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What's Hidden UNDER The Sahara's Sand?
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Mar 31, 2025
The Sahara is, perhaps, one of the most mysterious places on the planet. Not only is it the world's largest hot desert, but it's also a place that used to be much different! Around 5,000 years ago the Sahara was a much greener and wetter region. And human flourished in the region. This means that, hidden underneath all that sand is an incredible world of ancient human civilizations, dry riverbeds and deep canyons, and even long lost fossils of sea creatures from when the Sahara was literally under the ocean. So let's find out what's under all that sand!
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0:00
To most people, the Sahara Desert is just a vast ocean of sand
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But what if I told you there's a hidden world beneath the surface
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Thousands of years ago, the Sahara looked and felt radically different from how it does now
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And that world didn't go away. It's still there, buried under layers of sand
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So when you look at that landscape, if all you see are barren sand dunes
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you're only getting half the story. Let's find out what lies under the Sahara Desert
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And to do that, we need to first go 5,000 years back in time
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The Sahara Desert today is a huge and extremely dry region with endless dunes and rocky flatlands
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It's also the largest hot desert in the world, but it wasn't always this way
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During the African humid period, roughly 15,000 to 5,000 years ago, the Sahara's climate was significantly different due to a shift in the Earth's axial tilt
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This change affected the distribution of solar radiation, with more sunlight reaching the northern hemisphere during the summer months
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As a result, monsoon rains intensified, bringing much more rainfall than the region receives today
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and creating conditions suitable for lakes, rivers, and abundant vegetation. So what is now a mostly empty, very dry region was rich in natural resources
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supporting not just wildlife, but also early human civilizations. Evidence of this greener Sahara comes from multiple sources
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Archaeological findings, such as rock art discovered in places like the Tassili al-Nagir
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plateau in Algeria, depict animals and human activities that would be impossible in the
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modern desert. These images show scenes of hunting, herding cattle, and fishing, indicating the presence
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of water and the ability to sustain agriculture and animals. These ancient peoples are believed to have lived in relatively large communities, making
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use of the fertile land for farming and herding, and establishing a way of life centered around
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the seasonal patterns of rainfall. One of the most notable findings is the existence of ancient lakes
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Lake Megachad, for example, once stretched over a significant portion of the southern Sahara
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making it one of the largest freshwater bodies in the world at its peak. However, over time
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the region's climate began to shift. The African humid period ended as the monsoon rains weakened
2:17
and moved southward, leading to the gradual desertification of the Sahara. Today, only
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remnants of these vast lakes remain, with Lake Chad now a shadow of its former size. This took
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thousands of years, but by around 3000 BCE, the Sahara had largely transitioned into the desert
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we see today. This desertification forced human and animal inhabitants to migrate or adapt to the
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much drier conditions. Many people moved toward more hospitable regions, such as the Nile River
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Valley, contributing to the rise of the early Egyptian civilization. Others move southward
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closer to the remaining water sources, while some groups may have continued to live on the edges of
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the expanding desert, eking out a nomadic existence. Today, it's hard to imagine the Sahara as anything
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other than a scorching desert, but beneath its sands lie the remnants of a greener past
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Fossils of ancient fish, snail shells, and preserved plant material are all reminders of a time when
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the Sahara was a cradle of life. And by taking a closer look at its geography, we'll uncover more clues about what lies
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underneath the desert The Sahara is a land of extremes a vast expanse that stretches across northern Africa covering
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more than 9.2 million square kilometers. According to popular films, the Sahara is nothing but an endless sea of sand dunes, but
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it can actually be very diverse, marked by different types of desert landscapes, each
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with their own character and challenges. from the rolling sand dunes most often associated with it to rocky plateaus
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and from dry riverbeds to oasis towns. There's really no one singular Sahara
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Of course, one of the most iconic features of the Sahara are the sand dunes, or ergs
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which make up about 20% of the desert. The most famous of these is the Erg Cheby in Morocco
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where towering dunes, some reaching heights of 500 feet, create a constantly shifting landscape as the wind reshapes the sand
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These dunes, however, are just one type of desert landscape in the Sahara
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In fact, much more of the desert is made up of rock-strewn plains, known as regs
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where loose gravel and small stones cover the surface. These regions are flat, with few signs of life, giving them a harsh, otherworldly feel
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Walking across a reg is an experience of desolation, where the ground crunches underfoot and the horizon seems to stretch endlessly
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unbroken by vegetation or shelter. Another important feature of the Sahara's geography are the Hamadas
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barren, rocky plateaus that rise above the desert floor. These areas are stark and inhospitable
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with little to no sand, and the ground is often made up of exposed bedrock
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The Hamadas are difficult to traverse due to their rough terrain, but they provide our first clue as to what lies under all that sand
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Finally, interspersed among these harsh landscapes are the wadis, or dry riverbeds, that once carried water across the desert during wetter times
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Though they are now typically dry when rare rains fall, these wadis can quickly flood
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transforming the desert with a temporary rush of life. These fleeting rivers serve as a reminder of the Sahara's greener past
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and the possibility of regeneration, if only briefly. As we're going to see, diving under the Sahara's sand would reveal these waterways to be just the tip of the iceberg
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Now despite this overwhelming aridity, the Sahara is dotted with oases, small, fertile areas where groundwater reaches the surface
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allowing for the growth of plants and human settlement. Oases like those in Siwa in Egypt or Gadamis in Libya
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offer life-saving respite in the desert's vastness. These areas are often centers of agriculture
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where palm trees, dates, and citrus fruits are cultivated and where small communities have thrived for centuries
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Life in these oases revolves around the careful management of water, a scarce and precious resource in the desert
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Living in an oasis can feel like inhabiting a small island in a sea of sand
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Where the surrounding desert ocean is forever present and venturing out into it unprepared
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is basically signing your death warrant. Speaking of death, the Sahara is one of the hottest and driest places on Earth
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Daytime temperatures regularly soar above 40 degrees Celsius in the summer, while nighttime temperatures can plummet drastically, sometimes below freezing in the winter months
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The extreme heat, combined with the lack of humidity, creates a brutal environment where the body can lose water quickly
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making hydration a constant concern for anyone living or traveling in the desert
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The wind, too, plays a significant role in shaping life in the Sahara
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Hot dry winds known as the Sirocco or Comson can whip across the desert creating dust storms that reduce visibility to near zero and make travel deadly This is one aspect of life in the Sahara that wouldn change if we got rid of all the sand
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But of course, despite the overwhelming variety of geography within the Sahara
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it's the sand dunes that make up such an iconic part of it. Which leads back to the original question of this video
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What is under all of that sand? In a lot of ways, the Sahara sand dunes are like the ocean
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They shift and move around. They're fairly unstable, and yes, you can even sink into it
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And also, just like with the ocean, the sand isn't the ground
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It's merely something that exists on top of it and in great quantities. Which means there's something hidden beneath it
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If the sand were swept away, the Sahara would reveal not only its ancient geologic history
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but also evidence of past human civilizations and natural wonders long buried under the dunes
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One of the most fascinating discoveries under the Sahara is the existence of vast aquifers
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underground lakes and rivers that date back to a time when the region was lush and teeming with life
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These hidden water reservoirs are relics of the African humid period, when rainfall was much more abundant
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The largest of these aquifers, the Nubian Sandstone Aquifer System, stretches beneath
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the eastern Sahara and contains around 150 trillion cubic meters of water
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If the sands were removed, parts of this immense water system would be exposed, likely resembling
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ancient riverbeds and marshy lowlands. This underground water has been tapped in places, such as in the Libyan Desert where
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the great man-made river project has piped water from deep aquifers to supply cities
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But while the aquifer in the east is fascinating, it's the long-buried Taman Rasset River in the west that's perhaps the most shocking reveal
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Advanced satellite images have recently uncovered the presence of a deep river valley
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that stretches from the southern Atlas Mountains in present-day Algeria to the Atlantic Ocean in modern-day Mauritania
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This river was larger than the Nile River is today and would have supplied all the water that ancient human civilizations would have needed to survive
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And we know that civilizations once existed here because archaeologists have found evidence of prehistoric settlements, tools, and even entire cities that were once thriving hubs of trade and culture
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In Mauritania, the ancient circular structure known as the Raikat Structure, or the Eye of the Sahara, has puzzled scientists for decades
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This natural formation, approximately 50 kilometers in diameter, has concentric rings of rock that would be far more visible without the sand, revealing the true scope of this mysterious landmark
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Scientists theorize that early human settlements may have existed in and around this formation
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potentially serving as a focal point for ancient communities. During this time, the Sahara was likely once part of a network of trade routes
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that linked sub-Saharan Africa to North Africa and the Mediterranean. Evidence of these ancient trade routes, including the remains of caravanserais and abandoned towns
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lies hidden under the sand. Some believe that entire lost cities, like the fabled city of Zerzura
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remain undiscovered, buried beneath the shifting dunes. In this way, the Sahara sands have acted as a time capsule, preserving artifacts from these
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lost civilizations, from pottery shards to tools and even tombs. But humans have only been around for a short period of time relatively and it the rocks and ground beneath the sand that tell an even older story You see the Sahara sits on a foundation of ancient bedrock some of which dates back hundreds of millions of years
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If the sand were stripped away, you would see vast expanses of exposed rock
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including ancient mountain ranges and plateaus. One of the most remarkable formations is the Hogar Mountains in southern Algeria
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a rugged volcanic range that rises dramatically from the desert floor. Without sand, the sheer variety of geological features would be striking
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Jagged volcanic peaks, weathered mesas, and even canyons carved by rivers that once flowed through the region
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In many places, the sand is only a thin veil over these solid ancient structures
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Moreover, the sands of the Sahara have preserved countless fossils, mostly of animals that lived during wetter periods
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Remains of ancient fish, crocodiles, and other aquatic species have been uncovered
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along with evidence of the lakes and rivers that once crisscrossed the region
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But the most shocking discovery is that of a 37 million year old ancient whale skeleton
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Discovered in the early 1900s, Wadi al-Hitan, also known as the Valley of the Whales
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is a region of Egypt that contains hundreds of nearly perfectly preserved fossils of ancient
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sea creatures from a time when the Earth was radically different. Many of these creatures were likely alive during the Eocene approximately 33 million years ago
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when much of the Sahara was under the ocean. All of these fossils we see today were relatively shallow
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If we removed all of the Sahara's sand, we would likely find older, more ancient, and even more perfectly preserved ancient fossils
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Finally, if all the sand were removed, the Sahara would be far more contrasting than it is today
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Towering mountains, deep valleys, and rocky plains that have been hidden for millennia would suddenly be unearthed
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And the feeling of standing on this exposed terrain would be vastly different from the current experience of walking over soft dunes
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It would feel more like stepping onto the surface of an alien planet, with jagged rocks and sharp-edged cliffs replacing the smooth-flowing sands
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The heat would remain intense, of course, and the bare rock would radiate even more heat
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making the environment even more unforgiving than it is today. And the winds, which now shape the dunes, would howl across open plains and rocky surfaces
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creating a harsher, more abrasive landscape. Ultimately, the Sahara is not just a desert of sand
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Beneath its dunes lies a world of water, fossils, ancient human settlements
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and geologic wonders that tell the story of a region far more complex than its uniform sandy surface suggests
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Given enough time, all of this will be revealed. Whether humans are around to see it, however, remains to be seen
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As it turns out, there's an entire hidden world underneath the Sahara's sand
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Mostly because during the African humid period, humans lived and traversed the land
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And wherever humans go, we tend to leave a lot of things. The Sahara, in this regard, is no different
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And if that sand were to magically disappear overnight, we would see some truly amazing parts of our human history from long before
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