La Méga-Inondation Qui A Changé La Géographie De La Terre À Jamais

Sympa

Imaginez une inondation si massive qu'elle a remodelé des paysages entiers. C’est ce qui s’est produit avec les méga-inondations de l'ère glaciaire, connues sous le nom d'inondations de Missoula. D'énormes lacs glaciaires en Amérique du Nord se sont soudainement rompus, libérant de l'eau qui a traversé la terre à des vitesses incroyables. Cette force a creusé des canyons, créé de vastes vallées et laissé derrière elle des blocs massifs éparpillés comme des cailloux. Ce fut l'un des événements géologiques les plus dramatiques de tous les temps, - il a modifié à jamais la géographie de notre planète.  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

00:00About 5.3 million years ago, a major event radically remodeled the Mediterranean basin.

00:07A terrible flood re-supplied the sea, which until then was as salty as sterile.

00:13This event, called the Zanclean Transgression, forever altered the geography of the region.

00:20The Mediterranean Sea, surrounded by Europe, Africa and Asia, is reconnected to the Atlantic Ocean by the Strait of Gibraltar.

00:28This narrow passage measures about 13 km.

00:31Although it is not very wide, the strait plays a crucial role in balancing the water masses between the two streams.

00:38About 6 million years ago, various factors were able to isolate the Mediterranean from the Atlantic.

00:44Some evoke a glacial period, while others speak of tectonic movements, such as earthquakes.

00:50Whatever the cause, it led to the so-called Messinian salinity crisis.

00:56For about a thousand years, the sea slowly evaporated, leaving behind a dried up basin, located several kilometers below sea level.

01:05This crisis profoundly altered the landscape, creating conditions similar to those of the current dead sea.

01:11This means that the luxurious beauty of the Mediterranean outskirts was once an extremely salty environment.

01:17A salinity nearly ten times higher than that of the ocean.

01:21If you had the opportunity to visit this place, you could easily float on the small amount of water available.

01:27And without even being a seasoned swimmer.

01:29The high concentration of salt and minerals would have made survival difficult for most creatures.

01:35However, some robust microorganisms, such as bacteria, could not have adapted to these extreme conditions.

01:41Nowadays, at the bottom of the Mediterranean Sea, there are caves as impressive as the Grand Canyon.

01:47These formations seem to date from the period of dehydration mentioned above.

01:51Traces suggest that large rivers, such as the Nile and the Rhône, flowed directly into the Mediterranean at this time,

01:59digging deep canyons several thousand meters below sea level.

02:04At the time, people were looking for explanations for the drying up of the Mediterranean and invented all kinds of myths and legends.

02:13One of these stories comes from the inhabitants of the south of Iberia, which today corresponds to Spain and Portugal.

02:19This myth, also reported by the famous writer Plin the Elder,

02:23tells that the Mediterranean was once isolated from the ocean,

02:26until the hero Heracles, endowed with superhuman strength,

02:30made his way to the Garden of the Hesperides, through Gibraltar's current rock.

02:36This journey allowed the oceanic zoos to invade the Mediterranean,

02:40transforming it into the sea we know today.

02:44Some fossils also seem to corroborate the exceptional magnitude of this flood.

02:49Remnants of marine organisms have been discovered in layers well above the current sea level,

02:54indicating that these areas were once submerged.

02:57The fossils found include molluscs, fish and even marine mammals.

03:02Thanks to modern techniques, we now have an estimate of the moment when the Zanclean Transgression occurred.

03:08Researchers have used computer simulations to reconstruct this event,

03:13thus providing additional proof of its reality.

03:16They have also discovered that it was possible that the Mediterranean was undergoing new changes.

03:21Gibraltar's strait could close again, probably due to deep tectonic movements.

03:26This could lead to a new drying up of the Mediterranean over a period of about a thousand years,

03:31and if the African continent continues to move north and draws closer to Europe,

03:36the Mediterranean basin could even disappear entirely.

03:39One of the most famous major floods, albeit hypothetical, is that of the Black Sea.

03:44According to some scientists, about 8,400 years ago,

03:48the Mediterranean water could have overflowed into the Black Sea through the Bosphorus strait.

03:53This overflow could have caused a huge disaster,

03:56forcing the populations living around the Black Sea to leave their homes

04:00and move further into the lands of the European and Asian continents.

04:04These migrations could have favored the propagation of the stories relating to the cataclysm.

04:09The researchers who formulated this hypothesis also suggest that these migratory populations

04:14could have introduced new agricultural methods into their home lands.

04:18However, not all scientists are convinced.

04:22Some believe that, if an inundation did indeed take place,

04:26it occurred earlier and was much less significant.

04:30They do not think that this event could have inspired the story of Noah's Ark, for example.

04:35According to this myth, a very pious man would have been warned by God in person

04:39of the arrival of a prodigious flood.

04:42To save all living species, he would have gathered couples of animals

04:46and would have embarked them on a large ark.

04:49Some researchers also fear that getting too close to the true floods of ancient legends

04:54could end up blurring the boundaries between science and belief.

04:58There could be other explanations for the fact that the myth of the flood

05:02appears so frequently in different cultures around the world.

05:05One of the hypotheses is that these floods were absolutely devastating for the first farmers,

05:10pushing them to imagine myths that preceded the end of time.

05:14Another theory suggests that the discovery of fossils of marine creatures in incongruous places

05:19would have given birth to this belief in a great historical deluge.

05:23The parade of future floods could reside in floating cities.

05:28With the continuous elevation of the sea level, coastal cities such as Amsterdam,

05:32New Orleans and Venice may find themselves submerged.

05:36Floating infrastructures could then offer a viable solution

05:39and buildings capable of rising with the water level,

05:43while resisting extreme climatic conditions.

05:46The Netherlands, which has a long tradition of managing water-related risks,

05:50is at the forefront of these floating innovations.

05:53Faced with the exhaustion of the space available for urban expansion,

05:56we could be led to live on the waves.

05:59This adaptation would reduce the density of our populations

06:03and explore innovative agricultural methods such as floating gardens.

06:08In addition, these habitats could offer interesting energy alternatives

06:13thanks to the exploitation of solar and wind energy,

06:17while being potentially more economical in the long term.

06:20Such a floating city could soon see the light of day in the Maldives.

06:24This project aims to accommodate up to 20,000 people

06:27and will include residential and restaurant spaces, as well as shops and schools.

06:32Designed to imitate the shape of coral,

06:35the city will have canals arranged between nearly 5,000 floating islets.

06:40Construction will be carried out from modular units

06:43assembled on a construction site nearby.

06:46Once ready, these units will be towed up to the floating city.

06:50The next step will be to attach these units to a large core of submerged concrete,

06:55solidly anchored to the seabed thanks to steel pilots.

06:58This configuration will allow the modular units to move fluidly,

07:02in harmony with the movements of the sea.

07:04And for those who fear being sick,

07:06the surrounding coral reef will serve as a natural breakwater to mitigate the waves.

07:11Artificial coral banks will also be placed under the city,

07:15which will also help the coral to grow naturally.

07:18The long-term goal is to make the facility autonomous.

07:21It will have electricity mainly from the solar energy on site.

07:26Waste will be treated up close and reused as fertilizer for plants.

07:31Instead of air conditioning, the city will use deep-water cooling.

07:36This method pumps cold water from the depths of the sea to cool the area,

07:40thus saving energy.

07:42The Earth is not the only planet to have experienced major floods.

07:46Mars, in ancient times, also seems to have been affected by cranes,

07:51which played a significant role in the formation of its surface.

07:55Recent research reveals that several billion years ago,

07:58Mars underwent major flooding,

08:01contributing to the formation of its valleys and canyons.

08:05These floods were caused by heavy rains,

08:08which quickly changed the landscape of Mars,

08:10sometimes in a few days or weeks.

08:12Unlike the Earth, where rivers form slowly,

08:16floods on Mars have caused rapid changes,

08:19especially around 4 billion years ago.

08:22Although we have known for some time that there have been floods on Mars,

08:26this study has revealed their real extent.

08:29We now know that they were more extensive and frequent

08:32than we had previously believed.

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