In January 2019, a team of microbiologists at theFrench National Centre for Scientific Research (CNRS), led by Purificación López-García set out to explore environments that had never been studied before, in the deepest parts of the Danakil depression in Ethiopia. Hours in helicopters was required for the scientists to collect samples on isolated islands in the middle of soups of salt, at the bottom of inhospitable craters, or on the shores of multi-coloured mudflats.
The Danakil depression is a salt desert at the crossroads of three tectonic plates on the East African rift. Intense volcanic and hydrothermal activity occurs there, and shapes the hottest place on the planet. The region is often viewed as similar to the planet Mars, therefore it is an ideal place to research the physical and chemical limits of life on Earth.
Satellite images had to be carefully analysed and many overflights were conducted before finding the right zones to study. A seasoned pilot hired by the team circled the Danakil region looking for the safest places to land, as a helicopter was the only safe way to gain access to the site.
Filled with excitement and curiosity, the team disembarked with a plethora of measuring instruments and sampling tools. They sunk into mud and in tepid hyper-salted water, as well as walking on chaotic and sharp flows under the harsh heat of the desert, 120 metres below sea level.
For two weeks, the photographer Olivier Grunewald and the journalist Bernadette Gilbertas were part of this expedition. The scientists uncovered interesting discoveries while they were still on site: they found stromatolites, microorganisms which are known for building very old rock deposits. It was the first time such formations had been reported in Danakil and their discovery may be the largest one to date.
These samples were then taken back to laboratories in order to study the traces of life hidden in the mysterious landscapes of the Danakil depression.
The Danakil delta
Landscapes of the salt lakes of the Danakil plain. The largest lakes have names, Karum, Bakili, but many still unknown are not named. Some of these lakes, which are underwater for several years, may disappear or reappear according to the tectonic movements of the African Rift. Photo by Olivier Grunewald
The shores of Lake Bakili
Sample collection on the shores of Lake Bakili, east of the Gada Alé volcanic chain. These areas are totally inaccessible without a helicopter. Photo by Olivier Grunewald
Tricky landing sites
Determining where the helicopter would land was the first step in obtaining authorisation from the local military services. This research was done from satellite images by looking for areas with anomalies, such as particular volcanic configurations or islands on the lakes. The team foundformations of stromatolites, living organisms leaving mineral deposits, known in different parts of the world as the oldest forms of life that have left fossil traces. Photo by Olivier Grunewald
Heart of a volcano
Helicopter drop off and sample collection in the heart of the Catherine volcano crater in the Gada Alé volcanic chain. Photo by Olivier Grunewald
Investigating the crater
Purificación López-García and David Moreira, both microbiologists, collect samples insidethe heart of the Catherine volcano crater in the Gada Alé volcanic chain. Photo by Olivier Grunewald
Collecting stromatolites
Purification Lopez-Garcia is seen collecting some stromatolites, living organisms leaving mineral deposits, known in different parts of the world as the oldest forms of life that have left fossil traces. Photo by Olivier Grunewald
Volcano of Gada Alé
Collection of microbial samples on the shores of Lake Bakili east of the Gada Alé volcanic chain. The scientists had to work through the extreme heat of the Afar region of Ethiopia, in one of the lowest areas on the planet. Photo by Olivier Grunewald
The Yellow lake
Collection of samples in the first lakes of the Danakil depression south of the Dallol site, Yellow lake and Black lake. It is the study of these first lakes in the salt plain that motivated this mission to explore the lakes near the volcanic chain of Gada Alé and Erta Alé. Photo by Olivier Grunewald
The 'Black lake' from above, south Dallol Geothermal site. Photo by Olivier Grunewald
Sampling the black water
Collection of samples in the first lakes of the Danakil depression south of the Dallol site, known as Yellow lake and Black lake. Photo by Olivier Grunewald
Salt crystals
Back at the CNRS laboratory at the Orsay-Paris Sud University, France, samples of salt crystals and various micro-organisms brought back from the Danakil salt lakes are imaged by a microscope of 400x magnification.Photo by Olivier Grunewald
Microscopic bacteria
Cyanobacteria (unicellular microorganisms) are picturedunder a microscope of 400x magnification, as imaged by the CNRS laboratory at the Orsay-Paris Sud University, France. Photo by Olivier Grunewald
James Cutmore is the picture editor of BBC Science Focus Magazine. He has worked on the magazine and website for over a decade, telling compelling science stories through the use of striking imagery. He holds a degree in Fine Art, and has been nominated for the British Society of Magazine Editors Talent Awards, being highly commended in 2020. His main areas of interest include photography that highlights positive technology and the natural world. For many years he was a judge for the Wellcome Trust's image competition, as well as judging for the Royal Photographic Society.
O.Grunewald Danakil, mission in unknown land : Collecte d'échantillons dans les premiers lacs au sud du site de Dallol, le Yellow lake et le Black lake. C'est l'étude de ces premiers lacs dans la plaine de sel qui a motivé la mission de 2019 pour aller explorer scientifiquement les lacs plus au sud proche de la chaine volcanique du Gada Alé et de l'Erta Alé
