Beneath the sands of the Sahara Desert scientists have discovered evidence of a prehistoric megalake. Formed some 250,000 years ago when the Nile River pushed through a low channel near Wadi Tushka, it flooded the eastern Sahara, creating a lake that at its highest level covered more than 42,000 square miles.
The Sahara desert has dry valleys, mountains, salt flats, barren and rocky plateaus, and sand dunes. There are 20 lakes in the Sahara desert and almost all of them are saltwater lakes. The only freshwater lake in the Sahara desert is Lake Chad.
Today we invite you to touch down in Algeria and explore Timgad, a lost Roman city on the edge of the Sahara desert that remained hidden beneath the sand for nearly a thousand years.
The Eye of the Sahara, also known as the Richat Structure, is a geologic dome containing rocks that predate the appearance of life on Earth. The Eye resembles a blue bullseye and is located in Western Sahara. It is visible from space and has been used as a visual landmark by astronauts.
Stretching across the northern tip of Africa, this vast desert is challenging most difficult places on Earth to traverse due to its barren landscape and extreme temperature fluctuations. As a result, many parts of the Sahara remain uncharted, making it an exciting yet dangerous prospect for thrill-seekers.
The Sahara Desert was once underwater, in contrast to its present-day arid environment. This dramatic difference over time is recorded in the rock and fossil record of West Africa. The region was bisected by a shallow saltwater body during a time of high global sea level.
The next Northern Hemisphere summer insolation maximum — when the Green Sahara could reappear — is projected to happen again about 10,000 years from now in A.D. 12000 or A.D. 13000. But what scientists can't predict is how greenhouse gases will affect this natural climate cycle.
“We were able to conclude that the variations in Earth's orbit that shifted rainfall north in Africa 6,000 years ago were by themselves insufficient to sustain the amount of rain that geologic evidence shows fell over what is now the Sahara Desert.
The depth of sand in ergs varies widely around the world, ranging from only a few centimeters deep in the Selima Sand Sheet of Southern Egypt, to approximately 1 m (3.3 ft) in the Simpson Desert, and 21–43 m (69–141 ft) in the Sahara.
Atlantis of the Sands refers to a legendary lost city in the southern deserts of the Arabian Peninsula, thought to have been destroyed by a natural disaster or as a punishment by God.
By A.D. 700, only a few people lived in and around Petra. Over time, the city was lost to the outside world. More than 500 years would pass before the ancient city was rediscovered by Western explorers.
Do People Live In The Sahara? The population of the Sahara is just two million. People who live in the Sahara are predominantly nomads, who move from place to place depending on the seasons. Whilst others live in permanent communities near water sources.
But 11,000 years ago, what we know today as the world's largest hot desert would've been unrecognizable. The now-dessicated northern strip of Africa was once green and alive, pocked with lakes, rivers, grasslands and even forests.
No, around 11,000 years ago, the Sahara wasn't a desert at all. Instead, it was covered in plant life. It also held bodies of water. There was even a “megalake” that covered over 42,000 square miles.
However, scientists have observed that tropical latitudes are moving polewards at a speed of 30 miles per decade, and thus, the deserts within are expanding.
Then humans showed up. Today, the Sahara Desert is defined by undulating sand dunes, unforgiving sun, and oppressive heat. But just 10,000 years ago, it was lush and verdant.
It was long believed that the region had been this way since about 1600 BCE, after shifts in Earth's axis increased temperatures and decreased precipitation, which led to the abrupt desertification of North Africa about 5,400 years ago.
Once a region becomes arid, there's no vegetation or water to hold the soil down. Then the wind takes over and blows away the finer particles of clay and dried organic matter. What's left is desert sand.
At the time the Giza pyramid complex was built—between 2670 and 2500 BCE—the channel was about 40% as high as during the African Humid Period, a peak wet period more than 1,000 years prior. This earlier period saw relatively soggy conditions throughout northern Africa and a mostly green Sahara desert.
Antarctica is the largest desert on earth, almost twice the size of the Sahara Desert. How does Antarctica compare to other deserts on earth?
Photo by: Conceptual Image Lab, NASA/Goddard Space Flight Center. Scientists have just uncovered an incredible link between the world's largest desert (the Sahara) and its largest rainforest (the Amazon).
New research describes the ancient Trans-Saharan Seaway of Africa that existed 50 to 100 million years ago in the region of the current Sahara Desert.
The coastal desert of Namibia is located along Africa's Atlantic coast towards the south-west. The high sand dunes of Namib Desert and the point where the desert meets the sea are the key attractions of this UNESCO World Heritage Site.