What Makes This Lake Smell Like Rotten Eggs?

If a ticket to Mars is a little out of your price range, then a visit to Dallol in Ethiopia might be the next best thing. The colourful landscape looks as though it belongs on another planet, with green pools of acid, strange salt formations and toxic gases spewing from the surface. The area is actually a large volcanic crater, formed when rising basaltic magma made contact with salt deposits and ground water.

This caused the water to evaporate immediately, resulting in a huge eruption of rock, ash, water and steam. The Dallol crater was formed during an eruption in 1926, but the area is still alive with geothermal activity today. Hot springs spurt out a briny substance, created as hot water dissolves salt and other soluble minerals beneath the surface.


Dallol’s dramatic landscape features colourful acidic pools and salt deposits

As the brine evaporates in the hot climate, it creates salt formations that are coloured white, yellow, orange, green and brown by sulphur, iron oxide and other chemical compounds. The sulphur is emitted as gas from cracks in the ground, making the shallow green pools on the surface highly acidic, and the surrounding area smell of rotten eggs.

That’s not the only thing that might put you off visiting though, as Dallol is also one of the hottest places on Earth. The average annual temperature is 35 degrees Celsius (95 degrees Fahrenheit), but frequently exceeds 45 degrees Celsius (113 degrees Fahrenheit) in the summer months. It’s no wonder this harsh desert has been labelled the ‘Hellhole of Creation’.