ISS026-E-17074

Browse image
Resolutions offered for this image:
1000 x 664 pixels 540 x 359 pixels 720 x 480 pixels 4288 x 2929 pixels 640 x 437 pixels
Cloud masks available for this image:
Binary Heatmap

Spacecraft nadir point: 19.4° N, 16.8° E

Photo center point: 20.0° N, 18.5° E

Nadir to Photo Center: East

Spacecraft Altitude: 189 nautical miles (350km)
Click for Google map
Width Height Annotated Cropped Purpose Links
1000 pixels 664 pixels No Yes Earth From Space collection Download Image
540 pixels 359 pixels Yes Yes Earth From Space collection Download Image
720 pixels 480 pixels Yes Yes NASA's Earth Observatory web site Download Image
4288 pixels 2929 pixels No No Download Image
640 pixels 437 pixels No No Download Image
Other options available:
Download Packaged File
Download a Google Earth KML for this Image
View photo footprint information
Image Caption: Emi Koussi Volcano, Chad

Note: This caption refers to the image versions labeled "NASA's Earth Observatory web site".

The broad Emi Koussi volcano is a shield volcano located in northern Chad, at the southeastern 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).

Emi Koussi was formed from relatively low viscosity lavas--flowing more like motor oil than toothpaste--and explosively-erupted ignimbrites that produce a characteristic low and broad structure covering a wide area (approximately 60 by 80 kilometers).

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 kilometers by 15 kilometers in area bounded by a distinct rim (image center). The youngest and smallest caldera, Era Kohor, formed as a result of eruptive activity within the past 2 million years.

Young volcanic features, including lava flows and scoria cones are also thought to be less than 2 million years old. There are no historical records of eruptions at Emi Koussi, but there is an active thermal area on the southern flank of the volcano.