@article{36d75a9b289d4e739742d8ffbde3bc68,
title = "The Dallol Geothermal Area, Northern Afar (Ethiopia) - An Exceptional Planetary Field Analog on Earth",
abstract = " The Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperature Dallol : 36-38°C) and most acidic natural systems (pH Dallol ≈0) on Earth. Spectacular geomorphologies and mineral deposits produced by supersaturated hydrothermal waters and brines are the result of complex interactions between active and inactive hydrothermal alteration of the bedrock, sulfuric hot springs and pools, fumaroles and geysers, and recrystallization processes driven by hydrothermal waters, degassing, and rapid evaporation. The study of planetary field analog environments plays a crucial role in characterizing the physical and chemical boundaries within which life can exist on Earth and other planets. It is essential for the definition and assessment of the conditions of habitability on other planets, including the possibility for biosignature preservation and in situ testing of technologies for life detection. The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars. The work presented in this paper is an overview of the Dallol volcanic area and its hydrothermal field that integrates previous literature with observations and results obtained from field surveys and monitoring coupled with sample characterization. In so doing, we highlight its exceptional potential as a planetary field analog as well as a site for future astrobiological and exploration programs.",
keywords = "Astrobiology, East Africa, Extreme environments, Hydrothermal systems, Planetary science, Polyextremophiles, Terrestrial analogs",
author = "B. Cavalazzi and R. Barbieri and F. G{\'o}mez and B. Capaccioni and K. Olsson-Francis and M. Pondrelli and Rossi, {A. P.} and K. Hickman-Lewis and A. Agangi and G. Gasparotto and M. Glamoclija and Ori, {G. G.} and N. Rodriguez and M. Hagos",
note = "Funding Information: Barbara Cavalazzi acknowledges support by the International Cooperation Program between the Universit{\`a} di Bologna and the University of Mekelle. We are grateful to Franco Pirajno and an anonymous reviewer for taking the time to provide comments and suggestions. B.C. would like to kindly thank Ernesto Abbate (Universit{\`a} di Firenze), Judith Rend{\'o}n, (Hospital of Mekele), Livia Mercatelli (International Office of the Universit{\`a} di Bologna), Solomon Hishe (University of Mekelle), Birhanu Berhe (Temesgen Pharmacy in Mekelle), Zablon Beyene and Mikael Tamrat (Zab Tours Ethiopia), Sister Laura and the Kidane Mehret Mission in Adwa, the Associazione Amici di Adua Onlus and volunteers Samantha, Marina, Serena, Alberto, Tommaso, and Daniele. Finally, but most importantly, B.C. would like to thank the Afars from Hamed'Ela village, who have always been very welcoming. This is a contribution to the Europlanet 2020 Research Infrastructure programme funded under the European Commission's Horizon 2020 programme (No. 654208). Funding Information: Barbara Cavalazzi acknowledges support by the International Cooperation Program between the Universit{\`a} di Bologna and the University of Mekelle. We are grateful to Franco Pirajno and an anonymous reviewer for taking the time to provide comments and suggestions. B.C. would like to kindly thank Ernesto Abbate (Universit{\`a} di Firenze), Judith Rend{\'o}n, (Hospital of Mekele), Livia Mercatelli (International Office of the Universit{\`a} di Bologna), Solomon Hishe (University of Mekelle), Birhanu Berhe (Temesgen Pharmacy in Mekelle), Zablon Beyene and Mikael Tamrat (Zab Tours Ethiopia), Sister Laura and the Kidane Mehret Mission in Adwa, the Associazione Amici di Adua Onlus and volunteers Samantha, Marina, Serena, Alberto, Tom-maso, and Daniele. Finally, but most importantly, B.C. would like to thank the Afars from Hamed{\textquoteright}Ela village, who have always been very welcoming. This is a contribution to the Europlanet 2020 Research Infrastructure programme funded under the European Commission{\textquoteright}s Horizon 2020 programme (No. 654208). Publisher Copyright: {\textcopyright} Copyright 2019 Mary Ann Liebert, Inc.",
year = "2019",
month = apr,
doi = "10.1089/ast.2018.1926",
language = "English (US)",
volume = "19",
pages = "553--578",
journal = "Astrobiology",
issn = "1531-1074",
publisher = "Mary Ann Liebert Inc.",
number = "4",
}