A green savannah from an arid desert: 23 Degrees team heads to the Sahara
Distance travelled ~ 447'667'200 km: day 174
Today Kate Humble and the 23 Degrees team are in Egypt heading deep into the Sahara desert to one of the most fascinating most magical places on the planet. It's a place that holds clues to the extraordinary history of this part of the world.
The team are travelling from Luxor into the Sahara close to the borders of Libya and Sudan. It's a two-day trek across barren desert with temperatures hitting the high thirties and the low forties on a regular basis. The expedition has half a dozen jeeps, a military escort of Egyptian soldiers and enough provisions and water to last a week.
From Luxor their first stop is the Dahkla oasis, the last bit of civilisation for many hundreds of kilometres. From here on it's camping under the stars.
From Dahkla the team travels across endless white dunes until they reach a region of red sand, hills and ravines leading to a vast plateau rising up 300 metres. It's called the Gilf Kebir or Great Barrier. If you've read the book or seen the movie The English Patient, that might recognise the place as it features heavily in the story. In fact back in the 1930s the Gilf was explored by Hungarian adventurer Count Lazlo Almasy the inspiration for the main character in the book and film. He was looking for the legendary lost city of Zerzura. He didn't find Zerzura, but he did stumble across something that changed our understanding of the history of the Sahara. And that's what Kate and the team are heading towards.
Hidden in a gorge called Wadi Sora is one of humanities great treasures, the legendary and magical Cave of Swimmers. It is full of amazing drawings that are at least 8000 years old. There are over 300 figures; some are of hunters carrying bows. There are giraffes and deer even hippos.
There are dozens of handprints and footprints, created by blowing of coloured powder over the hands and feet. And within the many images is an extraordinary image of a child's hand inside an adult's hand, perhaps their father or mother. It's an incredible, romantic message reaching out to us from many millennia ago.
These paintings show that people once lived here, perhaps nomadic families who hunted the animals they depicted in the cave. But another image tells us something more about this region 8000 years ago. There is one painting that shows people swimming, giving this cave its name.
This particular image shows that once this region had water, lakes and rivers. So how does a desert become a lush savannah and a green savannah turn back to arid desert? To find out Kate and the team travel to another gorge about a days drive away called Wadi Bahkt. Cut into the surface is an 8-metre crack showing layer on layer of sediment. These sediment layers are created by seasonal rains. It's clear evidence that at one point this part of the Sahara had annual rains called Monsoons large enough to create rivers and lakes, with one believed to be the size of Belgium.
Like Asia, North Africa still has a summer monsoon. But now it's weak and only brings rain many thousands of kilometres to the west and south of here. But 8000 years ago, monsoon rains fell over the whole of the Sahara including the Gilf Kebir. So what happened?