Under Black Sea

Well, we'll try to guess a little bit, will we? In terms of volume, which is the volume of water that flows through a waterway, can you name the sixth largest river in the world? Of course, the first couple of rivers are easy to list, starting with the Amazon River in South America. And we'll also have Congo in Africa, and Ganges in India. You can name all the rivers of this world, but you'll never be any closer to an answer. Why? This river is not on the surface, it lies beneath the waves of the Black Sea.

In 2010, when the Bosphorus Strait was being studied by a team of scientists in Turkey, they found this river. An underwater channel has been identified by sonar scanning in the Black Sea. There was water flowing into the channel. It's at a depth of 115 feet, it turns out. That's more than three times the height of your average telephone pole. The water's flowing like a real river. It's got the rapids and waterfalls, its volume is 350 times greater than that of the river.

The Thames in London talks of a strong undercurrent. It'd have been the 10th worst news for the Madeira River in Bolivia and Brazil if it were a surface river. The present number six but how did this underwater river form the answer lies in the amazing features of the Black Sea. It's got two main sources of water. The first are the rivers that flow into it like the Danube Nipper and Dawn. There are plenty of D's but more importantly, it is all inland waterways on the other side.

In fact, there's the Mediterranean, and it's Salt Lake. Like a lot when this saltwater gets inside the Black Sea it goes straight to the bottom, and you see fresh water is lighter than Salt Water. This results in the stratification; this is a fancy word meaning that these two kinds of water don't mix. There's a higher density of salt water, and it drops immediately to the bottom. You can do a home experiment to see how it works by mixing mineral water and salt water in the same cup.

Then, each cup will be filled with a grape with table salt. You'll see how the grape will sink immediately to the bottom of the cup filled with fresh water and stay afloat in the cup filled with salt water. This is happening in the Black Sea as well but there's a different side to it. Oxygen is abundant in the upper layer of the water, which means that the bottom layer can support life, but it's anoxic. Yeah, that means there's no oxygen at the bottom, but it's not a big deal. The Black Sea shipwrecks have been able to survive for hundreds of years due to this characteristic, because oxygen has decomposed wood and from the materials that ancient people built their ships.

That's correct, timber recently in 2018 scientists discovered the oldest Greek shipwreck on Earth. The merchant ship lies more than a mile deep at the bottom of the sea. Experts estimate that the vessel is 2400 years old. The wreck was valuable for historians to study all the elements of ancient ship construction from the Mast to the rowing benches, it's all intact. The wreck lies some 50 miles off the coast of the bulk area, but no one has seen it in person.

Explorers sent a deep sea ROV or remotely operated vehicle to film the wreckage it was impossible for a diver to go down. The Black Sea, however, doesn't look so huge on the map. Would it be that deep? Yes, it is far more than the human mind can imagine. At the bottom of the Black Sea around 7257 feet you'd be able to build six Empire State buildings. This Inland Sea isn't the only place on Earth where researchers have discovered shipwrecks and underwater Rivers, one of the largest channels running along the ocean floor lies off the coast of South America. It runs from the mouth of the mighty Amazon and into the Atlantic Ocean.

It is not an easy task to study underwater rivers. Divers can't be sent down here because of the depth and strong currents. We need to make sure that the equipment for undersea research is robust, otherwise they'll be swallowed up by a current. That's why it made perfect sense for researchers to explore an underwater river in the Black Sea. Earth's oceans and seas are powerful but luckily for us, there are places where divers can admire underwater Rivers.

Ever heard of a Cenote? Sounds Spanish, well that's because it is. Cenotes are underground caves that form after the Limestone above collapses revealing the groundwater under them. The term Cenote is associated with the Yucatan Peninsula in Mexico. Ancient Maya used them as water sources. In the Mayan language, the word Cenote meant sacred. Well, researchers estimate there are some 10000 cenotes spread across the Yucatan Peninsula. You can also find them in other places such as Cuba and Australia.

There's beauty in the eye of the beholder, but unofficially, the most beautiful cenote in Mexico is just south of the city of Tulum. The name reflects the Cave's Divine Beauty Cenote Angelita, but people don't visit the Cenote to go swimming. Its bottom is much more interesting than a SCUBA tank. You need only see this underwater river for the first time in your life. The water is murky and dark, making it necessary for divers to use strong flashlights.

A spectacular sight emerges after a hundred yards of diving: an ocean river with some trees on its banks. Even some of them, as in any water flow across dry land, have blue leaves. However, it's not a river. So, here's the fascinating thing: remember how freshwater doesn't mix with salt water? There's a thick layer of fog between the two types of water in the river the divers see. To be exact, there are three feet of hydrogen sulfate.

It's a product used by water processing facilities to remove chlorine from drinking water. The substance is so heavy that its fog moves independently of the surrounding water, which makes it feel as though there's a river flowing underwater, yet other real rivers are playing tricks on you. Consider the mysterious river in Indiana, it's one of the oldest inland rivers in America. Explorers discovered the river and its Cave System Blue Spring caverns in the 19th century.

There are almost three miles of river that's accessible, isn't there? You can take a boat tour on any river that you don't see but the Saraswati River in India, which is one of the world's most mysterious rivers. The most interesting thing about this is, it doesn't exist. For centuries, it has been said to be a river only mentioned in ancient literature and people thought this was just a myth. Then satellite images showed that it might be real ancient texts spoke of a major Confluence of three Mighty Rivers the Ganges, Yamuna, and Saraswati.

Today, the first two can be seen, but where's the other one? This is what scientists have decided to discover, by looking at images from the U.S. satellite which show that there's underground water in this area. The scientists hadn't believed it to be a paleo channel until now. That means they have had water flowing through them for a long time, but to their great surprise, it looked like there was still water within the channels.

Scientists have estimated that, some 5000 years ago, the Saraswati River flows over the ground, but it hasn't dried up entirely. About 200 feet below ground level, it's already gone down. The experts believe the Saraswati River is still flowing slowly into the sea and has been hidden from view in the desert sand. In London, England this was done naturally, but a lot of rivers had been pushed underground because of the humans' activities.

Several dozen small and medium-sized Rivers now flow under the ground. Maps from the 19th century still show them as Rivers but today they only exist in the names of the streets that were built above them such as Fleet Street. It was like what happened in New York, but it does not signal the end of these streams. Engineers will still consult city maps from the 1800s when they're trying to build or renovate a building. Everyone doesn't want to flood their basement with a long-lost brook.