00:00Ah, the sea is kinda rough today.
00:05Nothing special, but still, you have that sinking feeling in your stomach.
00:09Call it a sense of foreboding.
00:11Something bad is going to happen, and then you hear terrified shouts.
00:16You turn around and see a giant wave, much higher than the one surrounding it.
00:20Is it a tsunami?
00:22That's true.
00:23When people think of frightening destructive waves, tsunamis are the first thing to come
00:27to mind.
00:28But the one that is going to crash against your ship has a different nature.
00:32It's a rogue wave.
00:35Both tsunamis and rogue waves can lead to catastrophic consequences.
00:39But the difference lies in what causes these walls of water and where the destruction they
00:44bring about occurs.
00:46So imagine a giant 60-foot-tall wave rolling over your ship.
00:51It's a miracle that the vessel doesn't sink.
00:54This massive wave, a rogue wave, seems to have appeared out of the blue, very suddenly
00:59and unexpectedly.
01:01But however mysterious, solitary, and ominous rogue waves may seem, they're actually not
01:06that rare.
01:08Now imagine the average room in your house.
01:11The ceiling there is likely 8 feet high.
01:13A typical two-story house is somewhere between 20 and 30 feet high.
01:17And the Statue of Liberty is 111 feet tall if we measure it from the toes to the top
01:23of the head.
01:24Now you have something to compare rogue waves with.
01:27The largest of such waves can reach a height of 50 to 90 feet.
01:32To be considered rogue, a wave must appear seemingly out of nowhere and be higher than
01:37other waves in the area.
01:39But how much higher is still under debate.
01:42Some experts think it should be at least twice as high as other large waves in the area,
01:47while others disagree.
01:49Rogue waves are also steeper than regular waves, which normally take the form of massive
01:54swells.
01:55This allows ships to maneuver up and down such waves, even when they're really high.
02:00A rogue wave, however, looks like a wall of water.
02:03And since it's steeper than other waves, it slams into a ship with enormous force,
02:09sometimes breaking over the vessel.
02:12Another reason why rogue waves are a mystery is that no one has ever filmed the formation
02:17of such a wave and followed its life cycle.
02:20There are several photos of rogue waves, but for many centuries, the only evidence of their
02:26existence was legends and stories told by sailors who survived them.
02:32Scientists are still not sure how rogue waves form.
02:35But one theory involves wave reinforcement.
02:38It happens when two waves interact, and their heights get combined.
02:43So when a 15-foot wave passes over a 30-foot one, let's do the math, it results in a
02:48short-living 45-foot wave.
02:52But rogue waves can occur not only in the ocean.
02:55On November 10, 1975, on Lake Superior, a group of three rogue waves, also known as
03:01the Three Sisters, might have sunk the SS Edmund Fitzgerald, an American Great Lakes
03:07freighter.
03:08The ship and the crew members were lost in the catastrophe.
03:12The waves followed each other too closely, so the ship couldn't recover and shed the
03:16water from the first wave before the following one struck.
03:20The captain of a ship that was not far from the Fitzgerald reported that his vessel had
03:25been hit by two 30- to 35-foot waves.
03:28These waves, likely followed by a third one, then moved further in the direction of the
03:32Fitzgerald and might have caused the sinking.
03:36Now let's wave bye-bye to that, and let's move on to tsunamis.
03:41It is an extremely dangerous natural disaster.
03:44It's very different from rogue waves.
03:46In most cases, a tsunami is caused by an underwater earthquake.
03:50Usually, when a tsunami is born, it's just a few feet high.
03:54But the closer it gets to the shore, the larger it grows.
03:58Soon it enters shallow waters and starts to slow down.
04:02The first tsunami wave crashes against the shore.
04:05Its top moves faster than the bottom, and that's what makes the wave so high and steep.
04:11The lowest point of the wave gets to dry land first.
04:14In the process, it creates a vacuum effect that pulls the water away from the coast,
04:19burying the harbor and seafloor.
04:22Those who recognize this first sign of an approaching tsunami still have a chance to
04:26save their lives.
04:28Five minutes later, an enormous wall of water hits the shore and wipes out everything in
04:33its way.
04:35But it's not just a single wave.
04:37There are many.
04:38This phenomenon is called a wave train.
04:41How fast this train is traveling depends not on how far it is from the source of the waves,
04:47but on the ocean depth.
04:49Tsunamis can move as fast as a jet plane in the middle of the ocean, but once they enter
04:53shallow waters, their speed drops.
04:56The first tsunami wave isn't usually the strongest, but lots of people don't know
05:01it and make the grave mistake that sometimes costs them their lives.
05:05After the first wave is gone, they relax and believe the danger is over.
05:10That's why the next waves, much bigger and more powerful, catch them off guard.
05:16Sometimes a tsunami comes as a torrent of foaming water.
05:19At other times, it makes the sea withdraw, leaving behind stranded fish and overturned
05:25boats.
05:26Also, if you spot a slight rise in sea level, it might be the sign of an approaching tsunami.
05:32The incoming water is the first tsunami wave.
05:35The second one can be even larger, and it comes some time later.
05:39You can also notice seawater bubbling, swirling, and creating bizarre patterns.
05:44It's another sure sign a tsunami is near.
05:48Repeated wave surges can also warn you about a tsunami.
05:52If you see unusual swells coming at regular intervals, it might be time to evacuate to
05:58high ground.
06:00Surprisingly, some of the largest tsunami waves in the world were caused by landslides.
06:06For example, a landslide in LaTuya Bay in Alaska formed a megawave, one of the largest
06:12ever recorded.
06:14Its height was 1,720 feet.
06:18A mega-tsunami surged over the headland, washing away trees, plants, and soil down to bedrock.
06:24The wave reached more than half the height of the Burj Khalifa, the tallest construction
06:29in the world.
06:30When a third of the East Molokai volcano in Hawaii caved in and collapsed into the Pacific
06:35Ocean, it triggered a tsunami the size of one of the tallest buildings in the world,
06:41Shanghai Tower.
06:42The wave was around 2,000 feet high.
06:47Another bizarre and dangerous ocean phenomenon is square waves.
06:51They appear when two different wave patterns crash into each other at 90 degrees.
06:56It often happens near peninsulas or land where two different seas or oceans meet.
07:02This phenomenon does kinda look spectacular, but only if you're watching it from the shore.
07:07Don't even think about getting in the water to play with such waves.
07:11Cross currents in that spot can easily pull even a skilled swimmer under the water.
07:16Square waves have caused many shipping accidents over the years too.
07:21And if you see wild choppy waves carrying ocean debris and seaweed, stay out of the
07:26water too!
07:27It can be a sign of a strong rip current.
07:30That can carry you far away into the ocean.
07:33And now let me tell you about a much larger, I would even say planet-wide phenomenon called
07:39raspy waves.
07:40There are two kinds of such waves – oceanic and atmospheric.
07:45Since we're talking about ocean waves, yeah.
07:48Slow-moving raspy waves are totally different from ocean surface waves.
07:52They don't look like those waves that break along the shore.
07:56No, raspy waves are giant movements of the ocean stretching horizontally across the planet.
08:03They can span hundreds of miles in a western direction and are so massive, they can change
08:08the climate conditions of our planet.
08:10They contribute to high tides and even flooding in some areas all over the world.
08:16The movement of raspy waves are complicated and depend on the location.
08:21For example, in the Pacific, waves that are closer to the equator take from a few months
08:26to a year to travel across the ocean.
08:29At the same time, waves further away from the equator often need more than 10 years
08:34to make this journey.
08:35So as it goes by, be sure to wave!
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