00:00July 17, 1998. The evening had begun peacefully, like so many others, in the villages scattered along the north coast of Papua New Guinea.
00:10Then, at 5.49 p.m., the ground crumbled with sudden violence. Without warning, a magnitude 7 earthquake shook the region.
00:19The shock waves spread in the surroundings, the walls were shaking, the dwellings were shaking, and the earth contracted and twisted under the feet of the villagers.
00:27The shock lasted for 19 seconds, with a house located 30 km deep and showing the characteristics of an ordinary earthquake.
00:35Although it caused damage, nothing foretold an imminent disaster.
00:40Deceived by this apparent calm, the inhabitants believed at the end of the event. They did not know that the worst was yet to come.
00:48Then, strange lights attracted the attention of some inhabitants. Everything began with a reddish glow on the horizon, a drift evoking a flame.
00:57This fleeting appearance occurred shortly after the first earthquake, and spread in the northern sky above the ocean.
01:04It shone with an intense flash before suddenly vanishing. What could be the origin?
01:10The hypotheses were whether it was a disturbing omen or simply a singular luminous effect.
01:16But as soon as the light had dissipated, a deafening rumble, coming from afar, resounded with force.
01:23No one understood its meaning, and, driven by curiosity, some went to the beach to scrutinize the horizon.
01:30What they saw was bloody ice. The ocean seemed abnormal, far from peaceful.
01:36The water was agitated, foaming, and seemed to boil in a disturbing, almost unreal way.
01:42It was then that they saw it, a titanic wave rising in the distance, rushing at them at a terrible speed.
01:49The panic seized the population like a powder keg.
01:53Some climbed the trees, others rushed their boats into the lagoon, hoping to escape the imminent horror.
02:00But it was already too late.
02:02The first wave fell with incredible power, destroying entire villages in an instant.
02:08The debris was thrown in all directions, trees were torn down, and some buildings were dragged up to 60 meters inland.
02:17Decades later, these villages remain inaccessible to some by road.
02:22At the same time, a strange phenomenon occurred.
02:26Many witnesses claimed to have seen a reddish glow at the top of the tsunami, giving the impression that the wave was carrying flames.
02:35As it approached the shore, this disturbing light took on a deep, unreal hue, perceptible from locations as far away as Haïtap.
02:44And it was only the prelude to horror.
02:47Two other waves rose shortly after, in rapid succession.
02:51The second was the most devastating, reaching 10 to 15 meters in height.
02:56When the ocean finally withdrew, it left behind only an unrecognizable landscape.
03:02Once the waves had ravaged everything and left the villages in ruins, the sky offered a final show.
03:09The survivors described a yellow or even reddish glow, which illuminated the celestial vault above the ocean.
03:17A survivor, hiding at the top of a tree, observed this persistent brightness stretching in the direction of Arop and Détap.
03:24In Malol, the sisters of Notre-Dame des Missions, turned to the sea, were seized by the strangeness of the spectacle.
03:31The water, of a liquid gold, was of an absolute calm, smooth as oil, bathed by this supernatural glow.
03:38The glow was so vivid that it flooded the ruined landscape with light.
03:42Luckily, this allowed the survivors to immediately begin the search for their missing loved ones.
03:47Many were those who attributed these lights to a supernatural phenomenon, seeing an omen there.
03:53This catastrophe struck with an unpredictable brutality, as sudden as devastating.
03:59The Royal Australian Air Force intervened without delay, dispatching aircraft loaded with emergency equipment.
04:05A question then became crucial. What could have caused such a cataclysm?
04:10Very quickly, investigations revealed that this tsunami was different from the others.
04:15Contrary to ordinary waves, those of a tsunami do not always manifest themselves by walls of water falling on the shore.
04:22Sometimes, the first sign before the runner is a sudden retreat from the sea.
04:26If you see the water abnormally moving away from the coast, stay alert. It's a warning.
04:32When the ocean returns, it does so at lightning speed, like a gigantic tidal wave with destructive power.
04:40In addition, a tsunami rarely occurs in a single wave.
04:44It often strikes by successive waves, destroying everything in its path.
04:48These phenomena occur when an immense mass of water, in an ocean or a large lake, is brutally displaced.
04:56Their main origin lies in earthquakes, which occur when tectonic plates of the Earth suddenly move under the ocean.
05:05By rising or collapsing, the seabed propels the water to the surface, generating waves of colossal magnitude.
05:13However, the tsunami that struck Papua New Guinea deviated from this classic pattern.
05:19At first, researchers thought it resulted from the sliding of the Australian and Pacific tectonic plates against each other.
05:27The earthquake itself was not the real problem.
05:31In reality, it was of a fairly modest intensity.
05:34However, it had triggered a gigantic undersea slide.
05:39When the ocean floor collapsed, it propelled a phenomenal volume of water.
05:44The waves reached nearly 15 meters, the equivalent of a four-story building.
05:48This is how we realized that a low-magnitude earthquake could trigger a devastating tsunami by causing an undersea flood.
05:57Worse still, this type of tsunami can occur without a real sign before the runner,
06:02because seismic warning systems do not always trigger in these circumstances.
06:06But what was the boiling and the effervescence of the water that some had observed?
06:11It was actually a sudden release of underwater gas.
06:15Under the ocean floor, gas pockets are trapped in the sediments.
06:20Among them, there is methane, present in oil and gas deposits, as well as hydrogen sulfide, or rotten egg yolks.
06:28During the earthquake, the seabed probably cracked or moved, letting its gases escape.
06:34This phenomenon caused a kind of boiling.
06:38In some areas, the water was able to warm up.
06:41And several witnesses reported that the waves were abnormally hot, even irritating to the skin.
06:47The presence of dissolved chemical substances in the water only aggravated this sensation.
06:52It is even possible that these gas eruptions contributed to amplifying the tsunami.
06:57Perhaps they destabilized the sediments that ended up causing this undersea slide,
07:02or they favored the elevation of the water at the time of their release.
07:06It would be like shaking a bottle of soda.
07:09If the pressure escapes abruptly, the reaction is spectacular.
07:13But what were the strange lights seen in the sky?
07:16This is a more complex question.
07:19There is a phenomenon known as seismic light.
07:23Observed in all four corners of the globe,
07:25they are translated by lightning, glow, or effects comparable to polar auroras.
07:30Their color generally varies between white, bluish, and multicolored shades.
07:35These lights can appear at any time of a earthquake,
07:38for a few seconds or several tens of minutes.
07:41If we rely on their description,
07:44the first red flash could have been caused by an electrical phenomenon.
07:48The earth's crust is full of quartz and other minerals capable of releasing electricity once under pressure.
07:55When the earthquake shook the ground, this electricity spread to the atmosphere.
08:00The gases already released before could also have played a role.
08:04They could have ignited or interacted with charged particles in the air,
08:09thus accentuating the brightness of the lightning.
08:12While the wave raised sand, rocks, and debris.
08:16Extreme pressure and intense movements probably generated other sparks.
08:21This could explain the strange reddish glow seen at the top of the waves.
08:26As for the yellow light, it could have been caused by these electrified gases rising in the atmosphere.
08:32Methane and other gases would have interacted with the Earth's magnetic field,
08:36producing an effect similar to that of a Boreal aurora.
08:40But all this is just speculation.
08:43What is most shocking in this story is that the Papua New Guinea disaster could have been avoided.
08:50Seismologists knew that a tsunami was imminent, although they were ahead of their predictions.
08:56The first wave broke out between 10 and 25 minutes after the earthquake,
09:00about five minutes earlier than they had anticipated.
09:03This means that its origin was immediately close to the coast.
09:08The reason why no one was able to evacuate in time is simple.
09:12Locals had no tsunami warning system,
09:15nor sufficient knowledge of these phenomena to understand that a quake could cause one,
09:21nor why the water was behaving strangely.
09:24This kind of event had not occurred in Papua New Guinea for more than 60 years.
09:29But this event served as a warning signal.
09:32From this tragedy were born lessons and a form of resilience.
09:36A year after the disaster, all survivors were able to follow a documentary detailing the causes of the disaster
09:42and teach them the gestures to adopt if it were to happen again.
09:46This initiative saved lives, because history has indeed been repeated.
09:51A quake and a similar tsunami hit the neighboring island of Vanuatu in November 1999.
09:57But this time, the islanders, sensitized by the documentary produced upstream, were prepared.
10:03Instead of panicking, they were able to react quickly.
10:06And fortunately, hundreds of lives were saved.
10:09Today, tsunami warning systems are in place in all developed regions.
10:14These systems can warn the population by means of sirens, SMS or TV programs
10:20as soon as a potential tsunami is detected.
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