00:00Nowadays, it's better to take a plane if you want to go from New York to London.
00:06But did you know that there was a time when these two cities were on the same continent?
00:11The explanation is a little more complicated.
00:14First of all, these two cities did not exist at the time.
00:17But the tectonic plates on which they are today were much closer.
00:24Almost 200 million years ago, all the continents of our planet came together to form a great supercontinent.
00:32This huge piece of land was surrounded by a single ocean.
00:36Today, we call this immense continent the Pangaea.
00:40Some parts of this continent separated and moved away.
00:44And that's how our maps got to their current configuration.
00:49There is even an interesting experiment that you can do to test this theory.
00:54Find a map online and print it on a sheet of paper.
00:58Then you just have to cut all the continents.
01:01When you start playing with them, you will quickly notice that they seem to fit into each other,
01:07like pieces of a puzzle.
01:09The most striking thing you will see is probably the way South America fits perfectly into Africa.
01:16What is even more fascinating is that it is not the first time in the history of our planet that supercontinents form and then disintegrate.
01:24Scientists have discovered that this has already happened at least three times.
01:29And if we consider the age of our planet, 4.5 billion years,
01:34the 200 million years that have just passed are barely a blink of an eye.
01:38How did scientists understand that the continents were moving?
01:44In addition to the current aspect of the continents, they have also found identical rocks in different parts of the planet.
01:50They seem to have formed from the same minerals and in the same weather conditions.
01:55Other clues?
01:57Dinosaurs.
01:59Fossils of the same species have been discovered in South America and Africa.
02:04This particular dinosaur, the Mesosaurus, would have lived on our planet long before the continents separated.
02:14It is difficult to imagine what life on Earth could have been like with a single continent.
02:19First of all, the climate must have been very different.
02:22Indeed, the median part of the Earth was probably very dry and had little or no water source.
02:29In addition, it was probably hidden behind many mountain ranges.
02:33It would also have been a barrier against humidity and precipitation.
02:39However, geologists have also studied coal deposits in the United States and Europe.
02:45This seems to show that at least part of the ancient supercontinent, which was close to the equator,
02:52must have been an incredible tropical forest.
02:55Just like the one we find today in the Amazon.
02:58Coal appears when remains of plants and animals are caught in swampy waters.
03:04If the water exerts enough pressure, the substance first turns into silt, then into coal.
03:11Our planet has existed in this continental configuration for more than 100 million years.
03:17And during this period, there was already a lot of life on Earth.
03:21It was the ideal time to be an insect.
03:24Animals such as coleoptera and libellules have thrived.
03:28At the same time, the Earth was traversed by the predecessor of all mammals, the synapsis.
03:36Life in the swamp was hard to experience during a later period.
03:41It is thought that a comet or an asteroid landed on the surface of the Earth about 251 million years ago.
03:48The theory of the asteroid or comet seems pretty well established.
03:53Because 90% of marine animals and 70% of terrestrial creatures disappeared at once.
04:00The comet may not be the only cause of this massive extinction.
04:04At the same time, there was an important volcanic activity in northern Asia, which also disturbed life on Earth.
04:13We may not notice it, but the continents continue to move right now.
04:19The configuration we observe today thanks to satellite imagery will certainly not be the last.
04:25Australia, for example, is slowly approaching Asia.
04:28But the most important proof that our continents continue to move is the eastern part of Africa.
04:34This region is simply separating from its neighbors.
04:40To be a witness to this, you should go to one of the warmest places on the planet.
04:45If you visit this piece of land located east of the African continent,
04:49you may be exactly at a place that will soon be divided in two by the sea.
04:58Under this region, three tectonic plates slowly separate from each other.
05:03If our data is accurate, in the near future, Africa will be divided in two and a new ocean will be born between the two regions.
05:11To confirm this theory, scientists have been studying for years
05:16a crack 56 kilometers long in the Ethiopian desert.
05:22It is estimated that it will take between 5 and 10 million years for this new ocean to form.
05:27The crust of our planet, being made up of multiple tectonic plates in perpetual motion,
05:33is the ideal place to study this process.
05:36These plates are all irregular in shape and they collide, slide under each other or overlap.
05:45The three tectonic plates found under this desert also move at varied speeds.
05:52One of them, the Arabic plate, moves away from Africa at a speed of about 2.5 centimeters per year.
05:59The other two plates move a little slower, between 1.25 centimeters and 5 millimeters per year.
06:06In addition, these movements lead to the rise of materials from the depths of the earth and the formation of an oceanic crust.
06:16All these movements lead us to wonder how and when the next supercontinent will form.
06:21So far, scientists have proposed several possible configurations, each bearing its own name.
06:28The new Pangea, the next Pangea or Amazigh.
06:32But these predictions still vary, because we do not know exactly how and why the continents actually move over time.
06:40We have a clue in the way the original Pangea split up.
06:45Anyway, it will take between 15 and 100 million years to see the next supercontinent appear.
06:52The new Pangea is the hypothesis of the continuation of current movements.
06:58In this scenario, the Atlantic Ocean continues to expand and the Pacific is shrinking.
07:05The two American continents first meet to the north.
07:09Africa, Europe and Asia also regroup, then a huge and unique continental mass is formed.
07:21Another possible scenario is the next Pangea.
07:24In this case, the Atlantic slows down its expansion and becomes an enclosed mass of water.
07:29North America, Africa, Asia and Europe form more or less parallel plots of land and completely sewn to each other.
07:39Below, South America, Antarctica and Australia complete the circle that surrounds the North Atlantic.
07:47A vast Pacific Ocean ends up surrounding all the lands.
07:54Amazigh is a somewhat difficult scenario to understand and to study at the moment.
07:59As several tectonic plates seem to move to the north, it is possible that all continents, except Antarctica, slide completely to the north pole.
08:10The climate would then be very different and much colder.
08:13In this scenario, the Pacific and the Atlantic would remain open water areas.
08:18Scientists believe that this possibility is real due to certain anomalies caused by the original Pangea in the depths of the Earth, in the part called the mantle.
08:30If we look even further into the future of our planet, it is estimated that in about a billion years, the brightness of the sun will be about 10% higher.
08:40The atmosphere of the Earth will then resemble that of a damp greenhouse.
08:46Due to the increase in heat, all the extensive waters of our planet will begin to evaporate.
08:53In 4 billion years, the temperature of our planet will make it similar to Venus.
09:00The Earth could become so hot that its surface will begin to melt.
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