This is the map of Africa.
If you look to the South, you will see lush vegetation, with lots
of greenery.
However, when you go north, things are different.
Covering multiple countries, it is the most gigantic desert
globally, with miles and miles of dune formation.
Altogether, the Sahara Desert covers 9 million square kilometers, meaning it will
swallow Spain 18 times!
However, did you know that this vast stretch of sterile sand covering a third of the
African continent was covered in lush vegetation thousands of years ago?
What happened to the Sahara?
And what is happening to it right now?
In this video, we look at the terrifying discoveries scientists made
under the Sahara desert!
The Atlantic Ocean borders the Sahara on the west, the Red Sea on the east, the
Mediterranean Sea on the north, and the Sahel Savannah on the South.
The enormous desert spans 11 countries: Algeria, Chad,
Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan, and Tunisia.
The Sahara desert is most famous for the sand dune fields often featured in movies.
The dunes can reach almost 600 feet or 183 meters high.
However, they cover only about 15 percent of the entire desert.
Other topographical features include mountains, plateaus, sand- and gravel-covered plains,
salt flats, basins, and depressions.
The Sahara used to be a tropical area, so how did it become the harsh arid region it
is today?
The answer to this question takes us several thousands of years back.
The Sahara has long been subject to periodic bouts
of humidity and aridity.
These fluctuations are caused by slight wobbles
in the tilt of the Earth's orbital axis, which in
turn changes the angle at which solar radiation penetrates the atmosphere.
At repeated intervals throughout Earth's history, there's
been more energy pouring in from the sun during the West African monsoon season.
During those times, known as African Humid Periods, much more rain comes down over North
Africa.
With more rain, the region gets more greenery and rivers and lakes.
But between 8,000 and 4,500 years ago, something strange happened:
The transition from humid to dry occurred far more rapidly in some areas than
could be explained by the orbital precession alone, resulting in the Sahara
Desert as we know it today.
In his study, Archaeologist David Wright tells us what happened next.
As he pored the archaeological and environmental data, obtained
chiefly from sediment cores and pollen records, all dated to the same period, he
noticed what seemed like a pattern.
Wherever the archaeological record showed the presence
of pastoralists, that is, humans with their domesticated animals, there was a corresponding
change in the types and variety of plants.
It was as if, every time humans and their goats and cattle hopscotched across
the grasslands, they had turned everything to scrub and desert in their wake!
This led Wright to conclude that by overgrazing the grasses, they were reducing the
amount of atmospheric moisture-you know, plants give off moisture, which produces
clouds-and enhanced albedo.
He says this may have triggered the end of the humid
period more abruptly than can be explained by the orbital changes.
These nomadic humans also may have used fire as a land management
tool, which would have exacerbated the speed at which the desert
took hold.
Now, when you think of the Sahara desert, do you imagine whales frolicking on the
rolling sand dunes?
While that is highly unlikely to happen since whales can't survive
outside water, there is evidence that the ancestors of the modern whale once swam
around right in the hot African desert!
Rewind to 1902 when a team of geologists guided their camels into a valley in Egypt's
Western Desert.
Centuries of strong wind had sculpted sandstone rocks into strange
shapes, and at night the moonlight was so bright, making the sand glow like gold.
A nearby hill was known as the "Mountain of
Hell" because of the infernal summer heat, but in this arid valley lay the bones of whales!
Some of the skeletons were 50 feet long, with vertebrae as thick as campfire logs.
They dated back 37 million years to an era when a shallow, tropical sea covered this
area and all of northern Egypt!
And although the geologists didn't realize it at the time, the prehistoric specimens
in the sand would offer clues to one of evolution's
most nagging questions: how whales became whales.
One clue found from these long-dead whales was the presence of feet!
Scientists had long suspected that whales were terrestrial mammals that had eased into
the ocean over millions of years, gradually losing their four legs.
Proof of this is that modern whales have vestigial hind leg bones.
But little in the fossil record illustrated the
transition until paleontologists began excavating hundreds of whale fossils buried at
Wadi Hitan and finding legs and knees!
Older specimens of footed whales have since been identified, but Wadi Hitan's are unparalleled
in their numbers and state of preservation.
The valley, about a three-hour drive from Cairo, is now a UNESCO World
Heritage site visited by some 14,000 people each year!
Paleontologists speculate that whales' landlubber ancestors were deer- or pig-like
scavengers living near the sea.
About 55 million years ago, they started spending more
time in the water, first eating dead fish along the shore and then chasing prey in the
shallows and then wading deeper.
As they did, some of them evolved traits that facilitated hunting in water.
Over time, since they no longer had to bear their total body
weight at sea, they got bigger, their backbones elongating and their rib cages
broadening.
Most of the fossils in the valley belong to two types.
Basilosaurus was the giant with an almost eel-like body.
The more petite but heavily muscled Dorudon looked more like a
modern whale, at least until its mouth opened to reveal a jaw lined with serrated
daggers instead of peg-like teeth.
Interestingly, the fossils of more than 75 whales have been found in the middle of the
Atacama desert in Chile.
How they ended up there has been a subject of debate among
scientists.
Now, have you heard about the lost city of Atlantis?
You will be shocked by how this famed city is connected to the next discovery
in the Sahara desert!
This takes us to the Eye of the Sahara, also known as the Richat
Structure or the Guelb er Richat!
It is a geological formation in the Sahara Desert
that resembles an enormous bull's eye.
The formation stretches across a 40 kilometer-wide
region of the desert in Mauritania.
For centuries, only a few local nomadic tribes
knew about the formation.
It was first photographed in the 1960s by the Gemini astronauts,
who used it as a landmark to track the progress of their landing sequences.
Later, the Landsat satellite took additional images and provided information about the
formation's size, height, and extent.
Geologists initially believed that Eye of the Sahara was an impact crater, created when
an object from space slammed into the surface.
However, lengthy studies of the rocks inside the structure show that its origins
are entirely Earth-based, prompting geologists to look for other explanations.
Geologists have concluded that the Eye of the Sahara is a geologic dome.
The formation contains rocks at least 100 million
years old; some date back to well before the appearance of life on Earth.
These rocks include igneous volcanic deposits and
sedimentary layers that form as the wind pushes dust and water deposits, sand, and
mud.
Today, geologists can find several types of igneous rock in the eye area, including
kimberlite, carbonatites, black, and rhyolites.
However, there is another explanation for this Eye of the Sahara!
According to this YouTube video, the remains of the ringed city
Plato spoke of in the fourth century BC can be found in the African country of Mauritania,
meaning it has been hiding in plain sight this whole time!
The search for Atlantis has been ongoing since Greek philosopher
Plato first described in 350BC a mysterious island that seemingly just vanished!
"We've been looking in all the wrong places for its location since everyone assumes it
must be under the ocean somewhere, such as in the depths of the Atlantic Ocean or the
Mediterranean Sea," says the host of Bright Insight YouTube channel known only as
Jimmy.
Show some clips from this video: https://www.youtube.com/watch?v=oDoM4BmoDQM
Instead, he proposes the Eye of the Sahara is the mythical city's actual location.
Solon, a statesman from Ancient Greece, is the man
who is thought to have passed on information regarding Atlantis to Plato.
Jimmy says it is not only the exact size and shape Plato said it was - 23.5km across and
circular - but mountains he described to the north can be seen quite clearly on satellite
imagery, as evidence of ancient rivers, which Plato said flowed around the city.
Plato said Atlantis was destroyed in a "single day and night of misfortune" and sank
beneath the waves.
The scientific record does show the Earth underwent significant
climate upheaval around 11500 years ago when Atlantis is alleged to have disappeared.
Jimmy also points out satellite imagery that resembles the aftermath of a tsunami unlike
anyone alive today would have seen.
Look at the satellite map of The Eye of the Sahara.
Doesn't the entire region look like it was blasted by flowing water or a tsunami?
The Sahara desert continues to serve up mysteries, and the next one is about an object
found there whose functions have not been known till today!
It is the Clayton ring, and more bafflingly, these rings were found in
the most inhospitable part of the Sahara desert in Egypt!
Named after the geographer and desert explorer P.A.
Clayton (1896–1962), Clayton rings are conical pottery cylinders open at
both ends.
They are always found with one or more perforated pottery disks that are always
just slightly larger than the ring's smaller opening but do not fit as lids.
Some were custom-made by potters as a set; others were
reworked from old pottery jars and sherds, like the ones on display.
These objects were not used by the Egyptians living along the Nile.
Instead, they formed an important part of the kit of the
nomadic herders inhabiting the Dakhla Oasis during Egypt's first dynasties called the
Sheikh Muftah culture.
Clayton rings and disks have been found in the oasis, around seasonal
hunting and herding camps of this culture, but remarkably also in caches up
to 300km away from permanent water sources and beyond the safe roaming range
of any herdsman or hunter.
What made these objects so crucial that people went to the trouble to take Clayton rings
far into the desert?
This is a question that is yet to be answered!
Let's hear what you think of the discoveries in the Sahara desert in the comment
section