The world's largest desert, the Sahara Desert , has stories and legends all over the world, and even those who haven't been there will be shocked by its vast sandy land and desolate sights.

desolate sahara desert

Just a small oasis can give hope to those lost here, and the Berbers who have lived here for generations have always found water in their own unique way.

If you want to dig water here, how deep do you need to dig into the sand to see the water?

In fact, it is very difficult to obtain a water source here. If you do not find the right location, even if you dig dozens of meters, there will be no water .

By the way, the deepest sand here reaches 180 meters , although it is not as deep as Shanghai, but this depth is enough to submerge a city.

Berbers in the desert

What will happen if you continue to dig down in the Sahara Desert, or even dig out the sand here? What will we see at the bottom? Where does the water in the Sahara Desert come from? How did this place become sand?

This article will reveal these answers one by one from various studies in the Sahara Desert.

Ancient river under the desert

The Sahara Desert is mainly composed of rocky hamada and sandy land, with many dunes over 180 meters high, with an average height of around 150 meters .

Covering most of the area from Algeria, Chad, Egypt to Niger, Western Sahara, etc., the desert area covering an area of ​​9 million square kilometers makes it the largest desert area on earth .

Sahara Desert

However, the Sahara is not all desolate areas, no grass grows. The driest area is in the middle of the Sahara, and in the northern and southern parts of the desert, including the highlands, there are relatively sparse grasslands and desert shrubs, as well as tall shrubs. There are many gatherings here.

To the south, on the Sahel border of the Sahara Desert, there is a dry savanna that receives a lot of rain during the summer rainy season.

In addition, there are several important cities around the place, such as Mauritania .

Thus, even the most desolate regions in the world are not necessarily completely lifeless.

Mauritania

Going back to the question mentioned in the article, what will you see if you dig these sands all the way to the bottom?

There may be a lot of oil and gas resources in such a vast sandy land. Will there be any if the desert is completely dug up? In fact, on the contrary, the sands of the Sahara desert are actually riverbeds and ancient lakes .

According to NASA's aircraft radar topographic map scan, there are traces of a prehistoric lake in the sub-Saharan desert.

Geologists see images of the bedrock with the help of radar using sediments blown by the wind, sediments created by running water.

The Sahara desert hides a giant prehistoric lake

Combining data from space shuttle topographic survey scans and ground samples, geographers estimate that the Nile once flooded Egypt's Kiseba depression , forming a huge lake here.

Scientists speculate that the ancient valleys and riverbeds at the bottom of the desert formed 250,000 years ago, when the Nile River flooded the Eastern Sahara when it passed by , forming a giant lake of 42,000 square kilometers.

According to the team, these buried ancient channels are periodically activated as river systems during the warming cycle, which a recent algorithmic analysis showed ended 6,500 years ago.

Armed with this data, the team went a step further, estimating that the river extends more than 520 kilometers beneath the desert.

The Nile River flowing through the Sahara desert

This may be related to a larger ancient water system known as the Tamanrasset Valley .

These rivers may have sunk in the past due to climate change and the activity of the land plate, which was later buried in the sand.

Scientists believe that if the river system wants to re-operate, it may have to wait until the next African tide , without considering the impact .

With the current increase in greenhouse gases and the disturbance of the global climate system, it may be necessary to wait until the climate model is fully established to fully analyze the river system.

Sahara Desert

At present, there is mainly a lack of surface feature links between ocean systems and continents, and it is difficult to use existing desert models to establish such links.

The bottom of the Sahara Desert is actually a huge river system, which is really surprising. How did it form?

cycle of desert

In fact, the Sahara was not what it used to be. In the past millions of years, solar activity and climate change have driven the dynamics of the North African monsoon and periodic wet events . Expansion of grasslands.

The so-called wet period in Africa is the result of a significant shift in the hydrological cycle in North Africa and the enhancement of the African summer monsoon due to increased insolation and northward migration of tropical radiation.

The Sahara was an oasis

The location of the rainbands affected by this led to the development of river networks in the Sahara, which increased freshwater delivery to the surrounding ocean.

During this period, lakes, rivers, wetlands and vegetation covered the Sahara and the Sahel and created a completely green Saharan region.

Archaeological evidence indicates that diatoms, mammals, and reptiles lived here, while organic-rich mudstones, evaporites, and limestones were deposited in underground river systems.

The discovery of subterranean river systems in the Sahara desert also allowed scientists to trace river deposits back 120,000 years ago .

The deposits were found on the seabed at the western end of the Sahara Desert, but there are no rivers flowing into the Atlantic Ocean on the western side of the Sahara Desert today.

The French research team later believed that cyclical wetting in the Sahara desert gave birth to the river between 11,700 and 5,000 years ago .

It can be seen that the humid period in Africa had a great impact on the Sahara Desert.

Current research believes that this cyclical event takes 20,000 years as a cycle, and the most recent one ended 5,000 to 6,000 years ago , which is the part mentioned above.

Also, during the last ice age , the Sahara Desert was much larger than it is today, extending south beyond its current borders.

And in 8000 BC, after the collapsed ice caps in the north disappeared, the northern Sahara dries up.

This trend was initially counteracted by the influence of the monsoons, but by 4200 BC, the monsoons retreated southward to where they are today, which led to the Saharan region becoming what it is today.

This also explains why there are many murals on the rock walls of the Sahara Desert, and there are traces of human life in many places.

As early as thousands of years ago, after the end of the Ice Age, humans lived in the Sahara for a period of time when they migrated here.

Many murals and rock art can even be traced back to 10,000 years ago. There are more than 30,000 murals related to river animals, and many dinosaur fossils have been discovered here.

Murals on the rock wall of the Sahara desert

Nubia, Egyptian civilization, Greek civilization, etc. were all beneficiaries of the Sahara Desert. The trade economy and culture developed by these ancient empires extended to all parts of the world.

Including the Berbers as we know them today, they are now the guardians of the Sahara Desert, and travelers lost in the desert might have been buried in the sand long ago without their help.

Is the Sahara Desert still an oasis today?

oasis of expectations

It can be seen from this that the Sahara Desert can be understood as a cyclical event. We mentioned earlier that global warming has brought an uncertain impact on this cyclic change in the future, and the changes to the future Sahara may be permanent. of.

global warming

Global warming of 1.5 degrees Celsius and the Fifth Assessment Report of the United Nations Climate Commission show that global warming may lead to increased precipitation in most of East Africa, West Africa, and parts of Central Africa, especially West Africa .

The Sahel is now getting greener, but overall precipitation hasn't quite returned to mid-20th century levels.

To a large extent, this change comes from people's greening projects. Although the precipitation caused by the increase in heat has increased, from another aspect, the survival time of plants will be shorter .

Unless the area of ​​greening and irrigation is increased, it is possible to promote vegetation growth to maintain such a state for a long time.

Greening West Africa's Sahel, captured by satellite

It's hard to imagine that such a sparsely populated area has such an amazing history in the past, and the Sahara isn't exactly as lifeless as it's been described. On the contrary, the life and civilization that once appeared here have affected the whole world invisibly.