00:00Now, at first glance, it seems like we're on a giant raft, called a continent, that's
00:05just floating around on some molten lava until it hits another continent.
00:10Okay, let's make a quick stop at high school science class.
00:15Our home planet is like a cake, with different layers of ingredients stacked up on top of
00:21each other – the Earth's core, mantle, and crust.
00:25Hey, where's the frosting?
00:27The cake batter on top represents the crust of the Earth, made up of three types of tasty
00:33rock – igneous, sedimentary, and – say it with me – metamorphic.
00:39These rocks are formed in different ways, such as from solidified lava, or from the
00:44deposits of particles and minerals.
00:47The crust is what we stand on, a home to our continents, oceans, and everything we see
00:52around us.
00:54Then you have the mantle – not the baseball player – the layer that lies right below
00:58the crust.
01:00Many people think that the mantle is just lava, but it's not quite like that.
01:05Just like how you mix different ingredients in the cake batter, the mantle is made up
01:09of different types of rocks that are constantly moving and shifting.
01:14And finally, we get to the sweetest part of the cake – the center, or in the case of
01:19Earth, the core.
01:21It has two parts, the outer and inner core.
01:24The outer core is made of molten rocks and metals that are incredibly hot, even hotter
01:30than the surface of the Sun.
01:32The inner core is solid, even though temperatures there are crazy.
01:36It doesn't turn into liquid because the pressure down there is amazingly strong.
01:41When you see all this, you can easily think that below us there are endless miles of lava
01:47and hot rocks.
01:49So how come tectonic plates move at all?
01:53The continents don't float on a sea of molten rock.
01:56The oceanic and continental crusts really sit on a mantle.
02:00Sure, there's a layer of liquid rock in our planet, the outer core, around 1,800 miles
02:06below the surface.
02:08But it's separated from the surface by the mantle that's thick and solid.
02:13So the Earth's tectonic plates move around because they're on a thick layer of solid
02:19rock, the upper mantle.
02:21Basically, this rock is under incredible pressure and heat, which makes it flow in slow motion
02:27over time.
02:28Think of it like honey or syrup that you pour over your cake layers.
02:33As you move the cake around, the honey or syrup will also move and flow.
02:38Similarly, the upper mantle can flow and drag the parts above it along, just way slower
02:44than honey.
02:46And the rock is both breakable and flexible.
02:49It can crack and break like a cookie, now I'm getting hungry.
02:53But it can also stretch and bend like a piece of taffy.
02:56When the plates get caught on each other, they can't move anymore.
03:00But when they break free, they start drifting again, like puzzle pieces shifting around
03:05until they find their perfect fit.
03:09Extremely high temperatures and pressure are the reason this flow happens.
03:13It's like a big pot of soup on the stove.
03:15As the soup heats up, it starts to move around, carrying heat from one spot to another.
03:21Is it lunch time?
03:23And speaking of lunch, I mean lava, it's not just molten rocks that travel all the
03:28way up from the outer core to volcanoes.
03:31When tectonic plates come together and one slides underneath the other, they create a
03:36lot of heat and pressure while grinding against each other.
03:41It's like rubbing your hands together fast and they start to get hot.
03:45Or when you start a fire with rocks.
03:47And as the melted rock, or magma, rises to the surface, it can create volcanoes.
03:54Now long ago, the Earth's land was not divided into continents as it is today.
03:59Instead, there was one giant landmass, known as Pangaea, meaning all-Earth in Greek.
04:07Whoa, imagine being stuck in the middle of this giant ocean!
04:11So over time, this supercontinent slowly broke apart.
04:16Its parts drifted away from each other and formed the separate lands we call continents.
04:22This idea first popped out in the 16th century when one cartographer realized the coastlines
04:28of Africa, America, and Europe appear like they could fit together like puzzle pieces.
04:35Later researchers realized the rock composition of their coastlines was similar, which means
04:41they used to be part of one giant mass, and they call that the theory of continental drift.
04:47At first, people were pretty skeptical about that idea because they didn't know how such
04:52massive lands could move around.
04:55Now we'd all be able to explain that part, right?
04:58So the Earth's crust is divided into a couple of large plates and many smaller ones.
05:04All of them are still moving, even though it's in slow motion.
05:08We can't sense it, and we won't see any particular changes during our lifetime.
05:13It's a process that lasts hundreds of millions of years.
05:17As the plates move, they interact with one another in fascinating ways.
05:22For example, when two plates collide, one may be forced beneath the other, which would
05:28help create a subduction zone.
05:31Over time, this is the way you get many cool things like volcanic islands, trenches, and
05:36even entire mountain ranges.
05:39Plates apparently started moving around 3.5 billion years ago.
05:44It took them a while to group into the first jigsaw supercontinent we know about called
05:49Ur.
05:50Today, its remains make up parts of Madagascar, India, and Australia.
05:56Pangaea formed 335 million years ago, but it probably won't be the last continent
06:01that will form.
06:03So some new generations in the distant future could live on something called the next Pangaea.
06:10When the oceanic crust of the Atlantic Ocean slowly takes its place under the continental
06:16crust, the oceanic basin of the Atlantic is going to close, which is why the continents
06:21will end up pulled together.
06:24This means the Americas will meet Africa, and Eurasia will be flipped on its side.
06:30So people might live on a giant landmass in the shape of a ring, clustered around the
06:35inner sea, or at least what's left of it.
06:38Or maybe continents will take another direction and make up a different jigsaw puzzle called
06:44Amasia.
06:45In this scenario, the Americans will drift westward, fuse with Australia, and pivot to
06:51around Siberia.
06:53And then there's more.
06:54Novo Pangaea is the option where the Americas swing together to embrace Antarctica and Australia,
07:02and Africa legs off to the northwest.
07:04Basically, all continents here get together to form a giant landmass that stretches from
07:10one pole to the other.
07:12Ready for one more?
07:13Nah, come on.
07:15A recent projection called Aurica gives an idea similar to Novo Pangaea.
07:21It's just that all continents here unite to become one gigantic land that clusters
07:26around the equator.
07:28Hmm, maybe this would be my favorite one to live at, with the sunny weather and the beach
07:33all the time.
07:35And who knows what kind of magnificent trenches, mountains, islands, and other geological beauties
07:41we'd get with this giant supercontinent.
07:44Novo Pangaea broke up about 175 million years ago.
07:48As the Atlantic and Indian Oceans began to widen towards the east, the Ring of Fire was
07:54formed.
07:55It's a path that goes along the Pacific Ocean with so many frequent earthquakes and
08:00active volcanoes.
08:01This way, Eurasia was unable to cross this border and continue moving westward.
08:07And now, Eurasia could move laterally along the Ring of Fire.
08:11The subduction zones kind of act like a barrier that forces the tectonic plates to move in
08:17different directions.
08:18So Eurasia could eventually collide with the Americas and form something similar to Amasia.
08:25It would be cool to sit there, grab the popcorn, and watch it from the side.
08:30But this is something that won't happen for the next 50 million years at least.
08:34I'm willing to bet I probably won't be here to see it.
08:38Different theories talk about different positions where this new supercontinent might end up
08:43one day.
08:44But it seems it will probably be somewhere in the polar area, centered on what we today
08:50recognize as the Arctic Ocean.
08:54Not my cup of tea.
08:55Bring me back the sunny one.
08:57Wait, scratch that.
08:58Let's go eat.
09:01That's it for today, so hey, if you pacified your curiosity, then give the video a like
09:05and share it with your friends.
09:07Or if you want more, just click on these videos and stay on the Bright Side!
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