Satellite images captured of water bodies scattered across the Sahara Desert emerged after a cyclone dumped a year’s worth of rain on northern Africa in just a few days.
Sebkha el Melah lake captured by Landsat 9 on September 29. (Image: U.S. Geological Survey)
The lakes appeared in the Sahara after a storm brought heavy rainfall to northern Africa, flooding many areas of the largest hot desert on Earth, according to satellite images. An extratropical cyclone swept through parts of Morocco, Algeria, Tunisia, and Libya on September 7 and 8, delivering rainfall amounts of up to 20 cm in affected regions, equivalent to an entire year’s worth of rain in just a few days, according to NASA’s Earth Observatory.
The heavy rainfall filled many temporary lakes in the Sahara, including Sebkha el Melah in Algeria and several other lakes around Erg Chebbi, a vast star-shaped sand dune region in Morocco. NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite also captured images of several temporary lakes appearing throughout Morocco and Algeria.
A newly formed lake at the edge of the Erg Chebbi sand dunes on October 1. (Image: Google Earth/European Union).
The lakes at Erg Chebbi filled with water after rivers 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. Images taken on October 1 by one of the Copernicus Sentinel-2 satellites show numerous new lakes scattered around the edges of Erg Chebbi.
Nasa’s Landsat 9 satellite captured images of the water-filled Sebkha el Melah in Algeria. Images taken from August 12 to September 29, shared by the Earth Observatory, reveal changes in the landscape, with the lake appearing as a vivid blue spot in the desert. The lake covers an area of 191 square kilometers and is approximately 2.2 meters deep, according to calculations by Moshe Armon, a lecturer at the Hebrew University of Jerusalem. Armon used satellite images to determine water coverage combined with a 3D map of the lake.
New lakes appearing throughout Algeria and Morocco from August 14 to October 9. (Image: NASA).
Since 2000, the water level in Sebkha el Melah has been higher than it is now on two occasions. In 2008, the lake filled with water after an extratropical cyclone caused exceptionally heavy rains. Four years later, the lake completely dried up again. The water filling Sebkha el Melah is likely to last for some time. “If there are no further rains, the current depth of 2.2 meters will take about a year to evaporate completely,” Armon stated.
Studying the rainfall event from the cyclone in September and its impact on the Sahara Desert will help researchers understand what this desert looked like thousands of years ago and how the landscape might change in the future due to climate change. Researchers predict that many areas in the Sahara will experience more rainfall.
