New satellite images have revealed more than a hundred ancient fortified settlements still standing in the Sahara. The settlements, located in what today is southern Libya, were built by the Garamantes, a people who ruled much of the area for nearly a thousand years until their empire fragmented around 700 AD. Information about the Garamantes is relatively scarce: Other than the accounts of classical historians (who aren’t known for careful accuracy) and excavations of the Garamantian capital city in the 1960s, archaeologists haven’t had a lot to go on. During the decades-long reign of Muammar Gadhafi, antiquities and archaeology weren’t exactly a national priority; the fortresses were largely ignored. As David Mattingly, the British archaeologist who led the project, said to OurAmazingPlanet of the discoveries: “It is like someone coming to England and suddenly discovering all the medieval castles.”
Sandfish lizards jostle back and forth, bending their bodies into a slithery S-curve to swim through the sands of the Sahara. Like scorpions and several other native desert species, they long ago mastered the difficult art of moving through the myriad grains of a sandy expanse to escape predators or the blistering African sun. And now physicists are close to cracking their secrets.
Daniel Goldman’s team has been trying to figure out just how the sandfish lizards do it for years now; in 2009 they built a robot to simulate the creature’s slithering motion. This time, for a study in the Journal of the Royal Society Interface, the scientists tried to model the physics of an animal knocking around so many grains of sand and see how the lizards burrow with such efficiency.
The team found sine-wave-like movement allows the lizard, and their robot, to push forward in sand, but creating computer models for the experiments proved problematic. Simulating all of the tiny sand grains required a lot of money to purchase time on powerful computers. So, the team performed the same experiments using 3-millimeter-wide glass beads instead of sand. “We wanted something easy to simulate that had some predictive power. We got lucky, because it turned out [the lizard and robot] swim beautifully in the same way through larger glass beads,” Goldman said. [Wired]
The “cradle of humanity” is thought to be located in Sub-Saharan Africa–meaning below the Sahara, the largest hot desert on earth. So how was humanity able to breach such an intimidating barrier to spread out across the rest of the world?
Until now, anthropologists typically argued that hominids could only have followed the lush Nile River valley north in order to reach the Middle East and beyond. But new research is suggesting that the Sahara might not have been an impassable barrier to those humans after all. Some animals (including several fish species) are found on both the north and south sides of the desert, and even in some safe-haven ponds in between. The researchers argue that if these ancestral fish could swim across the region that we now know as the Sahara, humans could have also made it across.
“Fish appeared to have swam across the Sahara during its last wet phase sometime between 10,000 and 6,000 years ago,” researcher Nick Drake, a geographer at King’s College London, told LiveScience. “The Sahara is not a barrier to the migrations of animals and people. Thus it is possible–likely?–that early modern humans did so, and this could explain how we got out of Africa.” [LiveScience]
It’s such a fertile time in the green technology sector, solar power plants may soon begin reproducing.
Using two resources that the Sahara has plenty of, sun and sand, the Sahara Solar Breeder Project hopes to build factories that will refine the sand’s silica into silicon. That silicon will be used to build solar panels, which will power more silica-refining and solar panel factories, which will be able to build more solar panels, and on and on and on.
The potential for exponential growth allows for some extreme optimism: The project’s leaders say they could build enough power stations to meet half of the world’s energy needs by 2050. Project leader Hideomi Koinuma believes the project is key to solving the world’s energy crisis, saying:
“If we can use desert sand to make a substance that provides energy, this will be the key to solving the energy problem. This is probably doable. Moreover, the energy we continually receive from the Sun is 10,000 times the energy currently used by mankind. So if we can utilize 0.01% of it skillfully, we won’t have a shortage of energy, but a surplus.” [DigInfo TV]
Hit the break for a video about the project.
The Sahara is the world largest desert, and getting larger. It threatens to creep ever further to the south and turn arable land in desert wasteland. The nations in its path have an idea, though: We’ll build a fence. Of trees.
The “Great Green Wall” would be a tree band that spans the breadth of northern Africa, 9 miles wide and nearly 5,000 miles long, from Senegal at the western edge near the Atlantic to Djibouti on the eastern edge near the pirate-infested Gulf of Aden. It may sound too dreamy or crazy to ever go forward, but this week at a meeting in Chad about desertification, the Global Environment Facility backed the belt idea with $119 million. Chad’s minister of environment, Hassan Térap, says it can be achieved:
When asked if the long-discussed but yet-to-be funded Green Wall initiative was too ambitious, Térap told IRIN: “We have to attack the problem, long ignored, through vision, ambition – and trees. What is wrong with ambition?” [IRIN Africa].
The first migration of Homo sapiens, when they left the East African landscapes where they evolved and began a long trek across the Sahara, may have followed a different route than previously believed. A new study shows that prehistoric river channels fed by monsoons once traced a path north through the desert and argues that the modern humans may have followed those channels, going from oasis to oasis until they reached the sea.
The Sahara has had several periods of increased rainfall that made it a wetter and greener place, including one interlude between 130,000 to 170,000 years ago when the researchers believe these river channels flowed with water. Now only visible with satellite radar, the channels flowed intermittently from present-day Libya and Chad to the Mediterranean Sea, says [lead researcher] Anne Osborne…. Up to five kilometres wide, the channels would have provided a lush route from East Africa – where modern humans first evolved – to the Middle East, a likely second stop on Homo sapiens‘ world tour [New Scientist].
A team of architects and environmental engineers has proposed covering swaths of the Sahara with vast “salt water greenhouses” powered by solar power arrays, in a plan they call the Sahara Forest Project. Charlie Paton, inventor of the salt water greenhouse, says the combined technologies could transform patches of the desert from arid wastelands into lush expanses that produce a bounty of fruits and vegetables for local people.
The plan is no doubt ambitious and unproved at this scale, but Paton says he has built demonstration greenhouses on the Spanish island Tenerife, as well as in Abu Dhabi and Oman; he says there is further interest in funding demonstration projects from across the Middle East, including UAE, Oman, Bahrain, Qatar and Kuwait. The cost is not as astronomical as one would think, and is estimated at approximately $118 million for a 20 hectare [50 acre] site of greenhouses and a 10MW concentrated solar power farm [Red Herring]. Paton is working with Exploration Architecture, a company that worked on the world’s largest greenhouse in England’s Eden Project.
In an arid and lifeless stretch of the Sahara, archaeologists have discovered a massive graveyard and remnants of early settlements that hark back to Stone Age days when the desert was wet, green, and habitable. Researchers say the find is a striking reminder that climates and environments can shift drastically over the geologically short time period of 10,000 years.
In an area of Sahara that’s known to nomads as the “desert within a desert,” researchers found evidence of thriving prehistoric cultures and rich ecosystems on the edge of a lake. There were also hundreds of animal bones. In addition to antelope and giraffe, [lead researcher Paul] Sereno quickly recognized the remains of water-adapted creatures like crocodiles and hippos, then turtles, fish, and clams. “Everywhere you turned, there were bones belonging to animals that don’t live in the desert,” said Sereno. “I realized we were in the Green Sahara” [National Geographic].
European Union officials say they’re considering an ambitious plan to draw energy from the sun that beats down relentlessly on the Sahara. By building a solar power plant the size of Wales (a small area, compared to the vastness of the Sahara) and laying down high-voltage transmission cables, the EU could potentially capture enough clean energy to power the entire continent.
Speaking at the Euroscience Open Forum in Barcelona, Arnulf Jaeger-Walden of the European commission’s Institute for Energy, said it would require the capture of just 0.3% of the light falling on the Sahara and Middle East deserts to meet all of Europe’s energy needs [The Guardian]. It’s more efficient to build such a system in the desert, officials say, because the intense sunlight of North Africa can produce three times more electricity than a similar set-up in Northern Europe.