page_title: Emi Koussi
hierarchical_section_title: Emi Koussi
caption_attribution_description: English: The broad Emi Koussi volcano is a shield volcano located in northern Chad, at the south-eastern end of the Tibesti Range. The dark volcanic rocks of the volcano provide a sharp contrast to the underlying tan and light brown sandstone exposed to the west, south, and east (image lower left, lower right, and upper right). This astronaut photograph highlights the entire volcanic structure. At 3,415 meters above sea level, Emi Koussi is the highest summit of Africa's Sahara region. The summit includes three calderas formed by powerful eruptions. Two older and overlapping calderas form a depression approximately 12 kilometres by 15 kilometres in area bounded by a distinct rim (image centre). The youngest and smallest caldera, Era Kohor, formed as a result of eruptive activity within the past 2 million years.
context_page_description: Emi Koussi is a high pyroclastic shield volcano that lies at the southeast end of the Tibesti Mountains in the central Sahara, in the northern Borkou Region of northern Chad. The highest mountain of the Sahara, the volcano is one of several in the Tibesti range, and reaches an elevation of 3,415 metres, rising 3 km above the surrounding sandstone plains. The volcano is 60–70 kilometres wide and has a volume of 2,500 cubic kilometres.
  Two nested calderas cap the volcano, the outer one being about 15 by 11 kilometres in size. Within it on the southeast side is a smaller caldera known as Era Kohor, about 2 kilometres wide and 350 metres deep. Numerous lava domes, cinder cones, maars, and lava flows are found within the calderas and along the outer flanks of the shield. Era Kohor contains trona deposits, and Emi Koussi has been studied as an analogue of the Martian volcano Elysium Mons. Emi Koussi was active more than one million years ago, but some eruptions may be more recent, and there is ongoing fumarolic and hot spring activity.
context_section_description: Emi Koussi (also known as Emi Koussou) is a high pyroclastic shield volcano that lies at the southeast end of the Tibesti Mountains in the central Sahara, in the northern Borkou Region of northern Chad. The highest mountain of the Sahara, the volcano is one of several in the Tibesti range, and reaches an elevation of 3,415 metres (11,204 ft), rising 3 km (1.9 mi) above the surrounding sandstone plains. The volcano is 60–70 kilometres (37–43 mi) wide and has a volume of 2,500 cubic kilometres (600 cu mi).
  Two nested calderas cap the volcano, the outer one being about 15 by 11 kilometres (9.3 mi × 6.8 mi) in size.  Within it on the southeast side is a smaller caldera known as Era Kohor, about 2 kilometres (1.2 mi) wide and 350 metres (1,150 ft) deep.  Numerous lava domes, cinder cones, maars, and lava flows are found within the calderas and along the outer flanks of the shield. Era Kohor contains trona deposits, and Emi Koussi has been studied as an analogue of the Martian volcano Elysium Mons. Emi Koussi was active more than one million years ago, but some eruptions may be more recent, and there is ongoing fumarolic and hot spring activity.
caption: Emi Koussi seen from space
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