Qualla: Dallol (hydrothermal system)

Dallol (hydrothermal system): Introduction

Thu, 23 Apr 2026 00:00:00 GMT

Photo credit Barrowbob, CC BY-SA 4.0. The Afar people gave this place a name that means 'dissolution' or 'disintegration.' In the language of the salt plains, Dallol is what happens to solid things that touch these waters. That is not metaphor. The hydrothermal pools of Dallol have a pH below zero - more acidic than battery acid - and dissolve flesh, bone, and most laboratory glass. The colours range from lime green to sulphur yellow to blood red, and they shift from week to week as new springs open and old ones go dry. Dallol sits in the Danakil Depression of Ethiopia, 125 metres below sea level, on salt flats that used to be the Red Sea.

Image: Barrowbob | CC BY-SA 4.0

Dallol (hydrothermal system): Below Sea Level, On Land

Thu, 23 Apr 2026 00:00:00 GMT

Photo credit A.Savin, FAL. The Dallol volcano and its surrounding salt flats form the lowest known subaerial volcanic vent system in the world - 45 metres or more below sea level at the vents themselves. The ground beneath Dallol is a salt dome, formed when basaltic magma intruded into an ancient marine se...

Image: A.Savin | FAL

Dallol (hydrothermal system): The Colours Are Not Alive

Thu, 23 Apr 2026 00:00:00 GMT

Photo credit Kotopoulou Electra, CC BY-SA 4.0. Colourful hot springs are, in most places on Earth, painted by microorganisms - the bacteria that give Yellowstone's Grand Prismatic Spring its iridescent rings. Dallol is different. The colours here come from inorganic iron chemistry: oxidation, precipitation, mineral deposition...

Image: Kotopoulou Electra | CC BY-SA 4.0

Dallol (hydrothermal system): An Ocean Being Born

Thu, 23 Apr 2026 00:00:00 GMT

Photo credit A.Savin, FAL. What makes Dallol geologically profound is not its extremity but its meaning. This is one of only two places on Earth where a mid-ocean ridge can be studied on land - the other is Iceland. The Afar Depression around Dallol sits at a tectonic triple junction where the Red Sea spre...

Image: A.Savin | FAL

Dallol (hydrothermal system): The Italians Who Came for Sulphur

Thu, 23 Apr 2026 00:00:00 GMT

Photo credit Rolf Cosar, CC BY 3.0. The first documented industrial activity at Dallol was Italian. During the colonial period - particularly after Italy seized control of Eritrea in 1885 and parts of the Danakil coast soon after - Italian entrepreneurs came to extract sulphur and potash from the exposed mineral fi...

Image: Rolf Cosar | CC BY 3.0

Dallol (hydrothermal system): Mars on Earth

Thu, 23 Apr 2026 00:00:00 GMT

Photo credit Electra Kotopoulou, CC BY-SA 4.0. In 2017 the New York Times ran a piece titled 'Gazing into Danakil Depression's Mirror, and Seeing Mars Stare Back.' NASA scientists have used Dallol as a terrestrial analogue for Martian hydrothermal systems - the thought being that if life could evolve in conditions this hostil...

Image: Electra Kotopoulou | CC BY-SA 4.0