One of the main reasons that rainless regions like the Sahara Desert are interesting from the perspective of landscape science is that the work of flowing water—mainly streams and rivers—becomes less important than the work of wind. Over millennia, if enough sand is available, winds can generate dunes of enormous size, arranged in regular patterns. Long, linear dunes stretch generally north to south across much of northeast Algeria, covering a vast tract (~140,000 square kilometers) of the Sahara Desert known as the Erg Oriental. Erg means “dune sea” in Arabic, and the term has been adopted by modern geologists. Spanning this image from a point on the southwest margin of the erg (image center point: 28.9°N 4.8°W) are a series of 2-kilometer-wide linear dunes, comprised of red sand. The dune chains are more than 100 meters high. The “streets” between the dunes are grayer areas free of sand.
Published Sep 11, 2006
This digital elevation map of the Badain Jaran Desert shows multi-generation dunes, with smaller dunes resting atop larger ones.
Published Apr 20, 2011
Layers of dunes march across a sand sea in the east-central Tenéré Desert of Niger in this astronaut photo from December 1, 2009.
Published Dec 28, 2009
Large linear dunes stretch across the Great Eastern Sand Sea of northern Algeria.
Published Apr 4, 2016
he Issaouane Erg (sand sea) is located in eastern Algeria between the Tinrhert Plateau to the north and the Fadnoun Plateau to the south. Considered to be part of the Sahara Desert, the Issaouane Erg covers an area of approximately 38,000 km2. These complex dunes form the active southwestern border of the sand sea.
Published Feb 7, 2005
Sand dunes and outcrops add color and dimension across the Namib Sand Sea.
Published Jan 13, 2020
Linear dunes dominate the landscape of eastern Namibia. Part of the Kalahari Desert, the dunes likely formed more than 10,000 years ago.
Published Dec 4, 2011
Complex wind patterns left these distinctive star-shapes in the sands of the Grand Erg Oriental.
Published Sep 29, 2013
Winds shape the sands that were left behind by an ancient river.
Published Jun 4, 2012
Dunes grow upon dunes at one of the most visually spectacular places on Earth, at least from an astronaut’s perspective.
Published Nov 21, 2016
Sand dunes sprawl along the coast of northeastern Brazil, sometimes extending kilometers inland.
Published Jul 11, 2010
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