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Explore the contrasting narratives of dynamic ice formations and prehistoric marine giants in this captivating video.
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00:00It was one of the biggest creatures ever to roam the Earth.
00:04It was longer than your average school bus and could easily weigh more than 10 elephants combined.
00:09But where did it live? How did it end up having this size?
00:13And most importantly, why is it extinct nowadays? Let's find out.
00:19The megalodon was the largest predator ever known in our planet's history.
00:23In terms of its location, the megalodon lived practically in all waters on our globe, except near the poles.
00:31The reason why there were no megalodon teeth found in Antarctica is probably that the gigantic creature adapted to only
00:37warm, tropical, and subtropical waters.
00:40The younger ones liked to keep to the shores, while full-grown adults preferred coastal areas.
00:46But they could easily move into the open ocean as well.
00:49How do we know the megalodon was so widely spread?
00:52We can only presume, based on the fact that they discovered the most northern fossils off the coast of Denmark,
00:59and the most southern in New Zealand.
01:01The discussion of how the megalodon got this size is still open in the scientific community.
01:07They recently found out that not all the specimens from this fascinating species reach the same huge size.
01:14This has to do with a little something called the Bergman's Rule,
01:17which says that the temperature of the surrounding environment affects the animal's body size because they either need to conserve
01:24or shed heat.
01:25The megalodons that reach cooler waters probably needed more body weight to make sure they survived in low temperatures.
01:32On the contrary, those living in warmer waters had to be smaller to avoid burning up.
01:37But what did this enormous fish look like?
01:40Most modern depictions show the megalodon resembling an enormous great white shark.
01:45But, well, it seems it may not necessarily be correct.
01:49The megalodon likely had a much shorter nose and a flatter jaw that looked almost squashed when compared with a
01:56great white shark.
01:57It also seems to have something in common with the modern blue shark.
02:01Extra-long pectoral fins.
02:03They needed these to support their weight and size while navigating the planet's waters.
02:08Lastly, the lady megalodons seem to have been about twice as large as the gentlemen.
02:15As for their offspring, even a small megalodon was enormous, at least 6.5 feet from nose to tail.
02:22How do we know that?
02:23Because specialists have stumbled upon megalodon nursery habitats in Panama, Maryland, the Canary Islands, and Florida.
02:30Even the piles of used diapers were enormous.
02:34Nah, not really.
02:36Surely, the scariest aspect of the megalodon's looks was its mouth.
02:40I mean, think about it.
02:42Megalodon had whales for dinner, so it obviously needed to open its mouth wide enough.
02:47Scientists have estimated that its jaw would span a mind-boggling size, 9 by 11 feet wide.
02:54Just to paint you a better picture, that means it could have easily gulped down two adult people side by
03:00side.
03:00Wait, which two adults?
03:02Those impressive jaws also feature 276 teeth.
03:07Based on modern reconstructions of the force of its bite, it looks like it may have been one of the
03:12most, if not the most, powerful animals of prey ever to exist in.
03:17For comparison, humans can have a bite force of around 1,300 newtons.
03:22Today, great white sharks have been estimated to be able to bite down with a force of over 18,000
03:28newtons.
03:29The megalodon tops all the records, with an estimated power of bite up to 10 times greater than that.
03:36It could basically crush a car with very little effort.
03:39Its teeth were also pretty amazing.
03:41Similar to sharks, the megalodon was fast in replacing its broken or worn teeth.
03:46With four or five rows of teeth in its mouth, it basically acted like a conveyor belt, growing back damaged
03:53or missing teeth within about 48 hours.
03:56This means that an adult megalodon probably would have grown several thousand teeth throughout its lifetime.
04:02It was nice of them to do that, though, since it's probably one of the reasons why megalodon teeth are
04:07so common in fossil records, and we're able to study them properly.
04:11To maintain its impressive physique, the megalodon had to eat somewhere around 2,500 pounds of food per day.
04:20Can't wrap your head around that?
04:22Well, it was the equivalent of one and a quarter cows per day to survive.
04:26It's like if you had to eat 3,300 cans of tuna every day.
04:30I've used the word megalodon a lot, but have I mentioned where it comes from?
04:35When translated from Greek, it means giant tooth.
04:39Ah, those clever Greeks.
04:40However, this giant shark's full scientific name is a bit more complicated, Carcharocles megalodon.
04:47But are these gigantic predators actually extinct?
04:51We tend to believe so, but let's be honest for a second.
04:55We've come to know more about the surface of Mars than the depths of our oceans.
04:59Like, we've only explored 15% of our oceans altogether.
05:03Who knows what may be lying out there in the deep?
05:07Maybe some ancient predators?
05:08The Mariana Trench is the deepest oceanic trench on Earth.
05:13The Challenger Deep, its deepest part, is so deep that you could dip the whole of Mount Everest in there
05:19and it would still be over a mile above the surface.
05:22That's deep.
05:23If a megalodon or two ever needed a place to crash, that would be a discreet enough location.
05:30However, the Mariana Trench is not a particularly comfy place to be in.
05:35You know, because it's cold and steeped in total darkness and all.
05:38The temperatures here are around 36 degrees Fahrenheit all year round.
05:43And to top it all off, the pressure is a thousand times stronger than at sea level.
05:47So, it's safe to assume that if any megalodon is hiding in here, its teeth and bones might not be
05:53looking so good.
05:55Because of the intense pressure here in the Mariana Trench, proteins and calcium start to dissolve and disintegrate.
06:01That's why, for example, the Haddell Snailfish, the deepest dwelling fish we've discovered, has evolved to feature flexible cartilage instead
06:10of bones.
06:11To survive here, the megalodon would also need to learn to navigate in complete darkness.
06:16That means they would have to either become luminescent or evolve to grow massive eyes like the giant squid.
06:23While it may sound like an intriguing and good idea for a movie script, most scientists don't think it's possible.
06:30Why?
06:31Well, most of them say it's because of the megalodon's size.
06:34Most foods that megalodons like to eat live in shallow ocean areas and not in the deep, deep sea.
06:41Specialists believe that if these animals were actually still roaming our waters, there's no way we wouldn't know about it.
06:47They would need to come up for dinner every now and then, right?
06:50Their food is also the most likely cause of why the megalodon is not alive anymore.
06:56While some specialists believe the megalodon became extinct because of a drop in the ocean water temperature,
07:02most scientists suggested that the shifting food chain dynamics may have been more to blame.
07:07Why?
07:08Because at some point, there was less and less of its primary food source, baleen whales.
07:13And at the same time, the numbers of its natural competitors, like smaller predatory sharks like the great white shark
07:20and whales, increased.
07:23The megalodon did live on this planet a lot more than we did, and way back when we didn't even
07:28exist yet.
07:29They were here for nearly 70 times longer than we, modern humans, have, inhabiting the oceans for around 20 million
07:36years.
07:37Homo sapiens appeared around 300,000 years ago.
07:41The megalodon managed to survive for so long mostly because of its unbeatable size.
07:46I mean, they can make a meal out of almost everything in the sea at the time.
07:51We may think about both of them as prehistoric creatures, but the megalodons and the dinosaurs never coexisted on Earth.
07:58The dinosaurs probably died out about 66 million years ago.
08:03Megalodons seem to have appeared a bit later.
08:05That's because the oldest megalodon fossils we have yet discovered are from the Myocene Epoch, which began 23 million years
08:13ago.
08:15So long, Meg!
08:18A colossal iceberg, more giant than a city, broke away from Antarctica in mid-2021.
08:25It's so big that it's 40 times bigger than Paris, hence 73 times the size of Manhattan.
08:32Imagine that you come out of your small holiday shack on the coast of South Africa, near the town of
08:37Port Elizabeth.
08:38You have a cup of tea in your hand as you've just woken up.
08:42You stand near the edge of your lookout, the vast Indian Ocean before you.
08:46Something catches your eye.
08:48To the right, there is something so monumental, you can't comprehend it.
08:53It's a giant slab of ice, 300 feet high and stretching away many miles, as far as the eye can
09:00see.
09:02It rolls slowly, but relentlessly on, heading out into the deep sea.
09:07If it goes far enough, it could reach the western coast of Australia.
09:11Playing in front of it are a pod of dolphins, like they sometimes do off the bow of a ship.
09:16Yet they're just specks compared to the mammoth's size.
09:20You're so shocked that you drop your cup.
09:23Your eyes are as big as saucers.
09:25It's like something out of a science fiction movie.
09:27Are you dreaming?
09:28Are you seeing things?
09:29Nope.
09:31It's A-76.
09:32It's real, and it's currently on the move.
09:35What could happen to it is anyone's guess.
09:38Well, scientists have a few theories, but let's get a grasp of its size first.
09:43The iceberg is 110 miles long and 16 miles wide.
09:48It's basically the shape of a gigantic finger.
09:51If you were standing at the coast of Dover, looking across the English Channel toward France,
09:56the iceberg would be almost as wide.
09:58The channel is 21 miles across at its narrowest.
10:02That means approximately two-thirds of that distance would be filled with the iceberg.
10:07That's if it were drifting, finger-pointing down, so to speak.
10:10If it were facing the other way, it could still enter the English Channel.
10:14But as it got closer to the narrowest points, it would smash into the coasts of both England and France.
10:20It would go up over land.
10:22It would slide over the green fields of England, the white ice bold against the rich green.
10:27It would cruise past the vineyards of France.
10:30It was temporarily lowering the temperature of everything around it.
10:34Those grapes would be like jelly crystals.
10:37It would skim right over highways, cars stopping to observe this colossal thing like a visitor from another galaxy.
10:44You could pluck chunks off it for your drink as it sailed past.
10:48Failing that, you could scale it and go ice climbing right on the outskirts of London.
10:53It would certainly be handy in the summer.
10:55But let's get back to what actually happened, and what scientists think will happen to it.
11:01As of the beginning of 2022, A76 is the world's most giant floating iceberg.
11:07It was calved from the Filchner-Ron ice shelf in Antarctica in the middle of May 2021.
11:13Ice calving, also known as glacier calving, is the breaking up of ice chunks from the edge of a glacier.
11:19It then pulls away from the ice mass into a separate entity.
11:23If you were nearby, you would hear a lot of cracking and a massive booming sound.
11:29Blocks of ice up to 200 feet would break free and crash into the water.
11:33It would cause huge waves.
11:35Not even adventurous surfers would want to tackle those breakers.
11:39Ice calving is a natural event.
11:41The area where A76 broke off has seen little change in recent decades.
11:46There have been even larger chunks of ice than A76, but this one is currently the largest in the world.
11:53Scientists at the British Antarctic Survey spotted it.
11:56There are satellite images of it breaking free, as captured by the European Space Agency's Sentinel-1A satellite.
12:03The size at the calving was an estimated 1,670 square miles.
12:09Right now, it's in the Weddell Sea around Antarctica.
12:12The Weddell Sea is part of the Southern Ocean.
12:14It was named after the Scottish sailor James Weddell, who entered the area in 1823.
12:20Scientists have deemed the Weddell Sea to have the clearest water of any sea.
12:25Imagine peering down into its depths from a boat.
12:28What a fantastic view it must be!
12:31The area is full of whales and seals.
12:33As you look down, you may see killer whales, humpback whales, minke whales, leopard seals, and crab-eater seals.
12:40And if you look towards land, you'll likely see a colony of Adelie penguins.
12:45They're the dominant penguin species in this area, because they adapt to the harsh environment.
12:50In fact, this is the only location in the world they live.
12:54What an incredible array of wildlife to observe, all from the comfort of the ship's deck, while you drink another
13:00cup of hot tea.
13:01It gets pretty cold in these parts.
13:04To get an idea of what could happen to A-76, scientists refer to other data, such as the even
13:10more enormous iceberg called A-68.
13:13It was calved from the ice shelf known as Larson Sea off Antarctica in 2017.
13:18While it may be exciting, though a little daunting, to think of it also sailing up the English Channel, A
13:25-68 floated out to warmer seas and, by early 2021, had all but dissipated.
13:31That was a relatively quick demise.
13:33Some icebergs have been observed floating around for up to 18 years.
13:37Suppose they remain in the relatively cold waters.
13:40It all depends on where A-76 decides to go.
13:44Satellites have helped scientists keep track of these monstrous movements, whereas they would go unnoticed in the past.
13:50That's how they know that by day 148, this iceberg had split into three fragments, imaginatively titled A-76A, A
13:59-76B, and A-76C.
14:02The numbers might be boring, but they're based on the Antarctic quadrant in which they were first sighted.
14:07If these enormous chunks do break up entirely, it will not add to rising sea levels, because it was already
14:14part of the floating ice shelf.
14:16Imagine these ice chunks in your glass.
14:18They already take up a certain amount of space.
14:20They will simply change form into water.
14:23Icebergs like this one are different from glaciers or ice sheets found on land.
14:28Those are the things that help to raise sea levels when they break off and melt.
14:31For example, if the whole of Antarctica's ice sheet were to melt, it could raise sea levels by nearly 190
14:38feet.
14:39If you think A-76 is enormous, and it clearly is, there was another that makes it look small in
14:46comparison.
14:47On record, the largest iceberg was sighted in November of 1956, 150 miles west of Scott Island in the South
14:54Pacific Ocean.
14:56Ironically, it was seen by a ship known as the USS Glacier.
15:00It was sized over 12,000 square miles.
15:03This iceberg was larger than the country of Belgium.
15:07What may happen to the chunks of A-76 will depend on a few factors.
15:11Ocean currents can make a significant impact, and wind direction and speed can too.
15:17They may move closer to coastlines, where they can freeze into pack ice.
15:21They can also drift into shallow waters and hit the seabed, called seabed gouging.
15:26The deepest part of the iceberg can act like the keel of a boat.
15:30It digs into the ocean floor, but the sheer size of the iceberg keeps it moving.
15:35Soon, it's tearing up the floor, creating a long, narrow furrow or a gouge.
15:40Fish would scatter.
15:41The earth would shake.
15:43The noise would be tremendous.
15:45It's actually quite common in offshore environments near where ice is found.
15:49You would not want to be scuba diving nearby when one of these rips through.
15:53However, it would make for a spectacular sight.
15:56Generally, icebergs deteriorate through melting and fracturing, which, as you can imagine, changes the mass and the surface area.
16:04Combined with wind and ocean currents, it can make iceberg modeling difficult.
16:09As for A76, we'll just have to wait and see.
16:13Before we go, let's return to our imaginary voyage down the English Channel.
16:18The island of ice, 73 times the size of Manhattan, with its gigantic frosty finger pointed down toward the Celtic
16:25Sea, rolling steadily onwards, unable to be stopped.
16:28Hundreds of thousands of people have flocked to the coasts of both England and France to watch this extraordinary spectacle
16:35as it cruises by.
16:37On top of the ice, there are thousands of penguins playing happily.
16:41They almost look to be waving back to the abundance of sightseers, who cheer them on their way.
16:46The children jumping with joy at the most spectacular sight they've ever witnessed.
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