00:00A tsunami striking large cities on or near the Mediterranean Sea and in the northeast part of the Atlantic Ocean is not a question of if, but of when.
00:10It is frightening and surrealistic to think that places like Cannes or Barcelona could suddenly be hit by a huge wave.
00:17But the fact is that the European coasts are in active tectonic zones.
00:23Only about 10% of all tsunamis in the world occur in the Mediterranean.
00:28And there have been at least 290 tsunamis in this zone since 1600 B.C.
00:34Despite the relatively small number, this phenomenon has caused many devastating catastrophes throughout the history of Europe.
00:43In 1755, a magnitude 8.5 earthquake whose epicenter was in the west-southwest of Cape St. Vincent
00:51triggered a tsunami that destroyed most of Lisbon, the capital of Portugal.
00:56About 40 minutes after the earthquake, this massive wave hit the port and the city center, quickly rising the river Tagus.
01:04The phenomenon was so fast that several people on horseback had to gallop to heights to avoid being carried away.
01:10And it was only the beginning of a nightmare, with two other terrifying waves that hit Lisbon just after.
01:16A disaster like this is similar to what we see in the Pacific Ocean several times a century.
01:22But in the Atlantic, it is very rare.
01:24This kind of major tsunami is supposed to occur every 3 to 5 centuries.
01:29But now, it could happen tomorrow.
01:34Marseille in France, Chipiona in Spain and other cities are on the list of important places that could be flooded soon,
01:42with a probability of about 100% of being hit by a tsunami over the next 30 years.
01:48Statistics show that the wave will probably reach more than 1 meter high.
01:52I know, it doesn't seem like much.
01:54Especially since when we think of tsunamis, we imagine terribly high waves, like the one that hit the Bay of Lituya in Alaska.
02:02In this case, the wave was more than 518 meters high.
02:06But we must remember that even waves of only 50 centimeters high can be dangerous for swimmers.
02:13Because it is not only the height of the tsunami that matters, but also the flow and movement of the water.
02:18Not to mention the floods, which can damage beaches, ports and streets.
02:23If the coast has a small port and the seabed is exceptionally low, like in Cannes, this natural disaster could be much more dangerous.
02:31Tsunamis of about 2 meters high can lift cars off the ground,
02:35while smaller waves can create water walls moving at 65 km per hour.
02:41In addition, there are these smaller events that may not destroy everything, but can still cost a fortune.
02:47For example, gigantic sand banks that move on the bottom of the ocean, like sand dunes that move in the desert.
02:55They can damage pipelines or underwater cables for internet and communication.
03:00And it ends up costing millions of dollars to companies and governments.
03:05That's why organizations like UNESCO are worried about the possibility that a dangerous tsunami will soon hit Europe.
03:12They do everything they can to prevent apocalyptic scenarios.
03:16Like what happened in 2004, when an earthquake off the Sumatra coast, Indonesia,
03:22caused waves of more than 30 meters high in coastal communities, resulting in the loss of more than 200,000 lives.
03:29And let's not forget 2011, when an earthquake off the coast of Tohoku, Japan,
03:35triggered a tsunami that reached about 9.6 km inland and caused a serious nuclear accident in an electric power plant along the coast.
03:45More than 16,000 people lost their lives in this tragedy, and the event caused billions of dollars in damage to infrastructure.
03:53These disasters were serious warnings, and we have come a long way since 2004.
03:59We are much safer today, largely because the tsunami warning system is very effective in quickly detecting this dangerous situation.
04:07Unlike many other natural phenomena, a tsunami can be anticipated.
04:13We may only have a few minutes to act, but if we all know what to do,
04:20many lives can be saved.
04:24And in most regions of the world, sirens are commonly used to warn people of tsunamis.
04:30To trigger the siren as soon as possible, initial tsunami alerts are generally based solely on seismic data.
04:37First of all, specialists receive information on an earthquake.
04:42Seismic waves move about 100 times faster than tsunamis.
04:46Thus, they have enough time to analyze the data and determine whether the earthquake could have generated a tsunami,
04:53and whether they should issue an initial tsunami alert.
04:57In American warning centers, for example, scientists usually issue initial alerts within five minutes of an earthquake.
05:05If a tsunami is suspected, these alerts can also include information on the time of arrival of the waves,
05:11recommended actions, and potential impacts.
05:16But triggering an alert is not enough.
05:19In order to save lives, coastal communities must also be trained to react quickly and in the best possible way.
05:26This is why UNESCO has produced this program called Tsunami Ready,
05:30which aims to train people living in coastal areas at risk on how to act in the event of a tsunami by 2030.
05:38The idea is to help communities stay safe by teaching them to protect their means of subsistence and to preserve their homes.
05:45Being recognized as Tsunami Ready by UNESCO does not mean that a community is safe from tsunamis, of course.
05:52It is rather a recognition that they have adopted all possible measures to mitigate the risks of tsunamis.
05:58Thus, authorities help communities prepare by installing evacuation boards,
06:05by establishing safety procedures and by creating plans to warn tourists.
06:10Like Spain, which has distributed tsunami warning signs along the entire coast,
06:14as well as signs indicating evacuation routes to higher ground.
06:19And Spain would do better to be prepared.
06:21I mean, only seven tsunamis have hit the country since 365, so it is difficult to predict the effects of such an event.
06:29But it could be devastating, given that Spanish coastal areas are so important economically.
06:35There is also a dangerous area in the Averoes fault, under the Alboran Sea.
06:40If an earthquake occurs at this point, people will only have 21 minutes to escape a tsunami.
06:49UNESCO has also established 12 tsunami warning centers, which also cover Europe.
06:55This initiative involves five centers located in the Mediterranean and North-East Atlantic regions.
07:01These centers can save thousands of lives because they monitor oceanic disturbances 24 hours a day and 7 days a week.
07:09Then, after analyzing the threat, they send messages according to the potential of the event to cause a tsunami.
07:16The intensity scale goes from no effect to completely devastating.
07:21And because of this, they understand that almost all brick buildings could be demolished by the waves,
07:26and even the most reinforced concrete structures could suffer heavy damage.
07:34So far, we have mainly talked about tsunamis caused by earthquakes along the borders of converging tectonic plates.
07:42In fact, earthquakes have represented more than 80% of tsunamis since 1900.
07:49But tsunamis can also result in landslides, volcanic eruptions and even meteorite impacts.
07:56Experts are also worried that, with the current climate changes, we could see more tsunamis in the Mediterranean.
08:06These are triggered by abnormal weather conditions and can disrupt any coast with a shallow seabed.
08:14They may not be as huge or famous as those caused by earthquakes,
08:20but they can still cause significant material damage and put people in danger.
08:26For example, in 2006, a tsunami hit the port of Ciutadella on the Spanish island of Minorca.
08:33Yachts were projected against each other and then fell on the bottom of the port as the water withdrew,
08:39which caused damage of several tens of millions of euros.
08:43Unfortunately, tsunami weather in the Mediterranean tends to be stronger in summer.
08:48So, if you plan to spend your holidays in Europe, stay vigilant in the face of all signs of dangerous waves.
08:55If you suddenly encounter a tsunami heading towards you, remember that it is time to react.
09:01Move to the heights as far inland as possible.
09:05Pay special attention to all emergency and information alerts.
09:09And follow the advice of local authorities.
09:12Above all, do not wait in place to take pictures.
09:16Leave the area as soon as you notice signs of this dangerous event,
09:20or if you hear an official tsunami warning.
09:22And be careful!
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