The Sahara is unimaginably vast; spanning some 9 million square kilometres, it’s the world’s largest desert outside those of the polar regions. Thus, as you would expect, there’s an awful lot of interesting stuff going on inside it. For this answer I’ve picked only the most fascinating tidbits I could find on this region.
- Despite its (deserved) reputation as a scorching wasteland, it does occasionally snow in the Sahara. Three instances of significant snowfall have been recorded here, all in Algeria, and in all cases the snow melted within hours of it falling. The last time it happened was January of 2018.
- In some parts of the Sahara Desert, especially Tunisia, desert roses form. These are beautiful crystals of gypsum, encrusted in sand, which are created by the evaporation of shallow water bodies. It’s easy to see how they get their name.
- In Mauritania you can find an immense circular rock formation known as the Richat Structure, or the Eye of the Sahara. It measures forty kilometres in diameter, and was originally thought to be an impact crater, but is now understood to be an eroded dome of volcanic rock.
- About 14,500 years ago, an era called the African Humid Period began, lasting up until ~6,000 years ago. During this time, the monsoon of West Africa became stronger, and the Saharan region saw a marked increase in rainfall. The desert gave way to lush savannah, leading to a Green Sahara.
- Lake Chad is currently the largest body of water in the Sahara, but it is a shadow of its former self. While the region was green, Lake Chad was Lake MegaChad, over 700 times its modern size! In fact, it was the world’s largest lake, by far, at more than a million square kilometres in area.
- The Sahara Desert contains more prehistoric rock art than perhaps any other part of the world. These ancient paintings date back as far as 12,000 years ago, and depict everything from warfare and farming to people swimming and now-extinct local wildlife. They are an invaluable window into the lush, rainy past of this now-bleak desert.
- In Eastern Morocco, there is an incredibly rich fossil site - the Kem Kem Beds - from around 95 million years ago. It shows that this part of the Sahara was once a marshy place which was the abode of some of the largest carnivorous dinosaurs of all time, 30-ton sauropods, giant crocodiles, sawfish bigger than minivans, and much more.
- The desert’s Saharan silver ants are spectacularly well-adapted to the extreme heat. Their beautiful silvery hair reflects sunlight, and they have special proteins which allow them to withstand up to 53 degrees Celsius! Even still, they can only spend 10 minutes per day in the sun, so they have to be speedy - in fact, for their size they are the third-fastest organisms on Earth.
(That paragraph was criminally short for an overview of these amazing ants, I’ll have to do them justice in a full answer some day…)
- The Sahara is home to a fascinating plant called Anastatica hierochuntica, also known as the rose of Jericho. When the dry season begins, it shrivels up and becomes fully desiccated, detaching from the ground and blowing away in the wind. Yet, upon contact with moisture in the following wet season, it “resurrects” itself, regaining its former vitality.
- In Chad, you can find Guelta d’Archei, a beautiful secluded oasis in a deep sandstone gorge. Every day, it is used by local herders to quench the thirst of thousands of camels, which have stained the waters black with their dung. The oasis is the only known remaining colony of West African crocodiles in the Sahara Desert, too.
- In 1993, electrician Emile Leray was travelling in the desert of Morocco when his car allegedly hit a rock and had its front axle destroyed. He dismantled the wreck, and used the parts to build a fully functioning motorcycle, which he dubbed his “Steel Camel” and rode to civilization.
(It’s worth mentioning that, while this is nevertheless really cool, it’s unlikely that it was a daring tale of survival as is often claimed. What’s much more probable is that Leray went to the Sahara with the explicit intention of building a motorbike out of his Citroen there.)
- The hottest known part of the Sahara Desert is Bou Bernous, a very small and isolated town in western Algeria. Its average temperature over the course of a day was once recorded at a blistering 47 degrees Celsius, the highest such measurement anywhere on Earth!
- If you look at a satellite map of Libya, you might notice an abrupt little black dot. That is Waw an Namus, a verdant oasis inside a volcano, famous for its black tephra (volcanic gravel, basically). It is rich in bird-life, unlike the surrounding wasteland.
- The Ancient Romans made several military explorations deep into the Sahara, even venturing into sub-Saharan Africa. One expedition party, for example, arrived at Lake Chad, which they called the “lake of hippopotamuses”. They stationed a small garrison here.
- In Mali’s Dogon region, in the southern extreme of the Sahara, there is a steep cliff known as the Bandiagara Escarpment. Here, the local people build spectacular villages of mud huts which hug the sandstone cliffside.
- The Mauritanian Railway is a rail route on which some of the world’s longest trains traverse. These trains can be up to three goddamn kilometres long, and weigh tens of thousands of tonnes! They carry iron ore and occasionally passengers.
- In Tunisia, there is a unique desert village called Matmata. Here, some local Berbers dwell in underground houses, formed around one or more large pits, perfect for shielding oneself from the scorching Saharan sun. The town was the main filming location of Tatooine in the original Star Wars film.
- One of Egypt’s UNESCO World Heritage Sites is Wadi El Hitan, or the Valley of the Whales. It is in fact a paleontological dig site, where exceptional fossils of the ancient whale Basilosaurus have been uncovered. Remains of sharks, sea cows, turtles and even the first ever pelican have also been found there, showing the sands were once a shallow sea.
- Morocco boasts the title of having the world’s largest concentrated solar power plant, the Ouarzazate Solar Power Station. Its construction began in 2013, and when it is finished it will produce an estimated 582 megawatts of energy. The project has cost around 2.5 billion dollars.
- Though not nearly as famous for the structures as Egypt is, Sudan is home to over 350 pyramids - more than twice as many as the former nation has. These were built by the Nubian people, who were then known as the Kingdom of Kush, starting at around 800 BC.
- When you think about Saharan scenery, you probably imagine featureless dune fields and rocky plains, but the Hoggar Mountains of Algeria feature many dramatic landscapes. These highlands are volcanic in origin, and some of their peaks are nearly 3 kilometres high.
- In the desert of Niger, you can find the world’s tallest mud-brick building, the Mosque of Agadez. It was built way back in 1515, and has gone practically unchanged since then.
- In Morocco every year, the Marathon des Sables is held - arguably the world’s most gruelling and challenging footrace. At 251 km in length, the course is six times longer than a standard marathon, and takes nearly a week to complete. Due to COVID-19, the race hasn’t been held since 2019.
- There is a 7,000 square kilometre lake in the Tunisian Sahara called Chott el Djerid which - in summer - becomes the desert’s largest salt pan. Due to evaporation, a crust of salt builds up over the water, thick enough to drive a car over. When winter comes, it returns to its watery state.
- On average, 182 million tonnes of Saharan dust are blown west over the Atlantic Ocean each year. Of that, 28.8 million tonnes settle in the Amazon Rainforest of South America. This seemingly plays a crucial role in the jungle’s biodiversity, as the dust carries vital minerals for fertility such as phosphorus.
- Some of that dust also ends up in Cape Verde, an archipelago off the west coast of the Sahara, and acculumates in the Viana Desert. This small field of sand dunes could be considered an extension of the Sahara Desert found way out in the Atlantic Ocean.
- Egypt is home to both a Black Desert and a White Desert. The former is a volcanic area full of mounds of basalt, in which dinosaur remains have been excavated. The latter is famous for its chalk rocks, which have been eroded into exquisite shapes.
So, I’ll leave it that for today. At first glance, the Sahara seems pretty empty, but upon taking a much closer look I’ve realized that I couldn’t possibly fit all of its interesting features in a digestible answer. I hope you enjoyed the ones that I selected.
As an aside, I know the phrase “Sahara Desert” is tautological, as the word Sahara itself derives from the Arabic word for desert.