Les Scientifiques Viennent De Faire Une Découverte Révolutionnaire en Antarctique

Sympa

Les scientifiques viennent de faire une découverte incroyable en Antarctique—ils ont trouvé de l'ambre de l'île Pine, un type super rare de résine d'arbre fossilisée ! Cet ambre a des millions d'années et pourrait contenir des indices sur les anciens écosystèmes qui prospéraient autrefois sur le continent gelé. Imaginez trouver de minuscules insectes préhistoriques ou du pollen piégé à l'intérieur, parfaitement conservés d'une époque où l'Antarctique était beaucoup plus chaud. Cette découverte pourrait réécrire ce que nous savons de l'histoire climatique de la Terre et de la manière dont les plantes et les animaux se sont adaptés à des changements extrêmes. Les scientifiques étudient maintenant attentivement l'ambre pour en découvrir les secrets. Qui sait quels mystères pourraient se cacher à l'intérieur ?  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

00:00Antarctica, a frozen world in a freezing cold of minus 43 degrees Celsius, covered with ice for millions of years.

00:08But this has not always been the case.

00:10Scientists have just made an incredible discovery.

00:14Deeply buried under the ocean floor, tiny drops of golden amber.

00:19This means that once, Antarctica was full of life and was covered with vast forests.

00:25However, an event has occurred.

00:27An event that could radically change our perception of the future.

00:31For millions of years, Antarctica has been a land swept by powerful winds, where no vegetation can grow.

00:38But researchers who have explored this region have decided to dig the depths of the Antarctic surface.

00:45They have drilled several thousand meters under the ice and extracted layers of ancient sediments.

00:50It was there, trapped in time, that they discovered these fragments of amber.

00:55Amber, fossilized resin from trees, is found on all continents and often contains perfectly preserved traces of extinct species.

01:04Insects frozen in their flight, pollen frozen in time.

01:08These golden drops can preserve ancient and tiny ecosystems.

01:13On all continents, but not in Antarctica until then.

01:19The tiny discovered drop, measuring between 0.5 and 1 mm, as small as a grain of sand, but of great importance,

01:29had flowed from the bark of a tree about 90 million years ago.

01:35What is even more fascinating is that amber is only formed in certain species of trees.

01:40Those that thrive in humid and temperate tropical forests or in the jungle.

01:45It was then that a revelation was made.

01:47Antarctica was once a tropical forest.

01:53These tiny fragments of amber, visible only under the microscope, tell us the living history of a flourishing ecosystem.

02:00About 90 million years ago, during the Cretaceous period, when dinosaurs dominated the Earth,

02:07Antarctica was to be covered by dense and swampy forests,

02:11populated by majestic conifers, ferns and ancient plants.

02:16Some of these fragments showed signs of damage,

02:20indicating that the trees at the origin of these drops had been damaged, probably by fires or parasites.

02:28Despite all this, and despite the millions of years spent in the seabed, this amber has surprisingly resisted well.

02:35It remains solid, transparent, without the slightest crack.

02:38In general, amber, when subjected to intense pressure and those of extreme temperatures, disintegrates little by little.

02:46But this fragment has survived, which suggests that others may also have survived,

02:52and that other discoveries could emerge from the ocean depths.

02:57That said, this discovery was not the first sign that Antarctica was not the frozen world we know today.

03:04In 2017, a team of researchers dug deep into the surface of the seabed,

03:09near the Ile-du-Pain glacier, on the west coast of Antarctica.

03:13They have thus extracted sediment carrots buried for millions of years.

03:17This discovery was amazing.

03:19In these layers of sediment, researchers have updated fossilized roots, pollen, spores,

03:26as much evidence as an ancient forest had thrived on these lands.

03:30Since this discovery, the team has not stopped analyzing these elements,

03:34dedicating several years to decomposing the sediments into thousands of fragments,

03:38and carefully examining them under fluorescent microscopes, without damaging anything.

03:44In 2020, this same team discovered another key element of the puzzle.

03:48New samples of sediment taken from the seabed highlighted a landscape made up of dense forests,

03:54rivers, and humid areas.

03:56An environment that looked more like that of the Pacific Northwest or New Zealand.

04:02But why was Antarctica so hot at that time?

04:06The answer lies in the atmosphere.

04:0890 million years ago, carbon dioxide levels were extremely high on Earth.

04:15This period corresponded to one of the hottest moments in the history of the planet,

04:19with temperatures even reaching the poles.

04:22Imagine, Antarctica had no ice caps.

04:26Instead, Antarctica could have sheltered swarming insects,

04:31and perhaps even wandering dinosaurs through these forests.

04:35But to understand what happened to them, the team still needs to discover more evidence.

04:40Antarctica remains a place full of mystery.

04:43Its snowy and icy cover makes its study difficult,

04:47to the point that we do not even know its true shape and dimensions.

04:51Some areas of the ice cap measure nearly 5 km in thickness,

04:56the equivalent of half the depth of the Marianas Gorge,

05:00the deepest oceanic gorge on the planet.

05:03Fortunately, the snow has remarkable quality.

05:06It manages to freeze time with perfect precision.

05:09Layer after layer, year after year, it buries the natural past, acting like a time capsule.

05:16At first, the fresh snow is light and moves easily with the wind, filled with air.

05:21But as the layers accumulate, they compress,

05:25expelling the air and hardening into a dense ice.

05:28This freezing pressure imprisons everything inside,

05:31preserving ancient plants, animals and even entire landscapes.

05:36The elements are literally frozen in time,

05:39because this extreme cold slows down the decomposition process.

05:44It stops the growth of bacteria, thus preventing putrefaction,

05:48and allows an almost perfect preservation for thousands, even millions of years.

05:54It is precisely this phenomenon that occurs in Antarctica.

05:58Scientists have to dig deep into this snow

06:01to discover what this place looked like millions of years ago.

06:06What they have discovered?

06:08An entire world lost, buried under kilometers of ice.

06:13This discovery is located under the thickest ice in East Antarctica,

06:17near subglacial basins Aurora and Schmidt.

06:22The weight of the ice, immense and constant for millions of years,

06:26has actually protected the Earth from erosion.

06:30Scientists call it the ghost of the landscape of Antarctica.

06:35And it's really not like the flat and smooth desert we see up there.

06:39They have discovered rivers that used to flow freely,

06:43now frozen on the spot.

06:45Valleys carved by the water.

06:47Even three huge hills at tight peaks.

06:51But what happened?

06:53To understand this, we have to go back in time,

06:57to the time when Antarctica was still part of a supercontinent that has now disappeared.

07:03Hundreds of millions of years ago,

07:05what we call today Antarctica was part of the Gondwana,

07:09a gigantic supercontinent that included South America,

07:13Africa, India, Australia and Antarctica,

07:18all merged together.

07:20However, as the tectonic plates of the Earth moved slowly,

07:25the Gondwana fragmented.

07:28Antarctica was torn apart, its land stretching and fracturing.

07:32The vast ice caps that formed later covered these broken lands,

07:37preserving them as frozen fossils.

07:39As the ice moved and melted,

07:43valleys emerged,

07:45and ancient rivers probably flowed the water to a coast,

07:49which was then located hundreds of kilometers from its current position.

07:54But that's not all Antarctica holds.

07:57If you removed the ice, you would not discover a flat and deserted continent.

08:02You would see a spectacular landscape, majestic mountains,

08:06deep valleys and even active volcanoes.

08:10In Western Antarctica, at least 138 volcanoes are buried under the ice.

08:15One of them, Mount Erebus, is still active,

08:19and inside it has hot enough volcanic caves to walk around in t-shirts.

08:26Ah, and if that doesn't seem strange enough,

08:30Erebus also spits out gold.

08:33Yes, real gold particles from the depths of the Earth.

08:37Scientists believe it happens because magma,

08:41this overheated and semi-melted rock under the Earth's surface,

08:45churns out liquid gold as it rises.

08:48Every day, Erebus releases about 90 grams of gold,

08:52which is about 6,000 euros per day.

08:55In one year, that's 29 kilograms,

08:58which is more than 2 million euros spent on smoke.

09:02Unfortunately, before we catch our shovels,

09:05we must remember that these are microscopic particles.

09:08They often measure less than 60 micrometers,

09:11which is thinner than a human hair,

09:14not to mention that they are scattered up to 1,000 kilometers from the volcano.

09:18Finding them is therefore impossible.

09:22This simply proves that,

09:24even in a place as pitiful as this vast white desert,

09:27many fascinating mysteries await to be revealed.

09:31Thus, despite the extreme conditions, life still persists there.

09:35In 2017, researchers dug deep under the ice of the Ross barrier,

09:40hoping to find water.

09:42But to their great surprise,

09:44what they discovered was much more incredible.

09:48A river, hidden under 500 meters of ice,

09:51lurking in the darkness.

09:53And inside, hundreds of small creatures,

09:56resembling shrimps.

09:59They rushed around the camera,

10:01obstructing the lens while welcoming the researchers.

10:05At the bottom of these frozen caves,

10:07DNA traces revealed the presence of moss, algae,

10:10and perhaps even tiny unknown creatures.

10:14So it seems that,

10:16even in one of the most extreme environments on the planet,

10:18life still manages to adapt.

10:20And who can say what else we could discover

10:23at the edge of the South Pole.

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