BackgroundThe large volcano of Emi Koussi at the SE end of the Tibesti Range forms the highest summit of the Sahara. The 60 x 80 km massif was constructed over a basement of Cretaceous and Paleozoic sandstones. Two nested calderas, 12 x 15 km in size, truncate the dominantly trachytic volcano, whose 3415 m high point lies on the southern caldera rim of the low-angle pyroclastic shield volcano. The calderas contain several explosion craters, lava domes, and young scoria cones, along with lava flows of recent and pre-modern age (Geze et al., 1959). The spectacular Era Kohor (Trou au Natron du Koussi) caldera on the SE floor of the 2nd caldera is 2-3 km wide and 350 m deep. The latest activity in the calderas produced three maars, and numerous basaltic cinder cones and associated lava flows have been constructed both within the calderas and on their outer flanks. The Yi-Yerra thermal area is located on the southern flank.
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8