00:00See how the Antarctic Peninsula looks just like South America, but upside down?
00:05This isn't just a coincidence. It's the ghost of a 30-million-year-old breakup.
00:11These continents were once connected, but their divorce gave birth to an ocean current so powerful,
00:16it was capable of completely freezing Antarctica and shaping its landscape.
00:21Here's how it went down.
00:24Tectonic plates pulled a sneaky move and cracked open a ridiculously narrow passage in the ocean.
00:28About only 500 miles wide, forcing 4.5 trillion cubic feet of water to flow inside this geological straw.
00:37This was the birth of an ocean current stronger than the Amazon River.
00:42This ocean current, called the Antarctic Circumpolar Current, by the way, flows in a circular motion,
00:49going clockwise because of the strong winds that blow over there.
00:52This circular motion around Antarctica caused erosion, shaping the landmass of the continent into a circle,
00:59except for that stubborn peninsula, which is being slowly dragged east like a kid refusing to leave a playground.
01:06Wait, South America and Antarctica used to be one?
01:10Yep, a long time ago, South America, Australia, and Antarctica were all part of a supercontinent,
01:16called Gondwana, which also included Africa at some point.
01:22Back then, South America and Antarctica used to be basically joined at the hip by a land bridge called the Antarctic Land Bridge,
01:30which just so happened to be a lush green forest, and also a great dinosaur highway.
01:35Yeah, you heard it right.
01:38Dinosaurs.
01:39A 95 million year old dino, whose name I can't pronounce, sorry, was discovered in Australia,
01:45and scientists found out it had actually been a distant cousin of Argentina's Sarmiento Soros.
01:52Same jaw, same chiseled teeth, same everything.
01:56These guys were like identical twins, separated by an ocean.
02:00How?
02:00Because back then, Antarctica wasn't a frozen wasteland.
02:05It was a temperate rainforest, like Oregon, making it a pretty nice travel route for a dino family.
02:11But the land bridge wasn't just for dinosaurs.
02:14About 40 million years ago, the ancestors of Australia's marsupials waddled to the land down under all the way from South America,
02:22taking the Antarctica route, another proof that these continents used to be connected.
02:27Things remained somewhat peaceful for the dinoes and the marsupials until Earth's ground started moving.
02:34This is what a German scientist called the Continental Drift Theory, back in 1912.
02:40Our German friend here basically looked at the coast of South America and went,
02:44Hey, this looks like it could fit into the coast of Africa.
02:47Like a scientific Sherlock Holmes, he noticed what others had overlooked for centuries.
02:52The continents were clearly pieces of a larger puzzle.
02:57And he was right.
02:59Here's the deal.
03:00Planet Earth is made of many layers of rocks and metals, like a cosmic onion.
03:05The outermost layer, the lithosphere, is divided into pretty solid tectonic plates
03:09that move atop a layer of softer, somewhat molten rocks, like slippery ice.
03:15This is why the plates move.
03:19In fact, they've been rearranging Earth's face for billions of years,
03:23with supercontinents forming and breaking apart in cycles,
03:27like a slow-motion game of bumper cars.
03:29This movement might be pretty slow since most tectonic plates only move 0 to 3.9 inches every year,
03:37except for the Nazca plate, racing ahead at 7.8 inches, about as fast as your hair grows.
03:43But don't let their snail's pace fool you.
03:46These shifting slabs are the ultimate planet shapers.
03:49Their slow dance gives us everything from earthquakes that build mountains, like the Himalayas,
03:55to rifts that birth oceans, like the Atlantic.
03:58All because the oceanic crust is dense and sinks like a stone,
04:02while continental crust floats like a cork.
04:06It's this density difference that explains why continents exist at all.
04:10Without it, Earth would be completely covered by shallow seas.
04:15This slow-motion planetary renovation project is exactly what tore South America and Antarctica apart 30 million years ago.
04:24The plates under these continents started to drift apart in a process called crustal extension.
04:30It's like the lithosphere was pizza dough being slowly stretched until it thins and splits.
04:35As the crust stretched, it became thinner and weaker,
04:39eventually cracking like the surface of a drying lake bed.
04:43This whole thing gave birth to a new tectonic plate, the Scotia plate,
04:47that emerged between South America and Antarctica, like a geological divorce lawyer.
04:53For a while, parts of this plate stayed above water as the last gasp of the Antarctic land bridge.
04:58It was Earth's version of that one thread still connecting your hoodie after the zipper breaks.
05:04These final connections might have persisted as chains of islands,
05:07but just like that fraying hoodie, the connection couldn't last forever.
05:12Eventually, this small but mighty plate became the final nail in the coffin of the land bridge connecting the two continents.
05:18Just like all the tectonic plates, this one was also on the move.
05:23As it expanded eastward, it opened a new passage of water called the Drake Passage,
05:29slowly covering the Antarctic land bridge with ocean water.
05:33The process was like pulling open elevator doors, at first just a crack,
05:37then wider and wider until the connection was completely broken.
05:41This geographical divorce had chilling consequences.
05:44The new Drake Passage allowed the Antarctic circumpolar current to form,
05:50creating an endless loop of cold water that isolated Antarctica,
05:53shaped its land, and even cooled the entire planet.
05:57This current acts like a wall around Antarctica,
06:00blocking warm water and invasive species while regulating global climate.
06:05Eventually, Antarctica turned into an icebox that is 98% covered in ice sheets,
06:11and that holds about 61% of Earth's freshwater.
06:16Nowadays, this continent holds the title of the windiest, driest, and iciest place on Earth.
06:22It's a frozen desert, where temperatures plunge below negative 128.6 degrees Fahrenheit,
06:28cold enough to freeze your breath mid-air.
06:32A layer of ice there can be more than a mile thick,
06:34and it expands even further in winter to cover an area larger than the continental United States.
06:41Today, if you want to travel to Antarctica,
06:44the quickest sea route is through the Drake Passage,
06:46a 500-mile-wide body of water that is narrow enough for the winds to scream across thousands of miles,
06:53transforming into monstrous waves that can tower up to 49 feet,
06:58though calm days create waves only 13 to 16 feet high.
07:03Still twice as tall as Atlantic waves, mind you.
07:06This is probably why sailors call this stretch of ocean the Drake Shake.
07:12But tectonic movement isn't just about shifting continents.
07:16It's Earth's ultimate life support system.
07:19You see, about half of our planet's heat comes from radioactive decay in the core.
07:24Thanks, Uranium-235.
07:26Something like nature's nuclear reactor.
07:29This heat is behind everything from volcanoes to the very plate motion that once connected Antarctica to South America.
07:37And it only comes out of the core because of tectonic movement.
07:40Without this internal heat engine, Earth would be just like Mars.
07:45When the plates move and release heat, they also release CO2 gases into the atmosphere,
07:52regulating the temperature of our planet.
07:54And when the plates move underwater, they take a lot of this CO2 back to Earth's interior,
08:00recycling all this gas.
08:02This is why the plates can change our air, climate, and even the evolution of life itself just by moving around.
08:10But billions of years ago, these plates were not moving around.
08:14Back then, it was like Earth was wearing a solid ceramic shell with many cracks.
08:19But even without tectonic movement, the heat managed to escape through these cracks in a process called
08:25stagnant lid tectonics, kick-starting all life on Earth.
08:31And no, tectonic movement is not a thing of the past.
08:34Earthquakes are the living proof that it is not just happening today,
08:38but might repeat again on a more dramatic scale in the future.
08:42You see, to form supercontinents like Pangaea, smaller megacontinents have to dive beneath another.
08:49And scientists predict that a similar process might create a new supercontinent
08:54called Pangaea Proxima in 250 million years.
08:59By then, humans might be extinct or living on Mars,
09:02but Earth's tectonic dance will continue, even without us.
09:06Not bad for something that moves more slowly than a traffic jam.
09:11Turns out, Antarctica and South America used to be BFFs before all that tectonic drama split them up,
09:19like a messy breakup that literally froze one of them out.
09:22Now, they just awkwardly mirror each other from across the Drake Passage.
09:26Classic Axis.
09:28That's it for today.
09:29So hey, if you pacified your curiosity,
09:32then give the video a like and share it with your friends.
09:34Or if you want more, just click on these videos and stay on the bright side.
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