Earth Imaging Journal: Remote Sensing, Satellite Images, Satellite Imagery
Breaking News
Orbit GT Releases Free Esri ArcOnline Widget for 3D Mapping Cloud and 3DM Publisher
Orbit GT releases the free ArcOnline Widget for Web...
Maxar Technologies Hosts Canadian Prime Minister Justin Trudeau
MONTREAL - Maxar Technologies (formerly MacDonald, Dettwiler and Associates...
Next Generation Infor Enterprise Asset Management Now Available
NEW YORK - Infor, a leading provider of industry-specific...
World Geospatial Industry Council (WGIC) Launched at UNGGIM
In a landmark development, geospatial industry leaders from across...
Argon Design Releases Argon Streams AV1
CAMBRIDGE, England- Argon Design Ltd, known for its award-winning family...

Taken through a window on the International Space Station by the EarthKAM camera, this photograph shows the boundary between a major dune field and dark hills along the border between Algeria and Libya. These landscapes are among the driest parts of the Sahara Desert. For scale, the dune margin shown in this photo is slightly more than 100 kilometers long.

Large dune fields are known to geologists as “ergs,” the Arabic term for these extensive regions of sand. This eastern erg (known as the Oriental) of Algeria includes hundreds of dune mounds. From more detailed images we know that these are “star dunes.” The erg itself occupies a vast area of approximately 600 kilometers by 200 kilometers.

Many winding water courses are visible on the right half of the photo. These typically dry channels drain occasional rainwater toward the edge of the vast erg. Sediment carried by such streams has accumulated over a few million years to make the dunes. The margin in the image marks the line between a zone dominated by wind as the main landforming agent and a zone dominated by water movement.

The wind-sculpted hills—sometimes called grooved terrain—have a remarkably straight pattern because they were eroded by one-directional winds from the north. A dry desert lake appears as a white surface near straight roads that cross this desert. Another lake appears as a dark patch due to the vegetation that grows in its shallow water.

A dense cluster of date-palms indicates the location of the Libyan town of Ghadames, population 10,000. The old part of the town is walled and has been declared a UNESCO World Heritage site.

Photo Credit: The photo has been enhanced to improve contrast. It is provided by the Sally Ride EarthKAM@Space Camp on the International Space Station.

Comments are closed.