- 9 months ago
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AnimalsTranscript
00:00Amazon. Even school children know it as the largest river in the world.
00:16But it's not just a river.
00:18The Amazon basin is almost the size of Australia, an entire continent.
00:24In high water, the river flows over such distances that not a single bridge has yet been built across it.
00:32Every 24 hours, the Amazon brings about 19 cubic meters of water into the ocean.
00:39This volume would be enough to cover the needs of New York for 12 years ahead.
00:45This amazing river even has a mysterious gloomy counterpart.
00:50A gigantic underground current that didn't reveal itself in any way up till now.
00:57The sheer scale of this place makes it seem like a whole separate world.
01:02The Amazon jungle is literally called the world's gene pool.
01:07Over a third of all biological species known to science lives here.
01:13And new ones are regularly discovered.
01:17In prehistoric times, terrible monsters lived here.
01:21And scientists still find their remains.
01:24Traces of ancient cultures are also found in this place.
01:28It's not clear where they came from.
01:31And it's even more unclear where they went.
01:34What's under the Amazon River?
01:53The Amazon is 6,275 kilometers long.
01:57This is the longest river in the world, which combines many smaller rivers.
02:04Many will object, saying that the longest river is the African Nile.
02:09But this question is still debatable in the scientific community and is subject to multiple interpretations.
02:16The main question is, what is considered the source?
02:21If the head of the river is Maranon, then the Amazon is 6,400 kilometers long.
02:27If we consider Apache the source, the Amazon becomes much longer, specifically 6,992 kilometers,
02:37and leaves a 6,650 kilometer long Nile far behind.
02:42And if the starting point is the source of the UK Ali, the Amazon is 7,100 kilometers long.
02:49And the Nile doesn't even come close to that.
02:52It's funny that the Amazon is so huge that some of its parts are called differently.
02:58Even without taking into account the confusion about the starting point,
03:02the Amazon changes its name six times along the way from west to east.
03:09In its middle part, the locals call it Solimois,
03:13and only the last relatively straight segment of the river,
03:17which accounts for a third of its total length, is called the Amazon.
03:23Many major tributaries of the Amazon get their names from the watercolor.
03:28And here, nature has a lot of fun playing with colors.
03:32For example, the water in Rio Negro appears black.
03:37While in Madeira, it appears golden scarlet, resembling the wine of the same name.
03:44Near Manaus in Brazil, the Rio Negro merges with the yellow and murky waters of the Solimois,
03:51rushing down the slopes of the Andes.
03:54The two rivers fall into one bed and for a long time act like two immiscible liquids.
04:01The entire Amazon basin is a huge lowland covered with rainforest,
04:07occupying the northern part of South America.
04:10This territory spans across Brazil, Colombia, Peru, and Bolivia.
04:16The basin area is 6.5 million square kilometers.
04:20This is about 5% of the entire land surface of the planet.
04:25Again, this can be easily compared to the area of Australia, which is almost 7.7 million square kilometers.
04:33Of course, the river is very deep.
04:37So much so that even ocean liners can go 3,700 kilometers upstream from the river mouth without any problems.
04:45At the lowest points, its depth reaches 100 meters.
04:50For comparison, Lake Erie is 64 meters deep.
04:54Of course, such a giant river system was formed over a very long time.
05:00Indeed, the history of the Amazon can be called an epic drama.
05:05The Amazon originated as a transcontinental river during the Miocene Epoch around 11-odd million years ago.
05:16Its modern outline formed about 2.4 million years ago in the early Plistocene.
05:22But before that, over the course of many millions of years, the river formed, reshaped itself, and changed the flow direction to the opposite.
05:33At one point, it even turned into an inland sea.
05:37Back in the Cretaceous, the Proto-Amazon was part of the Proto-Amazon Congo river system.
05:44It flowed west from the interior of present-day Africa.
05:48Hang on.
05:49What?
05:50Did I just say Africa?
05:52Yes, that's what I meant.
05:55Throughout its history, the Amazon managed to move from one continent to another.
06:01I know that it sounds crazy, but it's nonetheless true, roughly speaking.
06:06At that time, two huge continents were connected, forming western Gondwana.
06:1280 million years ago, the two continents finally split.
06:17And so it happened that the Congo and Proto-Amazon rivers ended up on different continents
06:23and became separated not by a strait, but by a whole ocean.
06:2815 million years ago, the main phase of the Andes uplift began.
06:34This tectonic movement was caused by the Nazca Plate sliding under the South American Plate.
06:41The rise of the Andes and the juncture of the bedrock shields of Brazil and Guyana blocked the river
06:48and turned the Amazon basin into a vast inland sea.
06:53Gradually, this huge body of water turned into a massive swampy freshwater lake
06:59and marine animals adapted to living in freshwater.
07:03Between 11 and 10 million years ago, waters broke through the sandstone from the west,
07:10and the Amazon began to flow in the opposite direction, to the east.
07:15The Cenozoic Ice Age was long over by that time, and life in the Amazon began to thrive in all its diversity that we see today.
07:26In addition to these dramatic transformations on the surface, a lot has happened under the river basin over these millions of years.
07:35In parallel to the river, its dark antipode was forming deep underground.
07:41And scientists didn't even know about it until recently.
07:48In 2011, at the 12th International Congress of the Brazilian Geophysical Society in Rio de Janeiro,
07:55a group of scientists presented the results of extensive geologic research of the Amazon basin.
08:02The report rekindled the scientific community's interest in the basin and became a source of much debate.
08:09Indian scientist Walia Manatal Hamza of the National Observatory in Brazil and colleagues used data collected from 241 abandoned oil wells in the area.
08:21Calculations have shown that there must be a large underground flow in this region.
08:26It's literally huge, and it's located right under the Amazon itself, but at a depth of 4 kilometers.
08:36The scientists immediately named this phenomenon in honor of its discoverer, the Hamza River.
08:43The only thing is, the term river can be applied here quite loosely.
08:48The data of many seismic sensors and other equipment in hundreds of old wells helped to identify the aquifer's location.
08:57It turned out that there is definitely a current.
09:00And it even follows the same flow direction as the Amazon itself.
09:05But that's as far as the similarities go.
09:08The most obvious differences are the width and the flow velocity.
09:12While the Amazon is from 1 to 100 kilometers wide, the Hamza River is 200 to 400 kilometers wide.
09:21Scientists are quite certain about this.
09:24And the data can only be further specified, but not refuted.
09:29The underground river is about 6,000 kilometers long.
09:33But the flow velocity is ridiculously low.
09:37While the average velocity of the Amazon is about 5 meters per second, the Hamza's speed is less than a millimeter per second.
09:48That is, Hamza doesn't really deserve to be called a river.
09:53This can be compared to Glacier's velocity.
09:56Therefore, even the discoverer, Waliyah Hamza himself, admits that the term river can only be loosely applied in this case.
10:05However, due to its immense capacity, the river Hamza contributes to the waters of the Atlantic.
10:12The discharge is about 3,000 cubic meters of water per second.
10:17Like the gloomy Amazon's twin, the Hamza follows its channel and flows into the ocean deep below its surface when passing from west to east.
10:28The Hamza and the Amazon rivers represent an unusual geological system of two rivers flowing at different levels of the Earth's crust.
10:39They are both major drainage systems of the Amazon basin.
10:43Thermal signatures of groundwater suggest that the Hamza flows west to east just like the Amazon, except at a depth of about 13,000 feet or 4,000 meters below the Earth's surface.
10:58Computer simulations suggest that a higher depth of about 2,000 feet or 600 meters, the river actually flows vertically.
11:08But no matter how unusual the very existence of these rivers are, the most interesting and even somewhat creepy tidbits about the history of this region were discovered much higher.
11:21Look at this fossilized bone. Nothing special, right? It's just a vertebra after all.
11:29But this is a vertebra of a snake.
11:33Well, you can say, why not? There exist some huge snakes, like anacondas.
11:39There's no doubt about that, but here's an anaconda vertebra for comparison.
11:45How do you like that now?
11:47What kind of ancient monster is this, that even the anaconda looks like a dull worm compared to it?
11:55A few million years after the well-known meteorite that killed the dinosaurs,
12:01Titanoboa appeared on the territory of modern Columbia.
12:06This is the largest snake ever.
12:09It could be up to 13 or even 15 meters long and way over a ton.
12:16The longest modern snake, the reticulated python, is half as long, no more than 7.5 meters.
12:25Such a monster, it would seem, could choose anything on the prehistoric menu.
12:30Even ancient turtles or crocodile ancestors.
12:34But in fact, as surprising as it sounds, it mostly ate regular fish.
12:40Just as giant whales prefer microscopic plankton and all kinds of small fish.
12:47Titanoboa became extinct long ago.
12:50But there are still enough creatures in the Amazon basin that it's better to avoid.
12:56In the Amazon forests, there are about a hundred species of poisonous frogs alone.
13:02Some can literally kill a person with one touch.
13:07Then there are crocodiles, electric eels, piranhas, poisonous snakes, vampire bats, and big wild cats.
13:17Brazilian wandering spiders can also be found here.
13:22For a long time, they were considered the most poisonous among arachnids.
13:27And even got into the Guinness Book of Records in 2010.
13:31Since then, it has lost this title.
13:34But doesn't make it any less dangerous.
13:37The famous bullet ants also live in these places.
13:41They got their formidable name from the most painful bites that can hurt up to one day.
13:48There are also giant centipedes living here.
13:51Even sharks swim into the river from the ocean.
13:55Moreover, the anaconda mentioned earlier also inhabits these lands.
14:02It's hard to imagine how some human tribes live here.
14:06They still preserve their original culture and are reluctant to contact civilization.
14:13But they have lived here since time immemorial.
14:17Archaeologists are still finding traces of ancient civilizations.
14:22Most recently, monumental structures abandoned almost 600 years ago were discovered,
14:29which were hidden from the eyes of researchers in the dense forests of Bolivia.
14:34A large-scale study about this was published in Nature.
14:39The history of this discovery began 20 years ago,
14:43when German scientists Dr. Heiko Prümers from the German Archaeological Institute
14:49and Dr. Carla James Bettencourt from the University of Bonn
14:53began archaeological excavations on two mounds near the village of Casa Rabe in Amazonian Bolivia.
15:01This area is known as Llanos Mojos.
15:04It lies in the southwestern part of the Amazon River Valley.
15:08Llanos Mojos is a plain that is flooded during the rainy season due to the rising water level
15:14and remains underwater for several months a year.
15:18Apparently, this cyclicality has been observed here for many hundreds of years.
15:23Such natural conditions, it would seem, aren't suitable for permanent settlements.
15:29However, it is here that scientists have discovered many traces of an ancient pre-Columbian culture.
15:36Its timeframe is not exactly established.
15:39Archaeologists suggest that it was at its peak around the end of the first and beginning of the second millennium AD.
15:48It was named after the nearest village, Casa Rabe.
15:54This culture's traces include not only man-made mounds, but also roads and canals.
16:01They often run for several kilometers in an absolutely straight line, cutting right through the terrain.
16:09Furthermore, scientists found that the settlements of the Casa Rabe culture occupied an area of about 16,000 square kilometers,
16:18and the mounds turned out to be the destroyed foundations of the pyramids and other buildings.
16:24It became more and more interesting, and no one could even imagine what else was hiding under the Amazon basin in the upper soil layers and the forest's shadow.
16:37The architectural details of the monumental structures and their surroundings were hidden by dense Amazonian vegetation.
16:45To learn more about these mysterious places, researchers used LIDARs for the first time in the Amazon Valley region.
16:54These are laser rangefinders that scientists have adapted to scanning terrain from height.
17:00The LIDAR was attached to a helicopter, which then circled the area.
17:05A high-precision laser device produced 1.5 million pulses per second, which made it possible to create a fairly accurate three-dimensional map of the territory.
17:17When the scientists superimposed the previously available maps with the locations of the Casa Rabe culture artifacts on a new digital model,
17:26they opened up a striking view of two large areas of 147 and 315 hectares with a rather complex planning system.
17:38So far, we can't estimate how many people lived there.
17:42However, the layout of the settlements themselves suggests that a large and well-coordinated team worked here.
17:50Previously, the settlements have already been found in other parts of the world,
17:55namely in Southeast Asia and Central America in Sri Lanka.
17:59But only with the discovery of the Casa Rabe culture, scientists were able to state for the first time
18:06that such settlements existed in pre-Hispanic times in the Amazon Valley.
18:12The researchers emphasize that we are just starting the real archaeological work in this region.
18:18The challenge for the future is to understand how these ancient cities functioned,
18:23where the settlers came from, and where they went.
18:28Radiocarbon analysis showed that the Casa Rabe culture settlements were abandoned around 1400 AD.
18:35Why? For now, it remains a mystery.
18:41The Amazon basin holds many more mysteries like this.
18:46And sometimes, as you can see, we don't even have the slightest idea about their existence.
18:53Well, hopefully, the more interesting it will be to find out the answers.
19:04Great.