Lakes appear across the Sahara desert after floods

Satellite images show lakes dotting the Sahara desert after a cyclone dumped a year's worth of rain on northern Africa in just days.

Lake Sebkha el Melah in this image taken on September 29 by the Landsat 9 satellite. (Photo: US Geological Survey)

Lakes have appeared in the Sahara after a storm brought torrential rains to northern Africa, inundating swaths of the world's largest hot desert, according to satellite images. The extratropical cyclone swept through parts of Morocco, Algeria, Tunisia and Libya on September 7 and 8, dumping up to 8 inches (20 centimeters) of rain in affected areas, equivalent to a year's worth of rain in just a few days, according to NASA's Earth Observatory.

The flooding has filled several temporary lakes in the Sahara, including Sebkha el Melah in Algeria and several others around Erg Chebbi, a vast star-shaped dune landscape in Morocco. NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite has also captured images of several temporary lakes appearing across Morocco and Algeria.

A new lake appeared on the edge of the Erg Chebbi star-shaped dunes on October 1. (Photo: Google Earth/European Union).

The lakes of Erg Chebbi filled up after a river from the nearby Atlas Mountains overflowed near Merzouga, a town not far from the Algerian border that serves as an entrance to the star-shaped dunes. This image taken on October 1 by one of the Copernicus Sentinel-2 satellites shows several new lakes dotted around the edges of Erg Chebbi.

NASA's Landsat 9 satellite captured this image of the flooded Sebkha el Melah Lake in Algeria. The images, taken between August 12 and September 29 and shared by the Earth Observatory, show the changing landscape, with the blue lake in the desert. The lake covers 191 square kilometers and is about 2.2 meters deep, according to calculations by Moshe Armon, a lecturer at the Hebrew University of Jerusalem. Armon used satellite images to determine the extent of the water and combined them with a 3D map of the lake.

Lakes appeared scattered across Algeria and Morocco from August 14 to October 9. (Photo: NASA).

Since 2000, the water level in Sebkha el Melah has been higher than it is now twice. In 2008, the lake was full after an extratropical cyclone dropped exceptionally heavy rain. Four years later, the lake dried up completely again. The water filling Sebkha el Melah will likely stay there for a while. 'Without any further rain, the current 2.2-meter depth would take about a year to evaporate completely,' Armon said.

Understanding how September's cyclone-like rainfall event affected the Sahara will help researchers better understand what the desert looked like thousands of years ago and how the landscape will change in the future due to climate change. Researchers predict that many parts of the Sahara will experience more rain.