Emi Koussi

Where is Emi Koussi?

Emi Koussi is part of the Tibesti Mountains.

You will find it in: Chad.

Summit: 19.793° N, 18.546° E

The story behind it

Emi Koussi is not a pointed peak but a giant flattened dome, sixty to seventy kilometres across, built from layer upon layer of lava over millions of years. Inside its summit sit two nested calderas: the outer one measures roughly fifteen by eleven kilometres, and within it the pit called Era Kohor is about two kilometres wide and three hundred and fifty metres deep. The volcano has not had a large eruption for a very long time, with the main activity dated between about 2.4 and 1.3 million years ago, yet hot springs at Yi Yerra on its southern flank still bubble out at around thirty-seven degrees, roughly body temperature. Less than twenty millimetres of rain falls here in a year, which is why the slopes are bare rock and sand rather than forest. The Toubou, especially the Teda, live in this part of the Sahara, moving with their herds between oases and rock pools called gueltas. Planetary scientists study Emi Koussi as an Earth stand-in for Elysium Mons, a huge volcano on Mars, because both grew above slow-moving hot spots with similar broad shapes. Heights given for the summit differ, from 3 415 metres in some catalogues to 3 447 metres in others.

Find it on the globe

Emi Koussi is there as a small peak with its own shape — a horn, a ridge, a volcano — standing on the surface. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.

It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.