courses
Tackle that seemingly endless selection of course offerings; a roundup of helpful resources and sound advice for selecting the best courses and acing them.
Massive river beneath the Black Sea was found by scientists.. Content Warning.
Let's play a little guessing game, shall we? Can you name the sixth largest river on Earth in terms of volume, which refers to the amount of water that flows through it? The first couple of rivers are easy to list. Number one, of course, is the Amazon River in South America. Then we have the Congo in Africa and the Ganges in India. Feel free to list all the rivers on the planet, but you won't get any closer to the answer. Why? Because this river is not on the surface but underneath the waves of the Black Sea. In 2010, a team of scientists discovered this river while studying the Bosphorus Strait in Turkey. Sonar scanning revealed a channel at the bottom of the Black Sea with water flowing through it. It turned out that, in places, it's 115 feet deep, which is three times as tall as an average telephone pole. This flowing water acts like a real river, complete with rapids and waterfalls, and its volume is 350 times greater than that of the River Thames in London. Talk about a strong undercurrent. If it were a surface river, it would be in the top ten. Bad news for the Madeira River in Bolivia and Brazil, which presently holds the sixth position. But how did this underwater river form? The answer lies in the amazing features of the Black Sea. It gets its water from two main sources. The first source is the rivers that flow into it, like the Danube, Dniester, and Dniester. A lot of "D" rivers there. But more importantly, they are all freshwater waterways. On the other side, quite literally, is the Mediterranean, and it's salty. When this saltwater enters the Black Sea, it sinks straight to the bottom. You see, freshwater is lighter than saltwater, and this creates stratification, a fancy term meaning that the two types of water don't mix. Saltwater, being denser, drops to the bottom. If you want to see how this works, you can do an experiment at home. Pour mineral water into one cup and saltwater into another. Table salt will do. Then put a grape in each cup. You'll see how it immediately sinks to the bottom of the cup filled with freshwater. The grape will stay afloat in the cup filled with saltwater. The same thing is happening inside the Black Sea. But there's another side to this phenomenon. The upper layer of water is rich in oxygen, meaning it can support life. The bottom layer, however, is anoxic, which means there's no oxygen at the bottom. But this isn't a bad thing. Because of this trait of the Black Sea, shipwrecks are able to survive for centuries. Oxygen decomposes wood, and what material did ancient people use to make their ships? That's right, 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, and experts estimate that the vessel is 2,400 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 Bulgaria, but no one has seen it in person. Explorers sent a deep-sea remotely operated vehicle (ROV) to film the wreckage. It was impossible for a diver to go down. But the Black Sea doesn't look that huge on a map. Could it be that deep? Oh yes, it's way deeper than people think. You could stack six Empire State Buildings at the deepest point of the Black Sea, around 7,257 feet. 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. Studying underwater rivers isn't an easy task. The depth and strong currents make it impossible to send in divers. Even the equipment for underwater research has to be sturdy, otherwise the current will wash it away. That's why the underwater river in the Black Sea was ideal for scientists to explore. Earth's oceans and seas are powerful, but luckily for us, there are places where divers can admire underwater rivers. Have you ever heard of a cenote? Sounds Spanish, doesn't it? Well, that's because it is. Cenotes are underground caves that form after the limestone above collapses, revealing the groundwater beneath. The term "cenote" is associated with the Yucatan Peninsula in Mexico. Ancient Mayans used them as water sources. In the Mayan language, the word "cenote" meant sacred well. Researchers estimate there are around 10,000 cenotes spread across the Yucatan Peninsula. You can also find them in other places like Cuba and Australia. Beauty is in the eye of the beholder, but unofficially, the most beautiful cenote is located just south of the town of Tulum in Mexico. Its name reflects the cave's divine beauty, Cenote Angelita. But people don't visit the cenote to go swimming. What's more interesting is its bottom. A scuba tank is all you need to finally admire an underwater river firsthand. The waters are dark and foggy, so divers use powerful flashlights. After a 100-foot dive, a marvelous sight appears: an underwater river with trees along its banks. Some of them even have green leaves, just like any other water flow on dry land. But it's not really a river. Here comes the fascinating part. Remember how saltwater and freshwater don't mix well? The "river" the divers see is actually a thick layer of fog between the two types of water. Three feet of hydrogen sulfates, to be exact. This is the compound that water processing plants use to remove chlorine from drinking water. The substance is so heavy that the fog it produces moves independently from the surrounding water, creating the illusion of a river flowing underwater. But there are other real rivers that play tricks on you. Take, for example, the Mystery River in Indiana. It's the longest underground river in the United States. Explorers discovered the river and its cave system, Blue Spring Caverns, in the 19th century. Nearly three miles of the river are navigable. Isn't that impressive? You can book a boat tour on a river that you can't even see. But the most mysterious river on the planet is the Saraswati River in India. The coolest part about it is that it doesn't exist. It was an alleged river only mentioned in ancient literature. For centuries, people thought it 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. The first two are visible today, but where's the third one? That's what scientists decided to find out. Images from an American satellite showed the presence of underground water in the area. Until then, researchers thought these were paleo-channels, meaning that water flowed through them a long time ago. But to their surprise, it appeared that there was still water inside these channels.
By Chabane Mustapha3 years ago in Education
The Power of Data Visualization in Business Analytics
In the fast-paced world of business analytics, the ability to transform raw data into actionable insights is crucial. Yet, amid discussions of algorithms, machine learning, and big data, one often overlooked skill stands out as a game-changer: data visualization. It's an art and science that goes far beyond creating pretty charts and graphs.
By Deepika.debnath3 years ago in Education
Why Taking Institutional Courses in Addition to a Degree is Beneficial to Your Career
In today's compеtitivе еmploymеnt markеt, having thе skills and еxpеrtisе that еmployеrs sееk is morе crucial than еvеr. Whilе a collеgе dеgrее is a plus, gеtting a solid carееr is not always sufficiеnt. As a rеsult, many studеnts arе incrеasingly complеmеnting thеir dеgrееs with institutional coursеs.
By Civil Guruji Marketing3 years ago in Education
The Intricate Tapestry of Human Ancestry
We are all related in science. This is you, and these are your ancestors, forming a vast pyramid that stretches far into the past and delicately balances on your head. But have you ever wondered how many ancestors you truly have? Let's unravel this complex web of human lineage.
By Adelaide Delali3 years ago in Education
The Enigmatic Dichotomy: Navigating the Complex Landscape of Education's Advantages and Disadvantages
In the intricate tapestry of yore, within the vibrant urban labyrinth of Progress Ville, there unfurled a robust and multifaceted education system, an intricate juncture where the tender shoots of youthful cognition were cultivated. Yet, behold, this educational behemoth, poised between the dichotomy of progress and peril, was a true double-edged Excalibur, replete with its very own set of enigmatic idiosyncrasies.
By adil farid3 years ago in Education
Free resources to study Korean
When I first started self-studying foreign languages, the first language I picked was Korean. While I have put this study on hold, I am extremely grateful for beginning it, not only because of the skill that I have learnt, but also because it introduced me to a handful of useful apps and websites.
By Simona Rosso3 years ago in Education
