Rodriguez |first13=N. |last14=Hagos |first14=M. |date=April 2019 |title=The Dallol Geothermal Area, Northern Afar (Ethiopia)—An Exceptional Planetary Field Analog on Earth |journal=Astrobiology |volume=19 |issue=4 |pages=553–578 |doi=10.1089/ast.2018.1926 |issn=1531-1074 |pmc=6459281 |pmid=30653331|bibcode=2019AsBio..19..553C }}</ref> They found [[microorganism]]s in most of Dallol's ponds, but not in the immediate proximity of the hot chimneys where the fluids reach the surface.<ref>{{Cite journal |last1=Sanz |first1=Jose L. |last2=Rodríguez |first2=Nuria |last3=Escudero |first3=Cristina |last4=Carrizo |first4=Daniel |last5=Amils |first5=Ricardo |last6=Gómez |first6=Felipe |date=2021-06-06 |title=Methanogenesis at High Temperature, High Ionic Strength and Low pH in the Volcanic Area of Dallol, Ethiopia |journal=Microorganisms |language=en |volume=9 |issue=6 |page=1231 |doi=10.3390/microorganisms9061231 |doi-access=free |issn=2076-2607 |pmc=8228321 |pmid=34204110}}</ref><ref>{{Cite journal |last1=Belilla |first1=Jodie |last2=Moreira |first2=David |last3=Jardillier |first3=Ludwig |last4=Reboul |first4=Guillaume |last5=Benzerara |first5=Karim |last6=López-García |first6=José M. |last7=Bertolino |first7=Paola |last8=López-Archilla |first8=Ana I. |last9=López-García |first9=Purificación |date=September 2019 |title=Hyperdiverse archaea near life limits at the polyextreme geothermal Dallol area |journal=Nature Ecology & Evolution |language=en |volume=3 |issue=11 |pages=1552–1561 |doi=10.1038/s41559-019-1005-0 |issn=2397-334X |pmc=6837875 |pmid=31666740|bibcode=2019NatEE...3.1552B }}</ref>

=== Hot springs === Around Dallol, several other [[hydrothermal]] springs are present, such as [[Gaet'ale Pond|Gaet'Ale Pond]] (also called Yellow Lake).<ref>{{cite web |title=Yellow lake is located in the Danakil Depression |url=https://independent-travellers.com/ethiopia/danakil_depression/yellow_lake/ |access-date=13 June 2017 |website=Independent Travellers |publisher=independent-travellers.com}}</ref><ref name=":8" /><ref name="perez">{{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 |bibcode=2017AqGeo..23..109P |s2cid=132715553}}</ref>

Gaet'ale Pond is a small [[hypersaline lake]] located over a tectonic [[hot spring]] in the depression. With a salinity of 43%, the pond is the [[list of bodies of water by salinity|saltiest water body on Earth]].<ref name="perez" /> The pond was created in January 2005 following an earthquake, according to residents of Ahmed'ela village, which reactivated the hot spring.<ref>{{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 |issue=1 |pages=1–9 |doi=10.1186/s13617-015-0042-x |doi-access=free|bibcode=2016JApV....5....1M }}</ref>

===IUGS geological heritage site=== In recognition 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 a ''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."<ref>{{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}}</ref>

==Features== The Danakil Depression is the hottest place on Earth in terms of year-round average temperatures. It is also one of the [[List of places on land with elevations below sea level|lowest places on the planet]] at {{convert|100|m|ft}} below sea level,<ref name="hydro">{{cite news |date=26 April 2016 |title=Hydrothermal Systems Show Spectrum of Extreme Life on Earth |url=http://astrobiology.com/2016/04/hydrothermal-systems-show-spectrum-of-extreme-life-on-earth.html |access-date=1 May 2016 |work=Europlanet |publisher=Astrobiology Web}}</ref> and without rain for most of the year.

It features several [[Endorheic lake|endorheic]] and saline lakes, such as [[Lake Afrera|Lake Afdera]], [[Lake Karum]], and Lake Bakili that sit on volcano-tectonic depressions.<ref>{{Cite journal |last1=Schaegis |first1=Jean-Charles |last2=Rime |first2=Valentin |last3=Kidane |first3=Tesfaye |last4=Mosar |first4=Jon |last5=Gebru |first5=Ermias Filfilu |last6=Atnafu |first6=Balemwal |last7=Foubert |first7=Anneleen |date=2021-07-01 |title=Novel Bathymetry of Lake Afdera Reveals Fault Structures and Volcano-Tectonic Features of an Incipient Transform Zone (Afar, Ethiopia) |journal=Frontiers in Earth Science |language=English |volume=9 |doi=10.3389/feart.2021.706643 |doi-access=free |bibcode=2021FrEaS...9..530S |issn=2296-6463}}</ref>

<gallery heights="100" widths="150" class="center"> File:Erta Ale crater.jpg|The [[crater]] of [[Erta Ale]] File:Erta-ale lac-de-lave 2001.jpg|A [[lava lake]] in the [[caldera]] of Erta Ale File:The hydrothermal system of Dallol.png|The [[Dallol (hydrothermal system)|Dallol]] salt volcano File:Danakil Salt Plain.jpg|The salt pan </gallery>

== See also == * [[Danakil Desert]]

==References== {{Reflist}}

==External links== * [https://www.bbc.co.uk/programmes/p00377pl Danakil Depression] – video clip from BBC Planet Earth

[[Category:Afar Region]] [[Category:Deserts of Ethiopia]] [[Category:Deserts of Eritrea]] [[Category:First 100 IUGS Geological Heritage Sites]] [[Category:Lowest points of countries]]