Les Scientifiques ont Enfin Cartographié ce Continent Perdu

Sympa

Il y a environ 70 000 ans, il y avait une immense étendue de terre au large des côtes de l'Australie qui aurait pu soutenir environ un demi-million de personnes. Cette terre reliait l'Indonésie actuelle à l'Australie et faisait partie du plateau nord-ouest australien. Elle faisait autrefois partie d'une masse terrestre plus grande appelée Sahul, qui reliait l'Australie, la Nouvelle-Guinée et la Tasmanie en un seul continent. Aujourd'hui, les scientifiques cartographient cette "Atlantide" perdue pour en savoir plus à son sujet. C'est fascinant de penser à ce monde ancien qui a autrefois existé !  Animation créée par Sympa. ---------------------------------------------------------------------------------------- Musique par Epidemic Sound https://www.epidemicsound.com   Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna​ ---------------------------------------------------------------------------------------- Nos réseaux sociaux : Facebook: https://www.facebook.com/sympasympacom/ Instagram: https://www.instagram.com/sympa.officiel/  Stock de fichiers (photos, vidéos et autres): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ----------------------------------------------------------------------------------------  Si tu en veux encore plus, fais un tour ici:  http://sympa-sympa.com

Transcript

00:00Scientists have recently discovered vestiges comparable to Atlantis near Australia.

00:06In the past, an entire continent was there, now submerged. Here is its history.

00:13About 70,000 years ago, during the last glacial period,

00:17a vast terrestrial mass called Sahel existed in the southwest of the Pacific Ocean.

00:21This ancient supercontinent connected what we know today under the names of Australia,

00:26New Guinea, Tasmania and the Aru Islands,

00:29forming an immense expanse of land.

00:31Imagine luxurious tropical forests surrounded by majestic mountains.

00:36The highest mountains of Sahel were located in the highlands of New Guinea

00:40and reached peaks of more than 3,900 meters.

00:44This exceptional place housed a diversity of unique animals, mainly marsupials.

00:49But there were not only koalas and kangaroos.

00:52Sahel housed various types of brooders, fowlers, caribou and predators.

00:58There was the gigantic Diprotodon, the formidable hunter that was the Thylacoleo,

01:03and the terrifying Megalania, a creature much larger than most of the lizards living today.

01:09This territory was quite unique because,

01:12while the rest of the world was populated by land animals such as wolves, elephants and humans,

01:17Sahel only had among its classic mammals bats and rodents.

01:23However, its different regions presented varied ecosystems.

01:26The regions of Timor, Arafura and Carpentaria were high and covered with savannas and dry forests,

01:32reminiscent of modern Australia with its arid deserts,

01:36its marshes, its steppes and its temperate forests along the east coast.

01:41At this time, humans migrated around the globe.

01:44They made an extraordinary journey from Southeast Asia to Sahel,

01:48and they arrived there for the first time 60 to 45,000 years ago.

01:52They traveled mainly on foot and crossed the sea using bamboo rafts and rudimentary boats.

01:58They came from the former continental plateau of Sunda, which included parts of Southeast Asia.

02:03By crossing a series of islands known as Wallacea, they finally spread across the Sahel.

02:09And it was not a small journey.

02:11The Sahel was immense, stretching over about 10.6 million square kilometers,

02:16a surface larger than that of the United States or Canada.

02:20It stretched from the equator to the southern part of New Zealand.

02:25Thus, by arriving in what is now Australia, these travelers became the first inhabitants of this land.

02:31Scientists estimate that the Sahel then had about 500,000 inhabitants.

02:36We have also discovered rock paintings dating from about 40,000 years ago,

02:40which represented hunting scenes for dwarfs or Anoa, facing human and animal figures.

02:46Researchers are trying to understand how these first settlers moved across the Sahel

02:51and where to find archaeological traces of their travels.

02:54To do this, they created a computer model of the evolution of the landscape.

02:58This simulation showed the transformations of the Sahel between 75 and 35,000 years,

03:03revealing potential migratory routes and archaeological sites.

03:08Humans were probably moving along the coasts and rivers.

03:13But how was the Sahel submerged, like the mythical Atlantis?

03:19During the last glacial period, a large part of the terrestrial water was trapped in huge ice caps,

03:26thus lowering the sea level.

03:28Subsequently, with the increase in global temperatures,

03:32these caps melted and the sea level rose as much,

03:35submerging the terrestrial bridges that connected the different parts of the Sahel.

03:40About 8,000 years ago, New Guinea separated from continental Australia.

03:45Then, about 6,000 years ago, it was the turn of Tasmania.

03:49But thanks to new technologies, we can still explore the submerged parts of the Sahel.

03:54Divers explore and collect samples directly from the bottom of the ocean,

03:59and underwater drones can reach areas too deep or dangerous for humans.

04:04Thanks to sonar cartography, scientists use sound waves to draw maps of the seabed,

04:10a bit like using an echo to see underwater.

04:13The waves bounce on the seabed and return to the sender,

04:17thus helping to compose an image of the surroundings.

04:20In the underwater depths, archaeologists have found tools made of stone and other artifacts.

04:25They have also discovered fossil animals such as the Diprotodon and the Thylacoleo.

04:30By studying the submerged terrain of the Sahel, they have highlighted the existence of rivers,

04:35lakes and coasts dating from the Ice Age.

04:38But still, the Sahel is not the only submerged continent in the world.

04:44It is not even the only hidden treasure of Southeast Asia.

04:48Take Sundaland, a region made up of Sumatra, Java, Borneo and a few other islands.

04:54This place was gigantic during the Ice Age, but today it is almost entirely submerged.

05:00Almost, but not totally.

05:03The submerged parts are still crawling with life.

05:06If you like birds, visit this place.

05:09It houses almost a fifth of the species of birds in the world.

05:12You can see colored birds like the Java Eagle and the Bali Turtles in the lush forests.

05:18It is also the home of a quarter of the species of fish on Earth.

05:22The waters of Sundaland are a haven for marine life.

05:25Even for the most exotic, such as Asian arowanas.

05:30It is also a real gold mine in terms of flowers.

05:33This is where you can find the Rafflesia and the Titan Arum, the largest flowers in the world.

05:38This makes it very similar to the continent of Zealandia.

05:42It is a long and narrow strip of land measuring half the size of Australia

05:47and which separated from Antarctica about 100 million years ago.

05:51Like Sundaland, it is not entirely submerged.

05:547% of its surface remains above sea level.

05:57This emerged fragment is what we call New Zealand today,

06:01as well as Stewart Island and a few small islands.

06:04These pieces of Zealandia are temperate and luxurious.

06:08It is full of volcanoes, mountain ranges,

06:11magnificent natural geysers and hot springs.

06:14The Maori use these to cook.

06:17They place corn, eggs and vegetables in baskets

06:20and immerse them directly in the thermal springs.

06:23Sometimes they also cook in a hollow oven filled with hot stones.

06:30Another lost world is known as Dargoland.

06:34This mysterious terrestrial mass was once part of Australia

06:38at the time of the dinosaurs, and it intrigued scientists for decades.

06:42We suspected its existence because it left a huge stretch on the seabed,

06:46the abyssal plain of Argo.

06:49About 155 million years ago, Dargoland separated from Australia

06:53and drifted north.

06:55Then, when it reached Southeast Asia, it simply disappeared.

06:59Scientists had no idea where it could have gone.

07:03But recently, they finally found its trace.

07:07It turns out that the lower parts of the unfortunate Dargoland

07:11began to sink into the pit of the probe,

07:14an oceanic abyss, terribly deep.

07:17The terrestrial crust sank into the mantle,

07:20and during this time, the upper parts of Dargoland were pushed up,

07:24integrating younger rocks to the surface.

07:27Because of this, Dargoland split into several smaller fragments.

07:31The latter formed parts of Borneo, Java, Celebes and other regions.

07:35The rest is deeply buried under Indonesia and Burma.

07:40Imagine a colossal terrestrial mass the size of Greenland,

07:44the Great Adria.

07:46Its journey began about 240 million years ago

07:49when it separated from the supercontinent of Gondwana.

07:53It began to drift north,

07:55and after 100 million years spent in warm seas,

07:58it suddenly hit Europe before breaking apart.

08:01Most of these pieces were deeply dragged into the terrestrial mantle,

08:05but some have been torn off

08:07and have become part of mountain ranges like the Alps.

08:11Today, the remains of the Great Adria are scattered in more than 30 countries,

08:15from Spain to Iran.

08:17That's why they are so difficult to locate.

08:22The Seychelles were also part of Gondwana.

08:25Yes, these idyllic islands rest on the remains of the old continent.

08:29We have learned a lot from these fascinating granitic eruptions.

08:34It was Alfred Wegener who suggested the drift of the continents

08:38nearly a century ago, but no one believed him at the time.

08:41And these eruptions helped him prove that the tectonic plates were really moving.

08:46The Seychelles separated from India and Madagascar

08:49and finally became a solitary archipelago in the Indian Ocean.

08:53This probably happened because of the intense volcanic activity of the Deccan Rift.

08:58Today, the islands are home to unique species,

09:01both on land and in the surrounding coral reefs.

09:07Mauritius' microcontinent separated from India after the extinction of dinosaurs.

09:12During its journey, it stretched to take the shape of a ribbon,

09:16before fragmenting.

09:17Today, these fragments are scattered throughout the Indian Ocean.

09:20Scientists have discovered this lost land

09:23by studying tiny ancient crystals called zircons.

09:27These zircons are similar to time capsules.

09:30They date back to an antediluvian period,

09:33which can go from 660 million to 2 billion years,

09:36much older than Mauritius itself.

09:39These ancient crystals suggested the existence of another Atlantis somewhere nearby.

09:44It seems that there are continents engulfed all over the world.

09:48And maybe we will discover many more in the future.

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