Since the September 8 earthquake in Morocco, amateur videos showing light phenomena presented as linked to the earthquake have been circulating on social networks. They are sometimes described as “seismic lights”, a phenomenon that science struggles to explain.
“I don’t work on crystal balls or birdsong,” quips seismologist Lionel Siame when mentioning the phenomenon of seismic lights. His colleague Jean Virieux, warns with a sigh: “It’s a subject that has already caused a lot of ink to flow.” And even more so since the deadly earthquake of September 8 in Morocco.
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Several videos published on social networks have revived interest in this phenomenon which science struggles to explain. Shared Saturday September 9 on (ex-Twitter), a video initially broadcast via TikTok has more than a million views. It shows, according to its author, “white balls” in the sky of Marrakech, “from night 8 to Saturday 9”. “Explain to me in comments”asks the videographer.
These flashes and luminous halos occurring before, during or shortly after an earthquake have intrigued researchers and simple earthquake witnesses for decades. “There are a lot of questions about the physical phenomena that can exist before the occurrence of an earthquake”immediately warns Jean Virieux, professor emeritus at the Institute of Earth Sciences in Grenoble, and seismic lights are surely one of the most important subjects of controversy within seismology.
In response to this video, certain messages pell-mell evoke “chinese spy balloons”, the Starlink satellites, and the American HAARP ionosphere study project. A regular recipient of conspiratorial fantasies, he had already been accused of having caused the earthquake of February 6, 2023 in Turkey and Syria. Another videowhere we see short flashes of bluish light, provokes the same type of reactions.
Faced with these crazy theories, many people in good faith retort that it is probably “seismic lights”. A seemingly scientific explanation used to counter sometimes openly conspiratorial discourse.
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“For me, these videos have no interest”, judge Michel Parrot, former research director at CNRS and French specialist in seismic lights. The scientist was very interested in these phenomena, but refutes the validity of amateur documents on the basis of which there is no point in working.“It has no interest, because we don’t know exactly where it was taken, we don’t know exactly how the phenomenon began, and we don’t know how it ends…”, justifies Michel Parrot. To move from amateur recordings of the phenomenon to scientific observation, “We would have to equip a seismic zone with devices that will operate 24 hours a day, but which must wait for the event. And we can wait decades before having an event in an area.”
“There has never been a scientific record of this kind of phenomenon”
Michel Parrot, former research director at CNRSat franceinfo
However, scientific hypotheses attempt to explain these seismic light phenomena. Lhe researchers have notably explored the avenue of electromagnetic reactions. “What happens underground” during an earthquake, could modify “the electromagnetic environment of the atmosphere”Jean Virieux cautiously advances. “During an earthquake, you have tremendous energy that comes into play. It compresses the rocks. All this modifies the current which circulates between the Earth’s surface and the ionosphere. explains Michel Parrot.
The ionosphere is the upper part of our terrestrial atmosphere located between 60 and 1000 kilometers above sea level, characterized by the ionization of the atoms found there: they lose electrons under the effect of UV rays from the Sun. By changing the current that flows between the Earth’s surface and the ionosphere, earthquakes could be “at the origin of lights that we see before earthquakes, during earthquakes or even after. These are transient phenomena, that is to say they last only a few milliseconds.says the former research director at CNRS.
Controversy between seismologists
According to United States Geological Survey (USGS) “Lgeophysicists do not agree” on the reality of these seismic lights. A scientist affiliated with this American institute, John Derr, who wrote an article in 1977 on the phenomenon. Amateur photographs of these lights are already reproduced there.
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In 1977, John Derr already wrote: “Great difficulties and uncertainties accompany any attempt to explain the phenomenon […] The existence of the phenomenon is considered well established, although no entirely satisfactory explanation has been put forward to date.” A good word in the American scientific community was that the study of seismic lights was “the darkest side of seismology” reports Michel Parrot.
“Earthquakes are unpredictable phenomena”
Seismologist Lionel Siame,at franceinfo
The scientist from the European Center for Research and Education in Geosciences Lionel Siame confirms this tradition of distrust at the mention of seismic lights. For this researcher: “We can only estimate that a fault can generate an earthquake. But don’t predict it. IThere are probably things we are missing, but even if the seismic lights were a warning sign, it would come too close to the earthquake to be useful in predicting it.”
Between 2004 and 2010: a French “earthquake sniffer” satellite
However, the idea was toyed with around twenty years ago: detecting seismic lights to predict earthquakes. A French satellite, Demeter, was even launched to explore this avenue. Active from 2004 to 2010, its scientific manager was none other than Michel Parrot. “Predicting the occurrence of an earthquake from space seemed, until recent years, to be a scientific imposture. was then enthusiastic Release in an article on this satellite “earthquake sniffer”. “However, this morning, Cnes (the French space agency) will put Demeter into orbit, a satellite whose mission will be precisely to test this idea.”
“The Demeter mission did not observe light phenomena because we did not have optical instruments on boardspecifies Michel Parrot. But we had measurements of the ionosphere in situ. When the satellite passed over an earthquake, we looked to see if there had been a variation in what we call the electron density of the ionosphere.” What were the conclusions of this research? “We did statistics, and before the earthquakes, there were many disturbances in the density of the ionosphere.”assures Michel Parrot. But in the current state of scientific knowledge “It is impossible to predict an earthquake”concludes Michel Parrot. “OAn alert can be issued saying that in a given area, abnormal parameters linked to seismic activity are observed. But we can’t predict exactly what will happen.”