How About What Hides Under the Sahara Desert?

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1:01In the north of Africa, the color green dominated. Plenty of rainfall meant that there were lakes, rivers, pastures, and even forests. A completely different image of the Sahara from the barren landscape of today. But then, the climate started to shift. The region became parched and the vegetation started disappearing. The wind did the rest. It took away the fine sediment after there were no plant roots to hold the ground together. Give it a couple of thousands of years and you get a familiar image of the Sahara. Sand and rocks stretching as far as the eye can see. But when it comes to volume, only a quarter of the Sahara is actually sand. The yellow sands of the Sahara are just one part of the story. The desert has many other features such as gravel plains, salt flats, and plateaus. Make you think if we understand the word desert correctly. For people who study such terrains, geologists, there is only one condition for defining a desert, precipitation.

2:05If an area gets little or no rain, then it's considered a desert. The Sahara certainly fits the bill. Its average annual rainfall is just three inches. Compare that to the nearly 45 inches a year in New York. When we look at precipitation, this sandy desert is only the third largest in the world. Number one and two are Antarctica and the Arctic. They are larger than the Sahara by millions of square miles. It sounds odd, but there is more than one type of desert. The first two are polar deserts, while the Sahara is a subtropical desert. But the difference in air temperature are staggering. In Antarctica's interior, temperatures plummet President Barack Obama. Virginia, we are counting on you. Republicans want to steal enough seats in Congress to raid the next election and wield unchecked power for two more years. But you can stop them by voting yes by April 21st. Help put our elections back on a level playing field and let voters decide not politicians.

3:12Vote yes by April 21st. Paid for by Virginians for fair elections. USAA knows dynamic duos can save the day like superheroes inside ticks or auto and home insurance. With USAA, you can bundle your auto and home and save up to ten percent. Tap the banner to learn more and get a quote at USAA.com slash bundle. Restrictions apply. To minus 76 degrees Fahrenheit. Compare that to the highest temperature on record in the Sahara of 136 degrees Fahrenheit. But this desert has a cool sign. At night, the temperature is roughly the same as the average yearly temperature in Denmark. This hot and cold roller coaster makes it hard to choose the right outfit when venturing into the Sahara. And what about the sand? How deep is it actually? The depth varies between 70 and 140 feet. That's not too deep. If you put the statue of liberty in a tall dune, half of it would still stick out of the sand.

4:13Its vast amounts in the Sahara were created by Eolean processes as Greek for wind. Over time, it blows and shapes the surface of the earth. In dry areas with sparse vegetation, winds erode the ground much faster. That's what happened in North Africa. Under all that sand is the bedrock and cracked clay. If you started digging, you would find the same everywhere on the planet, with one important difference. There is some type of soil covering the bedrock. This is not the case in the Sahara. Because of the erud climate and a lack of vegetation, sand covers the ground below. Over the course of thousands of years, a lot of interesting finds ended up in the desert sand. For example, there are petrified tree trunks. These are essentially preserved prehistoric trees. They date back to the time when the region was lush green. In some places, the trees of this fossilized forest are at least 65 feet tall.

5:13The wood is so well preserved that you can still see the texture and knots. There are even fossilized pine cones. In 1992, scientists found glass fragments in eastern Sahara. These canary yellow glass shards were scattered across hundreds of miles. They didn't belong to an ancient civilization. Although ancient Egyptians used them to make jewelry. In fact, the breastplate of King Tut at a beautiful scarab beetle centerpiece made from this desert glass. For a long time, scientists were puzzled about the true origins of these fragments. They finally concluded that the glass was around 29 million years old. It is an impact tape. If that sounds like it has something to do with the word impact, you are correct. These rocks are formed when a meteorite hits the surface of the earth. This generates a lot of heat. Scientists estimate that the temperature needed to melt this mineral was close to 3,000 degrees Fahrenheit.

6:17Apart from the regular fine grain sand, we also have melted sand in the Sahara. But the desert conceals other unlikely artifacts. Shark teeth are a common find in Morocco, which sits in the western part of the Sahara. What are the fossilized teeth of these marine predators doing in the middle of the desert? The art of the world looked entirely different millions of years ago. There was a sea cutting right through what is now a desert. Spring is here, and the shopping list is long. Time to make a lows run. Buy three bags, get three free of stay green, one cubic foot garden soil. Plus, right now, members can earn four times the points on an eligible purchase. Start spring off strong with these deals and more. Our best lineup is here at Loads. With three twenty-five, while supplies last, soil-offered scoots of Laskin and Hawaii, loyalty program subject to terms and conditions, sea lows dot com slash terms for details, subject to change, point booster subject to exclusions and more terms apply, one time only offer. The Trans-Saharan Seaway ran the length of present-day Algeria and Mali.

7:20It was around 165 feet deep. That was enough for all sorts of aquatic animals to inhabit it. Large catfish, sea snakes, and of course, sharks lived in the air. British archaeologists even on Earth, a turtle shell in Mali in the 1980s. For centuries, there was even an entire city hidden under the desert. Tim Gad was a Roman outpost constructed by the Emperor Atresian around the year 100 in the current era. For various reasons, its residents abandoned it around the year 700. The sands of the Sahara soon engulfed the city. It had remained hidden for nearly a thousand years. Then, in the 1700s, a Scottish explorer started digging out the city. His team first uncovered a sandstone triumphal arch 40 feet high, similar to the ones we can see in Rome and Paris today. An amphitheater soon popped out of the sand and it was followed by well-preserved statues of Roman emperors.

8:23The Scottsman's find was so impressive that no one believed him at first. It took two more centuries for archaeologists to fully excavate the city during the 1950s. The site covers a surface as large as ten hollow fields. The ruins reveal the full mastery of Roman city planning. All the streets meet at a right angle in what is known as an orthogonal grid. You can find the same layout in modern cities such as New York. Historians estimate that during its heyday, 10,000 people called TimGad home. Different nationalities lived here, from Romans to people of African descent. Today, more than two and a half million people live in and around the Sahara. They are spread across 11 countries in total, and their living space is growing. The desert is 10% larger than it was just a century ago. This process doesn't involve sand pouring out of the Sahara. The ecosystems on the edges of the desert simply change over time.

9:27The wind blows the soil away and vegetation dwindles, the perfect conditions for the formation of a desert landscape. These changes are happening in the Sahel, a region south of the Sahara desert. That's why the African countries have recently come together for a project called the Great Green Wall. The primary goal is to stop the desertification of the Sahel and hold back the sands of the Sahara. Their plan is ambitious and involves planning a wall of trees from the west to the east of the African continent. The proposed forest is not only going to be long, but wide as well. The Sahara and the Sahel share a historic bond. Since antiquity, camel caravans have been making the journey from Africa's Mediterranean coast in the north to the savannas in the south. The golden age of this trade kicked off in the 9th century. The perilous journey took several months to complete. The route was two and a half times longer than the length of the Grand Canyon.

10:31Explorers still find evidence of these ancient caravans hidden away under the sands of the Sahara. This episode is brought to you by Athletic Brewing Company. No matter how you do a game day, on the couch, in the crowd, or manning the snack table, Athletic Brewing fits right in. With a full lineup of non-alcoholic beer styles, you can enjoy bold flavors all game long. No hangovers, no buzz, no subbing out for water in the second half. Stuck the fridge for tip-off with a variety of non-alcoholic craft styles available at your local grocery store or online at AthleticBrewing.com. Near beer, fit for all times.