Un des volcans les plus dangereux de l'Alaska, le mont Edgecumbe, se réveille après être resté silencieux pendant des siècles. Les scientifiques ont récemment remarqué une activité sismique inhabituelle et un gonflement du sol dans la région, signes que le magma se déplace sous la surface. C'est un événement important car le mont Edgecumbe n'a pas érupté depuis plus de 800 ans, et maintenant il montre des signes de vie. Bien qu'il ne soit pas encore en éruption, les experts le surveillent de près pour comprendre ce qui pourrait se passer ensuite. Si une éruption se produisait, elle pourrait affecter les communautés environnantes et même le trafic aérien en raison des nuages de cendres. Pour l'instant, c'est un rappel de la puissance et de l'imprévisibilité de la nature, surtout dans un endroit comme l'Alaska ! Animation créée par Sympa.
----------------------------------------------------------------------------------------
Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
----------------------------------------------------------------------------------------
Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
----------------------------------------------------------------------------------------
Si tu en veux encore plus, fais un tour ici:
http://sympa-sympa.com
----------------------------------------------------------------------------------------
Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
----------------------------------------------------------------------------------------
Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
----------------------------------------------------------------------------------------
Si tu en veux encore plus, fais un tour ici:
http://sympa-sympa.com
Category
😹
FunTranscript
00:00The ground suddenly starts to shake, while clouds of gas rise and go into the sky, plunging the day into complete darkness.
00:08Some portions of the ground begin to deform, rise or even collapse, so many signs of an imminent eruption.
00:17And this scenario could well be repeated with Mount Spur.
00:20Located at about 120 km from Anchorage, one of the most dynamic cities in Alaska, Mount Spur represents a tangible threat.
00:29More than half of the state's inhabitants, the northernmost part of the United States, reside in Anchorage.
00:34Every day, an immense amount of air traffic passes through its international airport.
00:40Thus, when a volcano located so close to such a crucial crossroads shows signs of agitation, it inevitably attracts everyone's attention.
00:50Informally, about 350 million people in the world live in the risk zone of an active volcano.
00:59This means that 1 in 20 people are exposed to dangers related to a volcanic eruption.
01:05Alaskans would undoubtedly hope that the awakening of Mount Spur is fiction, but the reality is quite different.
01:12The Alaska Volcanological Observatory has recorded several characteristic signs of an imminent volcanic activity.
01:18To the point that the alert level has been raised to yellow, indicating an agitation exceeding the usual levels.
01:27Mount Spur erupted twice in the 1990s, and these events were quite powerful.
01:33On a scale of 1 to 10, they would probably get a grade of 6 or 7.
01:39Without being catastrophic, they nevertheless caused damage estimated between 10 and 17 million dollars.
01:46However, these figures seem ridiculous compared to the eruption of Mount Spur in Alaska in 1988,
01:53another volcano that caused astronomical damage, totaling 345 million dollars.
02:00The main reason lies in the volcanic ashes that disrupted the engines of the planes,
02:04like the KLM 747, whose engines stopped under the effect of ashes before restarting in extremis.
02:12If the unstable geology of Alaska had so far aroused little attention, this event undeniably changed the situation.
02:21When we mention the risks related to volcanism, the first image that comes to mind is often that of Pompeii, in Italy.
02:28Of course, this is the most dramatic scenario.
02:32A city engulfed by lava.
02:34Compared to Vesuvius, Mount Spur may seem less threatening, but it still left notable traces.
02:41During its last eruption in the 90s, it propelled volcanic aerosols at an altitude of more than 18,000 meters.
02:50Let's clarify an essential scientific point.
02:53Volcanic aerosols are liquid particles that are released into the atmosphere during an eruption.
02:59They are generally formed when volcanic gases, such as sulfur dioxide, interact with water and other particles in the air.
03:08These aerosols have the ability to cool the Earth's surface by directly reflecting the sunlight into space.
03:15The worst part?
03:16They can remain in the atmosphere for several years after an eruption, causing serious health problems.
03:23The eruption released flashing avalanches of burning gas and ash, called pyroclastic flows.
03:29Accompanied by thick, bubbling crusts, known as laars.
03:34Not to mention the gigantic blocks of volcanic rock.
03:37Some of them were over a meter in diameter and were projected out of the volcano,
03:41with the power of real cannonballs, crashing down to more than 10 kilometers away.
03:47The heat released melted part of a nearby glacier,
03:50triggering streams of debris that obstructed the Chacachatna River and formed a new lake in the valley.
03:58Despite everything, the first eruption of Mount Spur had a positive effect.
04:03The main lesson learned was the importance of volcanological surveillance.
04:07Thanks to local control systems, economic losses could be limited,
04:12which is essential for a city whose air traffic is so dense.
04:16Although considered as currently dormant, Mount Spur remains unpredictable and could erupt at any time.
04:23Volcanoes are generally classified into three categories.
04:26Active, dormant or extinct, depending on their level of activity.
04:30An active volcano still grows and erupts with a certain regularity.
04:36A dormant volcano has shown signs of recent activity, but is currently asleep.
04:42As for extinct volcanoes, they have been silent for so long that it is estimated that they will never wake up again.
04:50Among the most formidable active volcanoes in the United States is Mount St. Helens,
04:55responsible for the most violent eruption in the history of the country.
04:59During its last explosion, the intensity of the blast took about 400 meters from its summit,
05:04literally making the top of the mountain disappear.
05:07If Mount Spur's ash cloud seemed spectacular to you,
05:11St. Helens' cloud surpassed it by reaching 24 kilometers in altitude,
05:15plunging the east of Washington state into total darkness.
05:20But that's not all.
05:22In just three minutes, the eruption projected nearly 3.7 billion cubic meters of incandescent and dust rocks,
05:30enough to fill a million Olympic pools on a surface of 600 square kilometers of luxurious forest.
05:37The seismic shocks that announced the eruption had only begun several weeks before May 18, 1980.
05:44Finally, an earthquake of a magnitude of 5.0 caused a gigantic landslide on one of the sides of the volcano.
05:54At the end of this historical eruption, 57 lives had been lost.
05:59Nearly 7,000 large animals, such as deers and wapiti, had perished,
06:04while millions of birds were burying the calcined earth.
06:07Although experts do not expect Mount St. Helens to replay an episode of this magnitude in the near future,
06:14they continue to monitor it closely, because the volcano is far from being extinguished.
06:19For the record, the word volcano derives from Vulcan, the Roman deity of fire.
06:25Eruptions often occur at the meeting point of tectonic plates,
06:29these fragments of the earth's crust that come together like a puzzle.
06:33The famous belt of fire, located in the Pacific Ocean, constitutes the most active volcanic zone on the globe.
06:40It houses between 750 and 915 active volcanoes.
06:45The largest volcano of the belt of fire, and also the largest active volcano in the world, is the Mauna Loa.
06:52Culminating at more than 4,000 meters, it is located in Hawaii.
06:56Researchers estimate that this volcano has been erupting for at least 700,000 years.
07:01The most recent began on November 27, 2022 to end on December 13.
07:06Remained silent since the 1980s, the Mauna Loa finally woke up.
07:11Fortunately, thanks to the continuous surveillance ensured by the Hawaii Volcanological Observatory,
07:17its last eruption was not a victim.
07:20Scientists have invested massively in monitoring volcanoes,
07:24not only to limit economic impacts, but also to save lives.
07:28Their latest ambitious project is to forest directly in the volcanoes.
07:34Recently, scientists have made a trip to Iceland, a true volcanic hot spot.
07:40This country alone has nearly 33 active volcanoes.
07:44However, the one that particularly catches their attention is the Krafla Volcanic System,
07:50which has experienced about 30 eruptions in the last millennium.
07:54The most recent, dating from the mid-1980s.
07:57The Krafla Magma Testbed project, or KMT,
08:00aims to better understand the behavior of magma under the earth's surface.
08:06One of the main advantages of these drilling researches is the prediction of the risks of eruptions.
08:10But they also offer an opportunity to advance geothermal energy.
08:15Imagine a world where electricity would be powered by a source of energy
08:19as inexhaustible as the power of volcanoes.
08:22The KMT project team plans to start deep drilling in 2027,
08:28with the goal of reaching more than 1 km underground.
08:32Monitoring lava activity when it is on the surface is one thing,
08:36but studying it when it remains confined underground is another.
08:40According to the researchers, this approach will allow to truly listen to the earth's pulse.
08:46According to them, these researches could be as revolutionary as the conquest of the moon.
08:52And speaking of that, did you know that volcanoes existed elsewhere in the solar system?
08:57Yes, other planets and moons also shelter them.
09:01The largest known volcano is Olympus Mons, located on Mars.
09:05It is a shield volcano similar to those of the Hawaiian Islands,
09:08but it is nearly 600 km wide.
09:11If brought to Earth, it would cover almost all of Poland.
09:14Impressive.